What to do if the submersible pump is out of phase and always burns the motor?

The submersible pump is three-phase and always burns out the motor, indicating that phase loss is a common occurrence. Therefore, the maintenance approach should be carried out from top to bottom.

Finding the root cause of phase loss

If the cause of the phase loss cannot be found, then all technical measures are to address the symptoms rather than the root cause. The search approach is from top to bottom. When the motor is in phase loss, use a multimeter to determine which phase of ABC three-phase has a problem, follow the circuit to find the power control, such as AC contactor, air switch, etc., and then determine which component has a problem causing the phase loss.

If there is a problem with the AC contactor, it is necessary to determine whether the selected model or insufficient capacity has caused the contact to burn out, and the air switch is also the same. If all hardware problems are not found, it is necessary to continue searching until the final cause is found.

What measures can protect the motor

1. Phase loss protector

There are various types of phase loss/phase loss protectors on the market. It is recommended to purchase a dedicated phase loss protector for electric motors. When a phase loss is detected, the power supply should be cut off in a timely manner to protect the motor from being affected and prevent it from burning.

2. Thermal relay

Installing a thermal relay can cause overcurrent and heating when the motor is out of phase. Installing a thermal relay with appropriate capacity can timely disconnect the main power supply when the other two currents increase, protecting the motor from being burned out.

3. Frequency converter

If you want to solve the problem of phase loss at once, the best choice is a frequency converter. Due to the internal overcurrent protection, phase loss protection, short circuit protection, etc., the frequency converter can effectively protect the motor during phase loss and provide feedback. The price is relatively high, but it is acceptable.

Summary:

The continuous lack of phase in the electric motor is not a small matter, and the best way is to directly find the true cause of the lack of phase, otherwise the problem will always exist.