Instantaneous overcurrent setting disable

[panthripu]

Hi everyone,
Which condition , should the instantaneous trip setting in a circuit breaker(feeder) be kept off /disabled. I have seen sometimes this feature is disabled and came to know that it is as per outcome of ETAP software .

 

[Hv&Lv]

Here’s a good start. There are opinions based on maintenance vs arc flash, MCC protection etc…

To Instantaneous or Not on LV MCC

This issue keeps coming up in my head and to be honest I can not settle on one side of the fence. When implementing LSI (Long time, Short time, Instananeous) LVPCB (Low Voltage Power Circuit Breakers) for MCC main breakers, do you utilize the instantaneous function or not? MCCs are only rated...

forums.mikeholt.com