Propulsion Control Circuit
To move the locomotive, supply of Traction Alternator is send to traction motor through Power contactor, BKT, Reverser. This circuit is design to pickup above electro pneumatic contactor as and when require. In this circuit as per speed of locomotive two combination of traction motor are changed and during dynamic brakes traction motor convert into generator. Traction motor has following combination:
a) Series Parallel combination
Reverser Contactor Control – To move the locomotive, keep reverser handle in desired direction, put ON GFCO-1&2 and on opening master handle reverser contactor coil will energize as per working control stand
MH(M) NOI 6-13A L/C/S
MH(M) NOI 6-13B R/C/S
RH(F) NOI 13A-8 L/C/S
RH (R) NOI 13A-0 L/C/S
RH (F) NOI 13B-0 R/C/S
RH (R) NOI 13B-8 R/C/S
Rev. Forward coil Wire no. 8& 4
Rev. reverse coil Wire no. 0 & 4
Series parallel combination- series power contactors coil will get
Rev(F) NCI 8-8A
Rev(R) NOI 0-8A
BKR3 NCI 8A-8C
BKR1 NCI 8C-8D
ECS(Idle) NOI 8D-8AA
BKT(M) NCI 8AA-8E
TR NCI 8E-8F
GFC NOI 8E-8F
MCO NOI 8F-8FF
P1 NCI 8FF – 8M
S1 Contactor Coil 8M-4
P21 NCI 8M-8Z
S21 Contactor Coil 8Z-4
P31 NCI 8M-8G S31
Contactor Coil 8G-4
In this way S1, S21, S31 series power contactor pickup.
Parallel Combination (Ist transition) -When loco speed increases up to 41.5 km/h at that time TSSR energize and its contact 6AA-18A close and TR relay picks up through MCO, NCI 6-6AA and TSSR NOI 6AA-18A, due to which following changes will take place –
1. TR NCI 6E-6F open and GFC will drop.
2. TR NCI 8E-8F open and S 1, S21, S31 will drop.
3. TR NOI 8E-8L close and P1, P21, P31 will pick up through S31 NCI 8L-8S.
P2, P22, P32 will pick up in following way -
TR NOI 8E-8L
GFC NCI 8L-8R
BKT (M) NCI 8R-8K
MCO1 NCI 8K-8KA
S1 NCI 8KA-8U
P2 contactor picks up (8U-4)
MCO3 NCI 8K-8KB
S21 NCI 8KB-8W
P22 contactor picks up (8W-4)
MCO2 NCI 8K-8KC
S31 NCI 8KC-8V
P32 contactor picks up (8V-4)
As P32, P2 NOI (6D-6F) closes than GFC will pick up.
As P32 picks up its NOI (8E-8K) will close in parallel to P21, P31 NOI (8E-8K) and P2, P22, P32 supply will maintained.
In this way all six parallel power contactor pickup.
Throttle Not Responding to Loco/Load Meter Not Showing Current
Precaution To Be Taken Before Wedging GFC:-
1. Ensure that current available in wire no. 6 (If BKT are change its position from braking to motoring it means current is available in wire no.6)
2. Ensure that cranking contactors are in open condition.
3. Ensure that BKT is in motoring position.
Precaution To Be Taken After Wedging GFC:-
1. First notch current will be excess, so in order to avoid the jerk on the Loco, First open the MH then release loco brakes.
2. Parallel transition will not come, take manual transition.
3. Whenever GR/GFOLR operate bring throttle to idle immediately.
4. Do not use dynamic brakes.
