The choice of household AC contactor

When selecting an AC contactor, the load type should be the main consideration. It is necessary to determine the rated working voltage, rated working current, rated making and breaking capacity, and overload tolerance of the contactor based on the main circuit parameters. Besides, the coil voltage of the AC contactor should be determined according to the control circuit parameters and the auxiliary circuit parameters. It is also crucial to choose the relevant series or special specifications of the contactor based on the surrounding environment of the place of use. By taking these factors into account, a suitable AC contactor can be selected for optimal performance.

Let's say we have a compressor motor main circuit, with a 15KW compressor motor. The power factor is 0.9 and the rated efficiency is 0.85. Based on these figures, we can calculate the rated current of the motor, which comes to IN=15×10^3/1.732×380×0.85×0.9=30A.

To choose the right AC contactor, we can consider CJ20-40A/380V. This particular type of contactor has a coil voltage of 380VAC, making it a suitable choice for the circuit in question. By selecting an appropriate AC contactor, we can ensure that the motor functions reliably and safely, without any risk of damage or malfunction.

When choosing a household AC contactor, it is important to ascertain the rated current of the moving contact in accordance with the rated current of the load. If there is an occurrence of an undersized horse-drawn car, it will lead to a decrease in the contactor's lifespan. Additionally, it is crucial to select a contactor coil voltage that matches the voltage of the control power supply.