The subject says it.
I need to know what to call and where to get the little sheet metal "lever joiners" which can tie together the levers of the center two or the outer two of the levers in this kind of Siemens breaker.
I'm seeking them to fit the last breaker on this page:
Jeff
Jeff, unless the breakers have an internal common trip mechanism, tying the levers together may interfere with one of the breakers tripping in an overload situation. O_o
TDD
I always thought they were for a common trip, good to know
They are, in general, called "handle ties". I have never seen them for the half-width breakers in the link, other than what comes with the breaker. The linked breaker comes with a tie for the center 2 breakers and a tie for the outer 2.
I saw one place on line that has fairly cheap used "recertified" breakers, from which you could salvage the handle tie (if it comes off).
Should never happen. Breakers have a feature called "trip free". It will trip no matter what the handle is doing. If you are closing the a breaker on a fault the breaker has to trip even though you are still holding the handle in the on position.
On the other hand, if you tie the handles of separate breakers, a trip on one of them will not reliably trip the other one. Handle ties are for a common disconnect, not a common trip.
Ditto from me, I thought they were for common trip too.
Jeff (The OP)
Try WW Grainger
"bud
Douh! I forgot about the trip free feature which I've seen in action when I've investigated short circuits. I should have written "interfere with the indication of a tripped breaker". I could see a possibility of the 2 pole 30 amp tripping and turning off the 20 amp breakers if the handles were tied together. O_o
TDD
My first job out of college was working for an electrical supply company and there were samples of sectioned displays of circuit breakers showing the internal mechanisms. I had a Square D rep show me that you trip a loose breaker by slapping it into the palm of of your hand. If you look at the side of some single breakers, you will see a round slotted shaft end that's flush with the case. That shaft is connected to the trip mechanism and I assume that the manufacturer couples the shafts together when the breakers are stacked at the factory to provide a common trip so if one leg trips the other legs will trip too. If you come across one, you can stick a screwdriver in a the slot and a light twist will trip the breaker. ^_^
TDD
investigated short circuits. I should
a possibility of the 2 pole 30 amp
Yes TD I have work few years for company that actually use 4 breaker tie together externally 2 was 15 amp. and 2 were 30 amps. also same breaker had Tc for remote trip, cheap way handling power source but they did it and claimed that it was OSHA approved.
I've investigated short circuits. I should
see a possibility of the 2 pole 30 amp
The tie on the two outer breakers was in the form of a rather large square loop, big enough not to interfere with the tie between the center two breakers, which sat "inside" that loop.
To add more fuel to the fire, this article seems to say that handle ties became the rule in 2008.
I think I've about "saucered and blowed" this question now.
Jeff
This clearly shows the inner and outer handle ties.
When you have a multiwire branch circuit (includes Edison circuits), if you break a neutral connection the load-side neutral can be hot (if you turn off the circuit you are working on and leave other parts of the multiwire on). "Hot neutrals" are what a common disconnect is aimed at. The requirement, as you say, is "common disconnect" not "common trip".
For a 3-phase multiwire, disconnecting 'your' circuit and breaking a neutral connection can also result in way high voltage on one of the remaining circuits - like an open service neutral on a 120/240V service.
It was real common practice in a large building to run 120V and 277V branch circuits as a multiwire (3 phase, 4-wire) out of the panel. They can split at the first junction box, which can be far from the panel. No way that would be done now if a common disconnect is required for all 3 circuits. Each branch circuit would need a separate neutral. That requires 50% more wire and average voltage drop increases.
The disconnect for fluorescents (in the article) is easily done with a small plug and socket in the fixture wiring compartment. I think many fixtures come with them.
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