What do I have here?

[22lover]

My house was built in 1973. The original panel, along with the tag dated 1973, is still in the house. Somewhere along the line, the original owners put in a subpanel.

I can not see a "main breaker" in the original panel, so I don't know what kind of service I have. In addition, the breakers that are crudely labeled "subpanel" feed a subpanel that has appreciably more than 90 amps worth of breakers. In fact, it has more than the 125 amp "maximum" written on it. Both breaker boxes seem to be maxed out on breaker space.

Is it possible for me to determine what amp service I have to the house by myself or am I going to need to hire an electrician?

The genesis of this question is that I'd like to put 220V in the garage, as well as 3 or 4 additional 117V convenience outlets.


Main panel

Subpanel

Subpanel key

 

[Grumpy365]

Ok,

The total of the breakers is always more than the MAIN.

You aren't going to max all the load on all the circuits at the same time,even if you did, it would kick the main, that's why it's there.

What does your meter look like? The size service you have is determined by what is going into your meter. ( I have 400 am service, and it feeds 2 disconnects, each protecting a load center) looking at my load center tells you nothing about what size SERVICE I have to my lot.

 

[rockwithjason]

you have 125 amp service. the 125 refers to the max connected load not necessarily the total of the breakers. being that those are zinsco panels i would replace them both.

 

[22lover]

Got it...that scares the **** out of me now that I've looked up Zinsco. How do you know it's 125A service?

Is replacing a panel something I could do DIY? I'm pretty handy AND safe....have put in a ton of outlets/switches/fixtures, drawn wire, etc.

 

[Grumpy365]

Got it...that scares the **** out of me now that I've looked up Zinsco. How do you know it's 125A service?

Is replacing a panel something I could do DIY? I'm pretty handy AND safe.

It says 125 amp in the writing on the 3rd picture right top corner, right under the catalog number / model number

 

[RECox286]

Usually the Electrician and Power Company co-ordinate the diss and

re-connect for an panel change. You may want to enlist the aid of a

licensed electrician. Also, there may be considerations about where the

panel(s) may be located (code changes since your ancient Zinscos were

installed. Look at Cutler Hammer equipment. Their breakers are a bit

more pricey, but guaranteed for life. We have a fair amount of Zinsco

enclosures on the houses we take care of, and any time a house is

torn down, we are eager to salvage whatever breakers we can get

a hold of. They are still available, but cost an arm and two legs.

Uncle Bob

 

[22lover]

It says 125 amp in the writing on the 3rd picture right top corner, right under the catalog number / model number

I saw that but didn't know that meant the service was actually 125A. That is the subpanel. From what I've researched there's usually a main breaker within the main breaker box that can cast some light on the service amperage. In my case, in the first photo, there's not anything that I can identify as a main breaker. Just the 90 amp that feed the subpanel (that says 125A?) .

 

[mrb]

you dont have a main breaker. The size of your service is determined by the ampacity of your service entrance conductors, or the rating of the panel, whichever is less.

 

[22lover]

mrb - thanks. How do I determine the ampacity of my service entry conductors? I guess if I need to replace these Zinscos eventually it would make sense to get higher-rated panels.

 

[mrb]

is it overhead or underground?

 

[22lover]

It's underground... whole neighborhood is.

 

[JakeKohl]

My 1950's era house had a breaker panel added to replace an old glass fuse panel. The replacement (probably done in the 70's) didn't have a main disconnect either. I had that panel replaced with a new panel before I tied in my new garage service. I was told that you aren't required to have a specific disconnect if there are less than 6 mechanical throws in the panel (but who doesn't want to have a main disconnect to de-energize the box?). The only other way to remove power is to pull the meter....which you will have to do in order to do in order to replace that box. That should (technically) mean the involvement of the power company to remove and reinstall the meter...and that may require you to have a licensed electrician to at least sign off on the work.

 

[22lover]

Got it, and thanks. I'm going to have a look-see behind the covers tonight to see if I may have lucked out on these relics with copper bus bars vs. aluminum. That would at least make me sleep a bit easier until I figure out what I'm going to do.

 

[rlitman]

My main breaker isn't in what most would consider my main panel. Instead, it is in a panel next to my meters. Have you looked there?

 

[ishiboo]

Got it...that scares the **** out of me now that I've looked up Zinsco. How do you know it's 125A service?

Is replacing a panel something I could do DIY? I'm pretty handy AND safe....have put in a ton of outlets/switches/fixtures, drawn wire, etc.

Realize that while in the scheme of things they are far more dangerous than modern panels, there's also a much higher chance that you'll be killed in your car on your way to work tomorrow than by a Zinsco panel. Replace when appropriate.

 

[Norcal]

Zinsco is one of the 2 most reviled names in electrical equipment, Federal Pacific being the other, Zinsco / Sylvania breakers are super expensive & are Chinese knockoffs, that alone is a reason to consider replacement, GTE bought Zinsco Electrical Products in 1973 later rebranding them as GTE Sylvania.