Fixing Aircon Circuit Breaker Trips

If switching on your aircon causes the Earth Leakage Circuit Breaker (ELCB) or main Distribution Board (DB box) in your Singapore flat to trip immediately, a serious electrical fault exists.

Do not attempt to reset the breaker repeatedly without inspection, as forced power restarts can cause electrical fires or permanently burn electronic components.

Causes of Power Trips

• Short-Circuited Circuit Board (PCB): Water leaks or insect intrusion burning PCB traces.
• Grounded Outdoor Compressor: Motor insulation breakdown inside the compressor causing electrical current leakage to the metal chassis.
• Burnt Electrical Isolator Switch: Corrosion or loose wiring contacts inside the outdoor isolator box.
• Faulty Start Capacitor: Shorted capacitor drawing extreme over-current during startup.

Emergency Repair Steps

1. Electrical Insulation Resistance Test: Megger testing compressor windings to check ground insulation.
2. Isolator & Wiring Inspection: Replacing corroded outdoor switches and shorted wires.
3. PCB Module Repair: Solder-repairing or replacing shorted circuit board assemblies.