generator fed branch circuit

[soobturbo]

I am working in a building with all power de-energized and the contractor needs lighting for some of the interior work to be performed.
They are asking to hook a single circuit of existing lights (eight light fixtures total) to a portable generator to provide the light they need.
There is nothing else connected to this row of lights.
They have disconnected the the branch circuit from the feeder in a junction box and have connected this single circuit to the generator. (this has already been done and functioning properly when I was asked of the legality of it).
Question is, is this legal? I have been looking through the code book and found a reference not allowing it (250.34 A 1) The generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator. or both, but have not found anything allowing it.
I am thinking that since it is temporary there may be a code reference allowing it even though 590.3 (A) states: Except as specifically modified in this article, all other requirements of this Code for permanent wiring shall apply to temporary wiring installations.
Any help would be greatly appreciated. any code references would also be appreciated.

Thank you

 

[tom baker]

Your answer is in Art 702. Need to make sure the genny has a solid bond on the neutral.

 

[soobturbo]

Your answer is in Art 702. Need to make sure the genny has a solid bond on the neutral.

thank you sir!

 

[tom baker]

Thank you for using the forum. Don’t be a stranger.

 

[Todd0x1]

Your answer is in Art 702. Need to make sure the genny has a solid bond on the neutral.

Wouldn't this just fall under 590 since its temporary on a construction site?

 

[soobturbo]

Wouldn't this just fall under 590 since its temporary on a construction site?

That's what I was thinking but it's a bit vague to me. I think the problem is they are using installed building lighting as temporary fed from a generator.

 

[tom baker]

702 has the rules for a generator with no transfer switch, its premise wiring not temp wiring

 

[don_resqcapt19]

Wouldn't this just fall under 590 since its temporary on a construction site?

But if there is no specific rule in 590, the rules in all of the other code Articles and sections apply.
[/quote]590.2 All Wiring Installations.
(A) Other Articles.
Except as specifically modified in this article, all other requirements of this Code for permanent wiring shall apply to temporary wiring installations.[/quote]

 

[Todd0x1]

That's what I was thinking but it's a bit vague to me. I think the problem is they are using installed building lighting as temporary fed from a generator.

But if the building lighting is disconnected from the building's electrical system, wouldn't it become part of the temporary installation?

 

[gadfly56]

But if the building lighting is disconnected from the building's electrical system, wouldn't it become part of the temporary installation?

I would think that's so only if they roll up the lighting and take it with them when they are done. It sounds like existing lighting, which will remain after the work is complete, is being hooked up to the generator.

 

[soobturbo]

I would think that's so only if they roll up the lighting and take it with them when they are done. It sounds like existing lighting, which will remain after the work is complete, is being hooked up to the generator.

The lights will remain after the work is performed. But when complete, the lights will be connected back to building power (maybe). I think the lighting circuit should be considered temporary once removed from the building, and permanent once it is installed back as original. This is a major renovation job being performed on a large storage building, so, the scope of work is changing weekly depending on what the engineers want as a finished product( I have heard " oh yea, we can do this now" too many times).

 

[jim dungar]

They have disconnected the the branch circuit from the feeder in a junction box and have connected this single circuit to the generator.

So what your ruling be if they had made the connection at a manual tranfer switch instead of a junction box?
Are you saying portable generators cannot feed permanent wiring?

 

[tom baker]

702 has the rules for when no transfer switch is used

 

[synchro]

From the 2020 NEC:

590.4(G) Splices. A box, conduit body, or other enclosure, with a cover installed, shall be required for all splices. ...

Exception No. 2: On construction sites, branch-circuits that are permanently installed in framed walls and ceilings and are used to supply temporary power or lighting, and that are GFCI protected, the following shall be permitted:
(1) A box cover shall not be required for splices installed completely inside of junction boxes with plaster rings.
(2) Listed pigtail-type lampholders shall be permitted to be installed in ceiling-mounted junction boxes with plaster rings.
(3) Finger safe devices shall be permitted for supplying and connection of devices.

The wording in bold letters above corresponds to the situation that the OP described, and it is a condition in order for the exception to be applicable. This exception pertaining to splices in temporary wiring was added in the 2020 NEC.

 

[synchro]

Now the wording in 590.4(G) Ex. 2 "installed in frame walls" and its references to plaster rings is somewhat limiting. It wouldn't apply to exposed conduit installations. However, I think that there is a presumption in this exception that temporary power applied to existing branch circuits can be an acceptable practice if other requirements are met.

 

[soobturbo]

So what your ruling be if they had made the connection at a manual tranfer switch instead of a junction box?
Are you saying portable generators cannot feed permanent wiring?

I think this situation is fine. I have a safety officer who has an ongoing dislike for this contractor causing problems.

 

[soobturbo]

Now the wording in 590.4(G) Ex. 2 "installed in frame walls" and its references to plaster rings is somewhat limiting. It wouldn't apply to exposed conduit installations. However, I think that there is a presumption in this exception that temporary power applied to existing branch circuits can be an acceptable practice if other requirements are met.

I agree. This is one circuit, from the generator to the single line of light fixtures in an open ceiling. 3/4" RMC. It is gfci breaker protected and in no way connected to anything else in the building.

 

[jim dungar]

From the 2020 NEC:

590.4(G) Splices. A box, conduit body, or other enclosure, with a cover installed, shall be required for all splices. ...

Exception No. 2: On construction sites, branch-circuits that are permanently installed in framed walls and ceilings and are used to supply temporary power or lighting, and that are GFCI protected, the following shall be permitted:
(1) A box cover shall not be required for splices installed completely inside of junction boxes with plaster rings.
(2) Listed pigtail-type lampholders shall be permitted to be installed in ceiling-mounted junction boxes with plaster rings.
(3) Finger safe devices shall be permitted for supplying and connection of devices.

The wording in bold letters above corresponds to the situation that the OP described, and it is a condition in order for the exception to be applicable. This exception pertaining to splices in temporary wiring was added in the 2020 NEC.

Exception No. 2 is not applicable; the lighting is not temporary, it is permanent.

 

[synchro]

Exception No. 2 is not applicable; the lighting is not temporary, it is permanent.

It’s also not applicable to the OP’s case because Exception 2 is for permitting installation methods that are not allowed on permanent installations like the OP has, as long as GFCI protection is provided on the branch circuit. Exception 2 does, however, mention “branch-circuits that are permanently installed … and are used to supply temporary power or lighting”. And so permanent branch circuit wiring used for temporary lighting is presumably allowed.

I will note that permanently installed receptacle outlets are permitted to provide temporary power as long as GFCI protection is present:

590.6(A)(2) Receptacle Outlets Existing or Installed as Permanent Wiring. Ground-fault circuit-interrupter protection for personnel shall be provided for all 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets installed or existing as part of the permanent wiring of the building or structure and used for temporary electric power.

However, I did not see the use of permanently installed luminaires for temporary lighting mentioned in Article 590. Perhaps this is because no requirement for GFCI protection like those in 590.4(G) Ex. 2 and 590.6(A)(2) would be needed for permanently installed lighting?
Based on the different responses on this thread there seems to be some ambiguity in the interpretations of 590.

 

[ceb58]

I agree. This is one circuit, from the generator to the single line of light fixtures in an open ceiling. 3/4" RMC. It is gfci breaker protected and in no way connected to anything else in the building.

I had a wise inspector tell me once on a job with temp wiring and lights " you are the electrician it's your job to make sure it's safe as long as that happens you can do what you need to do for temp power"