Stablok panels

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Guest

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Re: Stablok panels

One breaker covered under your Etc. is Zinsco. I can't count the number of Zinsco failures I witnessed. One feature I liked about Zinsco was that each twin breaker picked up both legs of the bussing. It makes multi-wire circuits (Edison circuits) easier. In a sense the Zinsco had it right with the idiot proof way it's twin breaker attached to the buss. In say a Murray type breaker you would have to use a Quad to do a multi-wire circuit if you wanted to use wafer type breakers. And then there's the "offset" breakers with the "ears" that extend outside the breaker to grab the opposing buss.

The Zinsco appeared to be rugged, well engineered, and well made, but its performance contradicts that. It was all smoke and mirrors. The guts were defective.

My point is that some of these bogus and faulty breakers (FPE, Zinsco, Pushmatic, etc.) had some novel features that were worthy & useful. Too bad their technology wasn't picked up in the more "standard" residential circuit breakers.

../Wayne C.

breakers5thum.jpg


[ September 12, 2003, 05:00 PM: Message edited by: awwt ]
 

dcl34769

Senior Member
Location
saint cloud,fl
Re: Stablok panels

Awwt,
what part of the country are you in? I personally haven't seen too many Zinsco mass failures. I actually like their simple buss design and right side only terminations. Here in centralFL I see many outdoor FPE panels and every one of them is a nightmare. A type of breaker I don't like that hasn't been mentioned is the GE "thin" 2pole. The 20 and 30 amp ones don't seem to have many problems but the 40s and 50s used for A/Cs and such have a pretty high burn rate in the high heat and humidity. I try not to use them whenever possible. The extreamly small surface area of the buss clips scares me.
 
G

Guest

Guest
Re: Stablok panels

Originally posted by dcl34769:
Awwt,
what part of the country are you in? I personally haven't seen too many Zinsco mass failures.
San Francisco Bay Area, California. Don't quote me on this because my experience is dated, dusty, and rusty but I recall they were oil filled or something. They would burn internally or they would have excessive voltage drop across the breaker.

I actually like their simple buss design and right side only terminations.
Yes, they do a really clean looking install and it's easy to keep the neutrals and grounds on the left and the hots on the right. That is a good feature.

<snip> A type of breaker I don't like that hasn't been mentioned is the GE "thin" 2pole. <snip> The extreamly small surface area of the buss clips scares me.
Are those the ones with the little itty-bitty hooks coming out the sides that grab the buss? If so, the spring steel isn't very good. It seems more like pot metal. Once they loose their grip/spring they never grip right again. The hooks (ears) seem like junk. Are these the same ones? I call them offset breakers because when you fill up a panel you end up with 1/2 fillers on each side of the clutch of breakers. The buss clips are external to the breakers so on the right they stick out and on the left the clip is internal-- so they can straddle both busses.

Or, are GE's the ones that snap in like a Murray/Bryant/Westinghouse, etc., but have a thread of a buss clip?

../Wayne C.
 

noxx

Senior Member
Re: Stablok panels

The GE thins have a standard hook at the rear, and a small metal clip (vertical) at the buss. I think you're describing a "sidewinder" type breaker, which IIRC is a Murray product, and fortunately out of production. We consistently see burning on those due to poor connections at the buss.

GE Thin -

783164085686.jpg
 

noxx

Senior Member
Re: Stablok panels

San Francisco Bay Area, California. Don't quote me on this because my experience is dated, dusty, and rusty but I recall they were oil filled or something. They would burn internally or they would have excessive voltage drop across the breaker.
Close, what Zinsco's are full of is that nasty white grease (Lithium right?) that is intended to keep it's action smooth. Unfortunately, if the breaker isn't excerised, and they never are, that stuff dries up in big unwieldy chunks that play havoc with its' mechanical action. I'm out of CA as well, and like Wayne I see Zinsco failures on a near daily basis. Their clips don't seem to hold tension well at all, and I often find 30A and better Z's have welded themselves to the buss with arcing. In addition their panel design is difficult for the novice to close tightly, so once the H.O.'s been out there nosing around they are usually exposed to weathering as well.

Z's are not the worst breaker I see on the job, but here in CA they are certainly the most common of the "bad" list.

Suprised no one mentioned XO's on this thread, it says "circuit breaker" right on the body but have ya ever seen one trip?
 

pcb1

Member
Re: Stablok panels

True FPE, Zinsco and Pushmatic breakers were manufactured many, many years ago with design flaws that made them potentially dangerous. However, every manufacturer of circuit breakers at some point or another has recalled products because of factory errors or safety related problems that make them potentially deadly. Just a few years ago Westinghouse went 18 months into production of their 250 amp JD frames before they realized the arc chutes were missing! Talk about a potential hazard. My point is this: As with all circuit breakers regular maintenance and inspection will usually catch potentially hazardous problems. Don't trust ANY manufacturer who assembly-line produces hundreds of thousands of breakers to get it right every time. REPLACE suspicious breakers immediately with currently produced (UL or ETL certified) products. There are currently replacements for FPE, Zinsco and Pushmatic on the market that are as safe or more so than Square D, Siemens, etc. Remember, all circuit breakers produced as suitable replacements for FPE, Zinsco or Pushmatic have undergone MODERN UL and/or ETL destruction and safety testing to ensure that they meet todays requirements. A company called UBI produces all 3 of these lines and are readily available. For any out-of-production equipment another SAFE alternative is to consult a PEARL dealer (www.pearl1.org). They specialize in safe, tested high quality obsolete equipment and are setting the bar in the push for safer equipment and standards.
 
G

Guest

Guest
Re: Stablok panels

My experience is that when breakers go way south many times they burn the buss. Since you can't get Zinsco, FPE, or Pushmatic busses you are left to replace the panel too. Putting good breakers on a bad buss is not a good thing. The NEC says that damaged busses shall be replaced.

../Wayne C.

[ October 02, 2003, 07:19 PM: Message edited by: awwt ]
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Re: Stablok panels

Stablok panels? I'm not familiar with the term. Is this a Federal Pacific brand?
They're know in these parts as "Federal NO-BLOW " circuit breakers.

But I have to admit, I still have one of these in my house. The breakers trip and the panel is clean (no corrosion). One of these days (probably when I try to sell the house) I'll be forced to change it.
 

big jim

Member
Re: Stablok panels

I believe StabLoc was FPE's trademarked name for the way breakers were attached to the buss. The FPE in my house has been replaced. When we did an inspection before closing, we pulled the cover and a couple of breakers fell out. Scary stuff!
 

pcb1

Member
Re: Stablok panels

True when the bus bar is damaged when a breaker burns the bus needs to be replaced. On switchgear it is usually cost effective to do the repair instead of replacing the entire unit. On resi panels like FPE and Pushmatic replacing the panels is probably best. However, on Zinsco panels you can simply replace the old AL bus with new 1" Cu bus stock to remedy the problem. Its a simple job. My suggestion to service and replace potentially hazardous breakers was intended BEFORE any arcing causes bus pitting. But, most home owners won't notice any problems until a failure has already caused the damage. Just wanted people to know that there ARE suitable aftermarket replacements UL listed and safe for use in these panels, providing the panels are in good shape.
 

pcb1

Member
Re: Stablok panels

Make no mistake...these designs sucked. The contact points of the breakers (like FPE and Zinsco) to the bus became notoriously weak because of the "clamp on/in" designs that used tension in the stab assy's to hold on securely to the bus. Like a spring, when compressed for an extended period it will certainly lose a percentage of it's elasticity. Once it gets to a certain percentage of loss its ability to "hold on" to the bus becomes comprimised. Thus, the mysterious "falling out" of the panel problems associated with FPE Stablok and the pitting of Zinsco breakers against the bus. These problems have been addressed with the new manufacturers (Thomas & Betts for Zinsco and UBI for FPE) and don't seem to be a problem now. But we'll see after 25 years of use won't we? As far as the non-tripping, that's usually due to not being maintained properly. Inspectors should recommend annual testing/tripping of all breakers to home owners upon pre-home buying inspections.
 

lazorko

Member
Location
Philadelphia
Re: Stablok panels

pcp1 -
The failure to trip (at least in the Federal Pacific StabLok) is not an issue of poor maintenance! A study commissioned by the CPSC found extremely high rates of failure to trip with "virgin" breakers; the rate of failure increased to over 50% after the breakers were manually operated.
The problem was poor design; fudging test results provided to UL allowed the company to get the products accepted.
 
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