How can one tell the number of amps entering one's home at the main
service entrance? In doing a Google I've run across phrases like "100
amp service" and "200 amp service" and of a homeowner's 100 amp
service being "maxed out". Is there a standard number?
Look at the main circuit breaker (the big one) in your panel. It will
be stamped with a rating such as 100, 200, etc. This will usually,
but not always, give you the correct number. (Some older panels had
up to 6 multiple main breakers in which case you would have to add
Other places to look. It's usually included somewhere on the electric
meter and/or the manufactuers sticker that is pasted on inside cover
of the circuit breaker panel.
For houses built in the early twentieth century, 60 Amp service was
In the 1950's and 1960's there were more appliances and for a modest
size home, 100 Amp Service was the minimum.
These days, most modern houses will have 200 Amp service unless they
are mansions, in which case they might have an even higher service
This is Turtle.
The number that your speaking of is the ability of the house meter pan to accept
that amount of amps to the house circuits at one time. it does not mean anything
as to what the true amps are going into the house at any time but shows the max.
amp it will be let into the house at one time.
Now tell use what you really want to know by asking this question .
The best way to determine this is by the size of your service entrance
conductors. These are the underground or overhead wires that feed your
house, but not the conductors from the utility company, which are often
smaller. These are usually aluminum and standard sizes are: 4/0 = 200 amp,
2/0= 150 amp, #2= 100 amp. The main circuit breaker will determine this,
ONLY if there is a single main breaker
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