What is the reason for the heat of the sewage pump motor?

1. Reasons for the water pump

The power is not matched, the small horse-drawn cart is selected, and the motor is overloaded for a long time, which makes the motor temperature too high; the motor that starts too frequently and has a short-term or intermittent duty system works continuously. The number of starts should be limited, the thermal protection should be selected correctly, and the motor should be used according to the rated rating on the motor.

2. The reason for the motor itself

The connection method is wrong, and the △ shape is mistakenly connected to a Y shape, so that the temperature of the motor rises rapidly; the stator winding has interphase short circuit, interturn short circuit or partial grounding, the motor is partially overheated in light cases, and the insulation is burned out in serious cases; the squirrel cage rotor is broken If the motor runs for 1 to 2 hours, the temperature of the iron core rises rapidly; if the ventilation system fails, check whether the fan is damaged, whether the rotation direction is correct, and whether the ventilation hole is blocked; the bearing is worn, and the rotor eccentric swept makes the stator and rotor iron core. The rubbing produces a metal impact sound, the temperature of the iron core rises rapidly, and in severe cases, the motor emits smoke, and even the coil burns.

3. Reasons for power supply

The voltage is too high or too low. Under a specific load, if the voltage fluctuation range should be outside +10% to -5% of the rated value, it will cause the motor to overheat; the three-phase voltage of the power supply is asymmetric, and the three-phase power supply If the voltage phase-to-phase unbalance exceeds 5%, the winding will be overheated; during operation with open phase, experience has shown that more than 85% of the agricultural motor burned out is caused by open-phase operation, and a phase-opening protection device should be installed on the motor.

4. Reasons for the work environment

The motor windings are damp or dust, oil, etc. adhere to the windings, resulting in reduced insulation. The insulation resistance of the motor should be measured and cleaned and dried; the ambient temperature is too high. When the ambient temperature exceeds 35°C, the inlet air temperature is high, which will make the temperature of the motor too high, and efforts should be made to improve its working environment. Such as awning and sunshade. Note: If there is a failure due to electrical reasons, an electrician who has obtained a qualification certificate should be invited to repair it. People with little knowledge should not repair it blindly to prevent the occurrence of personal injury accidents.