Since the load of submersible sewage pump is heavier than horizontal pump, the current of the rated motor is larger relatively. Therefore, when we selecting the VFD, it should be according to the rated current of motor and VFD rated current, not just the power.
Pay attention to the submersible sewage pump installation environment, and protect the VFD when installed wet pumping station. Such as: strengthen the protection of PCB circuit board insulation paint, the protection of screw meteal parts and place then in the control box.
Submersible deep well pump work under 100m depth generally, and the distance between the VFD and pump is far. Therefore, it is neccessary to consider the thickening of cable diameter to reduce cable loss when pump working, and the VFD power should be better a little larger than motor power. Especially when the liquid is not clean water.
Check the pump set and VFD and maintenance regularly. For the submersible deep well pump set, check the pump surface, sealing, and insulation. For VFD, we should also check and clean regularly to ensure good condition. For the condition when pump set work continously, it is neccessary to make a standby control circuit to prevent the VFD from stop.
For safety, we should use leakage protection switch, If the leakage protection option is improperly adjusted, the tripping phenomenon will occir due to the leakage current of the inverter.