How do you determine the size of an optional standby generator?

[jar546]

When someone pulls a permit for an optional standby generator under NEC 702, what do you accept for the sizing of the generator?

Yes, you are limited for what you can accept for new construction so I would like to make this question more specific to existing buildings and homes for the residential crew.

I mean we see permit applications for the installation of optional standby generators all the time so how to you verify compliance when it comes to sizing? And btw, please don't bother with the "stand off" answer of leaving that to an engineer. 99% of the time an engineer has nothing to do with the installation of a generator on an existing home.

 

[steveray]

Is it automatic or manual? Manual I don’t care...We require the electrician to submit his load calculations on automatic systems.

 

[jar546]

Is it automatic or manual? Manual I don’t care...We require the electrician to submit his load calculations on automatic systems.

Automatic of course since there is no sizing requirement for manual as you eluded to.

 

[north star]

$ ~ $ ~ $ ~ $

Someone competent should submit the actual historical
Load Calculations and the "what is proposed" load calculations.
Article 702.5 [ in the `08 NEC ] provides guidance on the system
capacity.

$ ~ $ ~ $ ~ $

 

[steveray]

They can size it just like the size the service per proposed loads.....A smart person would make sure there is some load shedding just in case