power line injector panel

Power Line Signaling Unit

PLSI

Installation Guide (Document Version BGX501-139-R01)

Safety Instructions

Possible Electric Hazard

Attention

Please take note of the warning and caution icons, presented in this manual, as follows:

Existence of dangerous electrical voltage. This operation should only be performed by qualified personnel.

Kindly give special attention or take precautions whilst performing this operation. The procedure as described in the manual must be followed.

Deliverables 1. PLSI 2. Cables & Lugs, necessary for connecting PLSI

with Bus 3. Hand Gloves

PLSI Installation Guide

4 BGX501-139-R01

Contents About PLSI 5 Precautions & Safety Practices 7 Tools & Accessories 7 Setup Schematic 8 Pre-Installation Issues 9 Installation 9 Post Installation Issues 13 Changing the Firing Angle 13 Configuring Interval for Transmission Absence 14 Acknowledging the Fault 15 Ensuring Signal Strength 15 Viewing Failure Information 16

Annexure 1: Check List 17

Important Whilst every effort has been made in preparing the product documentation, the possibility of error always exists. We undertake to correct such errors wherever possible, and request feedback from users in this regard.

About PLSI

Entity 5

About PLSI

PLSI, an acronym for Power Line Signal Injector is installed as an integral part of the distribution metering system having dual supply sources i.e. Mains and Auxiliary. Such system demands a separate tariff to be applied for Main and Auxiliary supply. This requires recognising current source of supply by the meters for applying the corresponding tariff. PLSI, when installed on the secondary side of a distribution transformer, injects the desired signals into the downstream supply using the supply frequency itself. This signal is detected by the intelligent inbuilt receiver at the meter end. If the signal is available, main’s tariff is applied otherwise DG tariff is applied. As the absence of signals is observed as DG Supply, it is necessary to implement this system in such a manner that failure of PLSI is immediately detected and notified. A Failure Detection Unit (FDU) is built in the PLSI which turns ON a hooter on detecting PLSI failure.

PLSI Signaling Technology

The technical method, used for signaling in PLSI, is an innovative technique of intentionally creating a small distortion in the voltage waveform near the zero cross over.

The voltage distortion is created by causing a controlled short circuit, from phase to neutral, through a SCR. The controlled short circuit is achieved by firing the SCR at a very small measured angle just before the zero cross over, when the voltage is approaching to the zero from the positive half cycle (i.e. at. 180°). The voltage driving the short circuit current is very small as voltage is approaching zero value. The short circuit is sustained in the negative half cycle for the same angle value after the zero cross over. By this time, the SCR automatically switches off due to reversed polarity. Hence, the duration of the short circuit is generally only for a few electrical degrees, i.e. 24o to 48° (depending on the exact angle, before zero cross, when the SCR was fired), and this corresponds to a time of 1.3 to 2.6 milliseconds.

The inrush of currents, due to this temporary and controlled short circuit, has an imperceptible impact on the system equipment due to two reasons- Firstly, the peak current is not large enough to cause a mechanical stress and second, the duration of the short circuit is so small that the heating effect due to current (I2 x time) is also negligible.

The peak voltage driving the short circuit is very low (VpeakSin 12° to Vpeak Sin 24°, i.e. 24 volts - 94 volts), compared to the nominal value of 230 volts prior to the short circuit. The driving voltage also decreases sharply when the zero cross over approaches. Such a small voltage can only cause a small short circuit current, as the current is restricted by source impedance (i.e. impedance of transformer at the upstream).

The short circuit creates a distortion in the voltage waveform as shown in the following diagram:


6 BGX501-139-R01

The distortion of the voltage waveform travels along the power line and is available at all consumer terminals in the system. This method of creating a distortion in voltage waveform near the zero cross over enables the propagation of the distortion along distribution wires to all power recipients. The term "transmission" has been used in this document to describe this propagation.

A pair of consecutive sinusoidal cycles is used to describe a signal as "zero" or "one". For a "zero" signal, the first cycle has no distortion in the zero-cross over point and a distortion in the second cycle. For a "one" signal, the first cycle has a distortion in the zero-cross over point and no distortion in the second cycle. The baud rate for signal transmission is therefore 25 bauds (bits per second) for a 50Hz system. The baud rate for an American system, where the power frequency is 60Hz, would be 30 bauds.

A zero signal is as follows:

A one signal is as follows:

This signal is detected by in-built receiver module of the Liberty meter to verify the source of supply from distribution transformer. It is interesting to note that these signals (voltage distortions) are not transmitted to wires belonging to any other transformer. That is because the impedance of the transformer and upstream (source) impedance do not cause a short circuit current to flow in other transformers so as to observe a noticeable distortion in voltage waveforms.

Other Document to Refer

− Liberty User Manual (Dual Supply Meter) − Liberty Installation Guide (Dual Supply Meter)

Precautions & Safety Practices

Entity 7

Precautions & Safety Practices

Safety First

1. This product is designed for LT/LV applications only

and should not be used elsewhere. 2. To minimize the risk of electrical shock, avoid any

loose or exposed electrical connections near the installation. Use sleeves, and if necessary, you can also use any fast-drying insulation coating to cover such exposed electrical wire. Such coatings are easily available in varnish or aerosol form.

3. Disconnect the supply during the installation. Use

insulated hand-gloves while working.

4. Always use proper tools & tackles and avoid using damaged tools. Usage of damaged tools is a major cause of all types of installation related accidents. Additionally, it can cause an irreversible damage to the PLSI and other devices.

5. To prevent any potential damage, always install the

PLSI at a height considered to be safe. 6. Always refer to installation & associated

documentations and follow the instruction and the practices described.

Tools & Accessories

Attention

Never use improper &

damaged tools

Following tools & tackles are required for installation:

1. Hexagonal Bolt Tightener for M8 Size Bolts 2. Tabular Bolt Torque Screw Driver 3. Cross head Magnetic Screw Driver 4. Cable/Wire Cutting Knife 5. Pliers 6. Hand-gloves 7. Multi-meter


8 BGX501-139-R01

Setup Schematic The following figure describes the schematic for the PLSI Installation:

− PLSI Unit is installed just near the Distribution Transformer and is connected to the bus bar at the secondary side. The PLSI incorporates three Signal Injector Units; one for each individual phase. These injector units inject the signals into the distribution line.

− Three signal detector units are integrated with PLSI each of which detects the signal on individual phases. This signal detector detects the PLSI signal continuously for the respective phase. The absence of signal when the phase is available is considered as a PLSI failure and an alarm signal is generated by the Hooter.

From Distribution Transformer PLSI

R Y B N

R Y B N N

From Hooter Relay to Hooters

To MCCB & Neutral

Signal Injector Unit

Fault Detection

Unit

Indicator

MCCB

Pre-Installation Issues

Entity 9

Pre-Installation Issues

Before you proceed with PLSI Installation, you must consider the following: Selection of Mounting Location PLSI must be installed near the Distribution Transformer (DT) on the secondary side. PLSI should be placed on a concrete platform. The dimensions of the PLSI are 120 cm X 66 cm X 37 cm (Height X Width X Depth). A concrete platform 2-4 feet above the ground level is most suitable for placing the PLSI unit. A height convenient for user operations should be selected. Hooters must be mounted at a height of 6 ft. or above, to prevent it from any malicious activity. Ratings and Cable Selection

− The current ratings for the hooter should not exceed

2A. The supply voltage should be 230V AC. − Use 1.1 kV super flexible cables (supplied with the

PLSI) to connect PLSI with DT. If the length of the supplied cable is insufficient, never use a joint to expand the cable length. Use a complete length of another cable instead. The size of the cable should be selected according to the DT rating. Recommended sizes are tabularised as follows:

Sr. DT Ratings Conductor Area Current Capacity

In kVA In sq mm In amp 1 100 6 18 2 200 6 30 3 250 6 34 4 315 6 38 5 400 10 40 6 500 10 46 7 630 10 50 8 750 16 68 9 800 16 71 10 1000 25 90

Installation

Attention

You must fill up the form prescribed in the Annexure

at the time of installation

The step-by-step procedure for installing the PLSI system is described here. 1. Make sure that you have all necessary tools in hand. By

visual inspection, check any loose and exposed electrical connection near the installation. If any loose and exposed electrical connections are seen, make necessary arrangement to correct them.

2. Unpack the PLSI. Due to the size & weight of PLSI, it is

necessary to visually inspect and confirm that it is not damaged during transportation, loading & unloading. Open the front door of the PLSI. Now open the internal door of PLSI. Check for the healthy conditions of all mounted parts such as thyristors, inductors, MCCB etc. Make sure that all parts are tightly connected. Tighten any loose screw or bolt, if any. Perform for continuity test as prescribed in the Annexure. Make sure that all inductors are connected at 60T tapping position.


10 BGX501-139-R01

Possible Electric Hazard

Attention

It is necessary to earth the PLSI from both the

sides

3. First prepare the location for mounting the PLSI unit i.e. concrete platform or some place above the ground level. Now affix the base-frame (provided by SML) on this platform. If necessary, make use of grouting. Prepare a channel for cable passage. Lay down the connecting cables along the channel. Five cables are provided one for each phase and two for neutral. This ensures that high neutral current is distributed.

4. Close the internal door & front door of PLSI and Mount

the PLSI on the base-frame. 5. Make sure that conductors are terminated using the lugs.

If you are not using the supplied cables, you should terminate the cable using appropriate size lugs. Use colour coded sleeves.

6. Make sure that MCCB is off. Insert each connecting cable

into the PLSI panel using gland. Loosen the Rin, Yin and Bin terminals of the MCCB. Connect each of connecting cables to respective terminal (supplied cables are color coded).

7. Now connect the two neutral cables to neutral terminal

(one to each terminal) as shown in the picture. Two neutral cables help in distributing the high return current flowing through neutral at the time of transmission.

8. Earth the PLSI panel using the earth terminals provided

on each side of the panel. 9. Now, you can connect the hooter as shown in the picture.

Hooter rating should be 2A. Don’t use a hooter exceeding this rating. Please note this connection is for hooter activation only. Power Supply to the hooter should be provided separately. Initially, switch off the power supply of the hooter.

Rin, Yin, Bin Terminals

Two Neutral Terminals

Earth Terminal

To Hooter

Inductors

Thyrsitors

Installation

Entity 11

Attention

Default firing angle should be set at 18

degree. If this is not the case, you must change the firing angle to 18 degree as described in section “Changing the Firing

Angle”

Attention

Firing is off by default. If this is not the case, you must stop the firing

at the time of installation by entering code “00000-32423-0”

10. Isolate the bus bar from the distribution transformer. Now connect the PLSI unit with the mains supply from the Bus bar. Before making connection with the bus bar, make sure again that MCCB is switched off.

11. Resume the supply. Once the PLSI unit is connected to the

power supply, all three indicators should be glowing. In case any of the indicators is not glowing, recheck the connections. Check the phase voltage (P-N).

12. Switch on the MCCB and test the MCCB using the trip test

button. This must be healthy. Switch the MCCB again. 13. Make sure that fans available on both sides are working. 14. Once the PLSI is powered up, the default display cycle is

shown on the Signal Injector Unit. This cycle is repeated at a regular interval.

15. Similarly, the default display cycle is also shown on

Fault Detection Units. This cycle is also repeated at a regular interval.

Main’s On

“VOLTAGE” indicates that value of voltage on the connected phase follows

Voltage is 234.50 Volts

“FIR ANGLE” indicates that value of configured firing angle follows.

Current firing angle is 18 degree.

“FIR OFF” indicates that firing is inactive. This implies that signals are not being transmitted. “FIR ON” is indicated when

signal transmission is active. By default, the firing is off.

Test Display

“SIGNAL” indicates the signal strength follows

“45 BULS” indicates that signal strength is 45 BULS. Now press key “1”

“VOLTAGE” indicates that value of voltage on the connected phase follows


12 BGX501-139-R01

16. Check the displays of each individual phase for Signal

Injector Units as well as Fault Detection Units. 17. Now, you can start transmitting signals. This requires

you entering “00000-52425-9” when default display cycle is being shown on the Signal Injector Unit. Follow the procedure as shown below.

You must perform this operation on all the three Signal Injector Units one by one. Please note that you can stop the transmission by entering the code “00000-32423-0” in the same manner.

Voltage is 234.50 Volts

“50” indicates that total 50 messages received

till now

“Time” indicates that current time follows

Time is 12:45

“Date indicates that current date follows

Date is 02-10-2005

Press “*”

Press key “0”

Press key “0” four more times.

Press key “5”, “2”, “4”, “2”, “5” in the sequence

Press key “9”

Press key “#”

“ACCEPTED” indicates that your code has been accepted successfully and transmission has been

started. You can verify this with default display cycle. In case some error occurs

“ERROR” is shown on the display.

Post Installation Issues

Entity 13

Attention

You may notices some noise produced at the time of

transmission

18. Once the transmission is started, you should verify this

with the Fault Detection Unit. Check for the signal strength as follows.

19. Now, power up the supply of hooter. As the transmission

is started, the hooter should not make a noise. To check the healthy condition of hooter, stop transmission of a Signal Injector Unit by entering the code “00000-32423-9”. The Fault Detection Unit of the corresponding phase should detect the failure (with in pre-configured interval) and turn on relay of the Hooter circuit followed by the hooter activation. After two minutes, relay is turns off automatically. The Fault Detection Unit turns On the relay repetitively at 30 minutes interval, unless it is acknowledged as described in the next section.

20. Once you have checked all three phases, PLSI is ready for

operation. Now restart the transmission again. Close the internal door. If you wish to modify the firing angle and other default configuration, follow the instructions as described in the section “Post Installation Issues”.

21. Make sure that you fill up the form prescribed in the

Annexure 1.


Once you have installed, you can perform following operations with the Signal Injector Unit and Fault Detection Unit.

Changing the Firing Angle

The default firing angle for the transmission is 18 degree. However, you can change the default firing angle, if it is required. Enter “00000-51423-9”, when Signal Injector Unit is displaying the default display cycle. The procedure is as follows:

Press “*”

Enter “0000-51423-9” and press key “#”

“ACCEPTED” indicate that operation is successful


“45 BULS” indicates that signal strength is 45 BULS. Now press key “1”.

Display should indicate “OK” status


14 BGX501-139-R01

When you increase the firing angle, check current in the connecting cable of respective phase. This should not exceed 50 ampere.

Configuring Interval for Transmission Absence

The Failure Detection Unit continuously scans for the transmitted signals, and detects the absence of transmission if no signal is detected for a pre-configured interval. You can use the key “2” for displaying the configured period.

This interval is user defined and can be configured by entering “00000-00XXX-7” where XXX is the period in minutes. Follow the instructions as below:

Press “*”



“AGNLE CFG” confirm the firing angle configuration mode

Current firing angle is 24 degree. Press key “4” to increase the firing angle in steps of 3

degree

Current angle is 27. Press key “6” to decrease

the firing angle in steps of 3 degree

Current angle is 24.Press key “6” again to

decrease the firing angle in steps of 3 degree

Current angle is 21. Press key “#” to confirm the angle being displayed on the screen. Signal

Injector Unit switch to normal mode.

Press “2”, when the default display cycle is being displayed

“5” indicates that configured period is 5 minutes

Press “*”, when the default display cycle is

being displayed

Enter “00000-00XXX-7” and press key “#”. For example, enter “00000-00005-7” for configuring

5 minute



Entity 15

Acknowledging the Fault

When Failure Detection Unit detects the absence of transmission, it turns on the hooter relay. This relay automatically turns off after two minutes. The Failure Detection Unit keeps on repeating the same at thirty minutes interval until it detects the signal again or acknowledged by the user. User can acknowledge the fault by entering “00000-51423-9”.

Ensuring Signal Strength

For satisfactory information of the system, it is necessary to ensure that enough signal strength is available at each meter. The recommended signal strength at the FDU is 40-45 Buls. This implies that signal strength in the range of 25-35 Buls is received at the metering end. The signal strength at the Fault Detection Unit can be verified using the code “0000-51423-9”. You should also verify the signal strength at metering sites of the tail ends. The procedure for checking signal strength at the Liberty meter is as follows:

If the sufficient signal strength (20 Buls or above) is not available at the tail end of the distribution line, it is necessary to increase the strength of transmitted signal. There are two different ways to increase the signal strength:

Press “*”, when the default display cycle is

being displayed



Press “*” when default display cycle is being

displayed




“25 BULS” indicates that signal strength is 25 BULS.


16 BGX501-139-R01

- By increasing the firing angle at the transmission end. The maximum permissible limit is 27 degree.

- By reducing the inductor turns. You should use this

method only if is not possible by increasing the firing angle. When increasing the signal strength, ensure current in the connecting cable of corresponding phase doesn’t exceed 50 ampere. Use digital clamp millimeter for this.

When using inductor turns for increasing the signal strength, you should reduce the firing angle first and then reduce the number of inductor turns. You can increase the firing angle again, if required.

Viewing Failure Information

You can view failure information logged by the Fault Detection Unit as follows: Use key “1” for displaying the transmission status, date & time of last message received and total count of failure.

Press “1” when default cycle is being shown on the Fault Detection Unit

“OK” indicates that transmission is OK. “FAIL” is shown if transmission failure is detected.

Wait for 2 seconds

Time of last message received. Wait for 2 seconds

Date of Last message received. Wait for 2 seconds

Total count of failure. Example screen showing 50

Annexure 1: Prescribed Form for Installation Check List

Entity 17

Annexure 1: Prescribed Form for Installation Check List Please check for the following and write down any corrective action taken at the time of installation. Put any additional remark if necessary. Note: Note that following steps do not describe installation procedure. You must refer section “Installation” for this.

Sr No Checking Instructions Status(OK/NOK) To be checked before connecting PLSI to the Distribution Transformer

1 Check for any damage visible outside the PLSI Panel. 2 Check for any damage visible inside the PLSI Panel.

3 Check that all parts such as Inductors, Relays, MCCB etc. are at the right place and mounted properly. Any Loose bolts or screw should be tighten

4 Check that all three inductors are connected to the 60T tapping

Check for the continuity status. There should be discontinuity between followings lines:

**** R Y B N Y Y B Y Y N Y Y Y

5

E Y Y Y Y

To be checked after connecting PLSI and Distribution Transformer 6 Check that all indicators are glowing.

7 Check for the Phase to Neutral voltage for each phase. It should be within the suggested limit i.e. 240 Volts approximately.

To be checked after Switching On the PLSI MCCB 8 Check that both side fans are working.

9 Check that displays are working for Signal Injector Units. Set the firing angle to 18 degree. Make sure transmission is inactive.

10 Check that displays are working for Fault Detection Units. To be checked after starting transmission

11 Check for the Signal strength at the Fault Detection Units. It should be around 40-45 BULS. Check OK status on display for signal by using Key “1” sequence.

12 Check the currents in the neutral and all three phase cables. It should be below 50 amps in all cases.

13

Check for the signal strength at tail-end of the distribution line for different meters. If required, increase the signal strength. Check the current values again. Make sure that it does not exceed 50 amps. Write down the final value of currents.

Secure Meters Limited P.B. No. 30, ‘E’ Class Industrial Area Pratap Nagar, UDAIPUR - 313003, INDIA

Phone: ++91-294-2492300 to 2492304 Fax: ++91-294-2492310

Email: [email protected]

PLSI Copyright @ Secure Meters Ltd. 2006-2007 This manual is a copyright with all rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the copyright owner; the same is proprietary and copyright must be affixed to any permitted copies as were affixed to the original. Secure Meters Ltd. reserves the right to periodically change information. The results generated by PLSI are not subject to copyright, and there is no restriction placed on their use by the original purchaser. No warranties are expressed or implied with respect to the product described, its quality, performance, or suitability for any purpose. In no circumstance will the copyright holder or his agents be liable for direct, indirect, incidental or consequential damages resulting from the use of this manual. No statements contained in this package shall affect the statutory rights of consumers.

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