What are the precautions for using the submersible sewage pump?

What are the precautions for using the submersible sewage pump?

Before the pump is started, the system should be inspected by a qualified electrician to ensure the following electrical protection measures required for each of the followings:

1. Before the pump is running, use the 0~500 megohmmeter to check the phase and relative insulation resistance of the motor. The minimum value should be greater than 2MΩ;
2. The power supply unit should be safe, reliable and normal. The power supply voltage and frequency should be in accordance with the regulations (voltage is 380V±5%, the frequency is 50Hz±1%), and the instantaneous voltage difference should not exceed 10%. If the power supply is far away from the water pump, the cross-sectional area of the cable should be thicker, the joint should be as little as possible, otherwise, the voltage will drop too much, and the cable joint should be sealed and waterproof to prevent leakage;
3. In the four-core cable, the symbol “┴” is the grounding wire (usually green and yellow two-color wire or black wire). In order to ensure safe use, it must be firmly grounded and 50mm longer than other wires;
4. When the conditions permit, the electrical protection device may include: a grounding protector, a ground leakage current cutout, etc., but in any case, a slow-melting fuse must be installed in accordance with the rated current value of the electric pump;
5. The electrical control device should be moisture-proof, the well should be installed in the area of moisture-proof, the cable should be placed in the suction port of the pump;
6. Check the rotation direction of the rotor.

After the initial start or reinstallation of the electric pump, the rotation direction should be checked. If the rotation direction does not work correctly, the pump efficiency will be reduced, or the impeller will fall off and damage the pump.

In order to determine the rotation direction of the rotor, before the final installation of the pump, it should be lifted and jogged. The direction of rotation is correct according to the following conditions. Otherwise, the position of any two of the three-phase lines on the controller should be exchanged to change the direction of rotation.

1. Looking down from the top of the pump, the rotor rotates clockwise;
2. Looking up from the bottom (ie, the direction of the suction port), the blade is rotated counterclockwise.

Note: If several pumps are connected to the same controller, they should be checked separately.