Traction Rolling Stock - Indian Railways Institute of Electrical ...

drum MP.
5.8 AUXILIARY CONTROL CIRCUIT (Ref.fig. 5.5.2 & fig. 5.8.1)
5.8.1 GENERAL
The control circuits of the auxiliary motors are connected to 110 V dc supply from the
battery circuit and are protected by fuse CCA. The auxiliary motors can be started only if the main
circuit breaker DJ is closed. As soon as the auxiliary contacts of the main circuit breaker DJ and
relay QCVAR have picked up, Cl18 contactor is de-energized and auxiliary interlock of C118
closes after delay of 5 secs, and Q100 relay gets energized. Auxiliary interlock of Cl18 contactor is
having adjustable mechanical time delay arrangement which closes with a delay of 5 secs, after
opening of contactor Cl18.
With the help of switches HCP, HVRH, HVMT1 and HVMT the contactors of the
individual motor can be closed and opened.
The opening positions of the switches are as follows:
Position 0 – Auxiliary motors and functional relay disconnected.
Position 1 – Auxiliary motor & functional relay in service.
Position 2 – Auxiliary motor disconnected, functional relay in service.
Position 3 – Auxiliary motor in service, functional relay disconnected.
The contactors of the auxiliary motors are operated by the switches on BL key boxes in
cab1&2. With multiple unit operation the auxiliary motors of the trailing locomotive are controlled
from the leading locomotive. The contactor of the auxiliary motors in the trailing locomotive are
switched on only if the respective main circuit breakers (DJ) are closed and Arno of that
locomotive has started up. On the trailing locomotives the switched BLCP, BLCPD, BLVMT and
BLPV are kept open. The battery switch HBA must be closed and all fuses inserted at their proper
places.
5.8.1 STRUCTURE OF MAIN COMPRESSOR
After closing the switch BL1CP or BL2CP, the coils of contactor
C101,C102, C103 energize, provided the relay Q100 has picked up and HCP is on
''position 123".
On closing of the contactor, the motors MCP 1-3 get the 3-phase 380 V ± 22.5% supply
from the Arno. As soon as the pressure in the main compressed air line rises to 10 kg/cm²
the pressure switch contact RGCP closes, disconnecting compressor contactor and connecting
the compressor to through the unloader valve. The compressor is reconnected to supply when the
pressure has dropped to below 8.5 kg/cm².