Why is my main breaker only 70A?

[Slickdonkey]

Hi everyone,

I have an older house built in 1975, but the previous owners did some remodeling and electrical rewiring.

I'm wondering why my GE panel only has a 70A main breaker. I'm not sure whether I have 100A or 200A service (how can I tell?).

I've attached a picture -- the main breaker is on the right, second one down.

Thanks!

[WD8CDH]

That is a split buss main panel. The top 4 double breakers are the equivilent of the main breaker on more modern panels. The main breaker on that panel just doesn't cut off the other three double breakers on the top. By adding up the top 4 breakers, it looks like you have a 200 amp service.

I don't think split buss panels are legal on new installations any more.

Ron

[Slickdonkey]

Interesting.

Is it possible to pull out some of those top breakers and replace them with the new skinnier breakers in order to free up a few slots?

[HayZee518]

Those top stabs will only take a full size two pole breaker. The skinny ones are configured differently on how they fit onto the bus stab. Besides I don't know if you'll find a 15/30 or 20/30 mini breaker.

[WD8CDH]

They probably won't fit but even if they did, that is an illegal application of that type of panel.

You could feed a sub panel from one of those upper breakers and put the new loads on that sub panel.

Ron

[Slickdonkey]

They probably won't fit but even if they did, that is an illegal application of that type of panel.

You could feed a sub panel from one of those upper breakers and put the new loads on that sub panel.

Ron

Yeah, that's what this is coming down to, I think.

Another option is to replace the whole panel since it's so old. I'm not sure this would buy me very many extra slots though. As you can see, the panel is pretty full already.

The main reason to do this would be so that I can power all circuits in my house from my generator (currently there is a transfer switch with only 6 of the circuits hooked up). I know there are some panels that can be wired to do this without the use of a transfer switch on each circuit.

If this was your panel, what would you do? Does anyone care to make a ballpark guess as to what it might cost to have an electrician redo the entire panel for me this way?

Thanks so much for all your help everyone! I appreciate it.

[WD8CDH]

Do you want to run everything on the generator or just 120V loads?

Do you have room for a sub panel?

How tall of a panel do you have room for if you replace the old panel?


Yes, you can get a combo panel and transfer switch but over 100 amps is VERY expensive so if you can keep the loads that you want to run from the generator below that, the cost isn't too bad.

Ron

[Slickdonkey]

Do you want to run everything on the generator or just 120V loads?

I would settle for 120V loads, not a problem.

Do you have room for a sub panel?

Yes, shouldn't be a problem.

How tall of a panel do you have room for if you replace the old panel?

It could be almost as tall as I want. This is in an unfinished garage so there's plenty of room.

Yes, you can get a combo panel and transfer switch but over 100 amps is VERY expensive so if you can keep the loads that you want to run from the generator below that, the cost isn't too bad.

Considering the generator only support 30A, I don't need to go over 100. I don't plan to run everything in the house at once, it would just be nice to have more than 6 circuits available without having to run extension cords for the things I want to run during an outage.

Also it would be nice to have a Watt meter for when the generator is running. My transfer switch has one of these and it's quite helpful to know how close I am to reaching the 5500W rating of the generator.

Thanks Ron!

[HayZee518]

If you have an ammeter on your generator and a voltmeter then just multiply the two readings to get your watts - load. P=EI P = Watts.