Motor Diagnosis & Rewinding

Three-phase motor faults — windings, bearings and the supply problems that destroy otherwise healthy machines. Most burnt-out motors were killed by something outside them, so these guides diagnose the installation as well as the machine, and set out honestly when a rewind is worth it and when it is not.

Scope

• ▪Winding failure and insulation testing
• ▪Single-phasing and supply faults
• ▪Bearing failure and mechanical causes
• ▪Overload protection and duty
• ▪Variable-speed drive interaction
• ▪Repair, rewind or replace

Diagnosis guides

• Three-Phase Motor Failure — Diagnosis, and Whether to Repair or Rewind

  Three-phase squirrel-cage induction motors on direct-on-line, star-delta, soft-start and variable-speed drives

  9 diagnostic steps · advanced · qualified electrician

• Motor Overload Keeps Tripping — Diagnosis

  Three-phase motors on direct-on-line, star-delta and soft-start control, with thermal or electronic overload protection

  8 diagnostic steps · intermediate · qualified electrician