i didnt mean to come off as an ass, but now that i read it, i kind of do..

all i mean is that if you want to start doing the math, there are many
factors involved. the load conditions on startup. the load conditions
during running. and none of these are simple to calculate but most motor
manufactures will provide charts.

but in any case, if you cant run your 5horse motor on a 30 amp circuit,
something is wrong.

randy