Generator connection

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laketime

laketime

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I have a customer that wants to back up certain items in their house. The size generator they need is about a 20kw. The issue I have is the generator manufacturer sells a 20kw but the transfer switch controls the entire feed to the house. Article 702.5(b) says I need to use article 220 to determine load of the entire house. When I do it comes to 45kw. Does the code require me to provide a generator that will back up the entire demand of the house? I did an amp probe reading the other day and they were drawing a total of 7amps in the house when they were there. This is an older retired couple and their energy consumption is low.
 
Just searched and read another post that confirms that I would need to supply a generator that can handle the calculated load of the entire house. NOOOOOOOOOOOO!!!!!!!:grin:
 
Just install a subpanel. Feed the subpanel from the TS with the feeder from the main panel going to the TS also. Then move the loads they want to feed (less than 20kW) to the subpanel.

Mark
 
Another option is to arrange for the unwanted loads to drop out, such as interrupting the 24v of the HVAC.
 
if that house has over 20kw being used, then they must have one very high electric bill, a 20kw generator can handle quite a bit, and if this is a Generic you can order the load shedding option which will drop the non necessary loads and allow you to transfer the whole house, I have only done a load shedding once but it was because of electric heat, which would put the demand load just over the limit, but in real life the home owner said in the few power outages they have had, it never dropped any of the loads, so most times the actual usage and the calculated demand will be much different, most homes around here are all gas so very little demand, and for the most part the demand is between 45-65 amps, so even a 15kw will work, but once in a while I get homes with 2 or 3 freezers and or electric heat or both so each has to be correctly calculated. oh and that load shedding panel, look out its about 6' tall:roll:
 
You have several options. Install a sub panel for needed loads. If it is Generac you can get the 16 circ. ATS or install a manual transfer switch and let the HO decide what they want to run.
 
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