What circuit breakers are usually tied to one another?

[Robert Gift]

Several years ago I removed a metal tie between two circuit breakers.
Masking tape note has faded.
Any ideas of which circuit breakers are usually tied?

Thank you.

 

[wwhitney]

The typical case is that a 3 conductor (plus ground) cable is used for a multiwire branch circuit, with two ungrounded (hot) conductors on opposite legs of the supply supplied from adjacent full size circuit single pole breakers and a common neutral. Those two adjacent single pole breakers are required to have a handle tie.

So if you are qualified to do so, you can kill power to the panel, remove the dead front, and inspect the wiring. Typically 3 conductor cables have a red wire, and you can look for any red wires that terminate on a single pole breaker. Trace the red wire back to its entry to the panel, find the associated black wire, and trace it back to a breaker, which should be adjacent to the breaker with the red wire.

Cheers, Wayne

 

[Sponsor]

 

[Robert Gift]

...
So if you are qualified to do so, you can kill power to the panel, remove the dead front, and inspect the wiring. Typically 3 conductor cables have a red wire, and you can look for any red wires that terminate on a single pole breaker. Trace the red wire back to its entry to the panel, find the associated black wire, and trace it back to a breaker, which should be adjacent to the breaker with the red wire.

Cheers, Wayne

Thank you, Wayne.
What I was thinking!
No problem removing the cover. (HAM radioperator who also had a homeowner's electrical permit. Just do not know all the current rules.)
Shallook.
(Still dislike that if wife, who uses rice maker and other plug-in appliances, ever trips the 20-amp island circuit breaker, it also shuts off the "dedicated" 20-amp circuito the refrigerator.)

 

[wwhitney]

(Still dislike that if wife, who uses rice maker and other plug-in appliances, ever trips the 20-amp island circuit breaker, it also shuts off the "dedicated" 20-amp circuito the refrigerator.)

That is not necessarily true. As I commented in your other thread a handle tie does not enforce common trip. The only way that would happen is that when one pole trips, it tries to move its handle, and then through the handle-tie, the tripped side's handle applies enough force to manually disconnect the other side.

But the linkage between the internal trip and the handle moving is not solid; the internal trip will activate even if the handle is rigidly held in place externally. So I doubt that one side tripping generates enough force on the handle tie to actually manually disconnect the other side, although it's possible.

If you're really worried about this possibility, then I suggest you do a test, maybe a carefully monitored intentional overload with a couple space heaters. Then I expect you would find that one side is tripped, and the handle tie is askew, but the other side is untripped. I would be interested to hear the results of such an experiment.

Cheers, Wayne

 

[Robert Gift]

That is not necessarily true. As I commented in your other thread a handle tie does not enforce common trip. The only way that would happen is that when one pole trips, it tries to move its handle, and then through the handle-tie, the tripped side's handle applies enough force to manually disconnect the other side.
But the linkage between the internal trip and the handle moving is not solid; the internal trip will activate even if the handle is rigidly held in place externally. So I doubt that one side tripping generates enough force on the handle tie to actually manually disconnect the other side, although it's possible.
If you're really worried about this possibility, then I suggest you do a test, maybe a carefully monitored intentional overload with a couple space heaters. Then I expect you would find that one side is tripped, and the handle tie is askew, but the other side is untripped. I would be interested to hear the results of such an experiment.

Cheers, Wayne

Thank you, Wayne.
I thoughthathe tie was to trip the adjacent circuit breaker. Shall try a controlled overload to see if it really does.
(Don't know if I have enough to overload the 20-amp circuit. Well, the motor-driven tornado siren run on 120 VAC instead of 240 would overload! Must reconnect it from 240 to 120.)
If not, theno problem!
I haul the siren to the sidewalk and sound it at precisely 00:00:00 New Years Day according to WWV (303) 499-7111.

 

[wwhitney]

I thoughthathe tie was to trip the adjacent circuit breaker.

No, the purpose of the handle tie is to enforce common disconnect, that when you manually turn off one breaker you must turn off the other. If common trip is required, that whenever one side automatically trips, the other will trip, then a handle tie is not sufficient, and you need a double pole breaker with common internal trip.

Cheers, Wayne