Mobile Home Feeder

**Roland Miller** · 02-09-2009, 03:41 PM

I just inspected a mobile home. From the pedistal there is 2 inch pvc ran at the correct depth. The HO pulled type USE cable with an insulated equipment grounding conductor from the pedistal to the panel( 4/0 AL). Can this be ran all the way inside to the MH panel??

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Fred Warner · 02-09-2009, 05:09 PM

Originally Posted by Roland Miller

I just inspected a mobile home. From the pedistal there is 2 inch pvc ran at the correct depth. The HO pulled type USE cable with an insulated equipment grounding conductor from the pedistal to the panel( 4/0 AL). Can this be ran all the way inside to the MH panel??

Are you saying USE meaning each conductor is an individual USE conductor or are you saying SEC cable (4-wire with a concentric equipment ground) pulled in the PVC?
If it's individual USE it can be used as long as it's in conduit where it emerges from the ground all the way through to where it enters the MH panel.

**Roland Miller** · 02-09-2009, 05:12 PM

There I go again with the painting--it is a triplexed cable with a separate insulated equipment grounding conductor.

Jeff Remas · 02-09-2009, 05:27 PM

Are all 4 conductors 4/0?

PVC 40 or 80 just in case you are working on a conduit fill issue too.

Still a little confused, is this a jacketed cable?

**Roland Miller** · 02-09-2009, 05:32 PM

Three 4/0 s this is single conductors "triplexed " or layed together--no jacket. It is schedule 40 PVC. It is listed use/use-2. rhw/rhw-2 insulation.

Jeff Remas · 02-09-2009, 05:50 PM

This won't work because you need a 4 wire feeder as I am assuming the pedestal is where the disco is located.

If the PVC is not subject to physical damage where it comes out of the earth and connects to the MDP in the trailer then I don't see a problem unless there is a 4th wire in which case 2" PVC is too small.

**Roland Miller** · 02-09-2009, 05:57 PM

That would be 3-4/0s and a #6 equipment grounding conductor. So it should work. If it were straight USE could you pull it all the way to the MH panel??

Dennis Webber · 02-16-2009, 06:02 PM

Originally Posted by Roland Miller

That would be 3-4/0s and a #6 equipment grounding conductor. So it should work.
If it were straight USE could you pull it all the way to the MH panel??

Yes. It's my understanding that it can run from the disco into the panel board. (Just can't be used as interior wiring as it does not have a flame resistant covering.)

**Roland Miller** · 02-16-2009, 06:19 PM

Dennis--since it is duel rated there is no problem. Straight rated USE would be questionable. I have worked in jurisdictions where the AHJ required a J-Box underneath the house to accommodate the transition from USE to other insulated conductor for final termination in the panel.
http://www.ul.com/regulators/septoct2007.pdf

Dennis Webber · 02-17-2009, 09:12 AM

Originally Posted by Roland Miller

Dennis--since it is duel rated there is no problem. Straight rated USE would be questionable. I have worked in jurisdictions where the AHJ required a J-Box underneath the house to accommodate the transition from USE to other insulated conductor for final termination in the panel.
http://www.ul.com/regulators/septoct2007.pdf

Interesting reference to the IEAI article, thanks Roland.
However, you confused me in your reference to "dual-rated" and "single-rated". Re: "since it is duel rated there is no problem. Straight rated USE would be questionable. Were you referring to temperature rating (USE or USE-2) or to something else?
It's my understanding that either single conductor in conduit or a multi-conductor cable can be run directly into the panelboard mains. Is this also you understanding? (Did I miss something in the article?)

**Jerry Peck** · 02-17-2009, 09:35 AM

Originally Posted by Dennis Webber

Interesting reference to the IEAI article, thanks Roland.
However, you confused me in your reference to "dual-rated" and "single-rated". Re: "since it is duel rated there is no problem. Straight rated USE would be questionable. Were you referring to temperature rating (USE or USE-2) or to something else?

What I think Roland is saying is that if the USE is only rated as USE, then, no, single-rated USE cable cannot be used inside the building, except for termination at the service equipment or meter. Since the service equipment is outside at the pole/pedestal, USE is not allowed to terminate at the interior panel.

If the USE were also rated as RHW or XHHW (dual-rated), then it would be allowed to continue to the interior panel which is not service equipment.

Multi-conductor USE is available as USE or as USE/RHW or USE/XHHW (i.e., dual-rated), thus, depending on the rating of the USE in the installation, it may or may not be allowed inside the structure to the interior panelboard which is not service equipment.

Single-conductor USE is only available as USE (i.e., single-rated) and is therefore not allowed to terminate inside the structure to the interior panelboard which is not service equipment.

The key, besides the single- or dual-rating is that the service equipment is outside on the pole/pedestal, thus only dual-rated USE is allowed to terminate inside at the panelboard.

It's my understanding that either single conductor in conduit or a multi-conductor cable can be run directly into the panelboard mains. Is this also you understanding? (Did I miss something in the article?)

Only if the panelboard mains are the main disconnects and part of the service equipment.

With mobile homes, those main disconnects will be outside with the service equipment on the pole/pedestal.

**Roland Miller** · 02-17-2009, 09:44 AM

Jerry nailed it. Thanks Jerry!

Dennis Webber · 02-17-2009, 10:48 AM

Originally Posted by Jerry Peck

What I think Roland is saying is that if the USE is only rated as USE, then, no, single-rated USE cable cannot be used inside the building, except for termination at the service equipment or meter. Since the service equipment is outside at the pole/pedestal, USE is not allowed to terminate at the interior panel.

From the above, your saying that since it terminates at the outside disconnect, it can no longer be used to connect to the interior panel lugs. At this point one would expect to see SE (or other approved service conductors) running from the disco to the panelboard. That makes sense to me. (Hate to admit it, but I never thought of looking at this in that manner before. I normally don't get involved in this area of inspection.)

Multi-conductor USE is available as USE or as USE/RHW or USE/XHHW (i.e., dual-rated), thus, depending on the rating of the USE in the installation, it may or may not be allowed inside the structure to the interior panelboard which is not service equipment.

Ah, now I understand. My confusion was that there is no reference to this construction (single - dual rated) in the NEC or UL White Book (although I'm still using the 2006 book.) I changed the terminology from "rated" to "constructed" (same meaning, it's how I was able to relate to it.) It then became clear you were saying that the cable is dual "constructed", to function either as USE or XHHW. Crystal clear now.

Thanks Jerry (Roland). This is an excellent example of where direct experience has so much more to offer than just what's published in the Code.