Zinsco Electrical panel question

[carguy1nn]

In the panel foto below, there's a 70 amp breaker at the top right with no specific assigned circuit. It had been referred to as a disconnect, and had been blowing occasionally until the wires to it were "rerouted".
What might have been the purpose of this 70 amp breaker?

 

[Stuff]

Purpose of disconnect is to protect the overall panel and feed wires from being overloaded. What is between this panel and the meter?

Normal recommendation is to replace Zinsco panels as they have a reputation for breakers not tripping and instead starting fires.

 

[Sponsor]

 

[carguy1nn]

Purpose of disconnect is to protect the overall panel and feed wires from being overloaded. What is between this panel and the meter?

Normal recommendation is to replace Zinsco panels as they have a reputation for breakers not tripping and instead starting fires.

My understanding is that there is a main breaker above in the panel, which is fed with power from the meter; this 70 amp breaker was installed in some relation to the smaller breakers below

 

[hj]

What do you mean by the "wires were rerouted"? The purpose of the breaker is to protect whatever the wires were rerouted TO.

 

[Stuff]

Some panels are a split-bus where the 2 pole breakers are fed directly but smaller "lighting and appliance" breakers go through their own main breaker. Is there a panel diagram on the back of the door? Model number? Close up picture of the plate in the upper corner that is labeled main?

 

[carguy1nn]

What do you mean by the "wires were rerouted"? The purpose of the breaker is to protect whatever the wires were rerouted TO.

That's the language which the electrician had used in describing what he did-whatever it was, it solved the breakers blowing issue ( note this 70 amp breaker is now in the off position after this "rerouting")

 

[carguy1nn]

Some panels are a split-bus where the 2 pole breakers are fed directly but smaller "lighting and appliance" breakers go through their own main breaker. Is there a panel diagram on the back of the door? Model number? Close up picture of the plate in the upper corner that is labeled main?

That's the only foto available- all I know is that "rerouting" the wires solved the blowing breaker issue(note that this 70 amp breaker is now in the off position subsequent to this rerouting). Could some 20 amp breakers have been wired to this 70 amp breaker as some kind of extra overload measure?

 

[WorthFlorida]

It may have fed a sub panel and not the main breaker for this panel. The main breaker is probably at the meter. What is worrisome is you said it used to trip? But what tripped it? Do you know what size wire was connected to it?
Was the “reroute” performed by a licensed electrician? If it was you’re probably ok. You can google Zinsco and read horrid stories on this type panel. A good electrician would open the panel and checked for burns and corrosion. If any then get it replaced, not repaired.

 

[carguy1nn]

It may have fed a sub panel and not the main breaker for this panel. The main breaker is probably at the meter. What is worrisome is you said it used to trip? But what tripped it? Do you know what size wire was connected to it?
Was the “reroute” performed by a licensed electrician? If it was you’re probably ok. You can google Zinsco and read horrid stories on this type panel. A good electrician would open the panel and checked for burns and corrosion. If any then get it replaced, not repaired.

It tripped occasionally from normal electrical use in the house; could this breaker somehow have been directly wired to several 20 amp breakers as a failsafe or such? or was it likely just worn out and tripped for little to no reason. It was repaired by a licensed electrician, but what might the "reroute have been?

 

[carguy1nn]

Some panels are a split-bus where the 2 pole breakers are fed directly but smaller "lighting and appliance" breakers go through their own main breaker. Is there a panel diagram on the back of the door? Model number? Close up picture of the plate in the upper corner that is labeled main?

The riveted tag says "main service disconnect". Would perhaps just a few 20 amp breakers have been wired to this 70 amp main?

 

[Reach4]

Carguy1nn, if you are going to be living there for a while, new electrical service is worth considering, rather than investing effort and money in what is there now. Do you have a box outside near the meter or somewhere else? Stuff asked that in #2, but I thought I would ask you to re-search.

 

[carguy1nn]

Carguy1nn, if you are going to be living there for a while, new electrical service is worth considering, rather than investing effort and money in what is there now. Do you have a box outside near the meter or somewhere else? Stuff asked that in #2, but I thought I would ask you to re-search.

This search for possible answers relates to a house my friends owned when the issue came up; it has since been sold; I saw their fotos and was just sleuthing for what might have occurred, as they had no idea.

 

[WorthFlorida]

When these panels were manufactured aluminum wire was common. As far as a 70 amp breaker in a home it would only feed a sub panel, not anything in the same cabinet. All breakers plug into a buss bar. Even if it was split it makes no sense. Since you had a electrician do the work it all should be good. It’s his liability at stake to make it right.

 

[Stuff]

Found this discussion about that panel but with a slightly different breaker layout. Their configuration had the same spots for the riveted main tags but weren't used. http://www.inspectionnews.net/home_...-inspection/31329-zinsco-panel-split-bar.html

From the inside pics there is a left bus and a right bus. Your original configuration (using the rule of 6 throws) would have had 5 double pole "main" breakers on the left and one on the top right. Pictures show bigger lugs on the left designed to feed the panel. In your case the secondary feed through lugs that would have been used to power the 70 amp breaker protecting the right bus. So when it was tripping it was because the 20 amp breakers below overloaded it. Electrician bypassed it and ran wires directly from left bus to right bus lugs assuming external disconnect would protect panel.

I see there are mostly 20 amp breakers on the right side. This too is unusual as most houses back then had 15 amp circuits for everything. Even today most general purpose circuits are 15 amp. Wonder what the wire sizes are.

BTW - There are enough posts on electrician boards that show lots of them don't know what a spit-bus panel is. With that you can't assume it was fixed right.