How to choose a DC relay

1. Select the type of DC relay The type of DC contactor should be selected according to the type of load current and the weight of the load, that is, AC load or DC load, light load, general load or heavy load.

2. The rated current of the main contact of the DC relay The rated current of the main contact of the DC contactor can be calculated according to the empirical formula. IN main contact ≥ PN motor/(1~1.4) UN motor If the rotation is frequent, the rated current of the main contact of the contactor is generally lowered by one level.
3. The rated voltage of the main contact The voltage marked on the nameplate of the contactor refers to the rated voltage that the main contact can withstand, not the voltage of the attracting coil. The rated voltage of the main contact of the contactor should not be less than the rated voltage of the load when in use.
4. Selection of operating frequency The operating frequency refers to the number of times the contactor is turned on and off per hour. When the on-off current is large and the on-off frequency is too high, the contacts will be seriously overheated and even welded. If the operating frequency exceeds the specified value, it should be Choose a DC relay with a higher rated current.