3-phase breaker question

I riveted three together and pinned the switch handles. I now have 3-pole breakers that cost $10 rather than $46. Now, Are they going to explode or something?

You do lose the "common trip" capability of the breaker, but with an approved "handle tie" it may pass most inspector's muster.

In this circumstance, I would probably have used one 2-pole comon-trip breaker (A and C phases), one 1-pole breaker (B phase) and an approved handle tie, PLUS a "backfeet kit" on both breakers to ensure that both were solidly mounted to the panelboard enclosure.

Go find a local wholesale house that isn't charging you Full Retail when you walk in off the street, and get the right breakers. You know what you were paying at HD for 3-pole 20A 30A and 50A breakers, the prices should stay roughly in line. Or go to the HD "Special Services Desk" and have them order in the exact breakers you need.

The handle-tie is mostly there to be the visible part of the 'common trip' mechanism, most breakers also have a separate internal common trip linkage between the poles inside the body of the breaker assembly. While your external handle-tie breakers will /probably/ trip properly, they may not always - "Stuff happens".

I'll do things like that (wire handle-ties) in an emergency to get the customer back running, but I also track down the right breakers and get them installed within a few days.

And if the place does manage to burn down, the local fire inspector and your Insurance Company WILL be looking around very carefully to find out why. The fire department for an official cause, and the insurer would like nothing better than a clear reason to deny or reduce the claim (and hold on to those 20 years of paid premiums...)

-->--

Be careful with those jury rigged 3 pole breakers. I'm not sure but the connecting bar across 3 single pole breakers might be a bad idea. It seems to me if any one "phase" was overloaded and tried to blow the breaker there might be enough drag from the the connecting bar to prevent the breaker from opening. It could be bad news. I'd check with an electrician.

What brand of breaker?

I have had pretty good luck looking on Ebay for "generic"; SD, CH, etc; breakers in the 3 pole variety.

I have a secret source for some of the more esoteric - Sylvania, FPE.

JW

They are "Siemans" (never could spell) - the same mount as "GE"

They are "Siemans" (never could spell) ...

Seimens.

Incredible that foreign companies have taken over many old-line electrical equipment houses.

Square-D is now owned by Groupe Schneider (French).

Siemens is how you ought to spell it. HTH.

Yep, those Germans just don't spell things the same as English folk. I have mixed memories about the Sieman's floppy disk drives I used to run on the CP/M system. They were cheap...but, like HF stuff, varied wildly all over the map in terms of quality. I remember that on several occasions I had to go in and adjust the (metal) tension spring that held the backup pad against the floppy to lighten it up a bit to keep from grooving things in short order. Regards Dave Mundt

Let me guess, you built a "Big Board" or a Xerox 820? I built an 820 with a Ferguson 256k daughter board. Way cool! It's still in the basement with a few Sieman's drives. Used it to play text adventures.

Nope, sorry. Some models of the Crouse-Hinds/Murray/Siemens thick breakers might fit in a GE panel since the overall dimensions are the same, but GE uses an odd line-buss arrangement for their panelboards. For thin 1/2" breakers, it's GE only.

Some "Industrial Interchange" breakers (including Square-D "Homeline", Cutler Hammer/Challenger, etc.) will fit a GE panel, but NOT all.

-->--

this one?

For the cost of these I would just buy the "right" one and not have to worry about potential liability or voiding your insurance in the future.

It's not like the VERY expensive breakers I need for my panel (~$100 for 3ph 30A).

JW

Get the right breakers. The next time you replace a panel, go for one that accepts bolt-on breakers if the budget is adequate. They are far more reliable than stab-on type breakers. CH used to have a panel that accepted both, not sure if that is still the case.

The next time you replace a panel, go for one that accepts bolt-on breakers if the budget is adequate.

Indeed so.

At my former employer, all our house panelboards were custom made for the contractor, and utilized bolt-in breakers.

On our products, we also designed in bolt-in breakers from the power distribution units, to the sub-units.

The products were mainframe computers, and these presented a load to the source of from 70 to 140 KVA, 208 volts. The source was a 415 Hz motor-generator.

That's a 480V breaker, which bumps up the price a lot, and a 3-phase bolt-on that bumps it a little more. If you have a use for it (and the shipping isn't a deal-breaker) $20 for that breaker is a steal.

In the 240V bolt-on class, they are probably more interchangeable than the plug-0in style - almost all the bolt-on designs use a 10-32 screw in the same place for everyone. What makes them fit only in certain panels is their rejection features - bumps on the mounting pan and the "hook" on the edge of the pan under the Load terminals - they can make them a little different so only the right brand plugs in.

Federal Pacific Electric was famous for this - they have everything keyed three different ways for breaker rejection - several different rejection tabs on the backplane, the hook tabs on the edge of the tray (under the Load screws) and the Line Buss plug in pads had several different slots for the different types of breakers.

-->--