"bubblegummom" wrote in message
oups.com...
We're thinking of upgrading our 60 amp fuse box (presently overloaded)
to a circuit breaker panel. How do I know if we should get a 125 amp
or a 200 amp panel? According to Zillow.com our house is 1,240 square
feet, in case it's figured by square feet.

Thanks!

Loretta

Always check with your utility company when doing an upgrade. If you have
been getting by with a 60 ampere service you probably do not need more than
a 100 or 125 ampere upgrade.
Per Code Section 220.83(A) for upgrading an existing service for additional
loads where air conditioning and electric heat are not added the following
is used:
First 8 KVA of load at 100 per cent
Remainder of load at 40 per cent
Where load is 3 VA/ sq.ft or for you 3 x 1240 = 3720 VA
Small appliance load = 3000 VA
Household range (usually 8000 VA)
All other appliances pemanently connected (like a boiler motor or bathroom
fan) or fastened in place (dishwasher) at nameplate ratings.
(For good measure just add 3000 VA here.)

This gives 3720+3000+8000+3000 = 17720
First 8000 VA at 100 per cent + 0.40 x (17720-8000) = 11888 VA
11888 VA / 240 volts = 99 amperes
So using this calculation a 100 ampere service would suffice.

If you are adding or have air conditioning and electric heat or are planning
to add a two car garage and a shop, etc upgrade to a 200 ampere service.