62,
I looked this up but didn't really have any luck. I find that areas where there are electrical efficiency losses (with transformers and motors) there will be calculable heat gain but data for MCCs are not defined.
At the same time I've seen MCC rooms that get hot... I did find via search a study on this, but it was a study proposal. No results were given. If there's a known thumbrule for cooling load versus total MCC horsepower, I'm interested too.
Good post; I'll be checking in. -CB