kelman dga 900 operator guide - kama solutions...remotely over a network via a web-based interface...

MA-025 – DGA 900 Operator Guide – Rev 2.0 12-Apr-19 of 92

GE Grid Solutions

Kelman™ DGA 900 Operator Guide Transformer Oil Dissolved Gas and Moisture Monitor


Contents Page 1 Introduction ............................................................................................... 7

1.1 Product Overview ................................................................................................................................ 7

1.2 Scope ........................................................................................................................................................ 9

1.3 Front Panel LEDs .................................................................................................................................. 9

2 Safety........................................................................................................ 10

2.1 Symbols ................................................................................................................................................. 10

2.2 Warnings .............................................................................................................................................. 10

2.3 Hazardous Substances ................................................................................................................... 11

3 Technical Specifications ......................................................................... 12

4 Compliance .............................................................................................. 14

5 Power........................................................................................................ 15

6 HMI ............................................................................................................ 16

6.1 Introduction......................................................................................................................................... 16

6.2 Connections ........................................................................................................................................ 17

6.3 Start-Up Procedure .......................................................................................................................... 18

6.4 Login ....................................................................................................................................................... 18

6.5 Dashboard............................................................................................................................................ 19 6.5.1 Quick Access ................................................................................................................................................................. 21

6.6 GAS / Diagnostics .............................................................................................................................. 23 6.6.1 Active Alarms ............................................................................................................................................................... 23 6.6.2 Measurements ............................................................................................................................................................. 23 6.6.3 Duval Triangle .............................................................................................................................................................. 24 6.6.4 Gas Ratio ........................................................................................................................................................................ 25 6.6.5 Scheduler ....................................................................................................................................................................... 26

6.7 Calculations ......................................................................................................................................... 26 6.7.1 Gas Ratios ...................................................................................................................................................................... 26 6.7.2 Relative Saturation .................................................................................................................................................... 27 6.7.3 Gas Rate of Change ................................................................................................................................................... 27 6.7.4 Analog Inputs RoC Configuration ....................................................................................................................... 28

6.8 Alarms ................................................................................................................................................... 29 6.8.1 Gases ................................................................................................................................................................................ 29 6.8.2 Gas Ratios ...................................................................................................................................................................... 30 6.8.3 Gas Rate of Change ................................................................................................................................................... 31 6.8.4 Relative Saturation .................................................................................................................................................... 32 6.8.5 Analog Inputs ............................................................................................................................................................... 32 6.8.6 Analog Inputs Rate of Change .............................................................................................................................. 33 6.8.7 Digital Inputs ................................................................................................................................................................ 33 6.8.8 Digital Inputs Transition Total .............................................................................................................................. 34

6.9 Peripherals ........................................................................................................................................... 35 6.9.1 Peripheral Scheduler ................................................................................................................................................ 35 6.9.2 Analog Inputs ............................................................................................................................................................... 35 6.9.3 Digital Inputs ................................................................................................................................................................ 36 6.9.4 Input Measurements ................................................................................................................................................ 36

6.10 Settings ................................................................................................................................................. 37 6.10.1 Communications ........................................................................................................................................................ 37 6.10.2 Date & Time .................................................................................................................................................................. 38


6.10.3 SMS Alerting.................................................................................................................................................................. 38 6.10.4 Firewall ............................................................................................................................................................................ 39 6.10.5 Communication Services ........................................................................................................................................ 40

6.11 Service ................................................................................................................................................... 41 6.11.1 Measurement ............................................................................................................................................................... 41 6.11.2 Controller Reprogramming .................................................................................................................................... 42 6.11.3 I/O PCB Reprogramming ......................................................................................................................................... 43 6.11.4 Oxygen Sensor ............................................................................................................................................................. 44 6.11.5 Gas Normalization ..................................................................................................................................................... 45 6.11.6 Factory ............................................................................................................................................................................. 45 6.11.7 User Administration .................................................................................................................................................. 48

6.12 TransOpto ............................................................................................................................................ 50 6.12.1 Measurements ............................................................................................................................................................. 50 6.12.2 Rate of Change ............................................................................................................................................................ 50 6.12.3 Alarms .............................................................................................................................................................................. 51 6.12.4 Rate of Change Alarms ............................................................................................................................................ 52 6.12.5 Channels ......................................................................................................................................................................... 53 6.12.6 Settings ........................................................................................................................................................................... 53

6.13 Logout .................................................................................................................................................... 54

6.14 Shutdown Procedure ....................................................................................................................... 55

6.15 Error Notifications ............................................................................................................................ 56 6.15.1 Error Codes.................................................................................................................................................................... 58 6.15.2 Other Notifications .................................................................................................................................................... 59

7 Manual Oil Sampling ............................................................................... 60

7.1 Sampling Arrangement ................................................................................................................... 60

7.2 Local HMI for manual sampling ................................................................................................... 61

7.3 Sampling Process .............................................................................................................................. 65

8 Communications ..................................................................................... 67

8.1 DNP3 ...................................................................................................................................................... 67

8.2 IEC 61850 ............................................................................................................................................. 67

8.3 Modbus Protocol ............................................................................................................................... 67

8.4 HTTP / HTTPS Protocol .................................................................................................................... 67

9 Technical Support ................................................................................... 67

Appendix A Security Configuration ............................................................ 68

Appendix B Transportation PGA Lock ........................................................ 75

Appendix C Maintenance Activities ........................................................... 79

Appendix D Time Sync Implementation ..................................................... 85

Appendix E Alarm Settings: General Advice ............................................. 87

Contact & Copyright Details .......................................................................... 92


List of Tables and Figures Page Figure 1-1: Inside the DGA 900 ................................................................................................................................................ 7 Table 1-1: Hub front panel LED lights ................................................................................................................................... 9 Table 3-1: Measurements ........................................................................................................................................................ 12 Table 4-1: Type tests .................................................................................................................................................................. 14 Figure 5-1: Fuse holder ............................................................................................................................................................. 15 Table 5-1: External LED status indicators ........................................................................................................................ 15 Figure 6-1: Inside the Hub – LCD top left.......................................................................................................................... 16 Figure 6-2: Ethernet / USB HMI connection .................................................................................................................... 17 Figure 6-3: Log-in page............................................................................................................................................................. 18 Table 6-1: User access rights ................................................................................................................................................. 18 Figure 6-4: Local HMI: Quick Access page ....................................................................................................................... 19 Figure 6-5: Dashboard .............................................................................................................................................................. 20 Figure 6-6: Quick Access .......................................................................................................................................................... 21 Figure 6-7: Quick Access – Rapid Mode ............................................................................................................................ 22 Figure 6-8: Active Alarms ......................................................................................................................................................... 23 Figure 6-9: Measurements ...................................................................................................................................................... 24 Figure 6-10: Duval Diagnostic ............................................................................................................................................... 25 Figure 6-11: Gas Ratio ............................................................................................................................................................... 25 Figure 6-12: DGA Scheduler ................................................................................................................................................... 26 Figure 6-13: Gas Ratio Settings............................................................................................................................................. 26 Figure 6-14: Gas Ratio Settings – Ratio 1 definition .................................................................................................... 26 Figure 6-15: Relative Saturation Settings ........................................................................................................................ 27 Figure 6-16: Gas RoC Configuration ................................................................................................................................... 27 Figure 6-17: Analog Inputs Rate of Change Configuration ..................................................................................... 28 Figure 6-18: Gas Alarms Configuration............................................................................................................................. 29 Figure 6-19: Hydrogen alerts ................................................................................................................................................. 30 Figure 6-20: Gas Ratio Alarms Configuration ................................................................................................................ 30 Figure 6-21: Gas Ratio Alarms Configuration – Ratio 1 High-High Gas Rate of Change .......................... 30 Figure 6-22: Gas RoC Configuration ................................................................................................................................... 31 Figure 6-23: Relative Saturation Alarms Configuration ............................................................................................ 32 Figure 6-24: Relative Saturation Alarms Configuration – High-High .................................................................. 32 Figure 6-25: Analog Inputs Alarms Configuration ....................................................................................................... 32 Figure 6-26: Analog Inputs RoC Alarms Configuration.............................................................................................. 33 Figure 6-27: Digital Inputs Alarms Configuration ......................................................................................................... 33 Figure 6-28: Digital Inputs Transition Total Alarms Configuration ...................................................................... 34 Figure 6-29: Peripheral Scheduler ....................................................................................................................................... 35 Figure 6-30: Analog Inputs Configuration ....................................................................................................................... 35 Figure 6-31: Analog Input 4 (4-20 mA Temperature Sensor) .................................................................................. 36 Figure 6-32: Digital Input Configuration ........................................................................................................................... 36 Figure 6-33: Input Measurements ....................................................................................................................................... 36 Figure 6-34: Communications Settings ............................................................................................................................. 37 Figure 6-35: Date & Time ......................................................................................................................................................... 38 Figure 6-36: SMS Alerting ......................................................................................................................................................... 38 Figure 6-37: Firewall configuration ..................................................................................................................................... 39 Figure 6-38: Communication Services .............................................................................................................................. 40 Figure 6-39: Measurement Settings ................................................................................................................................... 41 Figure 6-40: Controller Reprogramming .......................................................................................................................... 42 Figure 6-41: Upgrade in progress ........................................................................................................................................ 42 Figure 6-42: I/O Board Reprogramming ........................................................................................................................... 43 Figure 6-43: Upgrade in progress ........................................................................................................................................ 43 Figure 6-44: Oxygen Sensor ................................................................................................................................................... 44


Figure 6-45: Gas Normalization Settings ......................................................................................................................... 45 Figure 6-46: Factory Settings ................................................................................................................................................. 45 Table 6-2: Factory Settings: Data and configuration cleardown ......................................................................... 47 Figure 6-47: Simulation mode ............................................................................................................................................... 48 Figure 6-48: Restart the device ............................................................................................................................................. 48 Figure 6-49: User Administration ......................................................................................................................................... 48 Figure 6-50: Change Password ............................................................................................................................................. 49 Table 6-3: Password Strength ............................................................................................................................................... 49 Figure 6-51: TransOpto Measurements ............................................................................................................................ 50 Figure 6-52: TransOpto RoC Configuration ..................................................................................................................... 50 Figure 6-53: TransOpto Alarms Configuration .............................................................................................................. 51 Figure 6-54: Channel 1 High alerts...................................................................................................................................... 51 Figure 6-55: TransOpto RoC Alarms Configuration ..................................................................................................... 52 Figure 6-56: Channel 2 High-High alerts .......................................................................................................................... 52 Figure 6-57: TransOpto Channels Settings...................................................................................................................... 53 Figure 6-58: TransOpto Settings ........................................................................................................................................... 53 Figure 6-59: Logout .................................................................................................................................................................... 54 Figure 6-60: Log-in page .......................................................................................................................................................... 54 Figure 6-61: System Info – Standby .................................................................................................................................... 55 Figure 6-62: Measurement started ..................................................................................................................................... 55 Figure 6-63: PGA and Oxygen Sensor Error States ..................................................................................................... 56 Figure 6-64: PGA Errors ............................................................................................................................................................. 57 Table 6-4: PGA Errors ................................................................................................................................................................. 58 Table 6-5: Oxygen sensor error codes .............................................................................................................................. 59 Figure 65: MicroSD card memory usage .......................................................................................................................... 59 Figure 7-1: Oil filter and oil ports (front view of Analysis module) ........................................................................ 60 Figure 7-2: Valve orientation .................................................................................................................................................. 61 Figure 7-3: Sampling assembly ............................................................................................................................................. 61 Figure 7-4: Luer fitting on assembly ................................................................................................................................... 61 Figure 7-5: Local HMI: Quick Access ................................................................................................................................... 61 Figure 7-6: Manual Sampling ................................................................................................................................................. 62 Figure 7-7: Purging Oil ............................................................................................................................................................... 62 Figure 7-8: Take manual oil sample ................................................................................................................................... 63 Figure 7-9: Manual Sampling cannot be started ......................................................................................................... 63 Figure 7-10: Dashboard: Stop Measurement ................................................................................................................. 64 Figure 7-11: Manual oil sampling flowchart ................................................................................................................... 65 Table A-1: External Interfaces................................................................................................................................................ 69 Table A-2: Protocols .................................................................................................................................................................... 69 Figure A-1: Settings > Communication Services........................................................................................................... 70 Figure A-2: Communication Services ................................................................................................................................. 70 Figure A-3: Firewall Settings ................................................................................................................................................... 72 Figure A-4: Default policy options........................................................................................................................................ 73 Figure A-5: Specific policy options ....................................................................................................................................... 73 Figure A-6: LAN interface ......................................................................................................................................................... 73 Figure A-7: LAN interface ......................................................................................................................................................... 73 Figure A-8: Accept HTTPS ........................................................................................................................................................ 74 Figure B-1: PGA lock – engaged ........................................................................................................................................... 75 Figure B-2: PGA lock – pins and locking bracket secured with cable ties ........................................................ 75 Figure B-3: PGA lock – remove pins .................................................................................................................................... 76 Figure B-4: PGA lock – remove plastic nuts .................................................................................................................... 76 Figure B-5: PGA lock – remove metal bracket ............................................................................................................... 76 Figure B-6: PGA lock – insert metal bracket ................................................................................................................... 77 Figure B-7: PGA lock – attach plastic nuts ....................................................................................................................... 77 Figure B-8: PGA lock – insert pins ........................................................................................................................................ 77


Figure B-9: PGA lock – pin to enclosure hole .................................................................................................................. 78 Figure B-10: PGA lock – pins and locking bracket secured with cable ties ..................................................... 78 Figure C-1: Controller PCB coin cell battery .................................................................................................................... 79 Figure C-2: Marshalling PCB coin cell battery ................................................................................................................ 79 Figure C-3: Hub fan air inlet .................................................................................................................................................... 80 Figure C-4: Detached inlet cover with filter – facedown .......................................................................................... 80 Figure C-5: Detached inlet cover with filter removed ................................................................................................ 80 Figure C-6: Filter mesh cartridge – face up ..................................................................................................................... 80 Figure C-7: Louvre catchment tray – attached ............................................................................................................. 81 Figure C-8: Louvre gasket – tray removed ...................................................................................................................... 81 Figure C-9: Louvre catchment tray – detached & filter removed ........................................................................ 81 Figure C-10: Louvre air filter ................................................................................................................................................... 81 Figure C-11: Oil connections .................................................................................................................................................. 82 Figure C-12: Oil filter ................................................................................................................................................................... 82 Figure C-13: Internal push-fit cover removal ................................................................................................................. 82 Figure C-14: Peltier cooler ....................................................................................................................................................... 84 Figure C-15: Fan group electrical connection ............................................................................................................... 84 Figure C-16: Peltier cooling fins ............................................................................................................................................ 84 Figure C-17: Fan group detached from cooler .............................................................................................................. 84 Table D-1: Timing ......................................................................................................................................................................... 85 Table D-2: UNIX time registers .............................................................................................................................................. 85 Table D-3: Access flags ............................................................................................................................................................. 86 Table D-4: Modifier flags .......................................................................................................................................................... 86 Table E-1: Main Tank: Gas Level Alarms ........................................................................................................................... 88 Table E-2: ROC alarms (key gas values) ............................................................................................................................ 88 Table E-3: ROC alarms (for ROC in ml/day) ...................................................................................................................... 90 Table E-4: Measurement intervals ....................................................................................................................................... 90

Related Documents Ref# Title

MA-024 DGA 900 Installation Manual

Abbreviations & Definitions Abbreviation Meaning

HMI Human Machine Interface

Controller PCB Controller Printed Circuit Board

I/O PCB Input / Output Printed Circuit Board

Marshalling PCB Marshalling Printed Circuit Board

PPE Personal Protective Equipment

PCC Power, Communications and Control (cable)

RoC Rate of Change


1 INTRODUCTION

1.1 Product Overview

The Kelman™ DGA 900 (the product) is a multigas online DGA (Dissolved Gas Analysis) and

moisture monitoring system for implementing Asset Performance Management (APM)

across electrical generation, transmission, distribution and industrial applications.

The product as shown in Figure 1-1 can detect and diagnose incipient faults and trend

asset health via the monitoring of critical gases including moisture in the transformer oil.

This includes any mineral oil or ester-based fluid (natural or synthetic). The product

measures nine certified fault gases: hydrogen, methane, ethane, ethylene, carbon

monoxide, carbon dioxide, acetylene, oxygen, nitrogen as well as water content and the

transformer load current. Such data provides insight on transformer condition criteria,

such as developing faults, paper degradation and electrical arcing.

Once installed, operation is intuitive and programmable. The product can be managed

remotely over a network via a web-based interface or locally via a touchscreen interface.

All results are stored within the product, but online management is recommended. Results

and the full product database can also be downloaded to a PC for analysis, aggregation and

trending with the Perception software suite.

Figure 1-1: Inside the DGA 900

The product features:

▪ An innovative two-enclosure design connecting the two modules by a Power, Communications and Control (PCC) cable for a more flexible installation configuration. The Analysis module contains the PGA measurement technology, whereas the Hub module contains the communications technology and HMI screen. The modules have IP56-rated aluminium enclosures (compliant in the installed upright position) and are powder coated to the RAL 9002 colour.

▪ Automated headspace gas extraction manifold to extract target gases from the oil sample.


▪ Advanced high precision Photo-Acoustic Spectroscopy (PAS) sensing technology based on a robust multi-point individual gas calibration process using certified gases to calibrate the PGA (Photoacoustic Gas Analyser).

▪ Complete multi-gas analysis (nine gases and moisture) with a user-configurable sampling frequency from once per hour to once every four weeks including remote alert capabilities. All gas sensing is carried out internally without a need for carrier gases or recalibration. Minimal maintenance*1 and no requirement for costly consumables.

▪ A new ‘Rapid Mode’ allows sampling to be completed in around 30 minutes using five key gases and is useful in critical situations to give immediate insight on fast-developing faults.

▪ Improved lower detection limits and measurement repeatability for earlier detection of imminent faults on the transformer being monitored.

▪ Transformer load tracking (CT analogue input as standard).

▪ Watchdog relay as standard to monitor power usage.

▪ Six configurable relay contacts based on absolute gas and moisture values (with one dedicated service).

▪ Five optional 4-20 mA configurable analogue input cards.

▪ Three digital inputs (optional configurations available).

▪ Compatible with AC or DC power.

▪ Four sunlight-visible LED arrays on the exterior of the Hub module — red for alarm, yellow for caution (both user-configurable) — and green for power, blue for service.

▪ A fully embedded microprocessor with 4 GB non-volatile internal memory storage, highly scalable analogue and digital I/Os, an embedded webserver, 8 GB SD card to hold measurement data and an integrated 7 in. colour LCD screen with resistive touch for simplified local user interaction and visualization of data.

▪ The infrastructure provides a platform for expansion and future feature enhancements complemented by an extensive range of secure communications options. These include Ethernet, RS-485, cellular modem (SMS Text Alerts /GPRS), and fibre optic options (IEC61850 or DNP3). Internal USB connection is provided for commissioning and service, or local data download. Other options may be available on request.

▪ Compatibility with GE’s Perception transformer fleet management software for data download, trending and analysis as well as other SCADA systems. The product is a DS-Agile and Predix-Grid APM ready device with support for industry standard protocols.

*1 Note: The only recommended maintenance is periodic cleaning of the air filters, in-line oil filter and battery replacement.


1.2 Scope

This guide outlines the use of the HMI, manual sampling function and general maintenance

activities.

1.3 Front Panel LEDs

Table 1-1 outlines the LEDs on the front panel of the Hub module.

Table 1-1: Hub front panel LED lights

LED Colour Symbol Meaning

Alarm

A measured parameter has exceeded a user-programmed “alarm” threshold.

Caution

A measured parameter has exceeded a user-programmed “warning” threshold.

Power

24 V Power OK.

Service

Service required. Triggered by a warning service event if the product detects internal issues or if equipment settings are exceeded. If scheduled, the product will still attempt another measurement and clear any service condition if the issue is no longer present.


2 SAFETY

2.1 Symbols

The meaning of symbols used on the Kelman™ DGA 900:

Caution. Refer to the Installation Manual / Operator Guide to prevent death, bodily injury, equipment damage or loss of data.

Electrical Hazard. Risk of electric shock.

Primary Protective Earth connection.

Hot surfaces may be present.

The meaning of symbols used in this guide:

Warning: A procedure, practice, or condition could cause death or serious injury and/or significant equipment damage.

[Caution]: A procedure, practice, or condition could cause minor injury, equipment damage or loss of data.

Electrical Hazard: Risk of electric shock.

Hot surfaces may be present.

2.2 Warnings

The following warnings must be observed:

WARNING: The minimum ambient temperature for installation and service activities is −10 °C.

WARNING: If the equipment is installed or used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.

WARNING: If working at height, third parties must have received appropriate training for working at height prior to work commencing. This includes, but is


not limited to, ‘Working at height’ and ‘Using Mobile Elevated Working Platforms’ training.

WARNING: If working at a height greater than 4 feet (1.2 metres) or at a height greater than that stipulated by national or site regulatory requirements, it is the responsibility of the installer to ensure that planned work complies with those requirements.

WARNING: The user shall also ensure that any third-party equipment, such as an approved platform, scaffold or lift is suitable and safe before commencing work. Ladders or improvised platforms do not meet GE service engineer requirements.

WARNING: Once installed, this product may have more than one source of supply. Disconnect all supplies at their source before accessing the cabinet for servicing. Follow the site lockout-tagout (LOTO) procedure.

WARNING: Disconnection from the supply is achieved through the external circuit breaker or switch.

WARNING: Ensure all power sources, including relays, are de-energised as stipulated by lockout-tagout (LOTO) requirements before performing any maintenance work inside the product.

WARNING: The product is operated with the door shut under normal use. The door shall be kept locked and should only be opened for service access by suitably qualified and authorised service personnel. During service access, hazardous voltages are accessible.

WARNING: Only GE-trained and certified personnel may commission GE Kelman products. Commissioning tasks include making any connections and/or performing any work within the enclosure, or performing tasks such as purging the oil circuit between the transformer and the product, and/or all first start-up procedures relating to equipment or firmware/software.

WARNING: The product provides IP56 water spray protection. It is possible for a water deluge system to exceed IP56 thresholds depending on the location, pressure and direction of the water jets. Should customers require testing a water deluge system in the area in which the product is installed, GE recommends powering down the product and draping it with a suitable waterproof covering.

2.3 Hazardous Substances

The gases measured in the product are extracted from the oil and expelled to the

atmosphere via the exhaust vent on the external base of the Analysis module. The area

around the exhaust vent should be kept clear and unobstructed. All expelled gases are at

concentrations that are nonflammable, nontoxic and quickly diluted in the surrounding

atmosphere. The expelled gases are not hazardous to health or life.


3 TECHNICAL SPECIFICATIONS

The product meets the following technical specification as outlined in Table 3-1.

Table 3-1: Measurements

PARAMETER VALUE/MEETS

GAS MEASURED *1 & 10 RANGE ACCURACY *2 & 3 REPEATABILITY *2

Hydrogen (H2) 5 – 5,000 ppm ± 5% or ± LDL

<3%

Methane (CH4) 2 – 50,000 ppm ± 3% or ± LD L <2%

Ethane (C2H6) 1 – 50,000 ppm ± 3% or ± LDL <2%

Ethylene (C2H4) 1 – 50,000 ppm ± 3% or ± LDL <2%

Acetylene (C2H2) 0.5 – 50,000 ppm ± 3% or ± LDL <2%

Carbon Monoxide (CO) 1 – 50,000 ppm ± 3% or ± LDL <2%

Carbon Dioxide (CO2) 20 – 50,000 ppm ± 3% or ± LDL <3%

Oxygen (O2) 100 – 50,000 ppm ± 5% or ± LDL <3%

Nitrogen (N2) *4 10,000 – 100,000 ppm ± 15% or ± LDL

<3%

Moisture (H2O) 0 – 100% Relative Saturation

*5

± 3.5% <3%

Measurement frequency Variable – Once per hour to once every 4 weeks

ENVIRONMENTAL*11 Operating external temperature range

−40 °C to 55 °C

Storage temperature range 0 °C to 45 °C

Oil temperature range *6

−20 °C to 120 °C

Altitude Up to 2000 m

Atmospheric pressure Up to 1050 mbar

Operating humidity 10 – 95% RH non-condensing

Enclosure IP56

Weight *7

Analysis module: 33.4 kg (73.6 lb)

Hub module: 18.5 kg (40.8 lb)

2 m PCC cable: 0.8 kg (1.83 lb)

Product weight: 52.7 kg (116.3 lb)

POWER REQUIREMENTS Nominal input voltage range:

100-250 V DC 4 A

100-240 V AC, 50/60 Hz, 4 A

Input voltage range:

90-264 V AC

90-275 V DC

AC frequency range:

45-65 Hz

Single phase Alarm Relays: NO and NC provided*

8

10 A 250 V AC, 10 A 30 V DC, 0.3 A 110 V DC, 0.12 A 220 V DC

Fuses *9 10 A 600 V AC/DC EATON KLM-10

Coin cells Panasonic CR2450 3 V 620 mAh

*1 Note: Parameters specified in application with mineral oil.

mailto:0.3%20A%20110%20V%20DC


*2 Note: Accuracy and repeatability are quoted for the detectors under factory calibration and test levels. Gas-in-oil measurements may be affected by sampling and/or oil type.

*3 Note: Whichever is greater.

*4 Note: Available on free-breathing transformers only.

*5 Note: Given in ppm.

*6 Note: Based on testing carried out using VOLTESSO™ 35 mineral oil over a ¼ in. pipe run of 10 metres or less from oil supply or return valve to product connection point, and on transformer oil supply valve volumes of 200 ml or less. For oil temperatures colder than −20 ºC, GE recommends the use of heat trace cabling on piping. Low oil viscosity reduces oil flow.

*7 Note: The weight depends on the order specification. The stated weight is for a base product without packaging and excludes options such as a mounting stand. Check the shipping document for the exact packaged weight.

*8 Note: Maximum DC breaking capacity for a resistive load.

*9 Note: Use only the approved and recommended fuse to ensure continued fire protection and compliance.

*10 Note: Laboratory results can vary greatly worldwide as has been established through many round-robin tests. Any comparison of DGA 900 measurement results against laboratory results need to be considered in this context.

*11 Note: It is possible for a small amount of condensation to form on the inner surface of the Analysis enclosure. This occurs under certain environmental conditions and does not affect the performance or reliability of the product.


4 COMPLIANCE

The product is designed to meet the following type tests as listed in Table 4-1.

Table 4-1: Type tests

CATEGORY STANDARD CLASS/LEVEL TEST

EMC Emissions EN 61326-1:2006

CISPR 11 A Radiated & Conducted Emissions

FCC Part 15 Meets the requirements of A

Radiated & Conducted Emissions

EN 61000-3-2 A Harmonic Current Emissions Limits

EMC Immunity EN 61326-1:2006

IEC 61000-6-5: 2015

EN 61000-4-2 IV Electrostatic Discharge

EN 61000-4-3 III Electromagnetic Field Immunity

EN 61000-4-4 III Electrical Fast Transients

EN 61000-4-5 III Surge Immunity

EN 61000-4-6 III Conducted RF Immunity

EN 61000-4-8 IV & V Magnetic Field Immunity

EN 61000-4-11 III Voltage Dips & Interruptions

IEC 61000-4-12 2.5 kV & 1 kV Oscillatory Wave

IEC 61000-4-16 A Mains frequency voltage

EN 60255-5 5 kV, 2 kV & 500 V DC

Impulse, Dielectric & Insulation resistance testing

Environmental IEC 60068-2-1 −40 °C Cold

IEC 60068-2-2 55 °C Dry Heat

IEC 60068-2-6 10 – 500 Hz, 0.5 g operation

10 – 500 Hz, 1 g endurance

Vibration

IEC 60068-2-30 55 °C, 95% RH Damp Heat

EN 60529 IP56 Degree of Protection

Safety IEC 61010-1 2010

EN 61010-1 2010


5 POWER

The product is wired directly to the mains so is continually powered on. The mains fuse

holder for the product is shown in Figure 5-1 and is located towards the bottom right-hand

side of the Hub module.

Figure 5-1: Fuse holder

The product uses four external sunlight-visible LEDs on the front door. Each LED has two

states – ‘Off’ (-) or ‘On’ as outlined in Table 5-1.

Table 5-1: External LED status indicators

Mode Alarm

red LED

Caution

amber LED

Power

green LED

Service

blue LED

Power Off - - - -

Normal - - On -

Alarm On - On -

Caution - On On -

Service - - On On

Fuse holder

Live Neutral Earth


6 HMI

6.1 Introduction

The local HMI features an integrated 7 in. colour LCD panel with resistive touch screen and

embedded webserver. The remote HMI is via a wireless comms option (or direct USB

connection) to a web browser. The latter being the preferred means of interaction with the

product since it offers the convenience of accessing the product from anywhere using a full

screen web browser. The remote HMI is optimised for Chrome, but has also been tested in

Chrome, Firefox and Internet Explorer. The local HMI allows operators to interact directly

with the product onsite without additional equipment. However, the local HMI facility is

intended as an alternative or secondary access method in situations where network

connectivity is unavailable.

To prevent exposure of the internal equipment to extreme weather or other

adverse environmental conditions, ensure additional cover is in place prior to

opening the door.

The LCD panel is in the Hub module and is visible when the door is open as shown in Figure

6-1.

Figure 6-1: Inside the Hub – LCD top left

The LCD and web server are powered on by default as soon as power is supplied to the

product. Access to the HMI can be gained locally via the resistive touch screen (using a

finger or stylus) or remotely through the Web from any computer. Both HMI experiences

are comparable with a similar look and feel.


Note: This guide uses screenshots from the remote Web access HMI. The images rendered on the local HMI are similar, but some have a different layout due to the smaller screen.

Note: This guide displays screens from an Administrator login. All user logins have a similar look and feel, but some features are dependent on the type of user.

Note: If there are any rendering issues on the remote HMI, press Ctrl + F5 to refresh.

Note: If using Internet Explorer 11, ensure that the option for ‘Compatibility View’ is disabled.

6.2 Connections

The remote HMI can also be accessed from a laptop via a direct physical connection to the

product. The product ships with the default IP address as shown in Figure 6-2. Use either

an Ethernet or USB cable to make the connection as shown in Figure 6-2.

Figure 6-2: Ethernet / USB HMI connection


6.3 Start-Up Procedure

When the product is powered on or rebooted, the PGA takes several minutes to initialise. If

using the remote access HMI, the icon denotes that the initialization process is not yet

complete.

6.4 Login

The log-in page prompts for a username and password as shown in Figure 6-3. The product

ships with a default username and password that can be changed after initial login.

Figure 6-3: Log-in page

The system supports three roles with different levels of access as outlined in Table 6-1.

Table 6-1: User access rights

Role Access

Observer View information only (includes downloading if using the remote HMI)

Operator View information and make configuration changes.

Administrator View information, make configuration changes and perform user administration e.g. change passwords.

Note: The session inactivity timeout is 10 minutes.

The Administrator can omit to set a password for the ‘Observer’ role. This means anyone

with physical access to the product or a connected computer can observe the gas levels

and measurements etc. without the need to supply a password. See Section 6.11.7 for user

administration details.

The opening page of the local HMI presents a Quick Access page as shown in Figure 6-4,

whereas the remote access HMI presents a detailed dashboard as shown in Figure 6-5. The

header on each page shows the signal strength, username and menu bar.


Figure 6-4: Local HMI: Quick Access page

Note: For manual sampling HMI functionality, see Section 7.2.

6.5 Dashboard

After a successful login, the remote HMI displays the Dashboard page in Normal Mode as

shown in Figure 6-5. The Dashboard page displays details of the Last DGA measurement, a

Quick Access panel, System Information and a trend chart below.

Note: The dashboard can be toggled between Normal Mode and Rapid Mode. See Section 6.5.1.3.


Figure 6-5: Dashboard

The Last DGA Measurement panel shows the measurement date and time stamp, gas

levels (with measurements in PPM) displayed numerically and represented graphically on a

bar chart marked with the configured Caution (H for High) and Alarm (HH for High High)

levels. Blue signifies a reading within the normal limits, yellow a caution — the reading has

exceeded the High (H) level, and red an alarm – the reading has exceeded the High-High

level. Rest the pointer on any gas to obtain the full name in a tooltip. After the next

measurement completes, the details automatically update.

The System Info gives the current date, time, product state, scheduler mode (Normal,

Alarm, Caution) and next scheduled measurement. Indicators show the status of the alarm,

caution and service LEDs as well as the six relays. There is also a free text ID field to assign

a meaningful name to the product. The default is the product’s serial number. Note: Only

Operator or Administrator changes will be saved. The product’s serial and firmware version

numbers are also listed.


A variety of trend charts are available to choose from — Historical, Thermal, Humidity, and

RTD Sensor. The default trend chart is an Historical Chart that plots selected gas readings

over time. Use the gas legend to identify the gas and the date selector control to change

the timeframe. Rest the pointer on any data point on a plot line to obtain a tooltip with a

timestamped gas value. Click a gas label on the legend to toggle the display of the plotted

gas on or off.

6.5.1 Quick Access

The Quick Access panel in the centre of the HMI as shown in Figure 6-6 offers additional

functionality. Note: Some features are disabled as they are still in development.

Figure 6-6: Quick Access

The following Quick Access features are available:

6.5.1.1 Diagnostics

Click Diagnostics to access the Duval Triangle or Gas Ratio diagnostics.

6.5.1.2 Download Log

Click Download Log to access the available log files. Choose from a System Log, TFD Log

and CFR Log. These service files contain product performance data that is used to check

product functionality. If requested, download and send the relevant log files to the GE M&D

Service Support team for analysis.


6.5.1.3 Enter Rapid Mode

Rapid mode is a means of on demand sampling and uses a smaller quantity of oil to deliver

a result in around 30 minutes. Rapid mode measures four critical gases — hydrogen,

acetylene, carbon monoxide, carbon dioxide — and water, and charts the measurements

below. The ability to invoke successive quick measurement cycles over a short period can

indicate the speed at which a fault is progressing.

Note: Rapid mode measurements are performed independently of all other measurements and do not affect alarms, relays or calculations.

Click Enter Rapid Mode to access the rapid mode options. The Quick Access panel

displays the available options as shown in Figure 6-7.

Figure 6-7: Quick Access – Rapid Mode

6.5.1.3.1 Start 1x Rapid Mode

To start a single rapid mode measurement, click Start 1x Rapid Mode.

6.5.1.3.2 Start 4x Rapid Mode

To start four rapid mode measurements in succession, click Start 4x Rapid Mode.

6.5.1.3.3 Stop Measurement

To cancel an active Rapid Mode measurement, click Stop Measurement.

6.5.1.3.4 Exit Rapid Mode

To exit Rapid Mode and return to the main dashboard, click Exit Rapid Mode.

6.5.1.4 Start Measurement

Choose Start Measurement to manually initiate a measurement cycle. The state in the

System Info pane updates to reflect that a measurement has started.


6.6 GAS / Diagnostics

6.6.1 Active Alarms

Select GAS / Diagnostics > Active Alarms to open the Active Alarms page as shown in

Figure 6-8.

Figure 6-8: Active Alarms

Note: Deadbands are specified in the units relating to what is measured. E.g. PPM for gas, degrees Celsius (°C) for temperature. See Section 6.8 for a definition of deadbands.

6.6.2 Measurements

Select GAS / Diagnostics > Measurements to open the Measurements page as shown in

Figure 6-9. The Measurements page reports the values of all variables from a measurement

cycle. The most recent measurement cycle is listed first. Use the scroll buttons to navigate

to previous measurements.


Figure 6-9: Measurements

6.6.3 Duval Triangle

Select GAS / Diagnostics > Duval to open the Duval Diagnostic page as shown in Figure

6-10.


Figure 6-10: Duval Diagnostic

6.6.4 Gas Ratio

Select GAS / Diagnostics > Gas Ratio to open the Gas Ratio page as shown in Figure 6-11.

Figure 6-11: Gas Ratio


6.6.5 Scheduler

Select DGA > DGA Scheduler to open the DGA Scheduler page as shown in Figure 6-12.

Use this page to schedule a DGA measurement cycle.

Figure 6-12: DGA Scheduler

6.7 Calculations

6.7.1 Gas Ratios

Select Calculations > Gas Ratios to open the Gas Ratio Settings page as shown in Figure

6-13.

Figure 6-13: Gas Ratio Settings

Choose the relevant > icon to expand the ratio definition as shown in Figure 6-14.

Figure 6-14: Gas Ratio Settings – Ratio 1 definition


Type a Ratio Name and select the relevant gases.

Note: Nitrogen (N2) is available as a choice only if Nitrogen Measurement is enabled.

Refer to the IEEE® C57.104 and IEC® 60599 standards for alarm settings or Appendix E.

6.7.2 Relative Saturation

Select Calculations > Relative Saturation to open the Relative Saturation settings page

as shown in Figure 6-15.

Figure 6-15: Relative Saturation Settings

6.7.3 Gas Rate of Change

Select Calculations > Gas Rate of Change to open the Gas RoC Configuration page as

shown in Figure 6-16. See Appendix E for more details on settings.

Figure 6-16: Gas RoC Configuration


6.7.4 Analog Inputs RoC Configuration

Select Calculations > Analog Inputs Rate of Change to open the Analog Inputs RoC

Configuration page as shown in Figure 6-17. The default is for a CT to be installed on

Analogue Input 1. The product supports up to five additional analogue inputs.

Figure 6-17: Analog Inputs Rate of Change Configuration


6.8 Alarms

Perception allows deadbands to be defined for each alarm. A deadband establishes

another limit for clearing the alarm and prevents an alarm returning to normal until the

alarm condition is cleared by the deadband. This reduces the number of false alarms and

the amount of chattering. For example, an alarm triggered at 200 ppm with a deadband of

3 will remain in the alarm state until the value falls below 197 ppm.

Note: Deadbands are specified in the units being measured. Gases are specified in PPM, temperature in degrees Celsius.

The host network must have the capability to transmit alarms and critical

messages during times of heavy use, including but not limited to network

storm conditions. If this requirement is not met or has not been tested, the

notification of hazardous gas levels could be delayed by a network slowdown.

6.8.1 Gases

Select Alarms > Gases to open the Gas Alarms Configuration page as shown in Figure

6-18.

Figure 6-18: Gas Alarms Configuration


Click on a gas alarm icon > e.g. Hydrogen to configure the type of alerts as shown in Figure

6-19.

Figure 6-19: Hydrogen alerts

6.8.2 Gas Ratios

Select Alarms > Gas Ratios to open the Gas Ratio Alarms Configuration page as shown in

Figure 6-20.

Figure 6-20: Gas Ratio Alarms Configuration

Click the relevant ratio icon > e.g. ‘D1 and R1 High-High’ to expand the ratio alarm

definition and configure the type of alerts as shown in Figure 6-21.

Figure 6-21: Gas Ratio Alarms Configuration – Ratio 1 High-High Gas Rate of Change


6.8.3 Gas Rate of Change

Select Alarms > Gas Rate of Change to open the Gas RoC Configuration page as shown in

Figure 6-22.

Figure 6-22: Gas RoC Configuration


6.8.4 Relative Saturation

Select Alarms > Relative Saturation to open the Relative Saturation Alarms

Configuration page as shown in Figure 6-23.

Figure 6-23: Relative Saturation Alarms Configuration

Click on a Relative Saturation icon > e.g. High-High to expand the relative saturation

definition as shown in Figure 6-24.

Figure 6-24: Relative Saturation Alarms Configuration – High-High

6.8.5 Analog Inputs

Select Alarms > Analog Inputs to open the Analog Inputs Alarms Configuration page as

shown in Figure 6-25.

Figure 6-25: Analog Inputs Alarms Configuration


6.8.6 Analog Inputs Rate of Change

Select Alarms > Analog Inputs Rate of Change to open the Analog Inputs RoC Alarms


Figure 6-26: Analog Inputs RoC Alarms Configuration

6.8.7 Digital Inputs

Select Alarms > Digital Inputs to open the Digital Inputs Alarms Configuration page as


Figure 6-27: Digital Inputs Alarms Configuration


6.8.8 Digital Inputs Transition Total

Select Alarms > Digital Inputs Transition Total to open the Digital Inputs Transition

Total Alarms Configuration page as shown in Figure 6-28.

Figure 6-28: Digital Inputs Transition Total Alarms Configuration


6.9 Peripherals

6.9.1 Peripheral Scheduler

Select Peripherals > Peripheral Scheduler to open the Peripheral Scheduler page as


Figure 6-29: Peripheral Scheduler

The Peripheral Scheduler allows the Measurement Time Interval to be set to 5, 10, 15 or 20

minutes.

6.9.2 Analog Inputs

Select Peripherals > Analog Inputs to open the Analog Inputs Configuration page as


Figure 6-30: Analog Inputs Configuration

If there are analogue cards fitted to the I/O PCB, these will auto populate with default

values as shown in Figure 6-31. The next step is to configure each card to the required

sensor.


Figure 6-31: Analog Input 4 (4-20 mA Temperature Sensor)

6.9.3 Digital Inputs

Select Peripherals > Digital Inputs to open the Digital Input Configuration page as shown

in Figure 6-32.

Figure 6-32: Digital Input Configuration

6.9.4 Input Measurements

Select Peripherals > Input Measurements to open the Input Measurements page as


Figure 6-33: Input Measurements


6.10 Settings

6.10.1 Communications

Select Settings > Communications to open the Communications Settings page as shown

in Figure 6-34.

Figure 6-34: Communications Settings

If a GPRS modem is fitted and the appropriate carrier sim is installed, the IP address also

displays.

See Appendix A.2 for more details on the external interfaces and supported protocols.


6.10.2 Date & Time

Select Settings > Date & Time to open the Date & Time page as shown in Figure 6-35.

Figure 6-35: Date & Time

6.10.3 SMS Alerting

Select Settings > SMS Alerting to open the SMS Alerting page as shown in Figure 6-36. In

this example, the system is configured to send ‘Richard’ an SMS message whenever a

‘System Error’ is raised.

Figure 6-36: SMS Alerting


6.10.4 Firewall

To create a custom security policy, select Settings > Firewall to open the Firewall Settings

page as shown in Figure 6-37. Rules can be added, edited or deleted to create a suitable

access policy for each type of interface. These rules are used to block unused ports and

specify distinct firewall actions (accept, reject or drop) based on the IP address or port.

Figure 6-37: Firewall configuration

See Appendix A.4 for more details on firewall configuration.


6.10.5 Communication Services

Select Settings > Communication Services to open the Communication Services page as


Note: This functionality is available only to ‘Operator’ and ‘Administrator’ users.

All configuration settings specified on this page apply to all interfaces (Ethernet, USB and

GSM-GPRS modem).

Figure 6-38: Communication Services

Select the relevant slider button to enable/disable the relevant communication service. E.g.

Modbus-TCP, SSH (Secure Shell) and HTTPS — but do not rely on the firewall settings.

To implement a custom security policy, upload a new certificate to replace the GE self-

signed certificate and enable HTTPS requests only.

A certificate can be uploaded from a USB drive. In the Upload certificate field, click the

Select file button, select the new certificate (PEM file) and click Open.

Click the ‘Save’ button in the application header to apply the changes and then restart

the DGA 900.

Note: SSL certificates are small data files that digitally bind a cryptographic key to an organization's details. When installed on a web server, it activates the padlock and the HTTPS protocol and allows secure connections from a web server to a browser.

Note: If HTTPS is disabled, the certificate will be applied when HTTPS is enabled.

Note: The HMI has no automatic redirection between HTTP and HTTPS (or vice versa). This results in the following browser message “Site cannot be reached over HTTP”.


6.11 Service

6.11.1 Measurement

Select Service > Measurement to open the Measurement Settings page as shown in

Figure 6-39. The Normalization Temperature is a thermostatically controlled internal target

temperature for the Analysis module. Depending on the region, one of two temperatures

can be set 0 °C or 20 °C.

Figure 6-39: Measurement Settings

The following Measurement Flags are available:

Nitrogen Enabled — displays measurement data for nitrogen. This also activates the

display of Total Dissolved Gases (TDG) (disabled by default).

TDG Enabled — lists the Total Dissolved Gases (TDG). Inactive if nitrogen measurement is

not enabled. TDG = H2 + CO2 + CO + C2H4 + C2H6 + CH4 + C2H2 + O2 + N2.

TDH Enabled — lists the Total Dissolved Hydrocarbons. (TDH). TDH = CH4 + C2H2 + C2H4 +

C2H6.

Estimated Safe Handling Limit (ESHL) – expresses the concentration of gases contained

within the oil sample as a percentage. This is a safety indicator and is used to assess the

associated risk of the oil sample. ESHL = H2/LevelH2 + CH4/LevelCH4 + CO/LevelCO +

C2H6/LevelC2H6 + C2H4/LevelC2H4 + C2H4/LevelC2H4.


6.11.2 Controller Reprogramming

Consult with Technical Support to confirm the availability of new firmware for the

Controller PCB. Upgrade to the latest version of the firmware via an Ethernet connection to

avail of new features.

Note: A firmware upgrade resets passwords back to their default values.

To upgrade the Controller PCB firmware, select Service > Controller Reprogramming to

open the Controller Reprogramming page as shown in Figure 6-40.

Figure 6-40: Controller Reprogramming

Drag and drop the firmware file into the circle or click in the circle to select the file. Click

Upgrade and the status information and a progress bar display as shown in Figure 6-41.

Figure 6-41: Upgrade in progress

Once complete, the firmware image is applied and the system restarts. On initial power up,

the product’s LCD screen remains blank, but the ‘On’ heartbeat LED and ‘Boot’ LED

illuminate (solid blue and red respectively). After a moment, the Boot LED switches off and

the ‘On’ heartbeat LED flashes blue to indicate normal operation. The restart sequence

takes approximately 3 minutes after which the onboard HMI loads up.


6.11.3 I/O PCB Reprogramming

Consult with Technical Support to confirm the availability of new firmware for the I/O PCB.

Upgrade to the latest version of the firmware via an Ethernet connection to avail of new

features.

Note: A firmware upgrade resets passwords back to their default values.

To upgrade the I/O PCB firmware using an Ethernet connection, select Service > I/O Board

Reprogramming to open the I/O Board Reprogramming page as shown in Figure 6-42.

Figure 6-42: I/O Board Reprogramming

Drag and drop the firmware file into the circle or click in the circle to select the file. Click

Upgrade and the status information and a progress bar displays as shown in Figure 6-43.

Figure 6-43: Upgrade in progress

Once complete, the firmware image is applied and the system restarts. On initial power up,

the product’s LCD screen remains blank, but the ‘On’ heartbeat LED and ‘Boot’ LED

illuminate (solid blue and red respectively). After a moment, the Boot LED switches off and

the ‘On’ heartbeat LED flashes blue to indicate normal operation. The restart sequence

takes approximately 3 minutes after which the onboard HMI loads up.


6.11.4 Oxygen Sensor

Select Service > Oxygen Sensor to open the Oxygen Sensor settings page as shown in

Figure 6-44.

Figure 6-44: Oxygen Sensor


6.11.5 Gas Normalization

Select Service > Gas Normalization to open the Gas Normalization Settings page as


Figure 6-45: Gas Normalization Settings

6.11.6 Factory

Select Service > Factory to open the Factory Settings page as shown in Figure 6-46.

Figure 6-46: Factory Settings


6.11.6.1 Alarm Reflash

The Alarm Reflash option ensures that a relay’s digital output reflashes (if already

activated) when another source triggers the same relay. An alarm reflash applies only to

relays 1-6 and is achieved by deactivating the relevant digital output for a duration of 1

second before reactivating it to achieve a flashing effect. This signifies to an operator or

control room in real time that multiple sources have triggered the same relay.

Note: This ensures that further alarms raised by the same source have no further effect.

6.11.6.2 Clear Historical Data Only

Clears all historical data — DGA measurements, alarm data and Transopto measurements.

Table 6-2 outlines the type of data items that get erased.

6.11.6.3 Reset Configuration Settings

Clears all historical data described previously and resets configuration settings (except

Communications) to the default state. Table 6-2 outlines the type of data items that get

erased.


6.11.6.4 Factory Reset

Clears everything — historical measurement data, configuration settings and

communication settings, so that the product returns to the initial factory state. Table 6-2

outlines the type of data items that get erased.

Table 6-2: Factory Settings: Data and configuration cleardown

Clear Historical Data Only

Reset of Configuration Settings

Full Factory Reset

DGA

Measurements

Scheduler

Calculations

Gas ratios

Relative Saturation

Gas RoC

Transopto RoC

Analog Input RoC

Alarms Alarms

Peripherals

Transopto Channels

Transopto Measurements

Analog Inputs

Digital Inputs

Settings Communications

Service

Measurement

Oxygen Sensor

Transopto

Gas Normalization

Factory

6.11.6.5 Simulation Mode

The dashboard environment can be switched to Simulation Mode to simulate a realistic

live environment before the product is physically installed or any measurement cycles have

started.

Click Simulation Mode to see the dashboard view populated with mock data. To

differentiate between real and simulation data, the colour scheme for the bar chart

simulation data uses grey scales and the DGA 900 state changes to ‘PGA simulation mode’

as shown in Figure 6-47.


Figure 6-47: Simulation mode

This allows the HMI to display realistic sample data for showcasing e.g. training and testing

purposes without affecting real-time data, but has no validity since it does not relate to

any underlying measurement cycles.

6.11.6.6 Restart Device

Some configuration changes require a device restart. Click Restart Device to restart the

device and then click Restart to confirm as shown in Figure 6-48.

Figure 6-48: Restart the device

6.11.7 User Administration

Select Service > User Administration to open the User Administration page as shown in

Figure 6-49.

Figure 6-49: User Administration

Click Change Password to enter a new password. On typing, the strength of the password

is assessed as shown in Figure 6-50.


Figure 6-50: Change Password

A password strength is categorised as listed in Table 6-3.

Table 6-3: Password Strength

Password Strength Rating Description

Not enough No password entered.

Weak 4 characters or more.

Medium 7 characters or more.

The string must contain at least one each of the following characters: lowercase alphabetical, uppercase alphabetical and numeric.

Strong 8 characters or more.

The string must contain at least one each of the following characters: lowercase alphabetical, uppercase alphabetical, numeric and special.


6.12 TransOpto

6.12.1 Measurements

Select TransOpto > Measurements to open the TransOpto Measurements page as


Figure 6-51: TransOpto Measurements

6.12.2 Rate of Change

Select TransOpto > Rate of Change to open the TransOpto RoC Configuration page as


Figure 6-52: TransOpto RoC Configuration


6.12.3 Alarms

Select TransOpto > Alarms to open the TransOpto Alarms Configuration page as shown

in Figure 6-53.

Figure 6-53: TransOpto Alarms Configuration

Click on a channel alarm icon > e.g. ‘Channel 1 High’ to configure the type of alerts as


Figure 6-54: Channel 1 High alerts


6.12.4 Rate of Change Alarms

Select TransOpto > Rate of Change Alarms to open the TransOpto RoC Alarms


Figure 6-55: TransOpto RoC Alarms Configuration

Click on a channel alarm icon > e.g. ‘Channel 2 High-High’ to configure the type of alerts as


Figure 6-56: Channel 2 High-High alerts


6.12.5 Channels

Select TransOpto > Channels to open the TransOpto Channels Settings page as shown in

Figure 6-57.

Figure 6-57: TransOpto Channels Settings

6.12.6 Settings

Select TransOpto > Settings to open the TransOpto Settings page as shown in Figure

6-58.

Figure 6-58: TransOpto Settings


6.13 Logout

Select the Logout option below the username as shown in Figure 6-59.

Figure 6-59: Logout

The Log-in page displays as shown in Figure 6-60.

Figure 6-60: Log-in page


6.14 Shutdown Procedure

If the product is to be shut down, perform the following steps:

Log in to the DGA 900 to observe the operating state on the dashboard as shown in

Figure 6-61.

Figure 6-61: System Info – Standby

If the product is in “Standby” state, then proceed to shut down the product as follows:

− Turn the external switch or circuit breaker to the ‘Off’ position.

− Turn the transformer oil valves that connect to the input and output of the product

to the ‘Closed’ position.

If the product is performing a measurement as shown in Figure 6-62, then

− Either wait for the product to finish the active measurement or manually stop the

measurement. For the latter, choose Stop Measurement as shown in Figure 7-10.

− The DGA 900 state changes to “Oil Draining”. This process may take several minutes

after which the product state returns to “Standby” as shown in Figure 6-61.

− Turn the external switch or circuit breaker to the ‘Off’ position.

− Turn the transformer oil valves that connect to the input and output of the product

to the ‘Closed’ position.

Figure 6-62: Measurement started

When the product is to be powered up again, first turn the transformer oil valves that

connect to the input and output of the product to the ‘Open’ position. Then turn ‘On’ the

external switch or circuit breaker. The product will be ready to resume taking scheduled

readings.


6.15 Error Notifications

The Measurements page reports all errors as shown in Figure 6-63: If there are no errors in

the current measurement cycle, the results are displayed as normal. Errors for the most

recent measurement cycle are listed first. Use the navigation buttons to move through the

various measurement cycles and examine any errors encountered in previous

measurement cycles.

Figure 6-63: PGA and Oxygen Sensor Error States

Errors are reported using a sequence of double-digit codes for the PGA and the Oxygen

sensor (if enabled). The PGA Error State denotes the most recent state within the

measurement cycle where the error occurred. All errors are listed as error codes and the

associated hexadecimal in brackets allows the most recent state to be identified. See

Section 6.15.1 for a definition of the error codes.

Note: The Customer Service Centre requires both the state code(s) and error code(s) to interpret any error.

For example, Figure 6-64 shows that the product has encountered two PGA errors. The

PGA Error code 04 denotes that there is an issue with the gas flow in the Main

Measurement state (23) and error code 13 denotes that the pump pressure is too low.


Figure 6-64: PGA Errors

Note: If the Oxygen sensor is not enabled, no Oxygen sensor state or error codes display.


6.15.1 Error Codes

Table 6-4 lists the PGA error codes. All the service alarm error codes are accompanied by

illumination of the blue Service light that is visible on the front door of the product.

Note: Error codes are offset by 1 from the Modbus register bit numbers.

Note: This information relates to PGA firmware version 18.1.5 for DGA 900.

Table 6-4: PGA Errors

Code Error Note

PGA Connection Error

Timeout

01 PGA power supply voltage too low

02 PGA chopper frequency outside range

03 PGA IR-source outside range

04 Gas flow lower than limit

05 Background noise/vibration too high

06 Microphone test failed

07 Not level sensor 1 pulses (level)

08 Not level sensor 3 (drain)

09 Fill level shows Oil

10 Over Fill shows Oil

11 PGA Air temperature outside limits

12 Bad communication with control PCB

13 Gas leak test: Pump pressure too low

14 Gas leak test: Pressure decay too high

15 Unusual ambient gas measurements

16 Oil temperature too low

17 Oil temperature too high

18 Oil pressure too low Check that all oil supply valves are open.

19 Oil pressure too high Check that all oil return valves are open.

20 Oil pump tacho count too high

21 Oil pump pressure too low

22 Oil pump speed out of range

23 Manual oil sampling switch

24 Oil pump tacho count too low

25 Oil pump not turning

26 - Not used.

27 Temperature Sensor(s) 1 disconnected

28 Temperature Sensor(s) 2 disconnected

29 Drain level shows oil

30 Conditioned oil temp. outside limits


Table 6-5 lists the Oxygen sensor error codes.

Table 6-5: Oxygen sensor error codes

Code Error Note

0 Oxygen sensor measurement has finished with no error.

1 System error. Internal state. Initial state of state machine.

2 System error. Internal error. Oxygen sensor thread is busy.

3 Oxygen sensor is disabled.

4 Measurement cancelled by user.

5 System error. Measurement just started.

6 PGA measurement has finished before we achieve state 6. We could not run Oxygen sensor measurement.

7 In attempt to write -1 to PGA Oxygen Saturation register, writing fails because the read value is not the same as which has been written.

8 In attempt to clear EE (Electronically Erasable) Store bit in Oxygen sensor Control register, writing fails due to a communication error.

9 PGA Oil Temperature reading fails due to a communication error.

10 Oxygen sensor Oil temperature writing fails due to a communication error.

11 Oxygen sensor (Dissolved Oxygen) DO Trigger command writing fails due to a communication error.

12 Oxygen sensor Status DO_DATA_RDY is not set.

13 Oxygen sensor DO Error Code reading fails due to a communication error.

14 Oxygen sensor Oxygen reading fails due to a communication error.

15 PGA Oxygen Saturation writing fails due to a communication error.

16 Reading PGA state fails due to a communication error.

17 PGA Transfix state is greater than 34. We lose time to write Oxygen Saturation and measurement result may have an error.

18 Oxygen sensor DO Error Code register is not null. Oxygen sensor has an error during measurement.

6.15.2 Other Notifications

If the onboard MicroSD card has exceeded 80% of its storage capacity, the SD card icon

displays. Click the icon to reveal the message as shown in Figure 65. The MicroSD card

should be replaced as soon as possible.

Figure 65: MicroSD card memory usage


7 MANUAL OIL SAMPLING

A manual oil sample can be taken via the following arrangement.

Before commencing work, ensure the use of suitable protective gloves, such as nitrile rubber.

7.1 Sampling Arrangement

The product has one manual oil sampling port fitted to the base. This consists of a quick-

connect body and a captive body-protector fitting as shown in Figure 7-1. The product

ensures that there is fresh oil at the sampling point when the sampling process takes

place.

Figure 7-1: Oil filter and oil ports (front view of Analysis module)

A male quick-connect fitting and valve assembly is provided in the product installation kit.

GE also recommends the use of a 50-mL ground glass syringe.

Note: The manual oil sampling arrangement and the quick-connect sampling port must not be cleaned with any type of solvent as this could affect results for subsequent oil samples.

Oil filter

Manual sampling port


Figure 7-2: Valve orientation

Figure 7-3: Sampling assembly

Figure 7-4: Luer fitting on assembly

7.2 Local HMI for manual sampling

The manual sampling functionality is implemented on the Quick Access page of the local

HMI only as shown in Figure 7-5. Press Manual Sampling.

Note: Before proceeding, ensure that the sampling assembly is fitted as outlined in Section 7.1.

Figure 7-5: Local HMI: Quick Access

CLOSED

Oil sampling valve assembly with Luer fitting

OPEN

Quick-connect body protector with pull-down collar for release


The Manual Sampling page displays. Press Start as shown in Figure 7-6 to start the manual

sampling process.

Figure 7-6: Manual Sampling

The oil purging process starts. Allow several minutes for the oil to purge and then press

Continue when done.

Figure 7-7: Purging Oil


The system prompts the user to take the manual oil sample. See Section 7.3 for more

details on the sampling process.

Press Finish to return to the home page as shown in Figure 7-8.

Figure 7-8: Take manual oil sample

If the product is already performing a measurement, manual sampling is prevented as

shown in Figure 7-9. Press Exit to return to the Quick Access page.

Figure 7-9: Manual Sampling cannot be started


Either wait for the current measurement cycle to finish or stop the current measurement

cycle. To stop the current measurement cycle, return to the Dashboard and press Stop

Measurement as shown in Figure 7-10.

Figure 7-10: Dashboard: Stop Measurement

The product is now ready to take a manual sample.


7.3 Sampling Process

Logon to the product using the local HMI and observe the product state on the Dashboard.

The product state must be in Standby to initiate manual sampling. Figure 7-11 and the

accompanying steps detail the process to obtain a manual oil sample.

Figure 7-11: Manual oil sampling flowchart

Close sampling valve

Remove male fitting and valve assembly

Replace quick-connect body

protector

Standby state Measurement state

Press Stop Measurement

Oil Drains

Standby state

Attach male fitting and valve assembly

with valve closed

Press Manual

Sampling, & Start

Wait at least several minutes for oil to

purge…

Press Continue

Press Finish

Remove quick-connect body

protector

Open sampling valve and take oil

sample


Observe the product state on the HMI Dashboard page. Either wait for the product to

return to the Standby state or use the HMI to stop the current measurement cycle.

If the product is in “Standby” state, proceed to step 3. If the product is in a

measurement state, manual sampling is prevented.

Navigate to the Dashboard page and press Stop Measurement. The state changes to

“Oil draining”. If there is oil in the headspace, the draining process may take several

minutes. The product returns to “Standby” state.

On the local HMI Quick Access page, press Manual Sampling.

When the product is in “Standby” state, remove the quick-connect body protector by

pulling the collar down.

Fit the male quick-connect fitting and valve assembly to the correct quick-connect body

on the base of the product as shown in Section 7.1. Ensure that the valve is closed to

prevent oil leakage.

Press Start.

An oil line purging process starts. The product state reads “Oil purging”. To ensure

accurate results, oil must be adequately purged before sampling begins. This brings

fresh oil from the transformer to the manual oil sampling port. Typically this means

waiting approximately 5–10 minutes, but the recommended wait time can vary

depending on the installation (longer tubing and lower temperatures can increase the

purge duration). Consult with Technical Support.

Press Continue when done. The product state reads “Oil sampling”. Note: This indicates

that the oil sampling process can begin.

Remove the Luer fitting cap, connect the oil sampling equipment e.g. syringe, and

perform the oil sampling as per standard process and procedures.

When finished sampling, close the valve and disconnect the oil sampling equipment.

Remove the male fitting and valve assembly, and replace the body protector fitting on

the quick-connect body.

Press Finish when done. The product state returns to “Standby”. Note: If left in the “Oil

sampling” state, the product reverts to “Standby” after one hour. Measurement then

begins at the next scheduled measurement time.

To start a measurement immediately, press the Start button.


8 COMMUNICATIONS

See the Communications section of ‘MA-024 - DGA 900 Installation Manual’ for available

communication options.

8.1 DNP3

Refer to the document CG-060 – DGA 900 DNP3 Objects & IO Points Index.

8.2 IEC 61850

Refer to the document DGA 900 – IEC 61850 Edition 2.

8.3 Modbus Protocol

Refer to the document CG-062 – DGA 900 Modbus IO Registers.

8.4 HTTP / HTTPS Protocol

The HTTP and HTTPS protocols are used for communication with the Perception software

suite. The login credentials for such communication are independent of the local and

remote HMI. The login credentials to communicate with Perception from the DGA 900 are

as follows:

Username: perception

Password: perception

Refer to the Perception software documentation (v 1.22.3 or later) for further details.

9 TECHNICAL SUPPORT

For technical support, please contact the GE Customer Service Centre (24 hours a day, 365

days a year):

T +44 1785-250-070 (United Kingdom)

T 1-800-361-3652 (United States and Canada)

T +1 514-420-7460 (worldwide)

[email protected]


Appendix A Security Configuration

A.1 Introduction

This appendix addresses security configuration for remote operations and the software

firewall.

A.1.1 General Recommendations

GE recommends the ‘Defence in depth’ approach. The Defence in depth approach

advocates multiple layers of independent security controls to make it as difficult as

possible for an attack to succeed. When using GE products and solutions, consider

adopting the following security best practices:

▪ Care must be taken when connecting hardware to a wide area network including but not limited to a corporate network or the Internet at large. The network segmentation and firewall rules at each network interface must be carefully considered to reduce the allowed traffic to the bare minimum needed for operation. Access rules customised to the site's specific needs must be used to access devices from outside the local control networks. Care must be taken to control, limit, and monitor all access, using, for example, virtual private networks (VPN) or Demilitarised Zone (DMZ) architectures. If a device is being used in a manner that does not require wide area network access, it is strongly recommended that the device not be connected to any wide area network to reduce the attack surface.

▪ Harden system configurations by enabling/using the available security features, and by disabling unnecessary ports, services, functionality, and network file shares.

▪ Apply all the latest GE product security updates, SIMs, and other recommendations.

▪ Apply all the latest operating system security patches to control systems PCs.

▪ Use antivirus software on control systems PCs and keep the associated antivirus signatures up to date.

▪ Use whitelisting software on control systems PCs and keep the whitelist up to date.

A.1.2 Sample Checklist

This section provides a sample checklist to help guide the process of securely deploying GE

products.

▪ Create or locate a network diagram.

▪ Identify and record the required communication paths between nodes.

▪ Identify and record the protocols required along each path, including the role of each node.

▪ Revise the network as needed to ensure appropriate partitioning, adding firewalls or other network security devices as appropriate. Update the network diagram.

▪ Configure firewalls and other network security devices.

▪ Enable and/or configure the appropriate security features on each GE product.


▪ On each GE product, change every supported password to something other than its default value.

▪ Harden the configuration of each GE product, disabling unneeded features, protocols and ports.

▪ Test / qualify the system.

▪ Create an update/maintenance plan.

A.2 Communication Requirements

Communication between different parts of a control system is, and must be, supported.

However, the security of a control system can be enhanced by limiting the protocols

allowed, and the paths across which they are allowed, to only what is needed. This can be

accomplished by disabling every communication protocol that isn’t needed on a particular

device, and by using appropriately configured and deployed network security devices (e.g.

firewalls, routers) to block every protocol (whether disabled or not) that doesn’t need to

pass from one network/segment to another.

GE recommends limiting the protocols allowed by the network infrastructure to the

minimum set required for the intended application. Successfully doing this requires

knowing which protocol is needed for each system-level interaction.

A.2.1 External Interfaces

The product features the following external interfaces as shown in Table A-1.

Table A-1: External Interfaces

External interface Comment

RS-485

Ethernet HMI/SSH access

Ethernet Multi-protocol module DNP3/IEC 61850

GSM-GPRS modem

microSD

USB host

USB device USB-Ethernet

A.2.2 Supported Protocols

The product supports the following protocols as shown in Table A-2.

Table A-2: Protocols

Network Layer Protocol

Link ARP

Internet ICMP

IPv4

Transport TCP

Application DHCP Server

SSH


HTTP Server

HTTPS Server

Modbus RTU Slave

Modbus TCP Slave

A.3 Secure Remote Operations

Select Settings > Communication services as shown in Figure A-1.

Note: This functionality is available only to ‘Operator’ and ‘Administrator’ users.

Figure A-1: Settings > Communication Services

The Communication Services page displays as shown in Figure A-2. All configuration

settings specified on this page apply to all interfaces (Ethernet, USB and GSM-GPRS

modem).

Figure A-2: Communication Services

Select the relevant slider button to enable/disable the relevant communication service. E.g.

Modbus-TCP, SSH (Secure Shell) and HTTPS — do not rely on the firewall settings.

To implement a custom security policy, upload a new certificate to replace the GE self-

signed certificate and enable HTTPS requests only.

In the Upload certificate field, click the Select file button, select the new certificate (PEM

file) and click Open.

Click the ‘Save’ button in the application header to apply the changes and then restart

the DGA 900.


Note: SSL certificates are small data files that digitally bind a cryptographic key to an organization's details. When installed on a web server, it activates the padlock and the HTTPS protocol and allows secure connections from a web server to a browser.



A.3.1 Enable/disable Modbus-TCP protocol

▪ Use the HMI to login as either ‘Administrator’ or ‘Operator’.

▪ Select Settings > Communication Services.

▪ Select the Modbus-TCP Enable slider button to enable/disable the Modbus-TCP protocol.

▪ Click the ‘Save’ button in the application header to apply the changes.

▪ Restart the DGA 900.

A.3.2 Enable/disable SSH service (root access over SSH)



▪ Select the SSH Enable slider button to enable/disable the Secure Socket Shell service.



A.3.3 Enable/disable HTTPS protocol



▪ Select the Enable HTTPS slider button to enable/disable the HTTPS protocol.




A.3.4 Apply customer certificates for HTTPS



▪ To implement a custom security policy, upload a new certificate to replace the GE self-signed certificate and enable HTTPS requests only.


In the Upload certificate field, click the Select file button, select the new certificate (PEM file) and click Open.




A.4 Software Firewall

The DGA 900 has a built-in firewall that defines the security settings for the various

interfaces. Firewall policies are configured separately for each interface (Ethernet, USB,

GSM-GPRS modem). The DGA 900 ships with a standard GE self-signed certificate with the

firewall enabled by default to accept all HTTP requests. You should customise the firewall.

To create a custom security policy, select Settings > Firewall to open the Firewall Settings

page as shown in Figure A-3.

Figure A-3: Firewall Settings

Rules can be added, edited or deleted to create a suitable access policy for each type of

interface. These rules are used to block unused ports and specify distinct firewall actions

(accept, reject or drop) based on the IP address or port.

A.4.1 Default Policy

The default policy is to accept all incoming requests and applies for all cases not covered

by specific policies. The default policy provides a dropdown list of three options as shown

in Figure A-4.


Figure A-4: Default policy options

A.4.2 Specific Policies

The specific policy adds exceptions to the default policy.

Click the ‘Create new rule’ button to create a new policy. The rule options are as

shown in Figure A-5.

Figure A-5: Specific policy options

A.4.3 Disable all Connections on a dedicated interface

In the Firewall Settings page, select the interface type e.g. lan and in the Default policy

dropdown, select REJECT as shown in Figure A-6.

Figure A-6: LAN interface

A.4.4 Disable all Connections except HTTPS

In the Firewall Settings page, select the interface type e.g. lan and in the Default policy

dropdown, select REJECT as shown in Figure A-7.

Figure A-7: LAN interface

Click the ‘Create new rule’ button to create a new policy. The policy requires

completing several fields as shown in Figure A-8.


Figure A-8: Accept HTTPS

In the ‘Rule Name’ field, type a descriptive name e.g. Accept HTTPS.

In the ‘IP’ field, select the IP checkbox and specify/edit the IP address e.g.

192.168.0.124.

In the ‘Port’ field, select the Port checkbox and type 443.

In the ‘Firewall Action’ dropdown list, select ACCEPT.

Repeat the above steps for each interface type to ensure that only HTTPS requests are

permitted on those interfaces e.g. ‘usb’ and ‘gsm’.

After all interfaces have been configured, click the ‘Save’ button in the application

header to save the security settings and then restart the DGA 900.


Appendix B Transportation PGA Lock

The Analysis module is equipped with a factory-fitted transportation PGA lock that

consists of a metal locking bracket, two metal securing pins, two plastic nuts and three

cable ties as shown in Figure B-1.

Figure B-1: PGA lock – engaged

The lock is engaged prior to shipping, but must be disengaged prior to operation of the

product. The lock must be refitted if there is ever a requirement to transport the module

(or if the product is ever to be laid horizontally). If the product is to be relocated or

transported, it must be shutdown using the procedure outlined in Section 6.14.

Note: If the product is to be removed from the transformer, ensure that the transformer inlet and outlet valves, and the pipework valves are closed before removing the pipework.

To access the lock, open the Analysis module, remove the black push-fit insulating cover as

described in Section C.3 and follow the relevant procedure outlined below.

B.1 Remove the lock

To remove the PGA lock after transportation of the product, follow this procedure:

▪ Cut the three cable ties to release the two securing pins and the locking bracket as shown in Figure B-2.

Figure B-2: PGA lock – pins and locking bracket secured with cable ties


▪ Pull each pin forward and out to remove it from the vibration mount assembly as shown in Figure B-3.

Figure B-3: PGA lock – remove pins

▪ Loosen and remove the two plastic nuts securing the metal bracket to the anti-vibration mounts as shown in Figure B-4.

Figure B-4: PGA lock – remove plastic nuts

▪ Remove the metal bracket as shown in Figure B-5. Note: Retain the metal bracket, pins and plastic nuts for future use of the lock.

Figure B-5: PGA lock – remove metal bracket

The transportation PGA lock is now disengaged rendering the PGA anti-vibration mounts

active. If the product is transported and reconnected to a different substation asset, it

must be recommissioned by a GE-approved commissioning engineer.


B.2 Fit the lock

To fit the PGA lock, reverse the procedure outlined in Appendix B.1:

▪ Insert the metal bracket into the vibration mount assembly as shown in Figure B-6.

Figure B-6: PGA lock – insert metal bracket

▪ Secure the metal bracket to the anti-vibration mounts using the two plastic nuts as shown in Figure B-9.

Figure B-7: PGA lock – attach plastic nuts

Note: Hold the base of the anti-vibration mount while tightening the plastic nuts to prevent twisting of the soft silicone.

▪ Push each metal pin into the vibration mount assembly as shown in Figure B-9.

Figure B-8: PGA lock – insert pins


▪ Ensure that each pin end is fully inserted into the hole in the back wall of the enclosure as shown in Figure B-9.

Figure B-9: PGA lock – pin to enclosure hole

▪ Use three cable ties to secure the pins to the metal bracket at the appropriate holes as shown in Figure B-10.

Figure B-10: PGA lock – pins and locking bracket secured with cable ties

The transportation PGA lock is now engaged rendering the PGA anti-vibration mounts

inactive. After the product is removed, ensure that it is stored in an upright position. Note:

Any remaining oil in the pipework should be drained into a suitable container.


Appendix C Maintenance Activities

C.1 Battery

The product uses non-rechargeable lithium coin cell batteries (Panasonic CR2450

3 V 620 mAh) — one in the Hub module on the Controller PCB as shown in Figure C-1, and

the other in the Analysis module on the Marshalling PCB as shown in Figure C-2. If either

battery needs to be replaced, data from the product must be backed up. Failure to do so

may result in historical data loss.

Figure C-1: Controller PCB coin cell battery

Figure C-2: Marshalling PCB coin cell battery

The following steps describe how to change the battery:

1. Back up the product data — contact your GE representative.

2. Power off the relevant module.

3. Open the door on the relevant module to locate the battery on the relevant board.

4. Slide the battery out of its housing.

5. Replace with a new Panasonic CR2450 3 V 620 mAh coin cell.

6. Close the door.

7. Power on the relevant module and confirm that all product data remains intact.

There is a danger of a new battery exploding if installed incorrectly.

Dispose of the used battery in accordance with local regulations — not in a fire or with household waste. Contact your local waste disposal agency for the address of the nearest battery deposit site. Perchlorate material — special handling may apply.

See: www.dtsc.ca.gov/hazardouswaste/perchlorate/


C.2 Air Filter Replacement

The Hub module draws air from the base and expels it via the air outlet on the front door.

The intake air is filtered to remove the largest particles, so depending on environmental

conditions, the air filter cartridge may need periodic replacement.

To replace the air intake filter:

First isolate the product through the external circuit breaker or external switch

and apply LOTO.

Remove the four M8 hex nuts from the four M2.5 hex bolts securing the filter holder

assembly as shown in Figure C-3 and then prise the holder off the base plate as

shown in Figure C-4.

Remove the used filter mesh cartridge from the holder and dispose of it as shown in

Figure C-5. Replace with a new filter mesh cartridge as shown in Figure C-6 in the

orientation shown in Figure C-4. Note: the metallic mesh cover must face

downwards and outwards in the holder.

Place the filter holder assembly back onto the module’s base plate and secure in

place using the four nuts and bolts previously removed as shown in Figure C-3.

Figure C-3: Hub fan air inlet

Figure C-4: Detached inlet cover with filter – facedown

Figure C-5: Detached inlet cover with filter removed

Figure C-6: Filter mesh cartridge – face up

The air outlet filter on the rear of the front door should also be periodically checked and

replaced if required.

To replace the air outlet filter:


First isolate the product through the external circuit breaker or external switch

and apply LOTO before opening the door.

Remove the eight M5 aerotight nuts that secure the Louvre catchment tray to the

top rear of the front door as shown in Figure C-7, and then lift the tray away from the

neoprene 3 mm gasket as shown in Figure C-8.

Remove the used white filter from the tray (it’s disposable and can be pulled out) as

shown in Figure C-9. Insert a new Louvre air filter as shown in Figure C-10 into the

tray ensuring that the filter evenly fills the entire space.

Refit the tray to the gasket on the front door and secure in place using the eight nuts

previously removed as shown in Figure C-7.

Figure C-7: Louvre catchment tray – attached

Figure C-8: Louvre gasket – tray removed

Figure C-9: Louvre catchment tray – detached & filter removed

Figure C-10: Louvre air filter

C.3 Oil Filter Cleaning

The oil is filtered to prevent particles from entering the product or being returned to the

transformer. Therefore, this filter may need occasional cleaning.

Note: A non-critical error in the product data file, such as error code 18 or 20 can be suggestive of such action.

Figure C-11 shows the oil connections on the base of the Analysis module.


Figure C-11: Oil connections

Figure C-12 shows the oil filter location with the filter element removed.

Figure C-12: Oil filter

Before removing the filter housing, first isolate the product through the external switch or circuit breaker and ensure that the oil supply valve is closed.

To clean the oil filter:

If a measurement is in progress, press Stop Measurement on the HMI to abort the

measurement process and return the product to Standby mode. Power off the

product at the external switch or circuit breaker once it is in Standby mode.

Close the product’s supply and return oil valves.

Open the door of the Analysis module.

Pull the black insulating push-fit cover by the moulded handle nearer the centre top

until the top of the cover opens, then lift the cover vertically up and out of the way as

shown in Figure C-13.

Figure C-13: Internal push-fit cover removal

Remove the four M3 hex bolts holding the oil filter cover.


Remove the stainless steel filter element and clean it using a brush and compressed air

(or replace with a new filter, order FITT01029H). Then replace the filter back into its

housing and re-secure the oil filter cover using the four M3 hex bolts.

Replace the black insulating push-fit cover by inserting the bottom end first. Note: Take

care to route the earthing cable through the groove in the insulation. And then press fit

the top of the cover home.

Close and lock the door.

Re-open the product’s supply and return valves.

Re-energise the product and it will automatically begin measuring at the next scheduled

time.

C.4 Peltier Cooler

The product uses a thermoelectric cooler attached to the outer left side of the Analysis

module to regulate the temperature within the module. The Peltier cooler as shown in

Figure C-14 is self-contained and requires minimal maintenance other than periodic

cleaning.

Follow this procedure to clean the cooler:

Power down the product as described in Section 6.14.

WARNING: Ensure the product is powered off and disconnect all supplies at their source before continuing.

Remove the six M2.5 hex bolts holding the external fan group as highlighted in Figure

C-14 and separate the mating connectors of the electrical cable to free the fan group

from the unit as shown in Figure C-15 to Figure C-17.

Use dry compressed air to blow any dust, insect matter or other debris from the

fans, cooling fins and the top vent (if necessary, remove the hood held by two M2.5

hex bolts).

Use a clean dry cloth to remove any hardened deposits from the general area.

If necessary, protect the electrical connector and use a non-pressurised hose pipe to

direct deionised water through the top fins of the cooler and continue to flush water

through the fins until the water running out from the bottom of the cooler turns

clear.

Reconnect the electrical cable at the clip, replace the external fan group (and hood if

removed), and secure in place with the M2.5 hex bolts.

Use only deionised water and a non-pressurised hose to direct water through both fan inlets for as short a time as possible; typically, less than 10 seconds is sufficient to clean each fan inlet (with a typical total duration of under 3 minutes).


Power on the product.

Figure C-14: Peltier cooler

Figure C-15: Fan group electrical connection

Figure C-16: Peltier cooling fins

Figure C-17: Fan group detached from cooler

Hood

Cooling fins Detached fan group

Electrical clip connector

Hex bolts (six highlighted)


Appendix D Time Sync Implementation

The product has a time-sync feature that allows users to synchronize the clock. This

Appendix explains the data format options for the “time sync” and its implementation.

D.1 Time Format

Under the standard Modbus® register list, the timing is defined in Table D-1.

Table D-1: Timing

Register Permissions Group Size

Description Data Format

1200

R/W 4*

UTC Clock: Years YYYY (BCD)

1201 UTC Clock: Months, days MMDD (BCD)

1202 UTC Clock: Hours, minutes HHMM (BCD)

1203 UTC Clock: Seconds, Day of week (0-6, 0 Sunday)

SSWW (BCD)

This R/W (read/write) register is in BCD format (Binary Coded Decimal). Some systems are

not compatible with this data format. *The time registers can be written separately in 5

second intervals in any order.

D.2 UNIX® Epoch register

A UNIX Epoch register was added to the host board firmware (v1.12.2) to make systems

integration easier in cases of system incompatibility. Both register formats (BCD & UNIX)

will be maintained in future firmware versions and both affect the same single clock. The

details of the UNIX time registers are listed in Table D-2.

Table D-2: UNIX time registers

Register Access Flags

Version Storage Class

Effect After

Name Description Data Format

1197 rg2,wg2 1.12.2 RAM immediately RTC_UNIX_TIME

Current Time UTC in UNIX format

32-bit integer 1198

These registers are readable and writable, but should be written together as a single 32-bit

value.

D.2.1 UNIX Time Format

The number of seconds from the UNIX epoch time of Jan 1st 1970 00:00:00.

D.2.2 UNIX Time Example

For reference, the time on a device is reported in the UTC format on the HMI as 11/29/2017

00:00:00 BST and the corresponding value in the registers mentioned above is

1511913600.


When testing, please check that you are reading registers 1197-1198 (assuming addresses

start at 999 +1) and decoding an unsigned 32-bit big endian number. The epoch time is in

UTC. This matches the device time. An online converter e.g.

http://www.epochconverter.com/ can be used to verify.

D.2.3 Register Access Control

The product registers are protected with access flags. The register map details the relevant

access flags for each register. Each register may have one or more access flags, separated

by commas. Table D-3 lists the supported access flags:

Table D-3: Access flags

Flag Access Description

R Read Read access to a single register

rgN Read group Read access to a group of length N (Nmax = 120)

W Write Write access to a single register

wgN Write group Write access to a group of length N (Nmax = 120)

Access flags may be modified with the addition of the modifier flags listed in Table D-4.

Table D-4: Modifier flags

Flag Access Description

u User Only accessible if the master is authorised with user access

c Config Only accessible if master is authorised as config (commissioning) user

f Factory Only accessible if master is authorised as factory (service) user

http://www.epochconverter.com/


Appendix E Alarm Settings: General Advice

Note: This Appendix is based on Technical Bulletin No 18 (amended below for DGA 900).

E.1 Introduction

There are published standards for interpretation of DGA results. The main internationally

recognised standards are IEEE® C57.104 and IEC® 60599. It is recommended that the

customer refers to these or local standards for more information on DGA interpretation.

As every transformer is different due to design, manufacturing tolerances, operating

regime, etc., there are no rules that can be applied to every transformer. Therefore, alarm

settings should be individually set for each transformer.

IEEE C57.104 provides a 4-level criterion to classify risks to transformers. Condition 1 gives

the average gas values below which a ‘normal transformer’ is operating satisfactorily.

If there is DGA history available for the transformer, then the customer should also consult

this information when deciding on the alarm settings for the transformer.

E.2 Setting Alarms

All online DGA monitors should have alarm levels set at commissioning. This will ensure

that the customer is alerted should the gas concentrations increase. While it is the

customer’s responsibility to set appropriate alarms, it is recommended that there always

be some alarms set on the DGA monitor as there have been some cases where alarm

levels have not been set and the transformer has failed without any notification to the

customer.

Customers with experience in monitoring transformers may have their own methodology

for setting alarms. In this case, the customer methodology should be used to set alarms on

the DGA monitoring system.

Where a customer wishes to monitor the transformer for a period before deciding on the

alarm settings, it is recommended that some preliminary alarm levels are set at the time of

commissioning using the method outlined in E.3.

E.3 Main Tank: Gas Level Alarms

If the customer does not have their own system for setting alarms, the following procedure

may be used, at the customer’s discretion, to set preliminary alarms on the DGA monitor:

• Run the analyser for several hours, preferably overnight, at hourly measurements.

• Compare the results to IEEE Standard C57.104-2008 to see if any of the results are

outside the established norms.


Table E-1: Main Tank: Gas Level Alarms

µL/L or ppm

Hydrogen

(H2)

Methane

(CH4)

Acetylene

(C2H2)

Ethylene

(C2H4)

Ethane

(C2H6)

Carbon

monoxide

(CO)

Carbon

dioxide

(CO2)

TDCG

IEEE STD Condition 1

100 120 1 50 65 350 2500 720

1) Set alarms to the following only if the measurements taken are LESS THAN the above values. (C2H2 is set slightly higher to avoid spurious alarms)

Caution 100 120 2 or 4* 50 65 350 2500

Alarm 120 144 3 or 6* 60 78 420 3000

* To avoid spurious alarms on the DGA 900, C2H2 Caution and Alarm limits should be set no lower than 2 and 3 ppm respectively.

2) Set alarms to the following only if the measurements taken are ABOVE the IEEE Condition 1 values.

Measured Value * yyy% = ppm caution/alarm value)

Caution Value *120% Value *120%

Value *120% Value *120%

Value *120%


Alarm Value *150% Value *150%


Value *150%


Note: The values cited in this table assume that no previous tests on the transformer for dissolved gas analysis have been made or that no recent history exists. If a previous analysis exists, it should be reviewed to determine if the situation is stable or unstable.

Note: See the example in Section E.8 at the end of this Appendix.

E.4 Main Tank: Gas Rate Of Change Alarms

Set the Rate of Change (ROC) alarms to the following values listed in Table E-2 for the most

critical gases:

▪ Daily Rate of Change (ROC) alarms – if oil volume is unknown

Table E-2: ROC alarms (key gas values)

ppm / day

Hydrogen

(H2)

Methane

(CH4)

Acetylene

(C2H2)

Ethylene

(C2H4)

Ethane

(C2H6)

Carbon

monoxide

(CO)

Carbon

dioxide

(CO2)

TDCG

Caution - - 0.5 0.5 - 2 - 2

Alarm - - 1.0 1.0 - 5 - 8

▪ Daily Rate Of Change (ROC) alarms – if oil volume or weight is known

If the oil volume is known, the severity of defects based on ROC depends on the volume (or

weight) of oil contained in the transformer. For instance, a 1 ppm/day gas increase in a

large transformer (80,000 l oil) means a ROC of 80 ml/day of such gas. In a smaller


transformer (4,000 l oil), the same 1 ppm/day gas increase means a ROC of 4 ml/day. In

either case there is a defect, but in the larger transformer the defect is much more severe.

E.4.1 Using Oil Volume

It is strongly recommended to use ROC in ml/day. Convert the ppm/day figure to ml/day

based on the oil volume or weight:

1) ( )

daymlmROC

ROC /

=

Transformer owner may calculate ROC in ml/day by using following formula (IEC 60599):

2) ( )

( )dayml

dd

myyROC /

12

12

−

−=

where:

▪ y1 is the last reading, in ppm;

▪ y2 is the previous reading, in ppm;

▪ m is the oil mass / weight, in kilograms;

▪ ρ is the oil density, in kilograms per cubic metre;

▪ d1 is the date of y1, and

▪ d2 is the date of y2.

Note: This is a very generic formula. As Kelman® equipment readings are taken every day, then (d2 – d1) = 1

E.4.2 Using Oil Mass

Should the transformer owner use oil mass instead of oil volume, then ρ = 1,000. Thus,

formula can be simplified to:

3) ( ) )/(12 daymlMyyROC −=

where:

▪ (y2 – y1) is the difference between two consecutive readings in 24 hours, in ppm

▪ M is the oil mass, in metric tons

Note: Pay attention to the units of measure.

▪ In formula 2), oil density is given in kilograms per cubic metre, thus typical oil density is about 960 kg/m3.

▪ In formula 3), gas concentration is given in ppm and oil mass is given in metric tons).

If using ROC in ml/day, use Table E-3 to set ROC alarms:


Table E-3: ROC alarms (for ROC in ml/day)

ml/day Hydrogen

(H2)

Methane

(CH4)

Acetylene

(C2H2)

Ethylene

(C2H4)

Ethane

(C2H6)

Carbon

monoxide

(CO)

Carbon

dioxide

(CO2)

TDCG

Caution 2.5 1 0.05 1 1 25 - 5

Alarm 5 2 0.1 2 2 50 - 10

E.5 Measurement Intervals

If the customer does not have a policy for measurement intervals, use the following

measurement intervals (in hours):

Table E-4: Measurement intervals

In Hours DGA 900

Normal 8

Caution 4

Alarm 1

E.6 Other Settings / Alarm Setups

In TransConnect, remember to map Caution and Alarm values to Caution/Alarm indicators,

Caution/Alarm modes, any wired relays and SMS messaging as required.

E.7 Important Notes

All alarm and measurement interval settings must be approved and signed off by the

customer.

After oil treatment (degassing, regeneration, drying, mixing, etc.), the alarm settings

should be reviewed and changed if necessary.

E.8 Example (Main Tank)

The maximum measured value of ethylene is 48 ppm.

This is close to the limit in Table E-1, so the Caution should be set to 120% of the value and

Alarm to 150% of the value.

Caution 58 ppm

Alarm 72 ppm

The rate of change alarms should also be set.

Caution 0.4 ppm/day

Alarm 1.0 ppm/day


E.8.1 Caution

There may be cases where the transformer suddenly fails (between measurements at the

normal measurement interval). The customer should be made aware that online

monitoring equipment is not capable of detecting such rapid (often catastrophic) failures.

DGA monitoring is designed for the detection of incipient slow-developing faults. Other

protective devices (Buchholz relay, pressure relief device, over-current and differential

current protection, etc…) should be used in conjunction with DGA monitoring equipment to

provide complete protection for the transformer.

E.8.2 Stray Gassing (CIGRE® TF 15/12.01.11)

Some modern, unused oils are recognised as ‘stray gassing’. This means that the oil itself

can produce some hydrogen in the absence of defects. Should the online monitor be

installed before or within a few months after the commissioning of the transformer,

hydrogen concentration may rise to 250 ppm. This should be taken into consideration

when establishing the caution and alarm settings.

In stray gassing oils, hydrogen concentration increases very rapidly when the transformer

is energised, reaches a plateau at about 250 ppm and then decreases slowly to normal

values. The transformer owner should know this behaviour before setting up caution and

alarm values and adapt them during the first year or two of transformer operation. If

Kelman equipment is installed on a transformer already in service, this note is not

applicable unless a passivator or an additive has been recently added to the oil.

After any oil treatment (degassing, regeneration, drying, mixing, etc.), the alarm settings

should be reviewed and changed if necessary.


Contact & Copyright Details

GE Grid Solutions (UK) Ltd

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Unit 1, 7 Lissue Walk, Lisburn, Co. Antrim

Northern Ireland, United Kingdom BT28 2LU

GEGridSolutions.com

For further assistance or queries please contact:

Customer Service Centre (24 hours a day, 365 days a year)

T +44 1785-250-070 (United Kingdom)

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[email protected]

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Other company or product names mentioned in this document may be trademarks or

registered trademarks of their respective companies.

GE reserves the right to make changes to specifications of products described at any

time without notice and without obligation to notify any person of such changes.

This material is accurate at the time of writing. For the latest release, please visit:

http://www.gegridsolutions.com/md/catalog/dga900.htm

Copyright, General Electric Company, 2019. All Rights Reserved.

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