The main function of the fire fighting jockey pump is to maintain the pressure of the pipeline. It is usually installed on the top floor of the high-rise building. It supplements the water pressure of the fire-fighting pipe network on the top floor. After setting the pressure value, it automatically fills the pipe network to reach the set pressure value. Stop automatically afterwards. It is usually installed when the height of the fire floor and the roof of the floor is less than 5 meters. In addition, the voltage regulator equipment is not controlled by the fire control room.
The use of fire fighting jockey pumps sometimes has a small problem, such as overheating the motor, for four reasons:
First, the power supply reasons: the voltage is high or low, under a specific load, if the voltage fluctuation range should be in the range of +10% to -5% of the rated value will cause the motor to overheat; the power supply three-phase voltage is asymmetrical, the power supply If the three-phase electric voltage phase 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 motor itself: the connection error, the △ 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, turn-to-turn short circuit or local grounding, when the motor is partially overheated when light, severe insulation 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 metal core of the stator to rub and emit a metal impact sound. The temperature of the iron core rises rapidly. When the motor is severe, the motor smokes and even the coil burns.
Third, the pump reasons: the choice of power is not matched, small horse-drawn carriage, motor overload operation for a long time, so that the motor temperature is too high; start too frequent, the quota for short-term or intermittent work system of continuous operation. 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.
Fourth, the working environment causes: the motor windings are damp or dust, oil stains, 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.