Magnetic Contactor Selection

- Jul 10, 2018-

The NEMA selection process always results in a choice of a contactor you can use over a broad range of operation conditions. 

For example, you could use a NEMA Size 5 contactor to use a 50Hp motor operating at 230V or a 200Hp at 460V.

Since a contactor should last for years, don't automatically replace one that fails with an identical unit. Instead, take a few moments to see if there is an obvious problem. A contactor really has only two basic parts: the coil and the contacts. The coil energizes the contactor, moving the contacts into position. The contacts transmits the current from the source to the load, heat can destroy either of them, so take a careful look at both.