Feeder and Branch Separation Point

Status
Not open for further replies.
F

freakydeakie

Member
Location
FL
Hi, could some one please explain to me the point at which the feeder stops and the branches start on the attached drawing. This is really bugging me and if I had hair it would all be ripped out by now,:D I am really struggling to under stand. Anyone's help would be most appreciated.
Thanks in advance
 

Attachments

  • EXAMPLE.pdf
    35.5 KB · Views: 4
The answer is found in chapter 100.

Branch Circuit. The circuit conductors between the final
overcurrent device protecting the circuit and the outlet(s).
Click to expand...

Feeder. All circuit conductors between the service equipment,
the source of a separately derived system, or other
power supply source and the final branch-circuit overcurrent
device.
Click to expand...
 
The biggest continuing controversy is caused by the fact that in some circuit layouts the definition allows for certain wires to be simultaneously branch and feeder conductors.
The disagreement centers on whether that means there is a flaw in the definitions and whether it means that any such circuit is prohibited by Code.
Personally I just accept it and find such circuits to be interesting special cases.

Sent from my XT1585 using Tapatalk
 
Many thanks for the reply guys. Peter, so anything after F4, F5, F6 and F7 are the branch, and anything before are the feeders.
I was unsure as I was thinking that the branches started after F1. Well that means that the power distribution block feeding F2 and F3 will have to conform to UL1953 for feeder spacing and I cannot use a terminal distribution block that comforms to UL1059.
Appreciate your help.
 
Last edited:
GoldDigger said:
The biggest continuing controversy is caused by the fact that in some circuit layouts the definition allows for certain wires to be simultaneously branch and feeder conductors.
The disagreement centers on whether that means there is a flaw in the definitions and whether it means that any such circuit is prohibited by Code.
Personally I just accept it and find such circuits to be interesting special cases.

Sent from my XT1585 using Tapatalk
Click to expand...

It is not real unusual to tap off a branch circuit thru an OCPD to feed another BC.

I can't think of any rules that would change anything NEC requirement wise if you did that.
 
freakydeakie said:
Many thanks for the reply guys. Peter, so anything after F4, F5, F6 and F7 are the branch, and anything before are the feeders.
Click to expand...
Depends on what is downstream of F6 and F7

"To inverter" might imply that it is a feeder.

Considering the definition of a Branch Circuit. "The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s)."

There are likely overcurrent devices downstream of an inverter.

Might just be a special case
 
freakydeakie said:
Many thanks for the reply guys. Peter, so anything after F4, F5, F6 and F7 are the branch, and anything before are the feeders.
I was unsure as I was thinking that the branches started after F1. Well that means that the power distribution block feeding F2 and F3 will have to conform to UL1953 for feeder spacing and I cannot use a terminal distribution block that comforms to UL1059.
Appreciate your help.
Click to expand...
Drawing doesn't clearly show an "outlet" or a load. Possible that everything on the drawing is a feeder.

Inverter is a source not a load so there is no outlet in that section of the system. That leaves us with F4 and F5 as the only possible branch circuits, but depending on exactly what PSU1 and 2 are the "branch circuit(s)" may still be further down stream.
 
GoldDigger said:
The biggest continuing controversy is caused by the fact that in some circuit layouts the definition allows for certain wires to be simultaneously branch and feeder conductors.
The disagreement centers on whether that means there is a flaw in the definitions and whether it means that any such circuit is prohibited by Code.
Personally I just accept it and find such circuits to be interesting special cases.

Sent from my XT1585 using Tapatalk
Click to expand...

I wrote a proposal to change the definition of feeder but I don't know if I sent it in. I think it was rejected. The definition can make a difference especially in areas of hvac units like the thread going on now. A wire from a panel to a fused disconnect is a feeder and the wire to the hvac unit is a branch circuit. However, take away the fuse disconnect and put in a non fused diso and the entire run is a branch circuit. The feeder definition should have an exception
 
Dennis Alwon said:
I wrote a proposal to change the definition of feeder but I don't know if I sent it in. I think it was rejected. The definition can make a difference especially in areas of hvac units like the thread going on now. A wire from a panel to a fused disconnect is a feeder and the wire to the hvac unit is a branch circuit. However, take away the fuse disconnect and put in a non fused diso and the entire run is a branch circuit. The feeder definition should have an exception
Click to expand...

True unless you are willing to categorize the fused disconnect as supplemental overcurrent protection instead of branch circuit protection.
That argument is harder to make if you make the fused disconnect a different size from the "branch" breaker, and it seems to be an open question whether a particular AHJ will go along with that classification.

I agree that the language should be improved to handle the case where a motor is involved and the branch circuit MCA may be lower than the MOCP.
But I can also see the CMP saying that it is all completely obvious to them already. :)
 
Status
Not open for further replies.
Top