Old Pushmatic subpanels

[Jim Katen]

There must be some significant regional variation on Pushmatics. They were popular here (SF Bay Area) in the early 1950s, and after that the other usual suspects became the equipment of choice. I might not feel bad about them if I had ever inspected one of those panels that wasn't a mess, but alas that is not the case.

Around here, it seems like we see the other side of that coin. I suspect that Pushmatic equipment was on the pricier end of the scale and, as a result, tended to be installed in the better homes and in commercial buildings in this area. I rarely see Pushmatic panels in tract homes or homes in working neighborhoods. They're usually in the homes on the hillsides with killer views. And they were usually oversized for the house. I suspect that's why I don't see the same kind of messy, messed up installs that you see down there; they're don't usually overlap with the do-it-yourself demographic.

I also find it interesting that they dropped from favor in the '50s in your area. Around here, they were going strong right up to 1990s. (When did they stop manufacturing them, anyway? The most recent one I've ever seen was installed in 1991.)

The original equipment is no longer made, and last I looked Siemens held the rights for the only UL listed replacement breakers, and charged a fortune for them. The effect of them having been out of our market for over a half century is that almost every panel I have seen with them has been a maze of double taps or direct taps to the bus bars, along with all the usual things you find in equipment that has become inadequate to handle the additional loads that folks will apply in the decades since the panel was installed.

My local hardware store has replacements made by three different brands, Connecticut Electric, Unique, and something called "TGW" (I might be remembering that one wrong.) All of them have a UL mark and all have a 10,000 amp interrupt rating. Prices are spendy, but not usurious at about $25 for a 15 amp single-pole breaker and going up to $59 for a 60 amp two-pole breaker.

Adding to their woes, few Bulldog breakers meet the modern standard for a 10k AIC rating, and with our power grids being increasingly networked, and with rising available fault currents, any pre-1970s breaker is at risk of explosion in a dead short. While I've only personally witnessed that with FPE, there is no reason to think that Bulldog will somehow be able to handle high fault currents for which they were never designed just because they made a better bus connection.

Agreed. But that's true of every 5,000 AIC breaker out there. Are you suggesting that home inspectors recommend replacement of all equipment with an interrupting rating less than 10,000 amps? I'm not sure that I'm ready to go there. Exploding breakers seem to be very rare. Even the FPE breakers that I've shorted (just for fun) have just buzzed menacingly.

It could be very different in other parts of the country. For instance, in Kurt's territory, conduit and EMT are the norm, and they create a separate grounding path. A bulldog subpanel with a bonded neutral might be repairable in the windy city, and it might not be as old as Kurt. Out here (in NM land), it is likely to require replacing an SEU cable that feeds the panel. The cost of replacing that feeder will usually make the cost of replacing the subpanel seem like small change.

We are in a very different era than that of the Bulldog panel. Today we have many more circuits, equipment grounding conductors, and AFCIs. As folks add more loads, any older panel is going to run up against the limit of its obsolesence, even if it was good equipment for its time. If I had a relative buying a house with a Bulldog panel, I would tell them to either replace it or use no electrical appliances manufactured since 1960.

Well, if a panel is too small, it's too small. That would apply to any panel, old or new. It's true that Bulldogs can't accommodate AFCIs, and if someone wants to upgrade their electrical system to include AFCIs then it makes sense to change out the panel. But most of the Bulldogs that I see aren't too small and most of my customers have little interest in adding AFCI protection. That leaves me with little reason to recommend replacment, whether the household appliances are old or new.

Attached is a picture of a very typical Pushmatic panel installation around here. It was installed in a 1951 house, but I think that this panel is actually from the late '70s. It's got a few things going on:

* A 240-volt circuit that originates at two single-pole breakers.

* A couple of double taps.

* One multi-wire circuit that originates from a single pole.

Those are all pretty easy things to fix. (And the breakers have a 10k AIC rating.)

I just don't see any good reason to recommend replacing this panel.

- Jim Katen, Oregon

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[Les]

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In Michigan we find the same situation(s) as Katen. There are exceptions, but generally Pushmatics are found in houses that were upscale.

The nagging question for inspectors must be what they report and why. Doug posted a very nice clear concise answer that every inspector should read until they fully understand what he is saying. To read it and then report all 40plus year old equpipment as flawed misses the point.

The "schools" must teach in a binary fashion and not encourage thought nor critical analysis. This is not just an electrical issue and it can be applied to cast iron plumbing (new and old), lead based paint, vinyl asbestos tile, vermiculite, horse hair plaster, etc.

Real inspectors have opinions.

[Tom Raymond]

Even the FPE breakers that I've shorted (just for fun) have just buzzed menacingly.

That reminded me that when I was a kid, 10 I think, I made a rig specifically to explode capacitors. My boy is 9, and since my wife won't let me teach him how to drive a stick (I was 9 when I learned, she's only fussy cause it's her car) maybe it's time to teach him the joy of a dead short.

[Jim Katen]

Even the FPE breakers that I've shorted (just for fun) have just buzzed menacingly.

That reminded me that when I was a kid, 10 I think, I made a rig specifically to explode capacitors. My boy is 9, and since my wife won't let me teach him how to drive a stick (I was 9 when I learned, she's only fussy cause it's her car) maybe it's time to teach him the joy of a dead short.

I've never exploded capacitors on purpose. There goes my afternoon.

[Tom Raymond]

Start small, the kabooms get exponentially bigger as capacitor size increases[]

[Marc]

They're electrolytic capacitors, meant for DC voltages. When I blew one in the lab at radio/TV school long ago (by mistake), it sent a small plume of smoke rising to the ceiling. My instructor came over asking if I was part American Indian. []

[Douglas Hansen]

Back to Pushmatics, after reading over everyone's contribution I think my problems with them really are attibutable to their age more than any other factor, and that seems to vary from one locale to another.

The AIC issue shouldn't matter if the panel is a subpanel. If it has a fuse main, the fuse will protect it from high fault currents. That said, I do see a couple of other problems. The picture Les posted is not exactly an argument for the case that these are somehow a more robust design, especially with the holes chewed through the fiberboard dividers. Next is the issue of handle ties. I have seen them on Pushmatics, though I would expect them to be hard to find. They are more likely to be needed now that all multiwire circuits require them. I suppose one could buy a 240-volt pushmatic breaker to get the handle tie, but it seems odd to have to pay $60+ for something that you could do for 60 cents on a modern panel.

Jim, be careful. We need you.

Douglas Hansen

[plummen]

Ok. thanks. If I don't see anything alarming in there I'll just describe what it is and let the client decide if it suits the purpose.

A while back I found this really pristine Pushmatic panel in the basement of a 1960's house. It has the bulldog cover over the main breaker and was installed with obvious loving care.

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Thats the kind of work i like to see! [:-thumbu]

[allseason]

Here is something that I have heard about the pushmatics, may be far fetched but is possible. Amateurs will connect wires to the screws that secure the breakers when the breaker screws are all used, thus no overcurrent protection.

[msteger]

They're electrolytic capacitors, meant for DC voltages. When I blew one in the lab at radio/TV school long ago (by mistake), it sent a small plume of smoke rising to the ceiling. My instructor came over asking if I was part American Indian. []

I used to blow these up in the electronics lab while in college. To me, a blown-up electrolytic smells like popcorn. Anyone else notice this?

[Paul N Frey]

I see Pushmatic panels occasionally (along with Jim K) and the only thing I have noticed is that if you trip a circuit sometimes they will not reset for a few minutes. I just walk away and reset it later and have never had a problem other than there are not many connections since the breakers are so large.