The motor protection is down stream protected by additional relays, but what i was questioning was the fact that the (equipment as in circuit breaker and cable) are only rated at 800amp and the only over current protecting this circuit breaker is set at 900amp. I would expect this to be below...
Please give me your opinion, We have an 11Kv HV network connected to the national grid. We have 4x(1200Amp) Incomers onto a Bus Bar and 800Amp Feeders feeding radial circuits. There are large 11Kv 3MVA Motors on some circuits, This particular Feeder relay over current protection is by IDMT set...