ECN Forum Forums General Topics of the Trade General Discussion Area Opening breaker under rated load.

We recently had a situation where a water line burst and some of the falling water made it's way to above one of our MCCs.
I shut off the 600 amp main breaker, in order to de-energize the MCC. Typically our load is 200-300 amps (@ 480Y/277). Someone suggested that I should have shut off the individual breakers prior to opening the main. I see no reason do this, particularly in this situation, however I would like opinions on opening the main (not necessarily regularly) under it's rated load.