What Are The Consequences Of Selecting The Wrong Submersible Pump Motor

Jul 15, 2025

The selection of submersible pump motor is incorrect: the power is too low, the insulation level is not good (the frequency converter requires F level or above), etc.
The three-phase current imbalance is caused by the inter turn open circuit of the phase winding, or there is a short circuit problem between the windings, which increases the phase current and causes the winding to heat up, resulting in overheating of the motor.
The stator winding wiring is incorrect, such as misconnecting the angular connection to the star connection.
The insulation of the motor winding is affected by mechanical oscillations (such as high current impact during startup, equipment oscillation, and rotor imbalance), causing the winding to experience phenomena such as inter turn looseness and insulation cracks. The destructive effect continues to accumulate, and thermal expansion and contraction cause friction on the winding, accelerating insulation aging and leading to insulation damage caused by carbonization until the winding is burned.
The adoption of maintenance grounding for submersible pumps is a mandatory national standard requirement. Only by adopting maintenance grounding can personal safety be ensured during use. If grounding is not maintained, once the casing leaks electricity, the water at the outlet of the submersible pump and the surface of the pumped water will become electrified, endangering human and animal safety and wasting a lot of electrical energy.

Submersible pump operation in water can cause simple electrical leakage, resulting in energy loss and even electric shock incidents. If a leakage protector is installed, as long as the leakage value of the submersible pump exceeds the operating current value of the leakage protector (generally not exceeding 30 mA), the leakage protector will cut off the power supply of the submersible pump.
If the power supply voltage of the place where the submersible sewage pump is used is slightly lower than the required voltage of the sewage pump, and the required cable length is also relatively long, the operating cable of the water pump will become larger. If the pump operates for a long time, it will be detrimental to the motor of the sewage pump.
The load of a submersible pump is relatively heavier than that of a regular pump, and the rated current of the accompanying motor is also relatively high. Therefore, when selecting a frequency converter, it is necessary to compare the rated current of the motor with the rated current of the frequency converter, rather than just power matching.