Table of Contents
This case study describes the process of diagnosing and repairing a faulty AC motor circuit in an industrial setting. It highlights common issues and troubleshooting steps used by technicians to restore proper operation.
Initial Symptoms and Inspection
The motor was experiencing intermittent operation, with frequent tripping of the circuit breaker. Visual inspection revealed signs of overheating and burnt wiring connections near the contactor and motor terminals.
Electrical Testing and Diagnosis
Technicians performed voltage and continuity tests. They confirmed that the contactor was receiving voltage but observed that the motor windings showed high resistance, indicating possible insulation failure. The motor’s thermal protection switch was also tested and found to be malfunctioning.
Identified Issues and Repairs
The root causes identified included damaged motor windings and a faulty thermal switch. Repairs involved replacing the motor with a new unit and installing a new thermal overload protector. Additionally, damaged wiring was replaced, and connections were tightened to prevent overheating.
Preventive Measures
- Regular inspection of wiring connections
- Periodic testing of thermal overload devices
- Monitoring motor temperature during operation
- Ensuring proper ventilation around the motor