NEC Feeder Definition

[Alwayslearningelec]

Feeders are essentially everything between the service equipment and the final overcurrent device. The NEC definition of feeder is “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.”

If you have a breaker in a panel feeding a disconnect next to the motor I assume the disconnect is technically the final OCPD??

 

[LarryFine]

If you have a breaker in a panel feeding a disconnect next to the motor I assume the disconnect is technically the final OCPD??

Technically, if it's an OCPD, then yes; if it's just a switch, no.

We often debate whether the entire thing is a branch circuit.

 

[infinity]

If you have a breaker in a panel feeding a disconnect next to the motor I assume the disconnect is technically the final OCPD??

If the disconnect contains an OCPD then technically yes. There is always the argument about the OCPD being supplementary overcurrent protection at the end making it a branch circuit.

 

[don_resqcapt19]

If that makes the conductors feeders, then you will not be permitted to used the rules in Article 430 for motor branch circuit conductors.

 

[LarryFine]

If that makes the conductors feeders, then you will not be permitted to used the rules in Article 430 for motor branch circuit conductors.

That was the reason for the debate; why the entire circuit couldn't use the same wire size.

 

[infinity]

If that makes the conductors feeders, then you will not be permitted to used the rules in Article 430 for motor branch circuit conductors.

That was the reason for the debate; why the entire circuit couldn't use the same wire size.

Is there someone smart who can rewrite this so there is no debate when there is supplementary protection and still satisfy the issue with motor circuits?

 

[wwhitney]

If that makes the conductors feeders, then you will not be permitted to used the rules in Article 430 for motor branch circuit conductors.

But if you apply the rules in Article 430 for feeders supplying just a single motor, you will get the same result as you would get with the rules for motor branch circuit conductors.

Cheers, Wayne

 

[don_resqcapt19]

Is there someone smart who can rewrite this so there is no debate when there is supplementary protection and still satisfy the issue with motor circuits?

If the device at the motor is supplementary protection then the supply side conductors are branch circuit conductors.

 

[LarryFine]

If the device at the motor is supplementary protection . . .

Okay, then what determines that?

 

[don_resqcapt19]

Okay, then what determines that?

The definition of feeder.

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. (CMP-10)

A supplementary OCPD is not a branch-circuit OCPD

 

[LarryFine]

The definition of feeder.

A supplementary OCPD is not a branch-circuit OCPD

Let me rephrase: what determines whether the local OCPD is supplemental?

Or are you saying that it always is on a dedicated (single-load) circuit?

 

[don_resqcapt19]

Let me rephrase: what determines whether the local OCPD is supplemental?

Or are you saying that it always is on a dedicated (single-load) circuit?

I was only replying to this:
"Is there someone smart who can rewrite this so there is no debate when there is supplementary protection and still satisfy the issue with motor circuits? "
However the only time I would let the OCPD at the equipment make the supply to the OCPD a feeder is where the code required the OCPD at the equipment. For example changing out an air conditioner with one that has a lower maximum OCPD. No real code to support that, but it is how I apply the current rules.

 

[tortuga]

Okay, then what determines that?

The listing of the breaker