Originally Posted By: mmason This post was automatically imported from our archived forum.
Hello All,
I have heard from a variety of sources that Zinsco residential circuit breakers are prone to overheat and can lead to a possible fire. Are they prone to defects or is this just a false rumor? 
-- Michael J. Mason
Mason Home Inspection
California Capitol NACHI Chapter President
Originally Posted By: Brian A. Goodman This post was automatically imported from our archived forum.
Michael,
Zinzco is one of the problem brands you should always be on the alert for, but I haven’t heard it as an overheating problem specifically. They have some design problems and cannot be trusted to trip on overload, though I’ve seen them last for decades sometimes. I’ll try to find a good link for you.
Originally Posted By: mmason This post was automatically imported from our archived forum.
Brian,
Thank you I would appreciate it. My father built our house in 1960 and used them. we did not have any problems with them other than they are very expensive now to buy if you need another one. The reason I am asking this question is that report host has a "canned" response that Zinsco breakers can fail and overheat so the people at Report Host also say to put a smoke alarm above a panel with Zinsco breakers. A client called me on my report about the breakers so I am trying to find supporting documentation or else I am going to have to retract my statement on the report.
-- Michael J. Mason
Mason Home Inspection
California Capitol NACHI Chapter President
Originally Posted By: Brian A. Goodman This post was automatically imported from our archived forum.
Man, I can find stuff on FPE but Zinzco is tough. All I could come up with right off is a post by Mike O’Handley. Hopefully he won’t mind if I share it. If you don’t know Mike, he’s famous for looonnng posts among other things.
1. The Zinsco panels were never de-rated by UL and CPSC never issued any recalls on them for defects.
2. When Zinsco went out of business in the mid to late 70's, Sylvania bought up the name, stocks and tooling and continued to manufacture them under the name Sylvania-Zinsco for a couple of years and then branded them only Sylvania. A couple of years later Sylvania dropped the Zinsco name altogether and went under their own name. A year or so later the Zinsco-designed panel was discontinued and Sylvania came out with their own design(which is a real dog) that was eventually discontinued.
3. There is a TON of anecdotal evidence out there that says the Zinsco panels are problematic, but you won't find much, if anything in print, except for in HI circles, such as Dan Friedman's website and in Doug Hansen's book, Electrical Inspection of Existing Dwellings.(I could have probably answered your question with just this, but I'll forge on, just in case there is one HI out there who hasn't heard the rest of this before.)
4. If you pole the electricians in your area about how they feel about these, you are liable to learn that roughly half don't want anything to do with them, while the other half say that they are no more prone to defects than any other brand. Some of them will say things like, "Can't stand the damn things. Can't even remember how many I've opened and found the breakers melted and literally welded to the main." Others will tell you that they don't work on them because breakers are no longer available for them. True, new, old stock OEM breakers are getting pretty hard to find. However, Thomas & Betts recently bought the rights to the Zinsco name and the manufacturing rights. They are making UL rated breakers for them NOW. I've spoken personally with their engineers and have been told that they are not experiencing an inordinate amount of complaints, considering the age of most of these.(Remember, the manufacturers only warrant these for a year to begin with.)
5. Douglas and Dan have often and rightfully pointed out that the basic Zinsco design offers scant room for wire bending and doesn't lend itself well to adding additional circuits. Also, only the later ones have a single main disconnect and when you open the panels they are usually overstuffed like a Thanksgiving turkey.
6. Probably your best, non-refutable ammunition will the age of the panels themselves. Many older Zinsco panels are beyond the 40 year maximum acceptable service life that the electrical industry pretty much universally uses. Older than 40 - panel is obsolete. Most electricians don't seem to dispute that.
7. Lastly, before taking a cover off, feel the breakers to see if they are warm. If a breaker is warm, it will probably be caused by arcing between the breaker and the mains.
In my initial inquiry into this on a series of electricians' bulletin boards in 1996, I received an email(now lost) from a fellow that claimed he was the engineer who was "the" troubleshooter for Sylvania when they bought the Zinsco name. He said his task was to determine if the reputation these panels had for melting down was earned or simply a myth.
According to this gentleman, his research was extensive and it determined that the breakers were NOT at fault and were NOT causing the melt-downs. He related that the melt-downs were found to be caused by loose breaker-to-main contact in the panel. Over time, expansion/contraction/vibration would cause the loose breaker contacts to begin arcing slightly and generating heat. As time went on, the arcing would scorch the mains and increase resistance, eventually causing enough heat near the contacts to melt down the plastic breaker casing. Once this occurred, total meltdown would take place, and electricians, finding the breakers melted to the bars would automatically blame the breaker when it was probably a careless electrician who caused the malfunction in the first place.
This fellow maintained that during intial installation electricians had to ensure there was good contact. If not, they should have squeezed the contacts together slightly - just enough to ensure there was plenty of contact tension. Failure to that, he said, caused the arcing and subsequent failure.
As for our inspecting them? He said we should feel for heat before taking the deadfront cover off and then GENTLY nudge each breaker back, forth, up and down to determine if they are tight and LISTEN for the sounds of arcing at the bar. If nudging the breaker slightly results in a faint sputtering sound, or a feeling like there is a gritty substance at the contacts, he recommended immediately calling for an evaluation by an electrician. Like Douglas and Dan though, he didn't recommend keeping them beyond 40 years.
Does this work? Well, I see Zinsco, Zinsco-Sylvania panels pretty regularly and have been using that procedure since mid 1996. In every instance where I thought I detected a very faint sputtering sound, the breaker was loose or there seemed to be a gritty feel to movement, I would call for an electrician to evaluate and repair as necessary. In all of those instances(probably a couple of dozen)except for one, the electricians found arcing severe enough to condemn the panel.
Obviously "mains" in that post refers main bus bars. I have the book he referred to, but that's copywrited stuff and Douglas is a friend. It agrees that the primary problem is the breaker to bus connection and corrosion of the bus bars themselves. Maybe someone else has a hard link they can post. Bob? Mr. Tedesco?
Originally Posted By: jpeck This post was automatically imported from our archived forum.
Brian A. Goodman wrote:
They have some design problems and cannot be trusted to trip on overload, though I've seen them last for decades sometimes. [/color]
Correct on both accounts.
Design problems and they last forever (because they never trip  ).
The main problem is that they burn bus bars up, I've seen them completely burned through.
Usually, you will never see it, unless they had a problem, and solved it by moving the breaker to a new location, leaving the arc marks on the bus bar exposed. The overheating come from the arc marks and burned connection points, which creates high resistance at the connections, which leads to overheating, and sometimes causes the breakers to catch on fire (I've seen that too).
Many times, when replacing a Zinsco, your first understanding of the real problem is when you go to remove the breakers ... and can't. They are arc welded to the bus bars, or the burned up breaker contacts are just plain stuck on the burned up bus bar, with the burned and arced metal surfaces meshing together like teeth on gears.
If you see an FPE, recommend replacement.
If you see a Zinsco, recommend replacement.
You may have an electrical contractor say that you don't know what you are talking about and that "there is nothing wrong with this panel". In those cases all you have to do is explain to your client that you do not want them to die in a fire in their new home, and if the electrician doesn't care if they do, have the electrician put it in writing with a copy of their insurance, because their insurance will probably be receiving a call from the surviving family member. If you client goes with 'that's okay, just leave it', you are covered, don't have the surviving family member call me.
Like at Hurricane Charley and Hurricane Frances when the police were evacuating people: "We cannot FORCE you to leave, but if you don't ... we want the names and numbers for your NEXT OF KIN."
Originally Posted By: rbracklow This post was automatically imported from our archived forum.
Hot Damn Jerry,
We finally see eye to eye on something - miracles never cease.  
All joking aside, you are absolutely correct! I have seen to many of the Zinsco Panels in the Southern California area cooked. Very bad materials, and poor workmanship.
There was an inspector Jerry Feldman, I believe he was a State Inspector that could tell you horror stories about Zinsco Panels.
Many of us PE's would not spec out Zinsco Panels after too many fires in the first year of operation and created too much of a liability for us, as well as aluminum wiring. The two of them together made for serious issues!!
The reason that they went out of business were too many legal issues.
Take care,
Ron.
-- The highest compliment my clients can give me, is the referral of their Friends, Family and Business Associates!
