Reno's got it - essencially it would need to be listed/rated as "Suitable for use as Service Equipment" if it is anywhere between the MCOP (Main CB) and the meter. And yep, if on the service conductors it opens another set of cans of worms involving the POCO. If say it were on a feeded to a panel only handling those loads (As they often are) then the POCO has no buisiness with you. As you would be on the protected side of the the main service breaker.
So now a question... A home that had a service calc that required 200A - only calc'ed 12KW as a "Connected Load" for the generator? How's that? I know the code offers alot of leeway in generator sizing for this application - but I don't think it would be a wise idea unless the owner had to manually swap over each load.
702.5 Capacity and Rating.
An optional standby system shall have adequate capacity and rating for the supply of all equipment intended to be operated at one time. Optional standby system equipment shall be suitable for the maximum available fault current at its terminals. The user of the optional standby system shall be permitted to select the load connected to the system.
If it say happened in peak use time you could be dropping POCO - then dropping in the generator on over-load. Say if an AC and Oven were on... Which is why often these are sized for either the whole house load - no call backs for over load drop. Or only for a few 'emergency' loads. (Refer, sump pumps a few lights and outlets here and there - but not the hot-tub, pool and entertainment center) If it takes on the whole house automaticly, the generator just might shut down right then and the owner might not know what to shut off. So in this case you have two options a bigger generator, or a ATS with an ammeter installed and instruction book about load shedding. Oh - or a load shedding shunt trip circuit.... It's not hard - but pricey. Use under-voltage trip shunts to drop all non-essential loads when POCO goes out, then the owner can turn them back on manualy after the generator connects. You would have to set it up with a momentary switch that would have to be flipped manually to latch a relay to re-power the shunts so the they could be reset only on generator power. But they would have to be re-set anyway even if the POCO came back on....
But an "Essential" panel, and "Non-essential" panel would be cheaper.
[This message has been edited by e57 (edited 11-09-2006).]
