service outlet in attic

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ddubbs103

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Not to sure and having trouble finding it, but here it goes. Can you run a 12/3 for an ac unit in attic 240v system and supply the service outlet off of one of those legs with neutral?
 
ddubbs103 said:
Not to sure and having trouble finding it, but here it goes. Can you run a 12/3 for an ac unit in attic 240v system and supply the service outlet off of one of those legs with neutral?
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It depends-- look at 210.23(A)(2)
What is the load of the unit.
 
thanks , I'm not to sure the load off the top of my head but I know it wasn't even close to 50% of branch ckt, so if I'm interpreting this right it my question would be answered yes. Thanks for the help.
 
You wouldn,t do it in Dennis's house like that.
Wouldn't do it, just wouldn't be prudent.
If the ac trips the breaker and needs repairs. You have no power in attic.
 
this question was made for you I think:-?

http://www.necplus.org/Lists/CodeTopic/DispForm.aspx?ID=9


A 20-A, 240-V nonfused disconnect for an air handler rated for 7.6 amperes is installed in the unfinished attic space of a dwelling unit. The 2-pole breaker is located in the basement panel. To install a duplex receptacle for servicing, can a 3-wire circuit (two ungrounded conductors and a neutral) be run to the nonfused disconnect, and one of the ungrounded conductors as well as the grounded conductor be used to feed the receptacle on the line side of the disconnect?

Answer

In accordance with 210.4(C), this type of multiwire circuit is permitted to supply the line-to-line load and the line-to-neutral load. Because the receptacle is being supplied on the line side of the ac unit disconnecting means, it is in compliance with the requirement of 210.63.
The fact that the ac unit load is 7.6 amperes allows the receptacle outlet to also be supplied by this branch circuit, per 210.23(A)(2). The nameplate on the ac unit must permit the overcurrent protection to be sized at 20 amperes for this to work. The installation of a fused-disconnect at the ac unit does not make a difference, as the conductors from the panelboard to the disconnect, fused or nonfused, are branch-circuit conductors protected by the 20-ampere, 2-pole overcurrent protective device installed at the panelboard.
 
buckofdurham said:
If the ac trips the breaker and needs repairs. You have no power in attic.
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Even if you made the repairs by running cords for the repair, you still wouldn't have a working AC.

Gotta reset the tripped breaker.

Why not turn off the unit at the disconnect, reset the breaker, and do the repair. . .?
 
M. D. said:
this question was made for you I think:-?

http://www.necplus.org/Lists/CodeTopic/DispForm.aspx?ID=9


A 20-A, 240-V nonfused disconnect for an air handler rated for 7.6 amperes is installed in the unfinished attic space of a dwelling unit. The 2-pole breaker is located in the basement panel. To install a duplex receptacle for servicing, can a 3-wire circuit (two ungrounded conductors and a neutral) be run to the nonfused disconnect, and one of the ungrounded conductors as well as the grounded conductor be used to feed the receptacle on the line side of the disconnect?

Answer

In accordance with 210.4(C), this type of multiwire circuit is permitted to supply the line-to-line load and the line-to-neutral load. Because the receptacle is being supplied on the line side of the ac unit disconnecting means, it is in compliance with the requirement of 210.63.
The fact that the ac unit load is 7.6 amperes allows the receptacle outlet to also be supplied by this branch circuit, per 210.23(A)(2). The nameplate on the ac unit must permit the overcurrent protection to be sized at 20 amperes for this to work. The installation of a fused-disconnect at the ac unit does not make a difference, as the conductors from the panelboard to the disconnect, fused or nonfused, are branch-circuit conductors protected by the 20-ampere, 2-pole overcurrent protective device installed at the panelboard.
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Would that be true for a well pump. And the light in the well house
 
I agree with Buck-- don't do it in my house. :)

If this unit were a heating system we may have a different issue.

2008 NEC said:
422.12 Central Heating Equipment.
Central heating equipment other than fixed electric space-heating equipment shall be supplied by an individual branch circuit.
Exception No. 1: Auxiliary equipment, such as a pump, valve, humidifier, or electrostatic air cleaner directly associated with the heating equipment, shall be permitted to be connected to the same branch circuit.
Exception No. 2: Permanently connected air-conditioning equipment shall be permitted to be connected to the same branch circuit.
Click to expand...
 
Yes I believe if you ran a 3 wire uf with ground to a well house you could tap off the one leg of the 240 volt pump if art. 210.23(A)(2) was satisfied.
 
You could also install a small panel in place of the HVAC disco, making the original branch circuit a feeder. Then you'll be able to have separate branch circuits.

The only problem with this idea, as well as the OP's quetion, is that most 240v HVAC equipment doesn't require a neutral, and most people don't install one.
 
I have no idea why people are saying 'not to do it at my house'

The NEC allows it, it is not unsafe and as Al points out any issues with the unit itself can be separated from the outlet by the required disconnecting means. (The NEC requires the service receptacle to be supplied from the line side of the units disconnect)

On commercial RTUs (Roof Top Units) most now come to the job with a factory installed service receptacle supplied by the feeder to the unit.
 
iwire said:
I have no idea why people are saying 'not to do it at my house'
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No one said it was unsafe-- in fact I said it was compliant, however, if there were a short in the unit that tripped the breaker then the receptacle would not work. Not a big deal but I would prefer to not do that. If I had too I would but not by choice.
 
iwire said:
On commercial RTUs (Roof Top Units) most now come to the job with a factory installed service receptacle supplied by the feeder to the unit.
Click to expand...


I havent seen one like that yet, do they have to special order them that way? or maybe it varies by manufacture?
 
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