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What is APU(AUXILIARY POWER UNIT)???
APU is a self-contained system with its own small diesel engine coupled to low capacity compressor and alternator to maintain main reservoir pressure, charge battery, operate driver cabin HVAC system and other small loads as per customer requirement. The main engine is started only when the locomotive is actually required for movement or traction.
The control system on the locomotive continuously monitors the locomotive battery status and other important parameters like MRPR, Loco IDLING status, Engine temperatures etc. If the loco idling time is more than 10 minutes,...
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the system shuts down the main engine and run the APU engine.
APU has a baby compressor, which produces compressed air and feeds to locomotive main reservoir to compensate the formation leakages.
While APU main engine is shut down and APU engine is running, The system continuously monitor the critical parameters and ensure they are with in limits.
MR pressure is maintained between 8 to 10 kg / cm 2 .
Locomotive batteries are getting charged and keeps the charging current with in limits.
Critical safety parameters both on main engine and APU are being continuously monitored. If any of the monitored parameters are deviated from the limits, Main engine is automatically started and APU engine is stopped.
The system is supplied complete with controls, sensors, accessories and application software.