Branch circuit or Feeder

Smart $

Esteemed Member
Location
Ohio
The first circumstance describes two branch/feeder circuits
IMO the second circumstance has only one OCPD for the branch/feeder circuit & the secondary protection is in the control box.
Hmmm... I'm not getting the gist of your post. I realize under the NEC it is possible for circuit conductors to be both branch and feeder, though some may disagree. But I don't see how your scenario has any branch/feeder circuit and using that terminology make your post hard to comprehend from an NEC-interpretation perspective.
 

Smart $

Esteemed Member
Location
Ohio
...i don't see how you get past the basic definition of supplementary OCPD which comes from how it is listed....
FWIW, I agree that a listed supplementary ocpd cannot be used for required branch circuit ocpd applications, but can we say the converse? That is, is there some prohibition from using a listed branch circuit ocpd as supplementary ocpd, or would it just never qualify as supplementary under the NEC? Note the NEC does not mention anything about listing of the breaker.
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
Hmmm... I'm not getting the gist of your post. I realize under the NEC it is possible for circuit conductors to be both branch and feeder, though some may disagree. But I don't see how your scenario has any branch/feeder circuit and using that terminology make your post hard to comprehend from an NEC-interpretation perspective.
I, for one, will have to disagree. By definition, a circuit conductor cannot be both a feeder conductor and a branch circuit conductor.

I think missing in the discussion so far is where is the "outlet" in the circuits under discussion.
 

GoldDigger

Moderator
Staff member
Does the NEC allow connecting an outlet directly to a feeder if that outlet is properly protected by the feeder OCPD?
If and only if that is allowed can we have the same conductors be both branch and feeder.
On the other hand we could have a long run of wiring with no side connections but a branch circuit breaker placed in the middle.
I would be willing to stretch and call that circuit both branch and feeder, but at any point the conductors will be exactly one of the two.

Tapatalk!
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
Does the NEC allow connecting an outlet directly to a feeder if that outlet is properly protected by the feeder OCPD?
If and only if that is allowed can we have the same conductors be both branch and feeder.
By NEC definition, an outlet would be connected to a branch circuit, not to a feeder.
 

GoldDigger

Moderator
Staff member
What I am trying to say is that there is nothing in the NEC definitions to say that one conductor cannot match both feeder and branch definitions unless there is a rule which makes such a wiring configuration illegal.
I am looking for that rule, not just the definition.
Saying that an outlet can only be on a branch by definition is not the rule I am looking for.
If you assert that the definitions of feeder and branch make them mutually exclusive, I do not see that in the words. It is just something that we assume.

Tapatalk!
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
What I am trying to say is that there is nothing in the NEC definitions to say that one conductor cannot match both feeder and branch definitions unless there is a rule which makes such a wiring configuration illegal.
I am looking for that rule, not just the definition.
Saying that an outlet can only be on a branch by definition is not the rule I am looking for.
If you assert that the definitions of feeder and branch make them mutually exclusive, I do not see that in the words. It is just something that we assume.

Tapatalk!
OK, try this...

A Feeder is all circuit conductors from the service equipment, separately derived system, or other power supply source to the FINAL branch-circuit overcurrent device.

A branch circuit is the circuit conductors from the FINAL overcurrent device to the outlet.

These definitions are mutually exclusive...In words...In black and white. Not an assumption, but part of the Code as written.
 

GoldDigger

Moderator
Staff member
Only if you assume that the final overcurrent device is the same for all wire paths. That is the assumption, IMHO.

Expanding on that, the final overcurrent device on the way to the outlet is the panel breaker feeding that conductor.
The final overcurrent device feeding some other load may be a downstream breaker.
That makes the upstream breaker both a branch and a feeder breaker at the same time. :(
Tapatalk!
 
Last edited:

Smart $

Esteemed Member
Location
Ohio
OK, try this...

A Feeder is all circuit conductors from the service equipment, separately derived system, or other power supply source to the FINAL branch-circuit overcurrent device.

A branch circuit is the circuit conductors from the FINAL overcurrent device to the outlet.

These definitions are mutually exclusive...In words...In black and white. Not an assumption, but part of the Code as written.
Only if you assume that the final overcurrent device is the same for all wire paths. That is the assumption, IMHO.

Tapatalk!
Removing the assumption. For the time being, rectangles represent outlets.



A minor oops, though irrelevant, but the 30A breaker was supposed to be 2-pole.
 

GoldDigger

Moderator
Staff member
Thank you for the perfect diagram.
And if that wiring configuration is allowed by the NEC, then the circled wire is both feeder and branch (or at least is branch beyond the junction) and the 30A breaker is both a feeder and a branch breaker.
Now, does the NEC allow this? Or are we going to try to fix things by calling the other breakers supplementary?

Tapatalk!
 

Smart $

Esteemed Member
Location
Ohio
There is self-contained and there are optional accessories. It doesn't change the OCPD in the enclosure.
But the entirety of the utilization equipment is not contained in the enclosure... so it is not self-contained.

On further consideration, there is likely self-contained utilization equipment out there which requires a feeder rather than a branch circuit. I have to think more than I care to right now to give more technical parameters... :p

So say we have a circuit leaving a panel that has a remote breaker (same rating as one in panel) in the circuit serving as a local disconnect before terminating at a single outlet. Are the circuit conductors between breakers feeder or branch?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
IMO, the nec needs work here however I cannot see how a piece of equipment with a built in overcurrent protective device can be considered standard overcurrent protective device. As far as whether the wire to the unit is a feeder or a branch circuit also needs work. IMO, if a circuit is run to a disconnect and that disconnect, with overcurrent protective device, feeds one piece of equipment then the entire run should be a branch circuit.

I brought this up recently to the cmp members (FWIW) and they totally agreed-- they said yes it is a feeder but it is really a branch circuit-- you can't have it both ways...
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
Thank you for the perfect diagram.
And if that wiring configuration is allowed by the NEC, then the circled wire is both feeder and branch (or at least is branch beyond the junction) and the 30A breaker is both a feeder and a branch breaker.
Now, does the NEC allow this? Or are we going to try to fix things by calling the other breakers supplementary?
Assuming that the square are "outlets" and the 20A c/bs are branch circuit breakers, then, No this wiring configuration would not be allowed.

You have "feeder" conductors that connect to an "outlet". The definition of feeder says that the conductors end at the final overcurrent device.
 

Smart $

Esteemed Member
Location
Ohio
Assuming that the square are "outlets" and the 20A c/bs are branch circuit breakers, then, No this wiring configuration would not be allowed.

You have "feeder" conductors that connect to an "outlet". The definition of feeder says that the conductors end at the final overcurrent device.
Where is it not allowed? Definitions by themselves do not constitute requirements.

It is not matter of it being one OR the other. As GD noted, the definitions are not mutually exclusive. It is a feeder circuit. It is a branch circuit. Depends on which outlet you are referring to at the time. I don't know what to tell you if you want to refer to all three outlets at the same time... but I'll hazard to call it that "subsystem"... :D
 

petersonra

Senior Member
the definition of branch circuit OCPD includes the word "capable". If the OCPD is capable of being a BC OCPD, then that is what it is by definition. You can't get around that.
 
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