Inspector needs load calculation

[Jhr]

I'm doing a job where 1673 sq feet of living area have been added to an exsisting home serviced by a 100 amp 1ph service, the electrical inspector needs a load calculation, the new addition has a jaccuzi tub, 30amp ac circuit two 220v general use recepts. all gas,new shop area for DIY, new master bath and bedroom, do I calculate the new area per the NEC standards and then add the 100amps, or what is the way to arive at the required load calculation This is the first time I have been asked for a load calculation from a inspector.

[ December 20, 2005, 08:09 PM: Message edited by: Jhr ]

 

[jimwalker]

Re: Inspector needs load calculation

He should ask for a load calc here.Simply figure in the old and new and print it for him.Sounds like a lot that your adding.

 

[bob]

Re: Inspector needs load calculation

Take the total sq footage and caculate per 220
adding all of the load, old and new. I think
there is a program at Mikes site that will do it for you.

[ December 20, 2005, 11:30 PM: Message edited by: bob ]

 

[gndrod]

Re: Inspector needs load calculation

Jhr, Could you elaborate a little more. Is the old service size being upgraded to...?, and what is the total livable sf after with remod? There may be an optional [220.82] method load calc depending on the additional configuration.[220.83]
rbj, Seattle

Delete kitchen add-on.

[ December 21, 2005, 03:27 AM: Message edited by: gndrod ]

 

[jwelectric]

Re: Inspector needs load calculation

220.83 Existing Dwelling Unit.
This section shall be permitted to be used to determine if the existing service or feeder is of sufficient capacity to serve additional loads. Where the dwelling unit is served by a 120/240-volt or 208Y/120-volt, 3-wire service, it shall be permissible to calculate the total load in accordance with 220.83(A) or (B).

This is not hard to do.

 

[haskindm]

Re: Inspector needs load calculation

You will need to do an article 220 load calculation for the entire dwelling (including the new addition) to determine if the existing 100-amp service is adequate. What are 220-v general use receptacles? What is the square footage of the original section? What is the actual load of the A/C unit? What is the load of the Jacuzzi Tub? Is there an existing A/C unit? Is the range electric or gas? Is there an electric clothes dryer or water heater? You need to gather a great deal of information to do this properly.
The question I have is how you bid the job before determining if a service upgrade would be needed?
The Inspector probably suspects that the original service will be inadequate for the added load. There is a good chance that he is right, unless the original strucure is very small and all appliances are gas.