Motor Starter Troubleshooting Guide

Motor starter troubleshooting is clearer when command, contactor operation, power delivery, overload response, motor condition, and mechanical load are treated as separate parts of the same system.

Use the operating symptom first: a starter that never energizes, a contactor that drops out, a starter that stays in while the motor remains stopped, and repeated overload operation point toward different evidence paths.

• Separate control-side symptoms from power-side symptoms.
• A moving contactor does not by itself prove every main power pole is healthy.
• Treat overload operation as diagnostic evidence rather than a nuisance condition.
• Include the connected motor and mechanical load in the reasoning.
• Verify Code-dependent installation and protection requirements in applicable legal material.