Hi,
I need some advice on a long 13.8 feeder that comes from a breaker to several underground MPC's.. (Mine Power Center) this is a vacuum breaker at the MPC. The MPC is basically a transformer that steps down from 13.8kV to 480V with 225A instantaneous trip breakers. There is a window on the MPC unit to view the switch inside. The main breaker (that feeds the first MPC in the group will not close unless the switch at the MPC is closed. There is a feed through setup on the line side of the MPC. From there another feeder is terminated on the line side feed through connectors then runs down about a 1000 feet to another MPC, then to another and another and another. 240.21 Says that a circuit must have OCP at the point where it receives its supply. An engineer is saying that this is allowed by 240.21(C)(2).

I think he is mistaken.

I and the other electricians here think that there needs to be OCPD at point where the circuit receives its supply. Is there a tap rule that would allow this?

MSHA says this needs a disconnect. Please see http://www.msha.gov/30CFR/0.0.htm

Thank you for any responses.

windmiller


We all live under one King