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About Haichuan Application of temperature switch of single phase motor user manual | Haichuan


Small household appliances, electric tools and other machinery and equipment using single-phase motors can adopt temperature switches to protect the motor from burning out the motor and winding due to motor heating, resulting in motor damage.

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For a single-phase motor started and operated by capacitance, a temperature switch is connected in series on the main winding of the hidden pole shaded pole motor at the common outgoing line of the main and auxiliary windings, which can be fixed at the end of the motor winding with wire or heat-conducting glue. When the single-phase motor is connected to the single-phase AC power supply for load operation, the motor will heat up due to copper and iron loss. 

When the temperature inside the motor is the same as the action temperature set by the temperature switch, the temperature switch will automatically disconnect, and the line has no current, and the motor will stop rotating. When the temperature drops to the safe temperature, the temperature switch in the motor will automatically turn on the power after the motor stops and turns to minutes, and the motor will run again. In fact, the temperature switch is heated and powered off at a certain temperature, and then automatically reset and power on at a certain temperature. 

The temperature switch also cannot be reset automatically. Generally, the temperature switch with automatic reset is best used in single-phase motor. According to the different insulation grade of single-phase motor, the model and action temperature of the temperature control switch connected in series in the motor stator winding are also different, which requires that the action temperature of the series thermal protector should be appropriate. as follows

Insulation grade of motor: Class A, class E, class B, class F

Maximum allowable working temperature of motor 105 ℃ 120 ℃ 130 ℃ 150 ℃

The optimal protection temperature of temperature switch is 110 ℃ 125 ℃ 135 ℃ 150 ℃

It can be seen from the above that the action power-off temperature of the temperature switch should be slightly higher than the maximum allowable working temperature of the motor, but the protection temperature should be selected according to the actual installation environment when selecting the temperature switch, so as to achieve the best protection effect.

Since the single-phase motor adopts the temperature switch, it will no longer burn out the motor due to the motor heating, which will reduce the undue losses. Therefore, the single-phase motor is best protected by installing the temperature switch.

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