Frequently Asked Questions On Integrated Power Systems For Railway Signaling

Frequently asked questions on Integrated Power Systems (IPS) - F A Q' s

What will be the safe working AC voltage range of an IPS (Integrated Power supply System)? •

The normal working input voltage range of an IPS is 150VA.C to 275V A.C, Incase of input voltage out of range IPS SMR modules will be shutdown and SMR modules will restore automatically when ever AC supply with in the specified limit.

CIn case of all SMR modules fails, what needs to be done in order to run the station with out blanking the signals? •

In case a SMR module fails, you can charge the battery with an external power supply of rated capacity (i.e. for 300AH battery needed charger is 126V/20Amps assuming 10 Amps for load and 10Amps for battery charging)

Does IPS system need any maintenance? •

Maintenance can be reduced by providing for proper ventilation to the system.

What is charging current is recommended for battery charging of 300AH battery? •

C/13 rate current is recommended for battery charging. For 300AH battery, the needed current is 22 Amps; however battery-charging current can be reduced.

Can we interchange DC-DC Converter modules from one group of loads to any other group? •

No, it cannot be interchanged, as each group has a limitation on the voltage it is rated for.

Battery is not providing proper back-ups? •

The battery will not give proper back up due to the following reasons.

a) There may be a problem in individual cell: Check for cell voltages as per the battery manual and replace faulty cells. b) Possible

loose

connections

in

circuit

or

in

ICC:

Loose connections lead to drawing high currents, which may further lead

to burning at those points. Higher currents on account of loose connections lead to draining out the battery faster and also improper charging. Further heavy dust when gets with heavy moisture leads to leakage currents. The battery currents may get diverted elsewhere instead of supplying to loads. Check for tightness of all icc’s and at all joints in the circuit. also keep battery dry and clean c) The

battery

may

not

be

in

full

state

of

charge:

On prolonged outages of power, the system runs on battery and in a 24hr cycle the outages should not be more than 10hrs; so that the balance 14hrs will be used for bringing the battery to full state of charge. Even if the power is available, if it is not within the specified window of 150-275V, the system will be powered by battery only, since the source to IPS is cut-off whenever the voltage is beyond 150-275V. Restore source within the voltage window and further the gen set should be in on condition till the battery attains full state of charge. also do not allow system to run on battery when once “start generator” alarm is annunciated. Can we bypass any cells that may have been found defective? and use the system with reduced number of cells whether VRLA or LMLA? •

It can be used but restricted to bypass only one or two cells with adjustments in the voltage settings in the system. Do not do it without calling manufacturer.

The system is supplied with 55cells VRLA battery. Can we connect LMLA battery to the system in place of VRLA and vice versa? •

We can connect LMLA but with appropriate number of cells.

Why does hunting occur in SMR /FRBC modules? •

This is due to the poor Capacity of the Input feeder, to avoid this use proper rated Input cable as well as Input feeder Or

Poor load regulation of the D.G.set., to avoid this specified rated D.G.set., to to be used. When do we have to switch ON GEN SET and switch OFF GEN SET? •

Whenever 50% DOD (start GEN SET) alarm present in ASM panel, we

have switched ON the GEN SET, and it has it has to switch OFF whenever the charger comes to float mode.