Comprehensive Knowledge Of Submersible Pumps

(1) Inspection of well diameter:
Before the installation of the unit, check whether the inner diameter of the well meets the requirements of the external dimensions of the part of the unit that will be lowered into the well.
(2) Inspection of the liquid and insulation resistance in the submersible motor chamber
Check whether the submersible motor chamber is filled with distilled water or clean water as per the regulations, and the water injection must be done carefully to prevent false filling. If it is found that it is not filled, it must be replenished.
Before connecting the lead-out cable of the submersible motor to the matching cable, use a 500-volt megohmmeter to measure the insulation resistance between the winding of the submersible motor and the casing. The value should not be lower than 150 MΩ.
(3) Inspection of the installation dimensions of the machine and pump
When the submersible pump and submersible motor need to be assembled on-site, it is necessary to check the matching dimensions of the submersible motor and the submersible pump, strictly control the movement deviation of the deep well submersible pump (generally within 1-2 mm), and require that the deep well submersible pump be rotated uniformly when the coupling is turned, without any jamming phenomenon.
(4) Inspection of the insulation and sealing treatment of the power cable connection points
Before the submersible pump is lowered into the well, when the lead-out cable of the submersible motor is connected to the matching power cable, the cable connection points must be reliably sealed, and the core wires of each phase must not cross each other.
(5) Inspection of the operating conditions of the deep well submersible pump
(6) Inspection of the electrical protection device of the deep well submersible pump
When the deep well submersible pump is started for the first time (infrequently) or when the grid capacity is small, it is best to use reduced voltage starting. The capacity of the control cabinet of the deep well submersible pump should correspond to the power of the submersible motor. If the customer prepares the control cabinet by themselves, the control cabinet must be equipped with protection devices such as short circuit, phase loss, overcurrent, and loss of rotation delay trip, which should be sensitive and reliable to ensure the safe operation of the deep well submersible pump. The minimum interval time between each start of the deep well submersible pump is at least 20 minutes.
(7) Inspection of the power supply voltage
The voltage of 380V should deviate by no more than ±5%, and the frequency of 50Hz should deviate by no more than ±1%. Three-phase AC power with special voltage or special frequency should be ordered in advance. If the voltage is too high or too low, it will affect the normal operation of the deep well submersible pump. In severe cases, it may damage the motor winding of the deep well submersible pump.
(8) Check if the selected head of the deep well submersible pump is appropriate
Ensure that the actual required head matches the rated head of the deep well submersible pump. Only in this way can the deep well submersible pump operate reliably and fully utilize its efficiency. The difference between the rated head of the deep well submersible pump and the actual required head should generally not exceed 20% of the rated head.
(9) Check the fixation of the power cable
When loading or unloading the deep well submersible pump, never drag the cable to prevent damage to the internal cable connectors of the submersible motor, which could lead to serious accidents such as water leakage or electric leakage. When lowering the pump, do not let the cable be in a free-hanging state because when the cable is long enough, the self-weight of the cable can cause excessive stretching or damage to the cable. At intervals of 3-6 meters, use special cable clamps to fix the cable on the outlet pipe.
(10) Check the submergence depth of the deep well submersible pump
For the deep well submersible pump, the submergence depth refers to the distance from the dynamic water level of the well to the deep well submersible pump. The correct submerged depth should be no less than 3 meters but no more than 70 meters. The bottom of the deep well submersible pump should be at least 5 meters away from the bottom of the well. If the submerged depth is too shallow, part of the air bubbles may be sucked in when the deep well submersible pump pumps water, affecting the water output and service life of the deep well submersible pump; if the submerged depth is too deep, it is likely to cause mechanical seal leakage and a decrease in the insulation resistance of the winding group of the submersible motor.