Recently I switched off several molded case circuit breaker (MCCB) and saw a flash at the back of the breaker for an instant. This happened to all the MCCB on-site (around 14). The MCCB are all rated correctly - 200A capacity with a feed in peak load of 145A.
Is this perfectly normal? My knowledge tells me that the flash is a normal occurrence because I am breaking the circuit at a high current (probably around 100A), hence, the breaker had a flash as it is breaking the circuit contact (which is intended I suppose).