Zinsco Sylvania GTE identifying Label (C) J Simmons D Friedman How to Identify GTE Sylvania (Zinsco) Electrical Panels & Circuit Breakers
     

  • IDENTIFY GTE SYLVANIA-ZINSCO PANELS - CONTENTS: How to Identify Zinsco-Sylvania & GTE-Sylvania-Zinsco Electrical Panels and Circuit Breakers. GTE-Sylvania-Zinsco Electrical Panels that used Zinsco circuit breakers and bus design & may involve similar electrical panel failures and safety concerns as Zinsco
  • POST a QUESTION or READ FAQs about how to identify GTE-Sylvania-Zinsco electrical panels and circuit breakers.
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GTE Sylvania Zinsco breaker & panel identification: here we provide text, labels, and equipment photographs used to help identify Zinsco and GTE-Sylvania-Zinsco electrical panels and circuit breakers, and we include photographs of a Zinsco look alike marketed by Kearney.

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How to Identify GTE-Sylvania-Zinsco Electrical Panels and Circuit Breakers

GTE Sylvania Zinsco breaker (C) J Weissman D FriedmanThis website discusses the electrical, fire, and shock hazards associated with Zinsco electrical components, circuit breakers, electrical panels, including certain Sylvania electrical panels and breakers which are in fact of the same product design and origin.

[Click to enlarge any image]

Note: photo shown at left of a recent GTE Sylvania Zinsco circuit breaker burn up was provided courtesy of Jeff Weissman who reports its occurrence in a GTE-Sylvania electrical panel.

This circuit breaker may have been installed in a GTE-Sylvania electrical panel that did not use the Zinsco-design circuit breakers and/or may be of a different brand or manufacture.

 

Below is a close-up of the bus connection end of a classic Zinsco circuit breaker - showing the difference between these devices.

Zinsco electrical panels were distributed in the United States, primarily in the Western states.

Zinsco circuit breaker close-up showing bus connection (C) Daniel Friedman

Photo (at left) of a recent GTE Sylvania Zinsco circuit breaker burn up courtesy of Jeff Weissman.

Some Sylvania brand electrical panels are essentially a "Zinsco in Sylvania's clothing".

The panel labels may identify it as "Sylvania", Sylvania-Zinsco, or GTE-Sylvania-Zinsco.

But the circuit breaker colors and other external details permit the inspector to identify the problem Zinsco-design electrical panel bus and circuit breaker materials.

 

Photographs of Zinsco Sylvania and GTE Sylvania Zinsco electrical panel labels courtesy of J. P. Simmons.

GTE Sylvania Zinsco (C) JP Simmons D FriedmanAn expert who opens the electrical panel or performs further disassembly (DANGER) can further identify the characteristic circuit breaker details but the circuit breaker toggle switch colors and unique labels should be sufficient for most inspectors and owners to identify this equipment.

 

IDENTIFY SYLVANIA-ZINSCO - How to Identify Zinsco-like Sylvania Electrical Panels and Circuit Breakers by Electrical Panel Labeling

Zinsco Sylvania GTE identifying Label (C) J Simmons D Friedman Zinsco Sylvania GTE identifying Label (C) J Simmons D Friedman
GTE Sylvania Zinsco (C) JP Simmons D Friedman

Some Sylvania brand electrical panels are essentially a "Zinsco in Sylvania's clothing".

The panel labels may identify it as "Sylvania", Sylvania-Zinsco, or GTE-Sylvania-Zinsco, but the circuit breaker colors and other external details permit the inspector to identify the problem Zinsco-design electrical panel bus and circuit breaker materials.

Photographs of Zinsco Sylvania and GTE Sylvania Zinsco electrical panel labels courtesy of J. P. Simmons.

An expert who opens the electrical panel or performs further disassembly (DANGER) can further identify the characteristic circuit breaker details but the circuit breaker toggle switch colors and unique labels should be sufficient for most inspectors and owners to identify this equipment.

Readers should also
see IDENTIFY ZINSCO SYLVANIA METER BASE and

see GTE-SYLVANIA-ZINSCO FAILURE MECHANISM,

as well as ZINSCO FAILURE REPORTS.

Contact Us with field reports and photos. We are pleased to credit and link-to contributors.

How to Identify Sylvania™ Brand Electrical Panels that are Zinsco™ Design

Reader Question: are these Zinsco Electrical Panels & Breakers? I was told I had to remove them.

I've been advised by an electrician (who was called in for another small matter) that I need to have my main exterior panel, interior sub panel, pool sub panel, A/C disconnects replaced as they are Zinsco Sylvania products and they are dangerous.

Sylvania Zinsco Electrical Panel (C) InspectApedia PG Sylvania Zinsco Electrical Panel (C) InspectApedia PG

I have searched the web and cannot find any of the identifying marks of a Zinsco panel on the panel I have.

It does day Sylvania and has what I assume is the model number: 390-205-09 on a label which has the bottom left corner torn off. Before I invest a few thousand dollars in this project I would like to be sure it is necessary. Can you assist with that?

I went to those sites and still cannot determine if mine is a Zinsco. I am sending you a picture, can you tell if it needs to be replaced? Thank you so much for your help.

Reply:

Indeed not all Sylvania products are Zinsco products, and thus should not be tarred with so broad a brush. Zinsco circuit breakers and the buss connections they use are easily identified regardless of the loss or absence of panel labels. But in your case we can see the familiar label in your photographs.

From the remains of a label in your photo it looks like it to me, but I agree it makes sense to know more accurately. To know with confidence what the breakers are in the panel an electrician will remove the cover, pull a breaker and compare it with the breaker designs illustrated as characteristic of Zinsco.

Or if your electrician doesn't know how to look at the Zinsco breakers we've illustrated, have her take some sharp photos of all sides of the breaker and email them to me.

Reader follow-up:

My electrician told me they were Zinsco and had to be replaced. I wanted corroboration so I could be sure I wasn't buying something that I really didn't need. - P.G.

Reply:

"Had to" is a technical opinion with which I agree. It is not a law. Your electrician agrees that the circuit breakers are a latent hazard - risking failing to protect your home from a fire or injury should an over-current hazard occur, so he or she recommended replacement. I agree with that advice, but I acknowledge that the data base of tested Zinsco equipment confirming the failures is smaller than that of the FPE Stab-Lok hazard discussed elsewhere at InspectApedia.

Reader Question: is this Sylvania™ Electrical Panel a Zinsco Product?

I have an MLB20 (15-30)C indoor mod 2 breaker box, is this prone to problems?
I [will] send pictures ...

Sylvania electrical panel identification sticker = Zinsco Design (C) InspectApedia LC Sylvania electrical panel identification sticker = Zinsco Design (C) InspectApedia LC Sylvania electrical panel identification sticker = Zinsco Design (C) InspectApedia LC

Reply:

I'd indeed like to see photos of the breaker panel you cite, in total, its labels, its bus bar design and its breaker details and labels. But WATCH OUT opening an electrical panel, if you touch what you shouldn't means dead Larry (or Dead Daniel if I do it).

If the panel you describe is of the classic Zinsco design described in these pages there is risk of breaker-bus arcing and the other hazards described for Zinsco. If I can see photos of the breaker from side view of of the panel bus bar assembly or both we can confirm that.

Follow-up:

Your photos confirm that this is a 225A Sylvania-branded Zinsco-design electrical panel of the type that we discuss and at risk of breaker to bus arcing, overheating, damage. It would be prudent to replace it.

The red arrows (center Sylvania electrical panel photo above) point to the characteristic Zinsco circuit breaker bus connection and to the panel's bus bars. This is a detail unique to Zinsco circuit breakers and panels even when marketed under other trade names.

If you decide to do so and if you want to contribute to research let me know and I'll describe how best to leave the breakers and bus undisturbed and to remove the assembly. I can ask Dr Aronstein if he can test this Sylvania - Zinsco electrical panel before we disturb conditions by actually pulling breakers.

Relationship among CEB, Commander, GTE, Sylvania Electrical Panel Brands

The following remarks from a licensed electrician were provided to us courtesy of Al Carson, Carson Dunlop Associates, a Toronto home inspection and home inspection education firm.

No-Trip Complaints involving Sylvania, GTE-Sylvania, Older Commander & CEB Electrical Panels

Pending research citations the following quote is opinion:

The Sylvania, GTE Sylvania, older Commander and CEB are really the same panel and it is was a very popular panel in the 70’s and 80’s. They have a reputation as the breaker which doesn’t trip. I have personally experienced it over 20 times for overcurrent situations and about 5 times in fault current situations. It is also the panel which had several 100 ampere main breaker fails which led to fires. As a consequence of this, in Ontario we had to mount drywall behind panels for years. The issue was that the bolt on breakers were not firmly seated allowing a good contact surface. This was because the threads on the bus bar were poorly manufactured and the electricians installing them would tighten it down, but not realize that the bolt was carrying the main current due to the gap. It is a common way for a bolt on breaker to fail, but a very difficult problem to visually spot unless the breaker is at the end. Infra-red scanning on a loaded breaker would be the best way to spot it. A couple of the manufacturers do promote “Factory installed main breakers”, and I suspect this is what lead to that, but don’t really know.

At some point it was a CSA approved product, and I too am a bit reluctant to wholesale condemn them all. I am always very careful what I say as many people quickly jump to conclusions that I am “upselling” or “Fear marketing”. But I would rather live in a house full of knob and tube than one of these panels. I should point out that the new Commander panels appear to be a good products. I should also point out that the 200 ampere mains are mounted differently and as far as I am aware had no problems like this. Maybe I have to work on my messaging for this, but it seems to me that this is one area where a Home Inspector’s opinion is more likely to be simply accepted as they have nothing to gain.

I have never heard of Kearney
[see IDENTIFY KEARNEY PANELS]
and was not aware that Zinsco made combination residential panels
[see ZINSCO SYLVANIA ELECTRICAL PANELS]. Although sometimes brand names change at the border. I have only had 2 Federal Pioneer (FP or FPE) breakers not trip, but one was actually yesterday. One of my staff accidentally cut the wrong wire. Lots of sparks and a hole the size of your pinky in his pliers and neither the branch nor the main opened under a few second long fault. We are changing the panel Monday. It appears to be less than 10 years old, but with some older breakers in it….still the main should have tripped. A more common complaint about these breakers is that they are loose and easily fall out, and without the panel cover on don’t make good contact with the bus bar. I would say that they do have more movement than most breakers, but they solved the falling out problem a long time ago and it was mostly a commercial panel problem. They have stopped making Federal Panels anyway.

I’m not sure what the best policy is here, but this much is true:

  • Breaker technology is constantly improving and new is better than old

  • Electricians are reluctant to “approve” installations by others or any old products. Most would encourage home owners to change the panel.
  • To unseat every breaker and check it and redo every other connection would likely cost about $300 - $400 less than a new panel installation which would come with a warranty.
  • When a female thread is poorly manufactured it is almost always due to excessive wear on the threading tool during manufacture. Almost always a tap can quickly be run through this hole and the problem solved. But when the female thread is located on a bus bar with insufficient space to run a tapered tap tool through it is tough to fix and in some panels rivets are used to mount the bus bar. I had a full panel years ago, and had this problem on the very last breaker. I ended up deliberately breaking the tap tool as a desperate measure at the end of a long day. Since then I have tried to always use push on breakers unless it is an industrial or vibratory environment.

I should simply say yes change these panels, but I know for sure someone will challenge that and it would be better to have reasons. I’m copying other Langstaff & Sloan Inc. staff in case they have any additional thoughts.

- Anonymous (pending author wish to be identified) to A.C. to D.F. 20 March 2015

Watch out: removing and replacing circuit breakers or "exercising" them by turning them on and off can in some cases actually increase the risk of a future failure because of scoring of a plated panel bus bar or because some breaker brands such as FPE show an increased failure to trip after being switched on and off. Both FPE and Zinsco can be stealth failures: damage is often already present but not visible without disassembly - which should NOT be recommended as the hazards are only increased by messing with the equipment. - Editor

Editorial Opinion on the above

There is among electricians an endemic problem common to everyone working in contracting: an unfamiliarity with solid technical research sometimes leads folks to assert that nothing was wrong with product X except that it was the nature of the times in which it was made or installed.

Sometimes that's true. But other times not. Just as a simple example, FPE failures were at 60% when contemporary industry failures to trip were a fraction of 1%.

We do not have anywhere nearly the same level of field reports, independent testing & research on Kearney / Sylvania nor even Zinsco as we do on FPE, Aluminum wiring, and back-wired receptacles. Some of these such as FPE involved outright fraud by people who knew perfectly well that the product did not perform properly.

We have published articles on these other panels in part to solicit field reports & research information. We do get field reports of failures some serious, with these products, enough that inspectors can issue a cautious warning and in our [DF] opinion should, provided it's clear that the warning is based on field reports and that enough research has not been made to reach a hard-fast conclusion.

See GTE-SYLVANIA-ZINSCO FAILURE MECHANISM

But watch out: there are surely plenty of other GTE panels that are a completely different design and don't have the GTE-Sylvania panel issues.

Also it was interesting ... that a New York Electrrical Engineer performing independent tests on samples of used circuit breakers of a variety of brands found in very preliminary testing was that there were a few other contemporary panel/breaker products that appeared to have high (compared with overall industry) no-trip rates. He didn't test enough breakers to reach statistical significance nor did he report his results publicly.

But the preliminary work supports the observation that based on field reports and some preliminary testing as well as on the history (of no-recalls) it would be both naieve and risky to presume that if a product is in the market place it's safe.

Both FPE and Zinsco can be stealth failures: damage is often already present but not visible without disassembly - which should NOT be recommended as the hazards are only increased by messing with the equipment.

and I am watching carefully Challenger as well as the others you name.

And I would give strong consideration to replacing any panel that had

  1. Aluminum bus bars
  2. Plated aluminum bus bars that get gouged-through when a breaker is inserted (mounting a breaker cuts through the plating and we see corrosion, overheats, failures)
  3. Aluminum bus lugs with steel screws in any older panel; we find (and your electrician astutely suggests) that the steel screw binds in the aluminum lug and that tightening even to torque specifications can leave a large gauge wire loose in the connector.
    I [DF] have personally investigated a few such cases that led to serious hazards.
    LOST NEUTRAL Shocks Homeowner

I would not replace ANY of these panels in a hysterical call to an electrician - doing so doubles the cost, but I would move with all deliberate speed.

For people who are too poor to make their homes safer by replacing questionable electrical equipment we suggest some initial or temporary hazard reduction measures:

  1. working properly-located smoke detectors
  2. mobile home doors that open properly - all buildings need safe functional fire exit passages
  3. turning off any strange-behaving circuits (flickering lights) with the caveat than in an FP/FPE case "turning off" may actually leave the circuit on as the breaker may not switch off internally)

 

 

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IDENTIFY GTE SYLVANIA-ZINSCO PANELS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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