Sylvania panel

[steelersman]

I went to a house to check out why some of the circuits worked sometimes and then other times didn't work unless the homeowner turned on her stove. At least that's what she told me.

So when I got there everything was working fine. I had her turn on all lights that didn't work sometimes and then I turned off all 2 pole breakers to see if the lights would go off. They didn't.

I proceeded to test voltages from all breakers including the main to ground and everything checked out.

Just a minute after that from the panel came a few crackling sounds and the lights turned off. I tested the voltages again and 1 pole on every 2 pole breaker was dead and a handful of other single pole breakers were dead.

So it turns out that there must be a loose connection from the main breaker to one of the busses, a sort od intermittent connection that disconnects and reconnects itself at various times. A few minutes after this it did reconnect itself and the lights came back on.

She did say that it happens mostly at night though. Also I've never seen this type of panel before. It's Sylvania 200 Amp 120/240 volt and all the breakers are on the left side of the panel. It's very strange but obviously an obsolete panel and also obviously one that was not very popular or common to install.

So I told her that the panel should be replaced and that's what I'm going to do. All wiring is modern style romex. It's very intact and none of the breakers felt warm at all to the touch. The house was built in 1981 so it's not that old.

I just don't understand why it would intermittently open and then other times close the bad connection. And I'm wondering if there's any truth to her saying that when she would turn on the stove the lights would work again, or if she just thought that because maybe she just happened to turn it on around the same time it came back on.

Anyone ever see these type of panels before? I will take pics of it tommorow and try to figure out how to post them.

 

[LarryFine]

I went to a house to check out why some of the circuits worked sometimes and then other times didn't work unless the homeowner turned on her stove. At least that's what she told me.

This one is easy: an intermittent line conductor or termination.

Just a minute after that from the panel came a few crackling sounds and the lights turned off. I tested the voltages again and 1 pole on every 2 pole breaker was dead and a handful of other single pole breakers were dead.

That's exactly what the symptoms of one open line are.

So it turns out that there must be a loose connection from the main breaker to one of the busses, a sort od intermittent connection that disconnects and reconnects itself at various times. A few minutes after this it did reconnect itself and the lights came back on.

The crackling is the arcing of the intermittent connection.

I just don't understand why it would intermittently open and then other times close the bad connection. And I'm wondering if there's any truth to her saying that when she would turn on the stove the lights would work again, or if she just thought that because maybe she just happened to turn it on around the same time it came back on.

That's what intermittent means: not continuous. Turning on the stove allowed the relatively-low resistance of the element to bridge the two lines.

This energizes the line-to-neutral loads on the side with the bad connection, but not the line-to-line loads. In fact, those loads help power the lights.

 

[steelersman]

sylvania panel

sylvania panel

Now I see that it's also referred to as Zinsco which I have heard of before but obviously never seen. Although it didn't say Zinsco anywhere inside the panel. At least I don't think it did. Also I now see that these panels are known to be dangerous : http://www.inspect-ny.com/electric/Zinsco.htm

 

[steelersman]

Turning on the stove allowed the relatively-low resistance of the element to bridge the two lines.

But when I was there they came back on without anyone touching anything except for me messing around in the panel.

 

[steelersman]

This energizes the line-to-neutral loads on the side with the bad connection, but not the line-to-line loads. In fact, those loads help power the lights.

After the stove bridging the 2 lines (re-energizing the other line) wouldn't it now be less than 120 that's re-energizing the dead line since it had to go through the resistive element of the stove. It'd be like a series circuit at that point thus reducing the voltage significantly I would think thus maybe making the lights burn very dim.

 

[LarryFine]

But when I was there they came back on without anyone touching anything except for me messing around in the panel.

What do you mean "except for...?" You were jostling the loose connection, and heard it as the crackling sound. It's most likely a problem you could pinpoint before deciding whether to just replace the whole thing.

If you agree thaty replacing the panel is best anyway, don't bother, but I believe in finding the problem. It's most likely either a line or load terminal on the main breaker, or where it attaches to the panel bus.

 

[LarryFine]

After the stove bridging the 2 lines (re-energizing the other line) wouldn't it now be less than 120 that's re-energizing the dead line since it had to go through the resistive element of the stove. It'd be like a series circuit at that point thus reducing the voltage significantly I would think thus maybe making the lights burn very dim.

That part you have correct, but remember, the voltage across each part of a series circuit depends on the relative resistances. The lights are dimmer, but maybe not by much.

Added: The main breaker itself could be bad, too.

You can find the problem by reading for voltage between points that should be at the same potential, such as conductor to line terminal, line terminal to load terminal, load terminal to bus, etc., but only during the problem occurring.

 

[frizbeedog]

And a crackling Zinsco has got to go.

:wink:

 

[steelersman]

What do you mean "except for...?" You were jostling the loose connection, and heard it as the crackling sound. It's most likely a problem you could pinpoint before deciding whether to just replace the whole thing.

If you agree thaty replacing the panel is best anyway, don't bother, but I believe in finding the problem. It's most likely either a line or load terminal on the main breaker, or where it attaches to the panel bus.

yes I first thought of replacing the main breaker but after deciding that it was probably hard to find and if found was probably going to cost alot of money I told her that she might as well pay for a new panel. Besides, if you read the link I provided above it sounds like these panels are just as bad if not worse than federal pacific.

 

[steelersman]

And a crackling Zinsco has got to go.

:wink:

yes you are right! And it will be gone tomorrow.

 

[Buck Parrish]

yes you are right! And it will be gone tomorrow.

I replaced one last week.
Some power companies use to supply these brands as meter base combos outside the house.
That crackling sometimes could be the bus bar deteriorating or corrosion.

 

[steelersman]

I replaced one last week.
Some power companies use to supply these brands as meter base combos outside the house.
That crackling sometimes could be the bus bar deteriorating or corrosion.

What's odd is that the buss bar looked spotless. Perfect. But smoke did rise out of the top of the main breaker during one of the crackling sessions! So it definitely has to go!! In fact now that I've discovered that link about Zinsco I'm going to call her and tell her to turn off all 2 pole breakers and not to use to much juice until I get there in the morning.

 

[steelersman]

yes you are right! And it will be gone tomorrow.

trying to upload some pics of the panel. I replaced it today and took some pics of the burnt buss right where the main breaker attatches.

 

[Cow]

Since we're on the subject of Zinsco panels, I figured I'd share a little too.

My latest found at a local motel....

You all guessed it......that runs the sign.

You can see how they wired the grounds together too, by twisting them into one big 3/0 bare!

 

[SEO]

Some pretty crafty guys. I haven't seen a timer installed that way. Take that red sticker out of the back of panel and install it on the cover.

 

[steelersman]

trying to upload some pics of the panel.

 

[steelersman]

trying to upload some pics of the panel.

Ok I'll use links:

 

[steelersman]

 

[steelersman]

 

[steelersman]