The answer is actually quite simple, but let me first explain why that locking device is there. Section 422.30 of the National Electric Code (NEC) requires a disconnecting means for all appliances.

Circuit breakers are easily switched on and off which can cause problems for professionals carrying out an intervention. Shocks and extreme injury can be the results of prematurely reactivating a ...

Reviewing a typical protective device trip curve (click here to see Fig. 2), it can be divided into three regions. First is the “instantaneous region,” which is the region intended to interrupt ...