Nec 210.4b
- Thread starter Strife
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curt swartz
Electrical Contractor - San Jose, CA
- Location
- San Jose, CA
- Occupation
- Electrical Contractor
A common trip is not required but all breakers must be handle tied for manual operation.
No, they do not have to have a common trip, they do have to have a means to open all the legs or phases simultaneously, this could be handle ties.
Roger
Isn't that what common trip actually means? I know some refer to common trip strictly in regards to the multipole breakers. Not sure who's right but to me common trip would mean something that trips all items in COMMON?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Yes, a common trip will open all ungrounded conductors. The responses were to let you know that it can also be handle ties on single pole breakers which are not common trip.
No, opening all poles manually and common trip are different operations and the latter is not required. Many people think the article requires a breaker that is common trip but it is not the case. Using handle ties might trip more than one pole but it may also not trip more than one pole and it would still be legal.
Roger
glene77is
Senior Member
- Location
- Memphis, TN
Roger,
This is the NEC quote from 210.4.B that confirms you response
"...that will simultaneously disconnect..."
New EE
Member
- Location
- California
I have an existing panelboard that we are now required to be in compliant with 210.4b. The supplier is telling me that they don't make handle ties for 3 individual 1P20A breakers. Is this true?
If this is true and you have a junction box with 3 circuits (sharing the same neutral) homerunning back to the panel, how can we meet 210.4b then?
If this is true and you have a junction box with 3 circuits (sharing the same neutral) homerunning back to the panel, how can we meet 210.4b then?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I know that Ge makes them and I am sure other manufacturers make them. Tell the supply guys to double check.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Tonight I heard that SD does not make them.
- Location
- Illinois
- Occupation
- retired electrician
Square D does have them for three QO breakers (look on page 3) and it is a much better design than the ones they sell for two breakers.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
This is what was said not my personal knowledge. The inspector teaching the class said that he spoke with the head of SD. Again heard it last night and have not verified his comment. May I add that he would not say something that he did not know as a fact for fear of egg on his face.
The subject came up because of multi-wired circuits using single breakers.
I will look at the links. I should have before I posted.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Don
Trying to understand 210.4(B). Does the QO1HT independent trip meet this requirement?
- Location
- Connecticut
- Occupation
- Engineer
Mike, the QO1HT handle tie (which creates an independent trip 2-pole c/b) would meet the requirements of 210.4(B).
Or the QO3HT handle tie could be used for an independent trip 3-pole c/b, also meeting the requirements of 210.4(B).
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
But it say simultaneously. Does the independent trip do this?
- Location
- Connecticut
- Occupation
- Engineer
210.4(B) says "Disconnecting means" not "overcurrent protection."
The handle tie (QO1HT) will ensure that the two circuit breakers of the MWBC will be opened at the same time when the circuit is "disconnected".
If, for example, one of the single pole c/bs tied together trips on overload, 240.4(B) does not require that the other single pole c/b trip at the same time. This is the point Curt & Roger made in posts 2 & 3.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
A 2- or 3-pole breaker will open all poles upon overload or fault, even with the handle tie removed. An added handle tie is for simultaneous manual operation.
While an added handle tie may allow one pole's automatic opening to cause the other(s) to open, it's not required to.
While an added handle tie may allow one pole's automatic opening to cause the other(s) to open, it's not required to.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
What was I thinking?
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