Starting WCAM-3 AC/DC electric locomotives

by Harsh Dinesh

With updates by Khalid Kagzi, 2009-03-13

Disclaimer: The information presented here is neither complete nor accurate. Complete details on the topics here are available only from Indian Railways and other official organizations. The material here is not a substitute for the official documentation or official training procedures, which are provided to duly authorized personnel. Do not use the information here to design, build, operate, repair, or maintain any equipment.

This is the general procedure for starting a locomotive of the WCAM-3 dual-power (AC/DC) class.

Compare to the starting procedures for other electric locomotive classes.

Note: Also see the page on auxiliary machines in locomotives

  • After signing the required documents, acquire the necessary levers and keys (BL key, ZPT and Reverser lever) from the shed staff, Loco lobby, Station Master.
  • Perform a thorough inspection of the loco prior to energization and make sure it is fit for duty.
  • The switches and valves in the loco should be checked for being in the correct postion. All program switches should be in the '1' position. The driver shall especially verify that no relay/contactor in the loco is 'wedged'. If any such wedged equipment is found, shed staff and TLC should be informed immediately. It is also advisable to inspect the logbook of the loco for the last 15 days to examine any abnormal bookings made by drivers.
  • Enter, preferably from Cab-2, and move the HBA switch to position 1, which connects the battery to the control circuit of the loco. If needed, switch on the lights. Then proceed to Cab-2 and move switch ZCPA to position 1, which starts the auxiliary compressor which charges the pantograph reservoir. The auxiliary compressor should be run until a pressure of at least 6kg/cm2 is available.
  • In the trailing cab, check that the A9 and SA9 cut-out cocks are shut and those in the driving cab are open. Make sure that the A8 BP charging cock is in the open position. In case of a multiple-unit consist the BP charging cock in each of the trailing locos MUST be in the closed position.
  • Check that the MU2B valve is in the 'lead' position in the leading loco, and in the 'trail' position in all the trailing locos.
  • Depress ZUBA button and ascertain the battery voltage to be 110V DC.
  • Insert and press the BL key in its slot in the cab which is to be activated and turn it to the ON position. This key acts as the cab activation key and ensures that only one cab remains operative at a time. Turning it to the ON position also releases the upper row of BL switches.
  • Once sufficient pressure has built up in the pantograph reservoir, put the panto key into the ZPT slot and raise the appropriate pantograph depending on the traction supply in the OHE. Check that the pantograph is raised and has come in contact with the OHE. As soon as the pantograph is raised and proper traction supply is available, signal lamp LSS is extinguished. If the wrong pantograph has been raised, an audible alarm sounds in the cab and it is not possible to close the DJ/DS. If a problem arises, try to trouble-shoot according to the TSD or report it to the shed staff.
  • The dials in the cab will start showing their respective readings. Make sure that the OHE voltage dial in the cab shows 1500V DC or 25kV AC depending in which territory the loco is (DC or AC).
  • Flip the BLDJ/DS switch and momentarily flip and hold the BLRDJ/DS to close the DJ/DS. Hold the BLRDJ/DS switch until LSDJ pilot lamp is extinguished. As soon as the DJ is closed the blowers which cool the resistance banks come alive. This is an automatic feature which is used as a safety measure to prevent the pilots from forgetting to switch on the blowers and burning out the resistance banks.
  • Switch on the main compressor by flipping the BLCP switch which begins MR pressure charging. Ascertain that the MR pressure cuts in at 8.5kg/cm2 and cuts out at 10kg/cm2.
  • Flip the BLVMT switch to activate the blowers required to cool the traction motors in the loco.


  • Once the loco is energized check all the controls, dials, etc., in the cab and make sure everything is working fine.
  • Check safety items: Headlights, Flasher lights, and whistles or horns.
  • Check that BP pressure is 5kg/cm2.
  • Apply the SA9 brake and check that the BP reads 3.5kg/cm2.
  • Fix the reverser handle into the MPJ-1/2 slot and put the reverser into forward or reverse from the Neutral position depending on the direction of movement of the loco.
  • Switch on the marker lamps by flipping the BLLF switch.
  • Once it is possible to apply the independent loco brakes by SA-9, release the hand brakes and remove all wooden wedges around the wheels and any other media which securing the loco in its position.