Resi. feeder and service sizing

[hey_poolboy]

Re: Resi. feeder and service sizing

Boy, go to work for 12 hours and see what happens!

I have to agree with iwire. The way it is worded in '05 I don't see how it can apply to feeders other than those from the disconnecting means to the panel board

 

[George Stolz]

Re: Resi. feeder and service sizing

NEC-2005 310.15(B)(6) 120/240 Volt, 3-wire, Single-Phase Dwelling Services and Feeders. For individual dwelling units of one family, two family, and multifamily dwellings, conductors, as listed in Table 310.15(B)(6), shall be permitted as 120/240 Volt, 3-wire, Single-Phase service-entrance conductors, service lateral conductors, and feeder conductors that serve as the main power feeder to each dwelling unit and are installed in raceway or cable with or without an equipment grounding conductor...

Man, that's long. That's one sentence!

Bob, I agree with your assessment. The analogy to 240.4(D) is dead on. This section allows us to ignore normal ampacities the same way, only in the other direction. It doesn't change the ampacity of the wire, it just allows us to "overload" the conductor. I'd almost call it "ampacity vs. rating."

[ July 20, 2005, 11:50 PM: Message edited by: georgestolz ]

 

[iwire]

Re: Resi. feeder and service sizing

I think things would be less confusing if 310.15(B)(6) just disappeared from the code.

 

[charlie]

Re: Resi. feeder and service sizing

I think things would be less confusing if 310.15(B)(6) just disappeared from the code.

 

[George Stolz]

Re: Resi. feeder and service sizing

I think it would be easier to comprehend if it were in a list format, instead of a couple of run-on sentences packed with details.

Example:

Conductors shall be permitted to be connected to equipment rated according to Table 310.15(B)(6) under the following conditions:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">(a) The supply is a single phase, 120/240 Volt, 3 wire system.
  (b) Laterals that serve only one individual dwelling unit.
  (c) Feeders that serve only one individual dwelling unit.
  (d) etc etc</font>

<font size="2" face="Verdana, Helvetica, sans-serif">

I think that would help immensely, IMO.

[ July 21, 2005, 07:08 AM: Message edited by: georgestolz ]

 

[charlie]

Re: Resi. feeder and service sizing

George, that sounds to me like another proposal.

 

[sandsnow]

Re: Resi. feeder and service sizing

Originally posted by hurk27:
George The first three words in 310.15(B)(6) allow that installation.

For dwelling units,

Units is plural, more than one.
No where does it say it's only for one famliy dwelling.

True enough, however all our big multi-family are served at 208y/120 so the table is out.

 

[iwire]

Re: Resi. feeder and service sizing

Originally posted by charlie:

I think things would be less confusing if 310.15(B)(6) just disappeared from the code.

 

[charlie]

Re: Resi. feeder and service sizing

Bob, that sounds to me like another proposal.

Is there an echo in here?