E5 error, compressor does not start or shuts down quickly

Safety: This involves high voltage and potentially high current. Turn off power at the main circuit breaker and outdoor disconnect. Use appropriate PPE (Personal Protective Equipment).

• Inspect power connections: Remove the condenser electrical panel. Check L1/L2 connections for tightness and signs of overheating (discoloration, melted insulation). Tighten or repair as needed.
• Test run capacitor: Safely discharge the capacitor, then test it with a capacitance meter. Replace if it is more than ±10% off the rated µF or if it is bulged/leaking.
• Check compressor amps: With a clamp meter and power restored, measure the compressor's starting and running amps. If locked rotor amps are sustained and the E5 error trips, the compressor may be mechanically locked.
• Check supply voltage: Verify the voltage at the contactor. High or low voltage outside the nameplate range can cause overcurrent.
• If compressor is shorted or locked: Replacement of the compressor or the entire Fraser‑Johnston condenser unit is typically required and should be performed by a professional.