Working principle of elevator DC portal crane system (electrical part)

When JKM is engaged, the current passes through the motor rotor DM on the one hand, and the door opening resistance RKM on the other hand, from m2 to m3, so that the door crane rotates in the door opening direction, because the resistance value of RKM is larger at this time, and the shunt through RKM is smaller. So opening the door is faster.

When the elevator door is closed to 3/4 stroke, the switch deceleration limit 1KM is opened, and most of the resistance of RKM is short-circuited, which increases the shunt through RKM, thus reducing the motor speed and realizing the door opening deceleration function. When opening the door, cut off the door and interrupt the limit, so that the door opening relay is released and the elevator stops opening the door.

Extended data:

Precautions:

1, the temperature of the elevator electrical room should not be too high, otherwise the inverter components will easily age, and it is best to install air conditioning, which will have good consequences.

2. Prevent rain from getting wet. Usually a typhoon blows, the doors and windows are damaged by the wind, and the inverter is drenched by rain.

3. Lightning protection, which is related to the lightning protection facilities of the whole building or all communities, was seriously damaged by the inverter in lightning strike.

4. The cooling fan of the frequency converter should be cleaned regularly. There are two maintenance methods for frequency converter: on-line voltage detection and DC resistance measurement. If it is noisy or does not work, it should be replaced.

5. The abnormal noise of elevator motor is usually caused by the failure of frequency converter. If the three-phase current of the motor is unbalanced, it is best to repair it at this time. If the inverter is incomplete, the damage may be serious.

Baidu encyclopedia-elevator

Baidu Encyclopedia-Elevator Control System