Open Search

Avoid Costly Motor Connection Mistakes

Publication: 
Maintenance Technology
Publication date: 
May 2016
Author: 
Mike Howell, EASA Technical Support Specialist

Manufacturers deploy various external connection schemes to produce three-phase induction motors for multiple voltages and/or starting methods. Be sure to follow the relevant connection diagram, which is usually affixed to the motor or contained in its manual. If the diagram is lost, damaged, or ignored, you could find yourself dealing with a costly rewind.

The tips in this article apply to connections commonly encountered on machines with one speed at power frequency. If the external connection information isn’t available, ask your local service center for assistance, especially if several lead tags are missing or there are multiple nameplate speed ratings at power frequency. The service center can also help with unconventional numbering or cross-referencing IEC and NEMA numbering.