How To Reduce Incident Energy On Low Voltage Main Breaker?
The incident energy on the low-voltage main breaker was usually high due to the limited functionality of the old electromechanical relays. The new digital relays have much more functionality, such as multiple time-overcurrent and overcurrent elements which help to reduce the incident energy.
Contactor Interrupting Rating And Protection Settings
Medium voltage contactor has limited interrupting capacity during a fault. The contractors are serially installed with the fuse to meet or exceed the maximum available fault current. It is important that protection relays operating the contractors are properly set so that contractors properly coordinate with the fuse and do not operate during a fault current higher than the interrupting capacity.