Starting WAM-4/WAP-4/WAG-5/WAG-7 electric locomotives

by Zubin Dotivala, March 2004

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 WAM-4, WAP-4, WAG-5, or WAG-7 class.

Compare to the WDM-2 diesel locomotive starting procedure.

  • Ascertain that A9 and SA9 cocks in non-driving cab are shut and those in the driving cab are open.
  • Ascertain that A8 / BP charging cock is in open position.
  • Ascertain that MU2B is in the lead position.
  • Enter cab two and put HBA on position one, depress ZUBA and check voltage in UBA. It should register 110 volts DC
  • Enter cab one and put ZVPA on position one. The 'baby' compressor comes to life. The 'baby' compressor should be run till pressure in ER pressure goes up to 8.0 kg/cm^2
  • BL key should be unlocked and it should be ascertained that LSDJ, LSCHBA, LSGR and LSB pilot lamps are glowing.
  • ZPT should be inserted and put on position one or two depending on pantograph to be raised. Ascertain that the pantograph has been raised.
  • To close the DJ BLDJ should be closed and BLRDJ should be depressed and kept depressed for four seconds or until LSDJ extinguishes (whichever is earlier).


  • BLCP should now be switched on and MCP running should be ascertained. MR pressure should be built up to 10 kg/cm^2.
  • It should be ascertained that the MCP cuts in at 8.5 kg/cm^2 pressure and cuts out at 10 kg/cm^2.
  • Ascertain that BP pressure is 5 kg/cm^2 and HS valve pressure is in the range of 1.4 to 1.7 kg/cm^2.
  • SA9 should be operated and it should be ascertained that the BC gauge reads a pressure of 3.5 kg/cm^2.
  • In case of a vacuum-braked rake BLPV should be switched on and the vacuum allowed to build up.
  • BLMVT should next be switched on and it should be ascertained that after five seconds MVRH MVMT 1/2 have come to life.
  • Exhauster lubrication should be checked.
  • In case of SLM mechanical exhauster oil feed rate for the bearing should be set at twelve drops per minute; for floating ring at eight drops per minute; and at three drops per minute for a Nordy type exhauster.