Feeder vs Branch Circuit?

[Tolbert]

How do we classify a supply conductor to a piece of industrial equipment? Is it a feeder or a branch circuit? I think it is a branch circuit if it only has a non-fused disconnect at the machine. If it has a control panel that has a circuit breaker or a fused disconnect then it would be considered a feeder from the main switchboard.

How do you classify this supply circuit?

 

[charlie b]

I think you have it right. The term "feeder" applies until you get to the last overcurrent device.

 

[hotwire1955]

Article 670 ( Industrial Machinery )should help

 

[augie47]

Tolbert, Welcome to the Forum

I agree with your statement and Charlie's answer, but, for fun, lets see if we can muddy the water.
We have ah HVAC unit with a MCA of 45 amps and a MOCP of 60 amps.
We have a NF disconnect at the unit, and a 60 amp breaker in the panel so the wiring from the breaker at the panel is a branch circuit... #8 THHN and a 60 amp breaker could be used.

Now, let's change the non-fiuse disconnect to a fusible. Does this make the wiring from the disconnect a branch circuit and the wiring from the panel a feeder ?
If the wiring from the panel is a feeder must it be rated at 60 amps ?

 

[iwire]

How about when I plug in a plug strip with a built in breaker, does that change the general purpose branch circuit to a general purpose feeder circuit?

 

[One-eyed Jack]

Tolbert, Welcome to the Forum

I agree with your statement and Charlie's answer, but, for fun, lets see if we can muddy the water.
We have ah HVAC unit with a MCA of 45 amps and a MOCP of 60 amps.
We have a NF disconnect at the unit, and a 60 amp breaker in the panel so the wiring from the breaker at the panel is a branch circuit... #8 THHN and a 60 amp breaker could be used.

Now, let's change the non-fiuse disconnect to a fusible. Does this make the wiring from the disconnect a branch circuit and the wiring from the panel a feeder ?
If the wiring from the panel is a feeder must it be rated at 60 amps ?

By definition it is a feeder. You can still protect at 60 amps because it is still ac/ref. equipment.

 

[augie47]

By definition it is a feeder. You can still protect at 60 amps because it is still ac/ref. equipment.

true... but can you still use the #8
Art 440 (unlike Art 430) does not seem to have a "feeder" section...so if the feeder has a 60 amp OCP what section do you use to allow a 45 amp wire ?

 

[One-eyed Jack]

true... but can you still use the #8
Art 440 (unlike Art 430) does not seem to have a "feeder" section...so if the feeder has a 60 amp OCP what section do you use to allow a 45 amp wire ?

215.3 Feeder ocp directs us to Part I of 240. Table 240.3 air cond/ref directs us to Article 440. You can size and protect the feeder the same as the branch circuit. 215.3 has already allowed us via table 240.3. This is the mud filter. If that dont work I guess I will have to use MapQuest or Co-Pilot cause I'm lost.

 

[david luchini]

215.3 Feeder ocp directs us to Part I of 240. Table 240.3 air cond/ref directs us to Article 440. You can size and protect the feeder the same as the branch circuit. 215.3 has already allowed us via table 240.3.

I'm not sure that this flies. 240.3 says that equipment shall be protected in accordance with the article listed in table 240.3.

240.4 talks about the protection of conductors. And the Parts of Art 440 listed in T240.4(G) only talk about branch circuit conductors for Air Conditioning & Refrigeration equipment. A feeder would have to be protected by 240.4.

I think the #8 feeder in Gus' example would be a violation.

 

[Dan coulstring]

Tolbert, Welcome to the Forum

I agree with your statement and Charlie's answer, but, for fun, lets see if we can muddy the water.
We have ah HVAC unit with a MCA of 45 amps and a MOCP of 60 amps.
We have a NF disconnect at the unit, and a 60 amp breaker in the panel so the wiring from the breaker at the panel is a branch circuit... #8 THHN and a 60 amp breaker could be used.

Now, let's change the non-fiuse disconnect to a fusible. Does this make the wiring from the disconnect a branch circuit and the wiring from the panel a feeder ?
If the wiring from the panel is a feeder must it be rated at 60 amps ?

Augie,
Some people would say we have a very warped sense of FUN

 

[augie47]

I agree , but, if we don't laugh at some of the positions we find ourselves in on Code issues we would go crazy.(ier)

 

[Tolbert]

I have read article 670 and that is how I interrupt the classification of a feeder and a branch circuit on the industrial machine. I am referring to a machine like an extrusion machine or injection machine.

 

[eprice]

Tolbert, Welcome to the Forum

I agree with your statement and Charlie's answer, but, for fun, lets see if we can muddy the water.
We have ah HVAC unit with a MCA of 45 amps and a MOCP of 60 amps.
We have a NF disconnect at the unit, and a 60 amp breaker in the panel so the wiring from the breaker at the panel is a branch circuit... #8 THHN and a 60 amp breaker could be used.

Now, let's change the non-fiuse disconnect to a fusible. Does this make the wiring from the disconnect a branch circuit and the wiring from the panel a feeder ?
If the wiring from the panel is a feeder must it be rated at 60 amps ?

Off of the top of my head, all of the reasons that I can think of for using a fused disconnect have to do with protection of the A/C unit, not the circuit conductors. I think this can fit easily into the definition of "Supplementary Overcurrent Protective Device". If it is a supplementary overcurrent protective device, then I think the supply conductors are still considered branch circuit conductors. The same reasoning applies to iwire's example IMO.

 

[charlie b]

How about when I plug in a plug strip with a built in breaker, does that change the general purpose branch circuit to a general purpose feeder circuit?

I thought we were going to let Gus be the trouble maker on this thread. :roll:

You and I have disagreed on the question of whether, beyond the point at which the "premises wiring system" ends and the "utilization equipment" begins, the NEC is no longer applicable. But this one, at least, is clear: the definition of "branch circuit" ends at the outlet, and the plug strip is not an outlet.

 

[iwire]

the definition of "branch circuit" ends at the outlet, and the plug strip is not an outlet. [/SIZE][/FONT]

Hmmmm ....

The device I plugged into the wall has outlets.

The device I plugged into the wall has a cord that the NEC applies to.

Or am I allowed to place that cord above a suspended ceiling? :grin:

 

[charlie b]

The device I plugged into the wall has outlets.

If you are speaking a layman?s language, yes. If you are using the NEC language, no.

The device I plugged into the wall has a cord that the NEC applies to.

This is a road we have travelled down before. As I recall, much depended on one?s interpretation of the word ?installation,? as used in 90.2(A).

Or am I allowed to place that cord above a suspended ceiling?

Yes, absolutely. You can ?place? it there. Now, were you perhaps interested in ?using? it there?

 

[don_resqcapt19]

I tend to say that if it is not "installed" it is not subject to the rules in the NEC. Pluging a cord or plug strip into an outlet above the ceiling is not installing the cord or plug strip.

I have stated in the past, and still maintian, that many of the rules in the code, especially in Article 422 are total invaild as they are completlety outside the scope of the code.

 

[iwire]

I tend to say that if it is not "installed" it is not subject to the rules in the NEC. Pluging a cord or plug strip into an outlet above the ceiling is not installing the cord or plug strip.

So are you saying the AHJ cannot force the removal of that plug strip based on Article 400?

I have stated in the past, and still maintian, that many of the rules in the code, especially in Article 422 are total invaild as they are completlety outside the scope of the code.

It would be interesting to see how that would play out if push came to shove in a court. But in the real world those sections are enforced and not looked at as outside the scope of the NEC.

If we want to stick within the scope all the required outlets and switches are design issues that should not be in the NEC yet they are and they are regularly enforced.

 

[charlie b]

I tend to say that if it is not "installed" it is not subject to the rules in the NEC.

I submit that that statement is not open to debate. It is absolutely true, as it is explicitly so stated in 90.2(A). What is open to debate, and what has in fact been debated, is whether the act of plugging a plug-and-cord connected item into a wall receptacle constitutes ?installation? of that device.

Plugging a cord or plug strip into an outlet above the ceiling is not installing the cord or plug strip.

I agree. Others might not.

 

[charlie b]

If we want to stick within the scope all the required outlets and switches are design issues that should not be in the NEC yet they are and they are regularly enforced.

The way I see the difference, Bob, is that nailing a box onto a stud, attaching a conduit to that box, running wires through the conduit and into the box and attaching them to a receptacle, then screwing the receptacle securely onto the box does, collectively, constitute "installing" the receptacle. Placing a portable lamp onto an end table and plugging it into a wall outlet does not, in my opinion at least, constitute "installing" the lamp.