Basic Knowledge Of Motors

First, check

1. Carefully check the data on the nameplate to confirm that the motor model meets the requirements for use.

2. Use a 500V megger to measure the insulation resistance of the motor winding to the casing, the insulation resistance should be greater than 0.5MΩ.

Second, the installation

1. The motor is generally installed in a clean and dry place indoors, the surrounding must be well ventilated, the maximum temperature of the ambient air should not exceed 40℃, the minimum temperature should not be lower than -15℃, and strong thermal radiation should be prevented.

2. Motor control electrical appliances should have phase loss protection and overload thermal protection devices. YA series increased safety motors must select appropriate overload thermal protection devices according to the nameplate tE time and the starting current ratio IA/IN.

3. According to the wiring diagram, the connection head of the power cord should be fastened. The motor with lead-out cables and wires can be directly connected to the power cord, and the joint should be insulated and sealed.

4. When the power line, the phase sequence and the electric thick terminal mark are connected correspondingly, the motor rotates clockwise when viewed from the shaft extension end. When you need to change the direction, you can change the position of the two power cables.

5. YD series and other variable-stage multi-speed asynchronous motors use the method of switching lead wires to control the speed change. In order to ensure the reliability of multi-speed motor operation, attention should be paid when designing and operating the control device. When switching from high speed to low speed , the neutral point of the 2Y wiring must be disconnected when the power is cut off, so as to avoid short-circuiting the power supply when the low-speed winding is turned on. In the process of switching from high-speed to low-speed, the power of the low-speed winding must be turned on after the motor stops. , in order to reduce the impact on the motor and the load. Pay attention to the steering of the motor when switching the speed.

6. The motor can be equipped with a coupling, gears, belts and the load are mechanically connected. The 2-pole motor above 4kw and the 4-pole motor above 30kw should not be driven by a belt. The second shaft extension of the double-shaft extension can only use the coupling. transmission. Couplings, pulley shaft holes and motor shafts should be properly tight and tight, and it is strictly forbidden to hit with a heavy hammer during installation. When the coupling is used for transmission, the center line of the motor shaft and the center line of the load machine shaft should be coincident, and the axial clearance of the coupling should be 1 to 3 mm. When the belt is used to convey the movement of the chamber, the center line of the motor shaft should be parallel to the center line of the load machine shaft, and the center line of the belt and the center line of the shaft should be perpendicular to each other.