InspectAPedia®

Zinsco Electrical Panel Hazards
Zinsco Circuit Breaker Information Website

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

This Zinsco electrical panel article 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.

We include advice on how to identify Zinsco, Sylvania Zinsco, and Kearney electrical panels and circuit breakers, and repair or replacement advice for those products.

In this article series we discuss: the hazards of Zinsco or Zinsco-Sylvania electric panels; Zinsco & Zinsco/Sylvania electrical panel identification guides & Kearney electrical panel identification guide. Independent testing of Zinsco breakers confirms failures. Zinsco failure reports, though few in number, indicate severe failures of Zinsco electrical panels / circuit breakers including failure of the circuit breaker to trip on overcurrent, arcing and burn-ups at the breaker to panel bus bar connection, and circuit breaker burn-ups.

Zinsco & Zinsco-Sylvania Panel Replacement Recommended, Zinsco Sylvania Panel Breaker-to-Bus Connection Arcing. How should Zinsco panels be repaired: electrical panel replacement alternatives, What are the typical costs to replace a Zinsco or Zinsco-Sylvania Electrical Panel?



Green links show where you are. © Copyright 2017 InspectApedia.com, All Rights Reserved.

Zinsco Electrical Panel Advice for Homeowners and Home Buyers

Zinsco breaker burnup (C) J P Simmons & D J FriedmanZinsco and Zinsco-Sylvania circuit breakers of the design described here do not offer the level of overcurrent and fire protection provided by most other electrical panels and circuit breakers.

Watch out: OPINION: we do not recommend installing "replacement" Zinsco circuit breakers as there some indications that the performance and safety of those devices may be poor.

Article Contents

Zinsco Electrical Panel & Breaker Test Results

Limited test results reported by Dr. Jess Aronstein (who is cited further at REFERENCES) indicate that the central Zinsco electrical panel and circuit breaker failure problem appears to be burn ups at the clip-to-bus connections such as shown in our photo of a burned Zinsco electrical panel bus and breaker. A circuit breaker whose bus connection burns can lead to overheating damage to the circuit breaker itself, rendering it non-functional.

For a summary of Zinsco and UBI-Zinsco-Replacement circuit breaker test results to date, see ZINSCO CIRCUIT BREAKER TEST REPORT - separate article.

Also see ZINSCO FAILURE REPORTS where we indicate that nearly 32% of the Zinsco circuit breakers tested to date failed to trip as required by the UL testing standard. A very small sample of UBI-brand replacement circuit breakers for Zinsco panels also failed to trip.

Photo at page top of a burned and failed Zinsco main circuit breaker, courtesy of J. P. Simmons - Mr. Electric. Simmons adds: "In this case the failure damaged the main wire to a mobile home also (you can see the melted wire to the left of the main). This is a good example of why I do not like to see anyone remove these breakers. You can not tell how bad they are damaged by looking at them.

Notice: request for Zinsco circuit breakers for independent testing

Dr. Aronstein has agreed to perform independent overload and trip testing on Zinsco circuit breakers that may be contributed by electricians or homeowners.

In order to obtain a valid Zinsco circuit breaker set for testing, specifically wanted are circuit breakers from Zinsco electrical panels at which no field failure has previously been reported.

Such circuit breakers may be obtained from Zinsco electrical panels that are being replaced out of homeowner concern for potential hazards, obsolescence, or the need to install a new, higher capacity electrical panel - a "heavy-up" job. The circuit breakers should be left un-touched, that is, don't switch them off and on, just un-plug them from the electrical panel.

Contact: Dr. Jess Aronstein, "Dr. Jess Aronstein" <protune@aol.com>

Zinsco Panel Field Failure Reports

With the exception of the more seriously failing FPE Stab-Lok electrical panels, we have not received any significant number of field failure reports concerning other electrical panel brands that also use aluminum parts and that are or were priced in the same range as Zinsco.

This means homes with this equipment may be at greater risk of fire or other electrical hazard.

Zinsco & Zinsco-Sylvania Panel Replacement Recommended?

Zinsco no-trip (C) InspectApedia

Where Zinsco electrical panels and Zinsco circuit breakers are in use, arcing, contact-point burn, and even circuit breaker case blow-out have been observed in the field.

We do not have statistically solid data that supports an unequivocal argument to replace Zinsco electrical panels.

However, based on field reports to-date and preliminary tests, where Zinsco and Zinsco-Sylvania electrical panels are discovered in buildings a homeowner should consider replacing the panel to reduce fire and shock hazards and owners should be careful to avoid overloading their electrical circuits where this equipment is installed.

Building owners or electricians encountering problems with this equipment are asked to contact us to add that information to our electrical failure data base in an effort to develop accurate safety information which is then shared with appropriate federal and state agencies. Thanks to Mr. James Simmons, a licensed electrician with extensive field experience and the contributor of most of the photos and case reports at this web page.

Our photo (above left) illustrates a burned-up electrical receptacle whose circuit was protected by a Zinsco circuit breaker that failed to trip and in fact had burned itself in the panel.

Zinsco Sylvania Panel Breaker-to-Bus Connection Arcing

A principal Zinsco™ circuit breaker (or Sylvania™ or GTE-Sylvania™ or Kearney™ electrical panel using this circuit breaker) point of failure appears to be at the point of contact where the circuit breaker contacts clip onto the electrical panel bus, combined with the use of an aluminum electrical panel bus.

As described at ZINSCO FAILURE REPORT PROCEDURE, expert testing on this equipment has shown that circuit breakers do not trip about 25% of the time when exposed to overcurrent - risking overheating, fire and other hazards. The failure rate of competitive-brand circuit breakers is much less than 1%.

In addition to advice on identifying Zinsco™ panels, inspecting Zinsco electrical panels, and repair/replacement advice, we provide field photographs of circuit breaker failures: overheating, burnups, failures to trip, overcurrent protection failure. This document includes field reports of failures and additional anecdotal evidence.

See ZINSCO FAILURE PHOTOGRAPHS and ZINSCO FAILURE REPORTS.

Zinsco Panel Repairs

Repair advice (replace the equipment) is provided at ZINSCO REPLACEMENT PANELS and

at REPAIR ELECTRICIANS we list electricians who have informed us that they have specific experience with this equipment. Lots of other licensed electricians are also qualified to replace electrical panels; it's best if your electrician is one who is familiar with this issue.

Replacement Zinsco circuit breakers and replacement copper-plated bus bars for Zinsco / Zinsco-Sylvania electrical panels are advertised. Without evidence of a design change in the product or support from independent expert testing, the effectiveness of these replacements is not clear.

As a not-for-profit activity, we have been collecting information and field failure reports for Zinsco/Sylvania electrical components since 1996 in an effort to develop credible failure-rate information which is then shared with the U.S. CPSC and with other electrical failure researchers and educators.

Zinsco History, Age, Dates & Patents for Zinsco Electrical Panels & GTE-Sylvania Zinsco Electrical Panels

Sturdivan Zinsco electrical panel patent schematic 1966[Citations needed, use the page bottom CONTACT link if you can provide additional data - Ed.]

Manufacturers or vendors of Zinsco-style circuit breakers include

Watch out: OPINION: we do not recommend installing "replacement" Zinsco circuit breakers as there some indications that the performance and safety of those devices may be poor.

Mike Holt has provided excerpts of a history of Zinsco Electric quoting the company founder's great-grandaughter Heather Hill (un-dated). - http://codeforum.mikeholt.com/

...


Continue reading at GTE-SYLVANIA-ZINSCO FAILURE MECHANISM or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see CIRCUIT BREAKER FAILURE RATES

Or see IDENTIFY GTE SYLVANIA-ZINSCO PANELS

Or see this

Zinsco Electrical Panel Article Series

Suggested citation for this web page

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

INDEX to RELATED ARTICLES: ARTICLE INDEX to ELECTRICAL INSPECTION & TESTING

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


...

Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman