It doesn't necessarily refer to the size and quantity of "main" breakers in
the panel, but to the size of the service entrance conductors. In all
likelihood you do have a 100 amp service, despite the main breakers only
totaling 80 amps. If the conductor size is #2 aluminum or #4 copper, you've
got a 100 amp service, regardless of the fact that your only tapping 80 amps
of it. Most modern residential panels will have only one main disconnect,
which makes determining the service ampacity easy, however you can have up
to six



"Steve Kraus" wrote in message
. net...
When someone refers to 100A service that means per leg, right? Or is it
summed?

Here's the issue. It said in the local paper today that my town is upping
the code requirement to 100A service and existing homes must upgrade when
they change hands. Naturally the article didn't go into greater detail.

What we have is a setup with two main breakers (two pairs). One is a
double-50A that feeds the rest of the panel. The other is a double-30A
that feeds just the dryer outlet. I presume that is considered 80A
service, not 160A.

The panel itself is a "Stab-Lok" from Federal Pacific, circa 1957.

There's a pair of connector blocks in the top half and another pair in the
bottom half. Incoming power from the meter goes to the bottom two blocks.
Main #2 (2-30A) is plugged into the bottom right position and as described
goes to feed the dryer outlet. Main #1 (2-50A) is in the bottom left
position and the output consists of short jumpers going from the breaker
terminals to the upper connector blocks of the panel. Up there there are
places for 4 single pole breakers (2 to each side) off the top block and
off the bottom block. One leftover space on the bottom block. And then
there is space between for two pole breakers that will plug into both top
and bottom blocks. The left side double pole space has the 2-pole for the
A/C condensing unit. The right side previously held a 2-pole for a large
room A/C but I removed the wiring and breaker long ago.

The panel is rated 125A so that sounds like it ought to be good for 100A
service but does that mean each connector block is only good for 50A?

Can one just have the utility give us a new drop, replace the 2 ft of wire
from meter socket to panel and the internal jumper (assuming it's not
already correctly sized, pop in a 2-100A breaker and that's that? Or is a
whole new panel a necessity? I don't want to make a small job into a
major
one unnecessarily. (Moot for now as the house is not for sale but good to
know and maybe take care of in advance.)