Use and installation of single-phase asynchronous motor

Single-phase asynchronous motors have low power and are mainly made into small motors. It is widely used in household appliances (washing machines, refrigerators, electric fans), power tools (such as hand drills), medical equipment, automated instruments, etc.

Before installing the motor, the insulation resistance of the stator winding to the casing and between the main winding and the auxiliary winding should be measured. The resistance at room temperature should not be less than 10MΩ. Otherwise, the winding should be dried, and the bulb heating method can be used.

The shaft extension diameter of the motor has been ground to a standard tolerance size before leaving the factory. Therefore, the user is required to select national standard accessories for the inner diameter of the pulley or other supporting parts. During installation, just push in or lightly tap the shaft extension table by hand. It is strictly forbidden to hit hard with a hammer, otherwise it will easily shatter the centrifugal switch, causing the motor to fail to start, damaging the bearings, and increasing the operating noise of the motor.
Before the motor is installed on the supporting machinery, the foot part of the motor must be carefully checked for cracks and problems that affect the mechanical strength. Once any problem is found, installation and use are prohibited. The motor should be installed on a flat plate with fixing holes and fixed with bolts suitable for the foot holes.
To ensure safety, before running the motor, be sure to connect the grounding wire to the grounding screw of the motor and ground it reliably. The grounding wire should be a copper wire with a cross-sectional area of ​​not less than 1 mm2.

The centrifugal switch used in single-phase asynchronous motors is a mechanical switch. When the motor speed reaches more than 70% of the rated speed, the contact is opened to disconnect the auxiliary winding (starting winding) or the starting capacitor is disconnected and does not work. When the centrifugal switch is damaged or the starting capacitor is often burned due to low voltage in rural areas, a time delay relay (220V type) can be used instead of the centrifugal switch. The method is to connect the two wires on the centrifugal switch inside the motor together, and connect the normally closed contact of the time delay relay outside the machine (in order to make the contacts durable, multiple sets of contacts need to be used in parallel or an intermediate relay is added) . The power supply of the coil of the time relay can be realized by connecting it in parallel with the main winding, and the action time is adjusted between 2 and 6 seconds. After many times of practice, the effect is very good. It can avoid burning the starting capacitor when the voltage is low in rural areas. The user is very satisfied.

Post time: Jan-10-2024