Contact person:

Director(S&T)

Indian Railway Centre for Advance Maintenance Technology

Maharajpur, Gwalior(MP)-474020

Ph:0751-2470185, FAX:0751-24700841

E-mail: dirsntcamtech@gmail.com

भारत सरकार - GOVERNMENT OF INDIA

रल मतरालय - MINISTRY OF RAILWAYS

कवल काराालरीन उपरोग हत

For official use only

CAMTECH/S/PROJ/2021-22/SP3A

May 2021

Target Group: SSE/JE (Signal) of Indian Railways

SMPS based

Integrated Power Supply (IPS) System

Introduction

The SMPS based Integrated Power Supply (IPS) system is meant

to give continuous supply to both AC & DC signalling circuits for

wayside and medium size signalling installations without AFTC

(upto 15KVA signalling load) in RE & Non-RE areas.

In Indian Railways, IPS systems conforming to following

specifications are in use:

RDSO Specification No. RDSO/SPN/165/2004 (Old)

RDSO Specification No. RDSO/SPN/165/2012 (New)

RDSO Approved firms for manufacture & supply of

IPS

M/s AMARA RAJA Power Systems Ltd., Tirupati

M/s STATCON Electronics India Ltd., NOIDA, G.B.Nagar

M/s HBL Power Systems Ltd., Hyderabad

Main modules of IPS System

SMPS based Float cum Boost Charger (FRBC) Panel

DC Distribution Panel

AC Distribution Panel

Status Monitoring panel for ASM's room

Battery bank

Lightning & Surge protection arrangements

1

FRBC Panel

FRBC Panel consists of two or more

Switch Mode Rectifier (SMR) modules

provided in (N+1) configuration.

Each module is rated for 110V/20A.

All the modules are connected in parallel

and share the load equally.

Output of the FRBC Panel is connected

to Battery Bank and to other two panels

DCDP and ACDP which require 110V

DC.

2

Controls & Indications of FRBC Panel

3

Indications on SMR module

Indication Description

Mains Mains supply to the module is on

Float The module is in float mode of charging

Boost The module is in boost mode of charging.

Overload/Short Ckt The module is overloaded

Under voltage The output DC voltage of the module is low

or it is sensing a discharged battery voltage

when all the three modules are off.

Output Fail The output DC of the modules is not

available.

Over voltage The output DC Voltage of the module have

Exceeded normal output operating range

Over Temperature The temperature of the module inside is more

than 75 C.

Fan Fail The cooling fan of the module has failed

Display panel Displays various parameters, of SMR panel.

Microcontroller based Distribution/Supervisory Control/

Alarm (DSA) Unit

All operating parameters of the System, SMR modules and

Battery can be changed through the menu driven LCD

provided in the DSA..

The above is the example of Statcon Make IPS. The indications

may differ from manufacturer to manufacturer.

DC Distribution Panel (DCDP)

These converters feed power to

different loads such as Axle

Counters, Point Machines, Relay

Internal, Relay External etc.

DC-DC converter for internal

circuit shall be in n+2 configuration

& for other circuits in n+1

configuration.

Push buttons are provided to scroll through the LCD menu and

to set parameters

LEDs to indicate the status of the system.

A typical DSA unit of Amararaja make IPS is shown below. It

may vary for other manufacturer’s IPS.

DCDP consists of DC-DC converters with different ratings.

All converters work on 110V DC input which is coming from

FRBC panel.

4

The standard converter ratings as per RDSO Specification are:

Sr.

No.

Converter Rating

1 Relay Internal 24-32V, 5A/10A OR 60-66V, 5A

2 Relay External 24-32V, 5A/10A OR 60-66V, 5A

3 Axle Counter 24-32V, 5/10A

4 Block Local UP 12-40V, 1A OR 40-60V, 1A OR

60-100V, 1A OR 100-150V

5 Block Local DN 12-40V, 1A OR 40-60V, 1A OR

60-100V, 1A OR 100-150V

6 Panel Indication 12-28 V,5/10A

7 Block Line UP 12-40V, 1A OR 40-60V, 1A OR

60-100V, 1A OR 100-150V

8 Block Line DN 12-40V, 1A OR 40-60V, 1A OR

60-100V, 1A OR 100-150V

9 Block Tele UP 3-6V, 0.1A

10 Block Tele DN 3-6V, 0.1A

For block proving by axle, the DC-DC converter of 24V-40V/5A

or 10A shall be used in place of block line DC-DC converters.

Common DC

Voltmeter

3 1/2 digit LCD/LED display with patch

cords To measure output DC voltages

Test sockets on each

Converter

To measure output DC voltages

ON/OFF Switch on

each Converter

To put the particular unit ON or OFF.

Indications on each

Converter

Input ON (Amber), Output OK (Green),

Conv. Fail (Red)

Controls & Indications of DCDP

5

AC Distribution Panel (ACDP)

ACDP is a combination of

Inverters, Step-Down Transformers

and Automatic Voltage Regulators

(AVR).

Inverter: Converts 110V DC to 230V

AC to cater for all signal 230V/110V

AC step down transformers in the event

of Mains 230 V AC failure.

There are three Inverters out of which

two are in hot standby mode while third

is in cold standby mode.

Automatic Voltage Regulator (AVR): Converts 150 – 275V AC to

constant 230V AC supply to cater for all signal/Track circuits

230V/110V AC step down transformers.

Step Down Transformers: Converts 230V AC to constant 110V AC

supply to cater for all signal/Track loads. The secondary of step

Down transformers have 100, 110, 120 & 130 AC taps.

AC Voltmeter & AC Ammeter: To measure AC Voltages & Signal

load current.

6

Inverter

Input MCB Extends input 110 V DC to the Inverter.

Switches ON, OFF /Reset switches

Indications Mains, Output, Inverter Fail, On Load, Fan

Fail

AVR

Input MCB Extends input 230 V AC to the AVR

Indications Output ON, Output Fail, Input ON

Test sockets For measurements of output AC voltages

Step Down Transformer

Input MCB Extends input 230 V AC to the Transformer

Indications Output ON, Output Fail, Input ON

Test sockets For measurements of output AC voltages

Controls and Indications of ACDP

Status Monitoring panel for ASM's room

This panel consists of status indications and critical alarms of IPS which

can be monitored from ASM's room. The monitoring panel shall be of

wall mounting type. 03-06V/0.1A DC-DC converters for Block Tele (Up

& Dn) are also provided in status monitoring panel.

7

Description Indication

& Alarm

Condition

Start

Generator

RED LED

& Audio

Alarm

Battery 50% DOD* (Approx 109

V). Audio alarm can be

acknowledged for audio cut off

Emergency

start

Generator

RED LED

& Audio

Alarm

Battery 60% DOD* (Approx 107

V) . Audio alarm can be

acknowledged for audio cut off.

System Shut

Down

RED LED

& Audio

Alarm

Battery 70% DOD* (Approx 105

V) Signal feed cut off and all DC-

DC converters to work. Audio

alarm will continue till Generator

is started.

Call S&T

staff

RED LED

& Audio

Alarm

Failure of any module or in case

battery gets disconnected from

circuit will give the alarm in

panel. Alarm can be

acknowledged for audio cut-off.

Stop

Generator

GREEN

LED &

Audio

Alarm

Senses availability of generator

and charging condition of Battery.

If Battery charge completes, stop

generator indication glows.

Indications on Status Monitoring Panel

*DOD –Depth of Discharge

Battery bank

IPS system is suitable for charging 110V battery bank of Low

Maintenance cells as per IRS:S 88/2004 or VRLA Maintenance

free cells as per IRS:S 93/96(A). The battery is to be installed in a

separate room.

8

Copper cable of suitable dia as per IS:

694 and grade 1100V: for connecting IPS

to Battery bank should be provided:

For 120AH battery – 10 Sq.mm

For 200AH battery – 16 Sq.mm

For 300AH battery – 25 Sq.mm

Lightning & Surge Protection

Stage 1 Protection (at the entry point of input 230V

AC supply in the power/ equipment room)

Class I/ B & II/ C type SPDs shall be provided at the entry point

of input 230V AC supply in Power /Equipment room in TT

configuration in a separate wall mountable box. The Class I/B

SPD shall be provided between Line to Neutral & Neutral to

Earth. They shall be spark gap type voltage switching device. The

Class I/ B SPD will be followed by Class II/ C SPD adjacent to it

and connected between Line & Neutral. It shall be voltage

clamping device, thermal disconnecting type. This will provide

least resistance path from line to neutral and neutral to earth when

surges & lightning spikes hits the line there by bypassing the

system. Earth pit resistance should be <2Ω.

9

How to identify that SPD has gone defective?

Class B SPDs work on spark gap technology. Whenever a heavy

lightning surge occurs, class B SPD passes this to the earth. If the SPD

is gone defective due to surges, a short circuit occurs in line & neutral.

The 63 Amp fuse will be blown and this is the only indication that SPD

has gone defective. Another identification is burning of SPD. Hence if

lightning/surges have suspected to be occurred, check for any burning

smell near LPD Box.

Class C SPD passes the lighter surges and do not affect the circuit.

Through the potential free contacts, the status of SPD can be extended

to the ASM Panel. In latest versions, indications are also provided on

the SPD. Green indication shows SDP healthy and Red indication

shows SPD is defective. 10

Additional Requirement as per RDSO SPN/165/2012:

Stage 2 Protection (at the output side inside the

distribution panel)

The Stage 2 protection shall consist of Class II/ C type SPDs

for ≥24V-110V AC/DC supplies at the output side inside the

rack of IPS. These shall be provided for External circuits i.e.

Relay external circuit, Axle counter circuit, point machine

circuit and at Inverter output. The Class II/C type SPD shall be

a single compact varistor of proper rating and in no case a

number of varistors shall be provided in parallel. It shall be

voltage clamping device and thermal disconnecting type.

Provision of class C SPDs in common and differential mode of

relay external, axle counter, point machine circuit and at

inverter output

Point Operation Inverter Output Relay External

& Axle Counter

11

Earthing Arrangement

The IPS systems and its individual modules shall have earth

terminals and shall be properly earthed to the IPS cabinets. Earthing

arrangement shall be done in conformity to Code of practice for

earthing and BondingRDSO/SPN/197/2008. The connections shall

be as given below:

Component/Bonding Material Size

Individual equipments to

SEEB using copper lugs

with stainless steel nut and

bolts.

Multi-strand single core

PVC insulated copper

cable as per IS:694

10

sq.mm

SEEB to MEEB using

copper lugs with stainless

steel nut and bolts.

Multi-strand single core

PVC insulated copper

cable as per IS:694

16

sq.mm

Surge protection devices

(SPD) to MEEB using

copper lugs with stainless

steel nut and bolts.

Multi-strand single core

PVC insulated copper

cable as per IS:694.

16

sq.mm

MEEB to main earth

electrode

Multi-strand single core

PVC insulated copper

cable as per IS:694

(Duplicated)

35

sq.mm

LPD Box

12

13

Brief Description of Working

Input Mains supply 230 V (150-275 V) AC comes to Lightning

Protection Device (LPD) Box.

From LPD Box, the 230 V AC goes to (i) FRBC Panel (ii) AVR

(Track) (iii) AVR (Signal).

SMRs in FRBC Panel Convert 230 V AC to 110 V DC which

are paralleled and fed to DC-DC Converters, Point operation

through a fuse and Inverters.

Normally both the Inverters are powered ON and both are

delivering the Output voltage but only Inverter1 is connected to

the Load.

Inverter 1 gives output 230 V AC supply to Step Down Signal

Transformers 230/110 V AC for feeding to Signals.

If Inverter 1 fails, Inverter 2 will take over and feed to the

signals.

In the event of AC Mains supply failure, Inverter will give 230

V AC output through 110 V DC Battery Bank.

As per RDSO SPN/165/2004, the output of both the inverters

shall be linked in such a way that on failure of one inverter, the

other shall supply to load automatically within 300ms. This

switching time is reduced to 60 ms in IPS as per RDSO

SPN/165/2012 to avoid blinking of signal aspect. As soon as

one of inverter becomes healthy, the load shall be automatically

transferred back to inverter.

14

As per RDSO SPN/165/2012, Ferro resonant Automatic

Voltage regulator (AVR) for Signal load shall always be in

‘switched on’ condition and shall supply the load within 60 ms

(300 ms in IPS of RDSO SPN/165/2004) in case of any failure

in Inverter/s and/or inverter changeover arrangement to

prevent blanking of signals.

The change over from inverter to inverter or AVR shall be

achieved through Static switch.

DC-DC Converters convert the 110 V DC input extended from

SMPS to the required voltage.

These converters feed different loads such as Relay Internal,

Relay External, Axle Counter, Block Line, Block Tele UP &

DOWN, Panel Indication, HKT etc.

All the groups of converters are provided in (N+1) or (N+2)

configuration to ensure uninterrupted supply.

Testing of Auto Changeover operation in ACDP

Connect one of the signal transformers outputs to the Digital

Voltmeter provided.

Stop Inverter1 by pressing STOP button.

The load should shift to Inverter 2.

Check ‘Load on Inverter’ LED on Inverter2.

Check voltage on digital display.

Now stop Inverter2.

15

The load should shift to AVR

Check voltage on display.

The voltage displayed indicates load on AVR.

For checking Auto-Changeover in Reverse order:

Start Inverter2 – load should shift on Inverter2 automatically.

Start Inverter1- load should shift on Invertrer1 automatically.

Manual Changeover operation in ACDP

A manual changeover switch is provided in the backside of

ACDP.

At the time of Auto-Changeover failure, this switch can be used

to connect signal loads to Inverter1 or Inverter2 or CVT (AVR)

manually.

This switch has four positions namely:

AUTO, INVERTER1, INVERTER2 & CVT

In normal working, the switch position is kept at AUTO.

16

Adjustment of Converter Output Voltage

Turning clockwise will increase the voltage and turning anti-

clockwise direction will reduce the voltage.

Adjust potentiometer with the help of pre-set driver (pot

adjuster) to get the desired output.

Ensure that output voltage of all converters in a group is same

in order to ensure proper load sharing among the modules in a

group.

Switch OFF DC-DC Converter and take out from the slot by

removing connectors.

Connect test points to Common Digital Voltmeter.

Connect input connectors and Switch ON the module.

Each DC-DC Converter is provided with a potentiometer on the

PCB which is accessible from the bottom side of the converter.

Potentiometer

17

Maintenance Required Period

Check if the O/P voltages are set as per requirement. If

not, correct them.

Once in 15

days

Switch OFF main Converter and observe if the stand-

by is taking the load.

Once in a

month

Switch OFF Stand-by Converter and observe if the

main one is taking the load.

Once in a

month

Check if all the converters are inserted properly. Once in 3

month

Remove one by one and clean the converter using a soft

cloth. Gently blow some air from top or Bottom to

remove the dust inside.

Once in 3

months

Maintenance Check points of DCDP

Note: It is advised to check these points as per above frequency

and only when there is in no train movement.

Ensure that all the screws to the modules/racks are tight.

If the total load is too low compared to the installed rectifiers

capacity use only necessary rectifier modules.

Provide good ventilation to the IPS/battery room.

Ensure the exhaust fan is working properly

General Maintenance

Check and ensure that feeder supply is between 150-275V.

Ensure that battery set is fully charged by taking its specific

gravity and voltage of each cell.

Check voltage drop from IPS to battery ≤ 0.5V.

Check battery-charging current.

Check leakage from AC to earth, DC to earth and Rack to

Rack earthing and Earthing to all the modules ER shall be less

than 1.0Ω.

18

Maintenance Check points of ACDP

Maintenance Required Period

Check that intake and exhaust air openings are not

obstructed.

Weekly

Remove dust and foreign particles within the Chassis

using compressed air or blower. Check mounting bolts

and terminals looseness. Tighten them.

Weekly

Inspect transformers for evidence of over heating,

damaged insulation or loose mounting screws. Correct

any malfunctioning before operating the unit. Tighten

any loose screws or nuts. Clean electrical contacts with a

cloth dampened in with carbon tetra-chloride. Do not use

cleaning solvents on electrical contacts. Replace if found

defective.

3

Months

Check all LEDs 3

Months

Check all controls for operability. Replace if any damage

or malfunctioning is observed.

6

Months

Check the cable for input and output power and internal

wiring to components. Check for cracks or broken

insulation. Replace as indicated.

12

Months

Inspect the general conditions of PCB. Check the

components for evidence of over heating cracks or

peeling. Repair or replace board if necessary

12

Months

Inspect Diodes, Silicon Controlled Rectifiers (SCRs) &

MOSFETS and their heat dissipaters for loose mounting

or defective electrical connections. Tighten screws and

nuts.

12

Months

Inspect SCR’s, PCB, sockets for loose electrical

connections. Tighten the mounting screws and replace

defective sockets, if any.

12

Months

19

Do’s & Don’ts

Do’s

Keep the AC Input MCBs of at least 2 SMRs always ON.

Keep the Inverter Input MCBs always ON.

In case of emergency or any problem, switch OFF all the

MCBs.

Remove control cable connector accessible from backside,

before pulling out inverters/ step Down Transformers /

Bypass CVTS

Whenever any module is removed and inserted again , ensure

that it is properly inserted and fixed on to the rack.

Whenever any PCB is Replaced, connect the wires as per

schematic drawing only. Else a severe damage to PCBs may

occur.

Keep the AC Input switches always ON in Step Down

Transformers.

In case of emergency or any problem, switch OFF all the

switches.

Keep the DC Input switches always ON in Converters

Keep the AC Input switches always ON in Bypass CVT

Regulator.

Check the healthiness of SPD periodically and whenever you

feel surge is occurred.

Keep the Auto-Manual bypass switch provided in the panel in

Auto position.

20

Don’ts

Do not take out plugs of modules when in working.

Do not connect batteries when modules are on.

Do not switch off the MCBs of both or in fact any one

inverter.

Do not remove the Inverter Input/Output connectors with

Inverter Input MCB ON.

Do not switch off the incoming of AVR.

Do not remove the flat cable connected to a DC-DC

converters.

Do not run AVR at no load.

Do not short output of transformer.

Do not connect Battery Bank to IPS without removing the

battery fuse.

Do not disturb the factory adjusted potentiometers used in

PCBs.

Do not restart the system without knowing the basic

cause.

Do not use wire fuses.

DISCLAIMER

The information given in this pamphlet does not supersede any existing

provisions laid down in Signal Engineering Manual, Railway Board

and RDSO publications. This document is not statutory and instruction

given in it are for the purpose of guidance only. If at any point

contradiction is observed, then SEM, Railway Board/RDSO guidelines

or Zonal Rly. Instructions may be followed. 21