Dual & Tap Wound Motors

Problem

Possible Cause

  

Recommended Action
High current draw and / or 'growling bearings' Tap-wound motors can create problems if the 'star point' contractor is not connected.  The motor will be fine in low speed but in high speed will have a high current draw and a severe electrical noise that sounds like noisy bearings.  The motor will not last long when run in this condition.  Dual-wound motors are rarely a problem.   Faulty wiring in the switchboard, check the correct contractor is connected.