Model: Deep well submersible pumps
A deep well pump that trips its protection is telling you something. The usual causes, from low voltage to a falling water level, and how to check each.
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Repeated tripping is one of the warning signs that a deep well pump should be stopped and checked. Resetting and restarting again and again shortens the motor’s life. Work through these causes.
| What you see | Likely cause | What to check |
|---|---|---|
| Trips soon after starting, current high | Low or unbalanced supply voltage | Voltage on all three phases at the panel, with the pump running |
| Trips after running a while | Water level falling to the pump inlet | Dynamic level; the inlet must stay at least 1 m below it |
| Current high, flow normal or high | Pump running at too low a head (beyond its curve) | Partly close the outlet valve and watch the current |
| Current high, flow low, noise | Worn or sand-jammed impellers | Lift and inspect the pump |
| Earth leakage trip | Damaged cable or a failed cable joint | Insulation resistance; below 0.5 MΩ means stop |
| Trips at once on every start | Cable too thin or too long for the motor | Cable size against the motor current and length |
Write down the voltage, the current and the flow each time it trips. If the cause is not clear, send us those figures with the pump model and we will help you read them.
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