1, the supporting power motor is overheated There are f […]
1, the supporting power motor is overheated
There are four reasons. First, the reason for the power supply: the voltage is high or low. Under certain load, if the voltage variation range should be +10% to -5% of the rated value, the motor will overheat; the three-phase voltage of the power supply is asymmetric, and the power supply is three. When the phase-to-phase voltage imbalance is more than 5%, the winding will be overheated; the phase loss operation, the experience shows that the agricultural motor is burned more than 85% due to the lack of phase operation, and the motor should be installed with phase loss protection device. Second, the reason for the pump: the power is not matched, the small horse-drawn carriage, the motor is overloaded for a long time, the motor temperature is too high; the motor that starts too frequently, the quota is short or intermittent work continuously.
The number of starts should be limited, the thermal protection should be selected correctly, and the scale should be used according to the calibration on the motor. The third reason is the motor itself: the connection error is wrong, the delta shape is mistakenly connected to the Y shape, so that the temperature of the motor rises rapidly; the stator winding has phase-to-phase short circuit, inter-turn short circuit or local grounding. When the light is light, the motor is partially overheated, and when it is severe, the insulation is severe. Burnt out; squirrel cage rotor broken or defective, motor running for 1 to 2 hours, core temperature rises rapidly; failure of ventilation system, should check whether the fan is damaged, whether the rotation direction is correct, whether the ventilation channel is blocked; bearing wear, rotor The eccentric broom causes the core of the stator to rub against the metal to make a sound, and the temperature of the core rises rapidly. When the motor is severe, the motor smokes and even the coil burns. The fourth is the working environment: the motor windings are damp or dust, oil, etc. are attached to the windings, resulting in lower 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, the temperature of the motor will be too high, and efforts should be made to improve the working environment. Such as scaffolding and so on. Note: If there is a malfunction due to electrical reasons, the electrician who has obtained the professional qualification certificate should be repaired. Those who know nothing about it should not be blindly repaired to prevent personal injury.
2. The deep well submersible pump does not have water or a small amount of water.
First look at the current difference between the current running at the pump and the current operation. If it is smaller than the normal operation time (basically 2/3 of the normal current), there are problems such as impeller wear and blockage of the uppermost check valve of the pump head. If the current is as large as in peace, it is a problem such as leakage of the tube gasket, leakage of the pipe, and leakage of the pump body. If the current is larger than when running normally, it is basically a problem that the wearing parts are worn. In addition, if the cable is damaged, the amount of water is the same as usual, but the current will become larger. The current of three 380V motors is generally 2.2A. The above reasons can be detected by the repair personnel who frequently repair the deep well pump.