Circuit breaker handle ties for line-to-line feed
- Thread starter ca2000
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Circuit breaker handle ties for line-to-line feed
Yes. 240.20(B) and 240.20(B)(3)
Yes. 240.20(B) and 240.20(B)(3)
Re: Circuit breaker handle ties for line-to-line feed
"or individual breaker with an approved handle tie for this situation?" which I'm assuming that you may be suggesting that an approved handle tie to the two 1-p breakers.If you have a L-L 208v load this doesn't get the job done as it doesn't provide "common trip."
If you are inferring that you would be replacing the (2)1-p breakers with a 2-p breaker which looks like (2) 1-p breakers with simple a handle tie added it most likely is marked or labeled as having a common trip which is the correct device.
"or individual breaker with an approved handle tie for this situation?" which I'm assuming that you may be suggesting that an approved handle tie to the two 1-p breakers.If you have a L-L 208v load this doesn't get the job done as it doesn't provide "common trip."
If you are inferring that you would be replacing the (2)1-p breakers with a 2-p breaker which looks like (2) 1-p breakers with simple a handle tie added it most likely is marked or labeled as having a common trip which is the correct device.
- Location
- Illinois
- Occupation
- retired electrician
Re: Circuit breaker handle ties for line-to-line feed
templdl,
The NEC does not require a common trip for line to line loads served from a 3 phase system. Look at the code section that Charlie cited.
Don
templdl,
The NEC does not require a common trip for line to line loads served from a 3 phase system. Look at the code section that Charlie cited.
Don
Re: Circuit breaker handle ties for line-to-line feed
Don,
I have reviewed the references again, and what I'm to understand here is that, even though the plotter is single phase 208v which may include only L-N loads or only a L-L load, or a combination thereof, that two individual 1P breakers tied together with a listed handle tie is approved.
Note the poster did not state whether or not the plotter required a neutral. If not the load must be L-L 208v. But assuming that it did the plotter has only L-N loads butr then again have a combination of both L-N an L-L loads.
If simply 120v L-N loads I would like to understand that it would be similar to where (2) 1p breakers with an approved handle tie must be used on home run circuit that lands on the same yoke.
If a combination of 120v and 208 loads wouldn't this be similar to a range or cloths dryer being supplied from a 1ph-3w, 120/240v source where a 2p common trip breaker must be used.
If simple a 208v L-L load wouldn't this be similar to supplying a 1ph-2w 240v A/C or water heater load which also requires a 2p common trip breaker?
I may be missing something here and I may not be seeing the forest through the trees but if the load consisted of all or part of a L-L 208v I would think that a common trip breaker should be applied here. I personally would like to clear both lines should one line overload or fault.
Thanks for your input.
Dave
Don,
I have reviewed the references again, and what I'm to understand here is that, even though the plotter is single phase 208v which may include only L-N loads or only a L-L load, or a combination thereof, that two individual 1P breakers tied together with a listed handle tie is approved.
Note the poster did not state whether or not the plotter required a neutral. If not the load must be L-L 208v. But assuming that it did the plotter has only L-N loads butr then again have a combination of both L-N an L-L loads.
If simply 120v L-N loads I would like to understand that it would be similar to where (2) 1p breakers with an approved handle tie must be used on home run circuit that lands on the same yoke.
If a combination of 120v and 208 loads wouldn't this be similar to a range or cloths dryer being supplied from a 1ph-3w, 120/240v source where a 2p common trip breaker must be used.
If simple a 208v L-L load wouldn't this be similar to supplying a 1ph-2w 240v A/C or water heater load which also requires a 2p common trip breaker?
I may be missing something here and I may not be seeing the forest through the trees but if the load consisted of all or part of a L-L 208v I would think that a common trip breaker should be applied here. I personally would like to clear both lines should one line overload or fault.
Thanks for your input.
Dave
Re: Circuit breaker handle ties for line-to-line feed
All,
I can only assume that the plotter does include a neutral (as I have not seen the schematic or looked at the wiring) as I figure that the fuser will use the 208V and the remaining circuity and computer interfaces will require 120V.
I personally would like to see the plotter placed on a common trip breaker, instead of using the handle tie. I do not trust the circuit breaker handle tie (in the case of a fault) to not damage the $65000 plotter since it will not act as a common trip. The electrician that wired the building knew what would be connected, and yet still installed two 1p 20A breakers without a handle tie. This is not the only Code issue that we have found from him.
Chris
All,
I can only assume that the plotter does include a neutral (as I have not seen the schematic or looked at the wiring) as I figure that the fuser will use the 208V and the remaining circuity and computer interfaces will require 120V.
I personally would like to see the plotter placed on a common trip breaker, instead of using the handle tie. I do not trust the circuit breaker handle tie (in the case of a fault) to not damage the $65000 plotter since it will not act as a common trip. The electrician that wired the building knew what would be connected, and yet still installed two 1p 20A breakers without a handle tie. This is not the only Code issue that we have found from him.
Chris
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
Re: Circuit breaker handle ties for line-to-line feed
My guess is the $65,000 plotter is well protected internally. i would not be all that worried about it.
- Location
- Illinois
- Occupation
- retired electrician
Re: Circuit breaker handle ties for line-to-line feed
templdl,
Don
templdl,
I assumed line to line load only. The two wire 240 volt single phase water heater does not require a common trip breaker per the NEC. Look at 240.20(B)(2). Likewise the 208 volt line to line load does not require a common trip breaker. See 240.20(B)(3). If there are both line to line and line to neutral loads, then a common trip breaker is required.
Don
poweringtech
Member
Re: Circuit breaker handle ties for line-to-line feed
templdl,
In the NEC 2002 handbook that I have read, minimum requirement for Line-to-line system voltage with grounded neutral should be "approved handle ties". Of course no one can prevent you from using a common trip.
Common trip is required if system voltage is not grounded.
I will post the name of the book and author next time.
templdl,
In the NEC 2002 handbook that I have read, minimum requirement for Line-to-line system voltage with grounded neutral should be "approved handle ties". Of course no one can prevent you from using a common trip.
Common trip is required if system voltage is not grounded.
I will post the name of the book and author next time.
poweringtech
Member
Re: Circuit breaker handle ties for line-to-line feed
The name of the book is National Electrical Code Handbook 2002 pages 159 to 160
If source system voltage is ungrounded common trip type circuit breaker is required
If source system voltage is grounded minimum requirement is approved handle tie.
However common trip is also allowed
The name of the book is National Electrical Code Handbook 2002 pages 159 to 160
If source system voltage is ungrounded common trip type circuit breaker is required
If source system voltage is grounded minimum requirement is approved handle tie.
However common trip is also allowed
- Location
- Illinois
- Occupation
- retired electrician
Re: Circuit breaker handle ties for line-to-line feed
Chris,
Look at 240.20(B).
Don
Chris,
Look at 240.20(B).
Don
Re: Circuit breaker handle ties for line-to-line feed
Even though I see the point in the code I am somewhat concerned when ever you have any L-L load feed by breakers tied together with an approved handle tie. If one pole tripped and the device stops functioning because there is no longer a completed circuit. But, there is still power appied by the untripped pole which energizes the line that it protects back through the load to the line that has opened. Dangerous?
Or, have I overlooked something.
Or is there now an opportunity for the same event that tripped the first breaker to also trip the second one.
Even though I see the point in the code I am somewhat concerned when ever you have any L-L load feed by breakers tied together with an approved handle tie. If one pole tripped and the device stops functioning because there is no longer a completed circuit. But, there is still power appied by the untripped pole which energizes the line that it protects back through the load to the line that has opened. Dangerous?
Or, have I overlooked something.
Or is there now an opportunity for the same event that tripped the first breaker to also trip the second one.
- Location
- Massachusetts
Re: Circuit breaker handle ties for line-to-line feed
Never assume anything is dead.
This is no different then loads protected by fused disconnects. Only one fuse may open on a ground fault leaving the other one or two fuses intact.
Never assume anything is dead.
poweringtech
Member
Re: Circuit breaker handle ties for line-to-line feed
Hello Iwire,
This is actually a concern on safety. Your right that one of the pole may still be live in a L-L source. Similar to a fuse (where we can have a handle tie) one of the fuse may not blow up in a line to line system.
Would the code limit the application of the fuse to Line to neutral system voltage for safety of personnel?
And require all circuit breakers to be common trip in a line-to-line system voltage.
This could be the safest if a code revision will be made.
Hello Iwire,
This is actually a concern on safety. Your right that one of the pole may still be live in a L-L source. Similar to a fuse (where we can have a handle tie) one of the fuse may not blow up in a line to line system.
Would the code limit the application of the fuse to Line to neutral system voltage for safety of personnel?
And require all circuit breakers to be common trip in a line-to-line system voltage.
This could be the safest if a code revision will be made.
poweringtech
Member
Re: Circuit breaker handle ties for line-to-line feed
Sorry in fuse we cannot have handle ties (wrong encoding
Sorry in fuse we cannot have handle ties (wrong encoding
Re: Circuit breaker handle ties for line-to-line feed
It appears as though fuses are driving this approved handle tie thing, the handle tie being similar to a fuse disconnect switch accomplishes the same thing.
If you think about it, if safety was in fact considered to be an important enough of an issue and common trip devices be required then the fuse manufacturers would be left out in the cold and cry foul. Not good for the fuse manufacturers.
It appears as though fuses are driving this approved handle tie thing, the handle tie being similar to a fuse disconnect switch accomplishes the same thing.
If you think about it, if safety was in fact considered to be an important enough of an issue and common trip devices be required then the fuse manufacturers would be left out in the cold and cry foul. Not good for the fuse manufacturers.
poweringtech
Member
Re: Circuit breaker handle ties for line-to-line feed
templdl,
You right templdl, Fuse manufacturers would cry foul if fuses will not be allowed to protect line-to-line system voltage.
However, there is a conflict in requiring a common trip circuit breaker and being able to use a fuse for line-to-line system voltage.
Suggestion might be to have a warning sign if a fuse is used for overcurrent protection.
Stating that one of the fuses may still be working in cases of electrical fault. Again, this is for safety
templdl,
You right templdl, Fuse manufacturers would cry foul if fuses will not be allowed to protect line-to-line system voltage.
However, there is a conflict in requiring a common trip circuit breaker and being able to use a fuse for line-to-line system voltage.
Suggestion might be to have a warning sign if a fuse is used for overcurrent protection.
Stating that one of the fuses may still be working in cases of electrical fault. Again, this is for safety
poweringtech
Member
Re: Circuit breaker handle ties for line-to-line feed
More or less similar to the required markings of Artcle 240.86(A)
A marking should indicate a warning sign that one of the fuses may not blow up in case there will be an electrical overcurrent condition.
We know that fuses were the protection used before circuit breakers were invented. And requirement of the code to have handle ties and common trip is for safety of personnel
More or less similar to the required markings of Artcle 240.86(A)
A marking should indicate a warning sign that one of the fuses may not blow up in case there will be an electrical overcurrent condition.
We know that fuses were the protection used before circuit breakers were invented. And requirement of the code to have handle ties and common trip is for safety of personnel
- Status