Pump troubleshooting
My pump keeps tripping the breaker or safety switch
When a pump trips the breaker or the safety switch (RCD), it’s a warning, not a nuisance. There are two broad reasons, and both are best treated as electrical faults to be checked by a licensed electrician rather than reset and forgotten.
The two kinds of trip
- Safety switch (RCD) tripping usually means earth leakage: current is escaping to earth, often through moisture getting into the motor windings, the terminal box, a damaged cable, or a failed seal letting water where it shouldn’t be.
- Circuit breaker tripping usually means overcurrent: the motor is drawing too much, from a stalled or seized pump, a jammed impeller, a failing capacitor, a locked rotor, or a mechanical bind.
What to check safely
- Don’t just keep resetting it. A repeated trip is a real fault.
- Note which device trips (the safety switch or the breaker) and whether it trips the instant you power on or only under load. It helps the electrician.
- Check for the obvious: a visibly damaged cable, water pooling in or around the motor, or a pump that won’t turn by hand.
- Have a licensed electrician test insulation resistance and current draw.
Safety: A tripping safety switch can indicate current leaking to earth, which is a genuine electric-shock risk. Keep clear of a wet pump that’s tripping and get a licensed electrician to check it. Don’t bypass or hold in a safety switch.
Common questions
Why does it only trip when wet?
Moisture bridging inside the motor or terminal box lets current leak to earth, which is exactly what a safety switch is built to catch. Drying it out may stop the trip temporarily, but the water getting in needs fixing properly.
Can I just reset it and keep going?
No. A safety switch trips to protect you from shock. Repeated tripping means something needs fixing, not resetting.