A coworker and I were having a disagreement this morning about the definition of a feeder and a specific application. The scenario was that we have a fused disconnect and a subpanel to install at the opposite end of the building as the MDP. My point was that it is ok to pull the conductors for the sub panel and disco in the same conduit as long as you de- rate the conductors and don't exceed the max fill of the conduit. He said that this would be a code violation since we would be pulling feeders to the sub panel and a branch circuit to the disconnect. The definition of a feeder according to the NEC does not apply to this as far as I can see, since they are both fed from the mdp on their own breakers. . I don't see where this would be prohibited.
Feeder or Branch Circuit?
- Thread starter ccrtech
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
The last overcurrent device in the run is the point at which the feeder ends, and the branch circuit begins. Since there is a fuse in the disconnect and (I presume) breakers in the subpanel, both of the runs you are describing are feeders. But it does not matter, given the nature of your question. You can install branch circuits and feeders in the same conduit, so long as you follow the rules that you named. There is a rule against service conductors sharing raceways with other conductors, but there is no similar rule for feeders or for branch circuits.
- Location
- Massachusetts
There is no question that the conductors supplying a 'subpanel' are feeders.
There is no question that the conductors supplying a 'fused disconnect' are feeders. (Unless they are service conductors)
However there is no rule in the NEC that prohibits mixing branch circuits and feeders in the same raceway.
Now that said, the derating required really kills the ampacity of the feeder so it is often not cost effective.
In you case your would be putting two feeders in the same conduit, if these circuits are larger than 30 amps the derating could be costly.
There is no question that the conductors supplying a 'fused disconnect' are feeders. (Unless they are service conductors)
However there is no rule in the NEC that prohibits mixing branch circuits and feeders in the same raceway.
Now that said, the derating required really kills the ampacity of the feeder so it is often not cost effective.
In you case your would be putting two feeders in the same conduit, if these circuits are larger than 30 amps the derating could be costly.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Where does it say that you cannot pull a feeder and branch circuits in the same raceway? The potential issue, as you've mentioned would be derating.
maghazadeh
Senior Member
- Location
- Campbell CA
I agree with all replies so far, and now we know the definition of feeder and branch circuit based on NEC. But as far as estimating world is concerned; any size wires that would fit in conduits up to 1" with respect to 40% max fill considers to be a branch circuit. 1 1/4" and up is feeder. Let's say we know you could pull 2 #12 in that 1 1/4" pipe.
:jawdrop:
:jawdrop:
- Location
- Illinois
- Occupation
- retired electrician
Why would the estimator care if the circuit is a branch circuit or feeder? The estimate would be based on the size of the conduit, the size of the conductors, the number of conductors, and the length of the circuit.I agree with all replies so far, and now we know the definition of feeder and branch circuit based on NEC. But as far as estimating world is concerned; any size wires that would fit in conduits up to 1" with respect to 40% max fill considers to be a branch circuit. 1 1/4" and up is feeder. Let's say we know you could pull 2 #12 in that 1 1/4" pipe.
- Location
- Massachusetts
In some estimating programs they call small feeders, 'branch circuits'.
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