Generator Sizing

[rwollenberg]

Where can I find info pertaining to the sizing of emergency generators for commercial business.

I've read through the NEC but I'm still confused about the sizing.

The building is an auto auction house with offices;

I'm running approximately 750amp load on a 1000 amp service

 

[bphgravity]

If the generator is to serve Emergency Loads, 700.5(A) applies.

If the generator is to serve Legally Required Standby Loads, 701.6 applies.

If the generator is Optional Standby Loads, 702.5 applies.