277 v. in a dwelling unit
- Thread starter LuisC
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Where does the feed come from? If there is a 480/277 volt source within the building, then you can certainly feed a device or or outside the building with it. But if it originates in one building, I don't think you can run it through another building to reach an outside light. I just took a quick look (all I have time for, right now), and didn't find a code reference. 230.3 prohibits such stuff for services, and I thought there was something similar for branch circuits or feeders.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
pete m. said:
I don't see how those articles are applicable to the OP's question. I believe he wants to run a feed through the building. As Charlie has stated there is a violation for services but I do not know of any for branch circuits. The 277 is not feeding the dwelling as I understand it.
- Location
- Massachusetts
That is correct, that section only applies to fixtures in the unit it has noting to do with conductors passing through.
The NEC does not prohibit 277, 480 or even 600 volts from passing through a dwelling unit.
Why would it?
The NEC does not prohibit 277, 480 or even 600 volts from passing through a dwelling unit.
Why would it?
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
I I. More Than One Building or Other Structure
225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.
225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Good find----add 225.32 to it also. This seems to mean that the OCP cannot be at the first building but must be on the building that the conductors pass thru.Pierre C Belarge said:
- Location
- Massachusetts
Dennis Alwon said:
225.32 has nothing to do with OCPDs.
I assumed the OP was about a multi-dwelling unit, not a separate structure.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
iwire said:
You may be correct... I was thinking pole lights rather than exterior wall lights.
I should also have stated OCP could not be the disco for the building it passed thru, given it was to a separate structure.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
I was not assuming either a separate building or not. I just posted the section based on the conversation as I read it.
Generally speaking, one does not see too much 277V in dwelling units...so maybe it is a building that is somehow attached - maybe a firewall in between buildings. Just a guess........
Generally speaking, one does not see too much 277V in dwelling units...so maybe it is a building that is somehow attached - maybe a firewall in between buildings. Just a guess........
charlie
Senior Member
- Location
- Indianapolis
OK, for what it is worth, we have about 50 units where we have given 480 volt single phase services to dwelling units. We required two phases and the neutral to the cash register (meter) from the 480Y/277V panelboard. The feeder had to contain a neutral and a grounding conductor (it is on the load side of the service disconnecting means). We use the neutral for the cash register's potential coil and the grounding conductor to ground the meter fitting in the normal neutral position. When the EC took the feeder past the cash register, he only took the grounding in the form of EMT and two phase wires. The feeder terminated in a transformer (separately derived system) that feeds the panelboard for the condo owner at 120/240V, 1?, 3w.
M. D.
Senior Member
Not sure I understand what is what here,... but that has never stopped me in the past ,so here goes .
What about 225.7 (c)? would this not a pply and there seems to be alist of places where 277 volt lighting can be used and a dwelling ain't one of them . Again not sure I understand the question being asked:-?
What about 225.7 (c)? would this not a pply and there seems to be alist of places where 277 volt lighting can be used and a dwelling ain't one of them . Again not sure I understand the question being asked:-?
- Location
- Massachusetts
M. D. said:
I think you understood it better then the rest of us, while at least better then I.
It seems you nailed it.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
225.7(C) might not be a player here. We still do not know where and how the circuit is proposed to be installed. The light fixture might be in the parking lot of an apartment building.
- Location
- Massachusetts
charlie b said:
It appears to me that 225.7(C) would prohibit that but 225.7(D) will allow it assuming ballasted fixtures.
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