Motor Testing

Motor testing instruments assess winding insulation, turn-to-turn and phase-to-phase integrity, and rotor condition, either offline with the motor stopped or online while it runs.

Megger, Sonel, AEMC, All Test Pro and Extech cover this range. Offline testing gives the clearest picture, combining insulation resistance, winding resistance balance and surge comparison to find faults that a simple megohmmeter reading passes. Online testing sacrifices some diagnostic depth but needs no shutdown, which is often the deciding factor on a critical machine. Confirm the motor voltage class and whether you need to test through the cable from the starter or directly at the motor terminals.