Need to program the SEPAM for instantaneous and curved (IDMT) over current protection.
The ANSI 50/51 protection option in SEPAM relays combine both ANSI 50 instantaneous phase over current protection and ANSI 51 delayed phase over current protection.
In order to activate ANSI 50 protection, an instantaneous delay of 0 ms must be set for the time delay. Confirmed instantaneous operation times are:
inst. < 50 ms at 2 Is for Is >= 0.3 In (typically 35 ms)
inst. < 70 ms at 2 Is for Is < 0.3 In (typically 50 ms)
In order to activate ANSI 51 protection, a delay greater than 50 ms must be set for the same parameter setting time delay. This will allow the end-user to use ANSI 51 delayed phase over current protection.
Below is a video to help program the basic needs for over current protection using circuit breaker control featuring the SEPAM™ 20 Series as an example: