First, the choice of contactor
Select the rated voltage and rated current of the contactor main contact: Normally, the rated voltage of the contactor contact is selected to be greater than or equal to the rated voltage of the load circuit. The rated current of the main contact is not lower than the rated current of the specified load circuit. Generally choose by 1.3 times.
Select the contactor to attract the voltage of the coil: the contactor attraction coil voltage is usually directly selected relative voltage 20V or direct use of 380V.
The number and types of contacts of the contactor should meet the requirements of the control circuit.
Second, contactor installation should pay attention to what matters
1. When the contactor is installed, the bottom plate should be perpendicular to the bottom surface and the inclination should be less than 5°;
2. When the AC contactor is installed, both free surfaces should be placed on the upper and lower positions to facilitate heat dissipation.
3. When installing the wiring, be careful not to lose the screws, coils, connectors, etc., so as not to fall into the contactor to cause mechanical jamming and short-circuit faults. And tighten the screws to avoid loosening.