Customer Challenge

  • As a part of Project customer was using one Line, Motor and Auxiliary (LMA) converter in their DM(MET/OS/LD) class cars and one Line, Motor and Auxiliary/Motor (LMM/A) converter in M car.
  • Due to the weight distributions and heavy weight of LMA we have a constrain in moving LMA boxes from middle of the car.
  • When using 400mm2 cables achieving bend radius is the big challenge at bolster location inside the cable trays and close to LMA converter


  • Harness routes between LMA converter and various electrical equipment’s in underframe.
  • While arranging cables in underframe cable trays, need to follow EMC guidelines, cable bend radius and easy to access respective electrical equipment's (No crisscross).


Underframe equipment layout.

Underframe harness layouts.

3D models of LMA converter and electrical standard equipment's


  • Utilised old cable trays from donor projects.
  • Routed cables within the cable trays and done investigation to identify best dropout locations for various electrical equipment’s.
  • Cable arrangements were reviewed with EMC team and approved for use.
  • Designed the support brackets to route harness to and from LMA converter, where the brackets are structurally accepted.
  • Ferrite clamps and Toroidal tape core are used to observe magnetic wave lengths/Sound which crated at converters.


  • Harness are routed between electrical equipment's and LMA, LMM/A.
  • All harness achieved respective standard bend radius.

Value addition

  • Cost saving - Utilised old cable trays by altering harness routes.
  • No crisscross in cables at LMA and LMM/A converters, so easy to identify/assemble cable to LMA or LMM/A.