Electric Service Amps

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.)

Reply to
Steve Kraus
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Per leg. . . .

If the panel is rated at 125A, then the bus-bars ought to also be rated at 125A.

You may not even need a new drop and service feeder, depending on what size they are. An electrician could look at it and tell you which bits need to be replaced, it MIGHT be as simple as just swapping the main breaker out for a bigger one.

OTOH, replacing everything from the service drop through the individual breakers isn't really all *THAT* major, in the grand scheme of things. I had my service panel replaced because it was rusting out, and upgraded my service to 200A at the same time, all for about $1200. Since you are clearly in a municipality where the socialists are in control, you can probably expect to pay about double that.

Reply to
Goedjn

My opinion only:

contact your town electric inspector (or utility company) and ask them.

Your existing box will work with no changes on a much higher capacity feed. You will not be able to exceed the draw on the main supply breaker.

It is probably worth replacing with a new panel to allow for the amount of circuits a modern house seems to require.

Reply to
marks542004

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

Reply to
RBM

100A 240V (that's 100A for EACH 120V leg) would make sense.

Reply to
Mark Lloyd

Something to consider:

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You can google up a hell of a lot of stuff about Federal Pacific Stab-Lok breaker boxes. I'm no expert on this, but I recall stumbling across this when house-hunting. Our home inspector stated that in some places, electricians are required by law to replace these on discovery.

Summary: Many FP breaker boxes like this can be a potential fire hazard.

YMMV, it could all be paranoid hype.

HTH.

Reply to
phaeton

Regardless of what your town wants you to do, you may want to replace the panel anyway. Google for "Federal Pacific Stab-lok", and you will see all sorts of things talking about those panels starting fires, class action lawsuits, etc.

Ken

Reply to
Ken

Regarding Federal Pacific panels and breakers: I've never met anyone in the electrical industry that had anything positive to say about FPE, I've read plenty of negatives, lawsuits and investigations. I'm sure there isn't a circuit breaker manufacturer out there that hasn't been sued and my guess would be that FPE was probably sued more than most. The company is long out of business, however "stab-lok" circuit breakers with U.L. certification are still being manufactured by the American Circuit Breaker co. and made exclusively to fit in those panels.

Reply to
RBM

I wouldn't necessarily assume this. In older towns and cities, there were many, many smaller homes wired for 60 Amp service, because, it was thought, that was all that would be needed. This was for homes built in the days before automatic dishwashers, air-conditioners, computers, media centers, and electric dryers. Over the years, it likely that many of these installations got upgraded to 100A or greater service, but not necessarily all of them.

If you are talking about one of these ancient installations, it is likely that your service conductors would need to be upgraded, replaced, etc. along with the service panel (which was probably fuses).

In the USA, it was recognized during the 1950's that 100A service was the typical minimum for a stand alone dwelling and this was later upgraded to 200A service for the modern "all electric home".

Beachcomber

Reply to
Beachcomber

I'm speculating this because he's already got 80 amps worth of main breakers and he's got a 125 amp panel, but his SE conductors need to be looked at by someone that can determine this for sure

Reply to
RBM

This would also be the first case where I heard of a town requiring this to be done just because of a sale of the property. While it's likely a good idea to have a decent size service, if it were me, I'd be raising hell with your municipal officials. Next they will want you to bring everything up to current code just because you are selling the place.

Reply to
trader4

If a new drop is required do utilities charge for this or is it one of those gratis things they do in hopes that you'll buy more power?

If the panel ought to be replaced is that a nightmare of replacing each conduit from the panel to its first junction box or do they just try to do some bending to align with the new box's knockouts? Pull the wires back temporarily and shove them back on into the new box? I guess every pipe could be cut short and a bit of flex put in or a conduit joiner to a new short piece with the required bends. Just wondering if there is a standard way they do these things or if each case is so different there is no telling. Even if one had a new panel the exact size of the old with a close match on knockout availabilities it would still seem like a big job to get it in and pipes into conduit connectors but maybe there are special ones to ease this. Seems like this would come up quite a bit.

Reply to
Steve Kraus

You are responsible for the masthead, downwire, meter base, and main breaker, the wires to the pole, and the stuff on the pole is the companies. This is of course for an overhead connection.

Typically this is done by a licensed electrician, since the next fuse is on the pole, and a thousand amps or so makes a real deadly mess of a short. That and the electric co has fewer problems with lic electrician tampering with the meter, than DIY.

That is why they (you) pay electricians the big bucks. Yes, it is different in each case.

It cost me $4K (Chicago suburbs, all conduit) to have the job done. They took out a fuse box, and sub panel, and replaced it all with a single box in a different location. A good days work for a 3 man crew, and they took care of pulling the license and the rest.

All that exists of the old fuse box is a single outlet box, where all the bx runs that couldn't be moved were run to, and covered with a cover plate.

Reply to
John Hines

Your utility drop and meter and service conductors are probably just fine. (Depends mostly on the wire size.) But you really ought to get rid of that FPE breaker box. They are dangerous. You can probably buy a new GE or SquareD or Siemens 125A panel and an assortment of breakers cheaper than you can get a replacement 50A Stab-Lok breaker and a few others that will fall apart (literally) when you take the cover off the box. If you have any good used FPE breakers when you are done, you can sell them on eBay for pretty good money.

Bob

Reply to
zxcvbob

If I remember correctly, the FHA won't loan money on anything with less than 100 amp service. And that was from 10 yrs ago.

Reply to
John Hines

Andy comments:

I have a cabin in an unincorporated area of north Texas where building inspections are not required. I replaced my service entrance myself, upping my 60 setup to a 200 amp setup. The main breaker panel cost me about $125 from Home Depot, and the meter base, pipe, gnd rod and wire added another 50 bucks or so. The local electric company provided a diagram of what was required before they would hook up to it..........Each electric company is a little different, but each that I have worked with was very helpful.....

I did the work in a weekend, and the guy from the electric company showed up in a few days, called me at my office on the phone to verify it was the correct address, and hooked up the power at the top of the weatherhead, using the same meter as before.......

So, in some places you can do the work yourself and if it meets the requirements of the local electric company, you are done. It ain't rocket surgery, but they will not hook it up if it doesn't meet all their safety requirements...

Now I am a registered professi " There's a customer borne every minute"

( Hay un pendejo borne todos los minudos )

Andy

Reply to
Andy

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