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Functionality Note

The Soft Load Automatic Transfer Switch will parallel one emergency generator to the utility. It cannot be used for controlling multiple generators or having multiple soft load systems control a single generator. This usually necessitates obtaining approval from the local distribution utility company and meeting the IEEE 1547 Standard for utility interconnection requirements. The generator set must be equipped with an automatic isochronous governor and solid state voltage regulator controls, each suitable for parallel with utility operation

PART 1 GENERAL

1.1 Scope

Furnish and install a soft load transfer switch (ZTSSL) with number of poles, amperage (4000 amps maximum), voltage and withstand/close-on ratings as shown on the plans. All components, testing, and services specified or required for a complete operable system shall be included and shall be the product of the same manufacturer.

1.2 General Design Requirements:

A. The ZTSSL shall consist of a power transfer switch, genset controller (GCP), and one utility/generator power management and protection (G30), The ZTSSL shall provide load transfer between the utility and generator source with the following selectable operating modes:

Transition Modes:

1. Closed (<100mS)2. Soft (1 second to 16 minutes)3. Open

Transfer Modes:

1. Automatic (Emergency Standby)2. Islanded3. Peak Shave (Continuous Parallel with Utility)

a. Base-loadb. Import / Export

KW Demand Mode: ON/ENABLE – OFF/DISABLE

GS-1108 1 of 24 ZTSSL Guideform Specification, 3/26/2008

B. The GCP shall retain master control of the Power Transfer Switch for all transfer functions, including conventional open transition; closed transition and soft load transfer operations. Upon loss of a power source, the GCP controller shall transfer the load to the generator via open transition (no overlap during load transfer).

C. The GCP shall handle the user interface for all control. All protective function settings shall be provided by a separate utility grade multi-function G30 relay. The GCP shall also handle the following functions:

1) Transmission of all generator alarm conditions, synchronization of power sources, voltage matching, VAR/power factor control, and generator loading/unloading control algorithms.

2) Generation of analog voltage signals and/or a pulse width modulated signal to drive external speed control, and voltage regulator.

3) All GCP screen displays, operating labels, and operator’s manuals shall be available in English and Spanish at a minimum.

D. Utility and Generator Power Protection and Management (G30)The G30 shall monitor the utility power parameters and provide protective relaying functions, including relay outputs for external circuit breaker tripping control. The protective relaying shall meet the requirements of IEEE 1547 Standard for utility interconnections. The utility power parameters and alarming information shall be serially communicated to the optional EnerVistaTM ViewPoint Monitoring software for control and display.


E. Soft Load System Block Diagram

The ZTSSL Softload Transfer switch shall be designed to control a single generator in parallel with a single utility supply. The GCP provides the softload control, while the Multilin G30 provides Utility-grade protection for both the Generator and Utility Supply. The Softload Transfer Switch shall send speed increase/decrease and voltage increase/decrease signals to the Genset-mounted control panel for synchronizing and load control functions

1.3 Related Sections

A. Section 16XXX: GeneratorsB. Section 16XXX:

1.4 Application Codes and Standards

A. IEC 60947-6-1 Low-voltage Switchgear and Control gear; Multifunction equipment; Automatic Transfer Switching Equipment.

B. IEEE Standard 446 – IEEE Recommended Practice for Emergency and Standby Power Systems for Commercial and Industrial Applications.

C. IEEE Standard 1547 – Standard for Interconnecting Distributed Resources with Electric Power Systems.


D. IEEE Standard 1547.1 – Standard Conformance Test Procedures for Equipment Interconnecting Distributed Resources with Electric Power Systems.

E. National Fire Protection Association (NFPA). NFPA - 70 - National Electrical Code

F. NFPA -110 - Emergency and Standby Power SystemsG. NFPA - 99 - Essential Electrical Systems for Health Care Facilities. H. NEMA Standard ICS10-1993 (formerly ICS2-447) - AC Automatic Transfer

SwitchesI. UL 1008 – Standard for Transfer Switch EquipmentJ. UL 508 Industrial Control Equipment K. UL 891 Dead Front Switchboards for circuit breaker versions

1.5 Manufacturer’s Qualifications

The Soft Load Automatic Transfer Switch shall be GE Zenith Controls Model ZTSSL. Any alternate shall be submitted to the consulting engineer for approval at least 10 days prior to bid. Alternate bids must list any deviations from this specification.

PART 2 - PRODUCTS

2.1 Power Transfer Switch

A. The power transfer switch shall be electrically operated and mechanically held. The electrical operator shall be a momentarily energized, solenoid mechanism. Main operators that include over-current disconnect devices; linear motors or gears shall not be acceptable.

B. All transfer switch ratings shall use the same kind of main operator for ease of maintenance and commonality of parts.

C. The switch shall be positively locked and unaffected by momentary outages, so that contact pressure is maintained at a constant value and contact temperature rise is minimized for maximum reliability and operating life.

D. All main contacts shall be silver composition. Switches rated 600 amperes and above shall have segmented construction for high withstand and close-on capability and be protected by separate arcing contacts.

E. Inspection of all contacts shall be possible from the front of the switch without disassembly of operating linkages and without disconnection of power conductors.

F. Designs utilizing components of molded-case circuit breakers, contactors, or parts thereof, which are not intended for continuous duty, repetitive switching, transfer between two active power sources, or field maintenance is not acceptable.

G. Where neutral conductors are to be solidly connected as shown on the plans, a neutral conductor plate with fully rated AL-CU pressure connectors shall be provided.


2.2 Transfer Switch and Soft Load Controller (GCP) A. The Transfer Switch Control and Load Control functions shall reside in one

integrated control unit (GCP). B. The Transfer Switch and loading functions, sensing and logic shall be

incorporated in a single microprocessor controller for maximum reliability, minimum maintenance.

C. The voltage sensing shall be true RMS type and shall be accurate to 1% of nominal voltage. Frequency sensing shall be accurate to 1%. The controller shall be capable of operating over a temperature range of -20 to +70 degrees C and storage from -30 to +80 degrees C.

D. The controller shall be connected to the transfer switch by an interconnecting wiring harness. The harness shall include a keyed disconnect plug to enable the controller to be disconnected from the transfer switch for routine maintenance. Sensing and control logic shall be provided on multi-layer printed circuit boards. Interfacing relays shall be industrial grade plug-in type with dust covers. The controller shall be enclosed with a protective cover and be mounted separately from the transfer switch unit for safety and ease of maintenance.

E. All customer connections shall be wired to a terminal block to simplify field-wiring connections.

F. The controller shall meet or exceed the requirements for Electromagnetic Compatibility (EMC) as follows:

1) IEEE472 (ANSI C37.90A) Ring Wave Test.2) ENC55011 1991 Class A Conducted and Radiated Emission. 3) EN61000-4-2 Electrostatic Discharge Immunity, Direct Contact & Air

Discharge. 4) EN61000-4-3 Radiated Electromagnetic Field Immunity. 5) EN61000-4-4 Electrical Fast Transient Immunity. 6) EN61000-4-5 Surge Immunity. 7) ENV50141 HF Conducted Disturbances Immunity.

2.3 Transfer Switch and Soft Load Controller (GCP) Display and Keypad

A two-line, 16 character LED display and keypad shall be an integral part of the controller for viewing all available data and setting desired open delayed transition and closed transition operational parameters. The following parameters shall only be adjustable via keypad on the controller. DIP-switch adjustment is not acceptable.

1) Nominal line voltage and frequency2) Single or three phase CT sensing3) Operating parameter protection

All instructions and controller settings shall be easily accessible, readable and accomplished.


2.4 Transfer Switch and Genset Controller (GCP) - Voltage, Frequency and Phase Rotation Sensing

A. Voltage and frequency on both the normal and emergency sources shall be continuously monitored, with pickup, dropout and trip setting capabilities.

B. Repetitive accuracy of all settings shall be within ± 0.5 % over an operating temperature range of -20 C to 70 C.

C. Voltage and frequency settings shall be field adjustable in 1% increments with the display and keypad.

D. Source differential sensing shall be provided for all operating modes where the utility and the generator are paralleled (load is simultaneously connected to both sources). The GCP shall enable paralleled transfer/re-transfer between live sources only when the two sources have a maximum voltage differential of 5 % frequency differential of 0.2 Hz with the sources being within 5 electrical degrees.

E. The GCP shall be capable of sensing the phase rotation of both the normal and emergency sources.

F. Source status screens shall be provided on the LED display described below for both normal & emergency to provide digital readout of voltage per phase and frequency.

G. The GCP shall include a synchronizing check function to ensure phase, voltage and frequency matching of both power sources. This function shall inhibit paralleling the sources until the voltage is within 5 %, the frequency to within 0.2 Hz and the phase angle difference reduces to 5 degrees and is approaching zero.

2.5 Transfer Switch and Soft Load Controller (GCP)- Time Delays

A. An adjustable time delay of 0.5 to 99.9 seconds shall be provided to override momentary normal source outages and delay all transfer and engine starting signals.

B. A load ramping rate shall be adjustable from 0.1% to 100% per second during transfer of load either from generator to utility or from utility to generator.

C. An adjustable time delay of 0.5 to 99.9 seconds to override momentary emergency source outage to delay all retransfer signals during initial loading of engine generator set.

D. Time delay shall be provided on re-transfer to normal. The time delays shall be adjustable from 1 to 3600 seconds. Time delay shall be automatically bypassed if the emergency source fails and the normal source is acceptable.

E. A time delay shall be provided on shut down of engine generator for cool down, adjustable from 1 to 3600 seconds.

F. A time delay activated output signal shall also be provided to drive an external relay(s) for elevator pre-signal control. The controller shall have the ability to activate an adjustable 0 to 60 second time delay in either direction.


G. The controller shall also include a built-in 10 to 999 seconds time delay on failure to synchronize normal and emergency sources prior to soft load transfer.

H. All GCP time delays shall be adjustable in either 0.1 or 1-second increments by using the LED display and keypad located on the enclosure door. The time delay value displayed on the LED or remote device shall be the remaining time until the next event occurs.

2.6Transfer Switch and Genset Controller (GCP)– Additional Features

A. A SPST contact, rated 2 amps at 24VDC, shall be provided for a low-voltage engine start signal. The start signal shall prevent dry cranking of the engine by requiring the generator set to reach proper output, and run for the duration of the cool down setting, regardless of whether the normal source restores before the load is transferred.

B. System Status - The controller display shall include messaging showing current operational processes such as timers timing down, alarm conditions, etc.

C. Self-Diagnostics - The controller shall show diagnostic messages for the purpose of detecting system errors. Messaging shall provide information on the status-input signals to the controller, which may be preventing load transfer commands from being completed.

The following features shall be available as required by the user:

D. Calendar Clock with Two Programmable Channels, Provide:

D.1 Engine Exerciser - A separate exerciser timer module shall be provided for engine exerciser. The engine exerciser shall allow the user to program up to 400 different exercise routines. For each routine, the user shall be able to:

1) Enable or disable the exercise routine. 2) Set the start time

- time of day- day of week- week of month (1st, 2nd, 3rd, 4th, alternate or every)- set the duration of the run

At the end of the specified duration the switch shall transfer the load back to normal and run the generator for the specified cool down period. A 6-year life battery that supplies power to the real time clock in the event of a power loss will maintain all time and date information. Timer programs shall be stored in non-volatile memory.

3) All exerciser timer programs shall be stored without use of additional controller EEPROM memory.

4) Daylight Savings Time?D.2 kW Demand programmable Period per the contract with local utility for

KW Demand Operation.


2.7 Transfer Switch and Genset Controller (GCP) - Soft Load Control:

A. All soft load control functions shall be integral part of the GCP.B. The GCP shall included a 2 x 16 LED display with touch sensitive membrane

keypad for viewing and setting all programmable parameters in the GCPGCP shall be capable of operating over a temperature of –-20 to +70 degrees centigrade.

C. The GCP shall be capable of displaying the following:

1) A digital multicolor LED synchroscope shall be provided to display the relative phase relationship between the utility and generator sources.

2) A digital display, showing power in both kW of total load, shall be provided for utility and generator sources.

3) Real, and reactive power, power factor active energy (kWh), line-to-line and/or line-to-neutral voltage, phase current, maximum current, frequency shall be displayed for generator power source.

4) Voltage, current, real power, and power factor shall be displayed for utility power source.

5) Active displays shall indicate source acceptability, circuit breaker and transfer switch positions.

6) Battery Voltage7) Operating Hours8) Engine Start Counter9) Screens shall contain three levels of security to protect against

unauthorized viewing or tampering of sensitive data.10) An event and setup log shall be provided which captures the following

information:- Transfer switch events- Power source status- Engine Start/Stop- Modes of operation- Alarms (protective relay status)

The log shall capable of storing up to 50 events with documentation of with time and date stamp.

11) GCP protective functions shall be viewable from front panel LCD display.D. The GCP shall contain the following inputs and outputs:

1) Analog output for governor control: fully adjustable up to +/- 9.0 VDC; or 10.0 Vpk, 500 Hz pulse width modulated (PWM).

2) Analog output for voltage regulator control: adjustable from 0 VDC to +/- 9 VDC.

3) Three relay contact outputs, form A, rated 2 amps @ 24 VDC, 0.3 amp @ 110 VDC, 2 amp @ 120 VAC to provide the following control and indication:

1. Control of alarm horn-Provision2. Ready for operation-Provision3. Engine Start Signal

4) Sixteen (16) configurable discrete alarm inputs.5) Seven (7) configurable/programmable output relays.6) Three (3) configurable 0/4-20mA analog measuring inputs.


7) Two (2) configurable Pt100 analog measuring inputs.8) Two (2) configurable VDO analog measuring inputs.

E. GCP shall have provisions for future integrated communication to engine controllers including (via CAN bus) standard SAE J1939, Deutz EMR, Scania S6, MTU MDEC; (via RS232) CAT CCM interface.

2.8 Utility and Generator Power Protection and Management (G30)

A. The Utility and Generator Power Protection and Management (G30) shall be an integral device. The Utility and Generator Protection and Management device shall meet the following requirements:1) Utility Grade rated device. Industrial grade devices are not acceptable.2) Capable of secondary, hot swappable, redundant power supply. Non- hot

swappable power supplies are not acceptable.3) Consist of modular design to easily facilitate upgrading or repair by

replacement of modules. Non-Modular devices not acceptable.4) Three (3) communication ports that operate independently and

simultaneously. They shall be arranged:i) One (1) RS232 port shall be front accessible. Port shall support

ModBus RTU at 19.2kbps protocol.ii) One (1) RS485 port shall support ModBus RTU and DNP 3.0 protocols

capable of baud rates up to 115kbps.iii) One (1) 10 Mbps Ethernet port supporting Ethernet Global Data

(EGD), IEC 61850, MMS/UCA2, ModBus/TCP, and DNP 3.0 or IEC 60870 protocols. The port shall be 10/100BaseT.

5) The faceplate shall include an alphanumeric vacuum florescent display.6) Contain an embedded web server and is capable of transferring web

pages to a web browser. Web server accessed via the integrated Ethernet port. Web pages are available showing DNP and IEC 60870-5-104 points list, ModBus registers, Event Recorders, and Fault reports.

7) RMS current, voltage, real power (watts), reactive power (VAR), and apparent power (VA) sensing shall be accurate to no more than +/-1% of nominal. Watt-Hours (positive and Negative), and VAR-Hours (positive and negative) sensing shall be accurate to no more than +/- 2% of reading. Frequency sensing shall be accurate to no more than +/-0.05Hz.

8) Shall be capable of operating over a temperature range of -40 to +60 degrees C and storage from -40 to +80 degrees C.

9) The controller shall meet or exceed the requirements for Electromagnetic Compatibility (EMC) as follows:

10) EN61000-4-2 Electrostatic Discharge Immunity, Direct Contact & Air Discharge.

11) EN61000-4-3 Radiated Electromagnetic Field Immunity. 12) EN61000-4-4 Electrical Fast Transient Immunity. 13) EN61000-4-5 Surge Immunity.14) IEC 61000-4-6 Conducted RFI. 15) IEC 610004-8 Power Frequency Magnetic Field Immunity16) IEC 610004-9 Pulse Magnetic Field Immunity17) ENV50141 HF Conducted Disturbances Immunity.18) IEC 61000-4-12 Oscillatory Transient.

The controller shall meet or exceed the following approvals:


1) UL listed for USA and Canada2) CE listed per LVD 73/23/EEC3) CE listed per EMC 81/336/EEC4) CE listed per IEC 1010-15) CE listed per EN 50081-26) CE listed per EN 50082-2

B. Have the capability of monitoring all the power parameters for both power

sources. Parameters shall be able to be monitored remotely by optional EnerVistaTM ViewPoint Monitoring software screens.

C. The following protective functions shall be provided for programming (in any

combination) by the user:C1. Utility protection and management:

1) Phase over current (device 50/51) for detection of a fault on the system for utility protection.

2) Reverse power (device 32) for installations where utility requires back feed detection.

3) Negative sequence over current (device 46) for unbalanced current detection.

4) Negative sequence voltage (device 47) to provide for permissive operation on closing to prevent connecting the generator to a three-phase bus.

5) Over/Under frequency (device 81O/U) for detecting islanding during parallel operations.

6) Under/over voltage (devices 27/59) for use in the event of a generator islanding due to a loss of utility or fault related tripping during paralleling operations.

7) Under Power for low forward power utility protection. 8) Synchronizing check relay (25)9) Device 86 lockout capable of collecting one or more protective

functions and signaling the output relays on the PMT to trip an external breaker connected to the utility source.

C2. Generator protection and management:1) Under/over voltage (devices 27/59)2) Over/under frequency (device 81O/U)3) Reverse power (device 32)4) Negative sequence overcurrent (device 46) for unbalanced current

detection.5) Excessive reverse VAR for loss of excitation (device 40)6) Generator ground fault residual Overcurrent (51N)7) Synchronizing Check relay (25)8) Tripping the generator breaker 9) kW overload alarm10) Phase over current (device 5 0/51) for generator protection


D. Sixteen digital inputs shall also be provided which can be programmed and displayed on the GCP.

E. Up to (12) protective functions and/or status inputs shall be capable of being programmed in the G30. If the G30 trips an external breaker as a result of a protective function, the system control shall log the reason for the trip and set the system alarm. Provisions for acknowledgement or automatic reset of all of these functions shall also be provided for the user to select.

F. Four relay outputs rated 1 amp @ 30 VDC, 0.5 amp @ 125 Vac shall be provided for circuit breaker tripping control and alarming. Contact inputs shall be supplied with Auto-Burnishing feature to remove contact sulfidation, oxidation, or contaminates on the contact surface. Output relay contacts without Auto-Burnishing are not acceptable.

2.9 Annunciation

A. The following items shall be annunciated using discrete Industrial Grade LED indicators:

Description Type of Annunciation ColorUtility Power Connected (IDEC) LED RedGenerator Power Connected (IDEC) LED RedUtility Power Available (IDEC) LED GreenGenerator Power Available (IDEC) LED GreenUtility Locked Out (IDEC) LED RedFail to Sync (GCP) Messaging TextExtended Parallel Alarm (GCP) Messaging TextEngine Running - Protection and alarms armed (GCP)

LED Green

Generator circuit breaker closed (GCP) LED Display GreenUtility circuit breaker closed (GCP) LED Display GreenUtility & Generator kW, total P.F. and Freq. (GCP)

Messaging Text

Utility and Generator Phase A volts, amps (GCP)

Messaging Text

Utility and Generator Phase B volts, amps (GCP)

Messaging Text

Utility and Generator Phase C volts, amps (GCP)

Messaging Text

Utility Power Failure (IDEC) LED RedTiming Retransfer (IDEC) LED GreenCommon Shutdown (IDEC) LED RedCommon Alarm (IDEC) LED AmberEngine Not in AUTO (IDEC) LED Amber


2.10 Enclosure and Exterior Controls / LEDs

A. The Soft Load Transfer Switch shall be furnished in a Type 1 enclosure unless otherwise shown on the plans.

B. All standard and optional door-mounted switches and annunciator backlit LED indicators shall be industrial grade type.

B1. Annunciation shall consist of the following:

1) Generator:a) Common shut-downb) Common alarmc) Availabled) Connectede) Not in auto

2) Utility:a) Failb) Availablec) Timing to retransferd) Connectede) Locked (86L)

B1.1 Auxiliary contacts, rated 10 amps, 250 VAC shall be provided consisting of one contact, closed when the transfer switch is connected to the normal source and one contact closed, when the transfer switch is connected to the emergency source.

B2. Control switches1. Transition Mode Switch (TMS): A three (3) position key switch (Closed -

Soft - Open) shall permit operation and be maintained (key removable), in all positions. Non-key operated selector switch is not acceptable. TMS switch shall function as follows:

1.1When the TMS is in the “Closed” position, the load will be momentarily overlapped across both sources before being transferred to the other.

1.2 When the TMS is in the “Soft” position, the load will be softly transferred from one source to the other.

1.3 When the TMS is in the Open position, the load will be open from any source before being transferred to the other.

2. Transfer Mode Selector Switch (TMSS): A three (3) position (ISLANDED - AUTO - PEAK SHAVE PRESET) key operated maintained TMSS switch, removable in all positions, provide the following modes of operation:

2.1When the TMSS is in the “ISLANDED” position, the engine-generator set will start and the load will be transferred to the generator and isolated from the utility based on the TMS mode.


2.2When the TMSS is in the “AUTO” position, the engine-generator set is on standby and will start whenever a remote start signal is received. When the start signal is removed, the load will be transferred from the generator to utility, depending on the position of the TMS. The engine will continue to operate for an adjustable cool down period before shutting down in readiness for the next operation.

2.3When the TMSS is in the “PEAK SHAVE PRESET” position, the engine-generator will start and synchronize with the utility. The peak shave mode of operation will be in accordance with the switch setting of the PEAK SHAVE MODE SWITCH (PSMS) described in paragraph 3.1 & 3.2.

3. Peak Shave Mode Switch (PSMS): A two (2) position (BASELOAD - IMPORT/EXPORT) key operated maintain PSPM switch, removable in all positions, provide the following modes of operation.

3.1 When the PSMS switch is in the “BASELOAD” position, the generator set will be soft loaded to the preset kilowatt base load level (set point via GCP keypad). The generator set will continue to operate in parallel with utility. The utility will respond to the load increase/decrease in the facility.

3.2 When the PSMS switch is in the “IMPORT/EXPORT” position, the generator set will be soft loaded until utility reaches the preset kilowatt import level (set point via GCP keypad). The generator set will continue to run parallel with utility and will respond to the load increased/decreased in the facility (for Exporting, consult factory).

4. Local/Remote Switch (L/RS): A three (3) position (LOCAL- REMOTE-LOCKOUT) key operated maintained L/RS switch, removable in all positions, provide the following modes of operation:

4.1 When the L/RS switch is in the “LOCAL” position, the customer supplied remote start for “Island Mode”, “Baseload Mode” and Import/Export Mode” have no influence to the local initiated system-operation.

4.2 When the L/RS switch is in the “REMOTE” position, the “Island Mode”, “Baseload Mode” and Import/Export Mode” operation can only be initiated from the signals coming from the customer.

4.3 When the L/RS is in the “LOCKOUT” position, the engine-generator set is locked out.

5. KW Demand Switch (KDS): A two position (ON/Enable – OFF/Disable), key operated maintained, removable in both positions, provides the following operations:5.1The TMSS switch must be placed in the “ AUTO” position5.2The KDS switch then can be placed in the “ON” position,


5.3When the Exercise-clock went into KW demand mode and the load exceeds pre-determined setting with time delay, the system will proceed to the KW demand operation until the demand level is dropped.

PART 3 - DESCRIPTION OF OPERATION

3.1 The Soft Load Transfer Switch shall provide soft load transfer between utility and generator source with the following selectable operating modes:

3.2 Automatic Operation:

3.2.1 Emergency/Standby (Automatic Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP is set to “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “CLOSED” The door-mounted Transfer Mode Switch (TMS) is in the “AUTO”

position.

1. Utility power fails:a) After a five second time delay (TD) (set point adjustable via GCP

keypad), the engine generator starts and comes up to nominal voltage and frequency.

b) As soon as nominal voltage and frequency are reached, the normal contactor transfers to the “OPEN” position and the load is switched open.

c) The emergency contactor transfers to the “CLOSED” position and the load is switched to the generator.

2. Utility power Restores:a) After a five-minute stabilization TD (set point adjustable via GCP

keypad), the GCP synchronizes the generator with utility. When synchronism is reached (displayed on the GCP screen), the normal contactor transfers to the “CLOSE” position paralleling the two sources.

b) The emergency contactor immediately transfers to the “OPEN” position and the load is once again on the Utility.

c) The engine generator cool-down TD (set point adjustable via GCP keypad), runs till expired and shuts down the generator.

3.2.2 Emergency/Standby (Automatic Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP is set to “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “SOFT”


The door-mounted Transfer Mode Switch (TMS) is in the “AUTO” position.





2. Utility power Restores:a) After a five-minute stabilization TD (set point adjustable via GCP

keypad), the GCP synchronizes the generator with utility. When synchronism is reached (displayed on the GCP screen), the normal contactor transfers to the “CLOSE” position paralleling the two sources.

b) The GCP starts soft-unloading the generator to 3 % load level of the rated generator capacity. When the level is reached, the emergency contactor transfers to the “OPEN” position and the load is once again on the Utility.


3.2.3 Emergency/Standby (Automatic Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP is set to “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “OPEN” The door-mounted Transfer Mode Switch (TMS) is in the “AUTO”

position.





2. Utility power Restores:


a) After a five-minute stabilization TD (set point adjustable via GCP keypad), The emergency contactor transfers to the “OPEN” position for the Open time delay (adjustable via the GCP keypad).

b) Normal contactor transfers to the “CLOSE” position and the load is once again on the Utility.


3.2.4 Islanded Mode (Closed Transition Transfer to Generator) (Automatic Operation)

Utility power is available. ATS is in Normal Position serving power to the load. GCP set to “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “CLOSED” The door-mounted Transfer Mode switch (TMS) starts from the

“AUTO” position.

1. When the door mounted Transfer Mode Switch (TMS) is placed in the “Island Mode” position:a) The engine generator starts and comes up to the nominal voltage

and frequency.b) After a five second TD (set point adjustable via GCP keypad) with

preset nominal voltage and frequency reached, the GCP starts to synchronize the generator with the utility. When synchronism is reached, the emergency transfer operator transfers to the “CLOSE” position.

c) Both normal & emergency contactors are in the “CLOSE” position. d) The normal contactor immediately transfers to the “OPEN” position.

The load is powered by the generator in the Islanded mode.

2. When the door-mounted Transfer Mode switch (TMS) is placed back in the “AUTO” position:a) The engine generator synchronizes with the utility.b) When synchronism is reached, the normal contactor

transfers to the “CLOSE” position.c) Both normal & emergency contactors are in the “CLOSE”

position. d) The emergency contactor immediately transfers to the

“OPEN” position. The load is now powered by the utility.e) The engine generator cool-down TD (set point adjustable via

GCP keypad), runs till expired and shuts down the generator.

3.2.5 Islanded Mode (Soft Load Transfer to Generator) (Automatic Operation) Utility power is available. ATS is in Normal Position serving power to the load.


GCP set to “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “SOFT” The door-mounted Transfer Mode switch (TMS) starts from the


1. When the door mounted Transfer Mode Switch (TMS) is placed in the “Island Mode” position:a) The engine generator starts and comes up to the nominal voltage


preset nominal voltage and frequency reached, the GCP starts to synchronize the generator with the utility. When synchronism is reached, the emergency contactor transfers to the “CLOSE” position.

c) Both normal & emergency contactors are in the “CLOSE” position. d) Once the load is transferred from the Utility to the Generator, the

normal contactor transfers to the “OPEN” position. (Soft-loading ramp time set point adjustable via GCP keypad).

e) The load is powered by the generator in the Islanded mode.

2. When the door-mounted Transfer Mode Switch (TMS) is placed back in the “AUTO” position:a) The engine generator synchronizes with the utility.b) When synchronism is reached, the normal contactor transfers to the

“CLOSE” position.c) Both normal & emergency contactors are in the “CLOSE” position. d) The GCP starts soft-unloading the generator to 3% of the generator

capacity. When the level is reached, the emergency contactor transfers to the “OPEN” position and the load is once again on the Utility.

e) The engine generator cool-down TD (set point adjustable via GCP keypad), runs till expired and shuts down the generator.

3.2.6 Islanded Mode (Open Transition Transfer to Generator) (Automatic Operation) Utility power is available. ATS is in Normal Position serving power to the load. GCP set to “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “OPEN” The door-mounted Transfer Mode Switch (TMS) starts from the


1. When the door mounted Transfer Mode Switch (TMS) is placed in the “Island Mode” position:a. The engine generator starts and comes up to the nominal voltage

and frequency.


b. As soon as nominal voltage and frequency are reached, the normal contactor transfers to the “OPEN” position and the load is switched open.

c. The emergency contactor transfers to the “CLOSED” position and the load is switched to the generator.

2. When the door-mounted Transfer Mode Switch (TMS) is placed back in the “AUTO” position:a) The emergency contactor transfers to the “OPEN” position for the

Open time delay (adjustable via the GCP keypad). b) Normal contactor transfers to the “CLOSE” position and the load is

once again on the Utility. c) The engine generator cool-down TD (set point adjustable via GCP

keypad), runs till expired and shuts down the generator.

3.2.7 Base Load (Automatic Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP set in “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “SOFT”. GCP set to base load at XXX kW. The door-mounted Peak Shave Mode switch (PSMS) set at “Base

Load”.

1. When the door-mounted Transfer Mode Switch (TMS) is placed in the “Peak Shave Preset” position: a) The engine generator starts and comes up to the nominal voltage



c) The engine generator starts soft loading until it reaches the preset XXX kW base load set point. (Soft loading ramp time set point adjustable via GCP keypad).

d) The ATS operates with both normal & emergency contactors in “CLOSE” position. As the load is increased the utility responds and picks-up the load while the generator remains at constant preset base load level (level adjustable via GCP keypad).

2. When the Transfer Mode Switch is placed back in the “AUTO” position:

a) The engine generator starts to soft unload.b) After the engine generator reaches 3% of capacity, the emergency

contactor transfers to the “OPEN” position.



3.2.8 Fixed Utility Import Power (Automatic Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP set in “AUTO” position. Transition Mode Selector Switch (TMSS) is set at “SOFT” GCP set to import utility power at XXX kW. Set the Peak Shave Mode switch (PSMS) to “Import/Export” position.

1. When the door-mounted Transfer Mode Switch (TMS) is placed in “Peak Shave Preset” position:a) The engine generator starts and comes up to the nominal voltage



c) The engine generator starts soft loading until the utility reaches the preset XXX kW import level set point (generator soft loading ramp time set point adjustable via GCP keypad).

d) The ATS operates with both normal & emergency contactors in “CLOSE” position. The generator responds to the load increase from the facility while the utility remains at constant preset import level (level adjustable via GCP keypad). As the load is increased from the facility, the utility will respond to the load increase if it’s beyond generator capacity.

2. When the Transfer Mode Switch (TMS) is placed in the “AUTO” position:a) The engine generator starts to soft-unload.b) After the engine generator reaches 3% of capacity, the emergency

contactor transfers to the “OPEN” position.c) The engine generator cool-down TD (set point adjustable via GCP

keypad), runs till expired and shuts down the generator.

3.2.9 KW Demand Operation (Automatic Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP set in “AUTO” position. Transition Mode Selector Switch (TMSS) is set at any position GCP set to import utility power at XXX kW (adjustable on the Key

Pad). Set the Peak Shave Mode switch (PSMS) to any position. KW Demand Switch set at “ON” position The Calendar Clock (CC) must be programmed for the demand

periods per agreement with utility


The GCP must be programmed for KW demand level.

1. When the programmed demand period from CC occurs, the KW demand mode is enabled; the indicating light on the door will be on. Only after the KW demand setting on the GCP met with the time delay expired, the system will proceed the KW demand operation:

2. The sequences of operation will be the same as the Import Mode operation.

3. When the KW demand start signal is reset by either the removal of KW demand level or clock or placing the KW demand switch to “OFF” position. The generator will be unloaded and its breaker opens, and then shuts down.

3.3 Manual Operations

3.3.1 Emergency/Standby (Manual Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP set in “MAN” position. Transition Mode Selector Switch (TMSS) is set at either “OPEN”,

“CLOSED” or “SOFTLOAD” The Transfer Mode Switch (TMS) remains at “AUTO” position

(allowing the operator to manually control from the GCP panel).

1. Utility power fails:a) The “START” pushbutton is pressed on the GCP, which starts the

engine generator.b) After the engine generator starts and comes up to the nominal

voltage and frequency, press the “OFF” pushbutton of the main breaker to open the normal contactor, then press the “ON” pushbutton of the generator breaker to close the emergency contactor on the GCP.

c) The emergency contactor transfers to the “CLOSE” position.

2. Utility power restores:a) After main breaker “ON” pushbutton is pressed on the GCP, b) If the TMSS is in OPEN position, the emergency contactor will open

and the normal contactor will close.c) If the TMSS is in “CLOSED” position. the generator synchronizes

with the utility. When synchronism is reached (displayed on the GCP screen), the normal contactor transfers to the “CLOSED” position. The emergency contactor transfers to the “OPEN” position.

d) If the TMS is in the “SOFTLOAD” position, the generator synchronizes with the utility. When synchronism is reached (displayed on the GCP screen), the normal contactor to transfers to


the “CLOSE” position, the generator starts unloading to the pre-set level, then the emergency contactor opens

e) The engine generator is manually shutdown by pressing the “STOP” button on the GCP.

3.3.2 Base Load (Manual Operation): Utility power is available. ATS is in Normal Position serving power to the load. GCP set in “MAN” position. GCP set to base load at XXX kW. The Transfer Mode Switch remains at “AUTO” position, (allowing the

operator to manually control from the GCP panel).

1. With Utility Power available:a) The “START” pushbutton is pressed on the GCP, which starts the

generator.b) After the generator voltage and frequency reaches the nominal set

points, the generator breaker’s “ON” pushbutton on the GCP is pressed.

c) The GCP synchronizes the generator with the utility. When synchronism is reached, the emergency contactor transfers to the “CLOSE” position.

d) The generator starts soft loading until it reached the preset XX kW base load set point. (Soft loading ramp time is adjustable on the GCP).

e) The ATS operates with both normal & emergency contactors in “CLOSE” position. As the load increased from the facility, the utility responds and picks-up the load while the generator remains at constant preset base load level.

2. Return to utility:

a) Reduce the kW load on the generator by adjusting the kW baseload set point

b) The generator breaker’s “OFF” pushbutton is pressed on the GCP, the emergency contactor transfers to the “OPEN” position.

c) The generator is manually shutdown by pressing the “STOP” button on the GCP.

3.4 Additional notes on operation:

A. When both sources are paralleled and any external source breaker is signaled to trip, the transfer switch main contacts connected to the source with the tripped breaker shall also be signaled to open & the condition shall be alarmed on the panel.

B. If the normal source is restored after failure with load connected to emergency and the emergency source is available, transfer to normal shall be completed depending


on what mode was selected from the TMS switch. If the PEAK SHAVE Preset Mode is selected on the TMS is activated, operation will be as selected from the PSMS switch i.e., if base load mode was selected, the GCP shall synchronize both sources and return to that mode.

C. The ZTSSL shall be capable of automatically soft load transferring or paralleling when a utility demand set point is exceeded. It shall automatically retransfer to the utility when the total (utility plus generator) demand falls below a dropout set point for a preset time.

D. If the contactor that is required to be open does not open during closed or soft transition then the GCP will open the other contactor.

PART 4 - ADDITIONAL REQUIREMENTS

4.1 Withstand and Closing Ratings

A. The Soft Load Automatic Transfer Switch (ZTSSL) shall be rated to close on and withstand the available RMS symmetrical short circuit current at the switch terminals with the type of over-current protection shown on the plans.

B. The Soft Load Automatic Transfer Switch (ZTSSL) shall be UL listed in accordance with UL 1008 and UL 891, and be labeled in accordance with that standard's 1½ and 3 cycle ratings. Transfer Switches that are not tested and labeled with 1½ and 3 cycle (any breaker) ratings and have series, or specific breaker ratings only, are not acceptable.

4.2 Tests and Certification

A. The complete Soft Load Automatic Transfer Switch (ZTSSL) shall be factory tested to ensure proper operation of the individual components and correct overall sequence of operation and to ensure that the operating transfer time, voltage, frequency and time delay settings are in compliance with the specification requirements.

B. Upon request, the manufacturer shall provide a notarized letter certifying compliance with all of the requirements of this specification including compliance with the above codes and standards, and withstand and closing ratings. The certification shall identify, by serial number(s), the equipment involved. No exceptions to the specifications, other than those stipulated at the time of the submittal, shall be included in the certification.

C. The Soft Load Automatic Transfer Switch (ZTSSL) manufacturer shall be certified to ISO 9001 International Quality Standard and the manufacturer shall have third party certification verifying quality assurance in design/development, production, installation and servicing in accordance with ISO 9001. Manufacturers not meeting the ISO 9001 requirements above are not acceptable.


4.3 Service Representation

A. The Soft Load Automatic Transfer Switch (ZTSSL) manufacturer shall maintain a national service organization of company-employed personnel located throughout the contiguous United States. The service center's personnel must be factory trained and must be on call 24 hours a day, 365 days a year.

B. The manufacturer shall maintain records of each switch, by serial number, for a minimum of 20 years.

PART 5 - INSTALLATION ASSISTANCE

The manufacturer of the Soft Load Automatic Transfer Switch (ZTSSL) shall provide the services of satisfactory trained technician to provide installation assistance.

5.1 It shall be the responsibility of the installing contractor to verify that the following items have been completed and are ready to perform as specified before the arrival of the factory technician.

A. Inspect for obvious shipping damage. B. The Soft Load Automatic Transfer Switch (ZTSSL) is securely installed and

properly grounded. C. All power cables have been terminated. D. Install customer control wiring to external equipment including engines,

batteries, associated motor control including communication, etc. E. The engine generator set is installed and ready to run. F. Associated motor controls, plumbing, building utilities are complete and

operational.

Note: Sufficient building load must be available at start-up procedures to properly test and qualify soft loading control operations. Available building loads must equal 100% of engine-generator set tested. Should building loads be less than 100% of the engine-generator set tested, load banks shall be required on-site at additional cost to installing contractor.

G. The Factory trained Technician shall perform the following service onsite:

1) Verify contractor connections, control power availability, and visually inspect relay settings.

2) With the engine generator supplier's technical representative controlling the engine, verify that the ZTSSL and control equipment are fully operational and perform per the sequence of operation specified. The engine generator set supplier shall provide any equipment or special services.


3) With the engine generator supplier's technical representative controlling the engine, demonstrate all functions of the control system, both automatic and manual, to the satisfaction of the approving engineer.

4) Provide documentation in the form of function checklists and recorded data for each section to the approving engineer.

5) Provide plant operator with instruction on the plant operating procedures and major component maintenance after acceptance by the approving engineer.


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