Aluminum wiring in mobile home

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We will be doing a troubleshooting call this morning on a 1970's era mobile home that has numerous circuits not working (including the swamp cooler, in the midst of a heat way). The job is @ 30 miles from our shop, so I didn't look at it first. But I did explain to the caller that the likely cause was bad connections with aluminum wiring, and that if that was the case, we would need to redo every connection in the home using special connectors. I've ordered 150 Alumiconn's for the repairs.

Then I got to thinking: is it necessary to redo the grounding connection? Cost and labor aren't the issue, but I'm wondering if space in the device boxes will be.
Your thoughts forum?
 

renosteinke

Senior Member
Location
NE Arkansas
Mentioning 'alumniconn' threw me; I've called those things 'King connectors' (after the Manufacturer).

Mentioning a trailer put me into high gear.

Let me be blunt: I've done this once, and once is plenty. I'll explain where the worries are in this minefield- and there are plenty!

Problem #1 is the wiring method. Not just that aluminum wire was used - but that the ground wire is undersized, the boxes are smaller than anything you'll see in a real house, and the cables run unprotected just under the panelling (no drywall).

This means that the ground wire will almost certainly break as soon as you pull the device out - and it will break at the crimp fitting in the back of the box. Doom on you.

It means that there's no room for devices AND pigtails. Larger devices, like GFCI's just won't fit. The connectors make the problem worse. Plan on using some "Wiremold" extension boxes.

Opening the walls is easy, but closing them up neatly is a challenge. Be CAREFULL! The wires run just under the panelling, through notches (not holes) in the half-size 'studs.' In the ceilings, you don't have even that much structure; the ceiling material can be best compared to a dry sponge, rather than any wood product you've ever seen.

Perhaps you need not use the special connectors; there are aluminum-rated switches and receptacles readily available, and the price isn't bad. For GFCI's, though, you're out of luck.

Actually, the REAL reason things are not working probably has little to do with the aluminum wire, and more to do with simple age. The trailer I rewired had dead shorts in two places: the insulating partitions in the control section of the oven had failed (letting the little wires in there short out), and a screw had penetrated a cable when they re-lined the shower stall.

After my experience, I concluded that mobile homes are designed to NOT be worked on, and instead to be disposed of as soon as something breaks.

Finally, it should be noted that States have begun to require special licenses to work on mobile homes, and your EC licence might not be enough. If your state has a "Mobile Home" division, chances are they have separate licensing.
 
Mentioning 'alumniconn' threw me; I've called those things 'King connectors' (after the Manufacturer).

Mentioning a trailer put me into high gear.

Let me be blunt: I've done this once, and once is plenty. I'll explain where the worries are in this minefield- and there are plenty!

Problem #1 is the wiring method. Not just that aluminum wire was used - but that the ground wire is undersized, the boxes are smaller than anything you'll see in a real house, and the cables run unprotected just under the panelling (no drywall).

This means that the ground wire will almost certainly break as soon as you pull the device out - and it will break at the crimp fitting in the back of the box. Doom on you.

It means that there's no room for devices AND pigtails. Larger devices, like GFCI's just won't fit. The connectors make the problem worse. Plan on using some "Wiremold" extension boxes.

Opening the walls is easy, but closing them up neatly is a challenge. Be CAREFULL! The wires run just under the panelling, through notches (not holes) in the half-size 'studs.' In the ceilings, you don't have even that much structure; the ceiling material can be best compared to a dry sponge, rather than any wood product you've ever seen.

Perhaps you need not use the special connectors; there are aluminum-rated switches and receptacles readily available, and the price isn't bad. For GFCI's, though, you're out of luck.

Actually, the REAL reason things are not working probably has little to do with the aluminum wire, and more to do with simple age. The trailer I rewired had dead shorts in two places: the insulating partitions in the control section of the oven had failed (letting the little wires in there short out), and a screw had penetrated a cable when they re-lined the shower stall.

After my experience, I concluded that mobile homes are designed to NOT be worked on, and instead to be disposed of as soon as something breaks.

Finally, it should be noted that States have begun to require special licenses to work on mobile homes, and your EC licence might not be enough. If your state has a "Mobile Home" division, chances are they have separate licensing.

I've worked on more then one :) , and my experience has been that the most common cause of circuit failure was loose connections in device boxes, due mostly to the natural contractions of aluminum wire under load.

And unless I'm mistaken, by the 70's under sized grounds were no longer allowed.

My question was since space is often very limited, given that mobile homes typically use the absolute cheapest and smallest boxes they could get away, with, did anyone have a thought on the necessity of using Alumiconn's on the grounding conductor, since it is non-current carrying.

Thanks for your thoughts on licensing. I hadn't thought about that, though I have rewired trailers in the past and had to pull a permit through a state licensing entity instead of the local city or county.
 

tshea

Senior Member
Location
Wisconsin
I have not worked on trailers since the early 80s. If I recall it was all copper.
The receptacle and switch boxes were cutin types that the wires physically terminated on clips in the switch or receptacle box. An insulating cover was snapped in place. The romex was split for the device and pushed into place, almost like phone blocks!
There was no typical box. Size was just big enough for the wire.
The problems I found were mostly in the breaker box. Bad breakers and what not. The wiring was usually ok but did find problems especially at high usuage devices (receptacles mostly).
Since I was in trailer country, parts were available at the mobile home dealer.
Good luck! If I never work on another trailer it will be too soon!
 

renosteinke

Senior Member
Location
NE Arkansas
I will agree that, by the 70's, reduced size ground wires were long gone. I should know, I was there :)

Yet, it was not until later (1976 I think) that the Feds got into mobile home certifications. At first voluntary, now mandatory, the HUD regulations were the first to apply the NEC to mobile homes, regardless of whether they were permanently anchored or not. As a result, mobile homes were often assembled in manners different from the usual.

Did I say "were?" Better make that "were then- and still are now!" Since a mobile home is made in a factory under engineering supervision and quality control, manufacturers continue to be allowed to make all manner of design changes that no one else is allowed.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Other than working sewage treatment, it's difficult to imagine a less deniable task than the one you are undertaking.
(I have done both..be a difficult choice)
 

renosteinke

Senior Member
Location
NE Arkansas
I have never seen aluminum used as a grounding conductor. The trailer I re-wired had a #16 copper ground with #12 aluminum circuit conductors.
 

Sparky555

Senior Member
Thirty years ago I was in a mobile home owned by a retired electrician. All the original wiring was disconnected and he had installed new surface boxes, conduit and a new service. I suggest you do the same.
 

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
I haven't seen many trailers with AL, maybe they all burnt before customer had a chance to call an electrician, maybe 10 or so in 30 years.

As far as working on trailers being some kind of nightmare, I prefer to consider it an opportunity, either a quick service call at full price or a day or two hard work at full price, not like having to low bid new houses to get the job.
 
I haven't seen many trailers with AL, maybe they all burnt before customer had a chance to call an electrician, maybe 10 or so in 30 years.

As far as working on trailers being some kind of nightmare, I prefer to consider it an opportunity, either a quick service call at full price or a day or two hard work at full price, not like having to low bid new houses to get the job.

It turned into a $1000 job. I couldn't agree more :D
 

dexterg

Member
Run as fast as you can away from this one. We dont work on mobiles period, much less the ones wired in aluminum. It is a fire waiting to happen and you will be the last one that worked on it so you will get the blame...
 

kwired

Electron manager
Location
NE Nebraska
We will be doing a troubleshooting call this morning on a 1970's era mobile home that has numerous circuits not working (including the swamp cooler, in the midst of a heat way). The job is @ 30 miles from our shop, so I didn't look at it first. But I did explain to the caller that the likely cause was bad connections with aluminum wiring, and that if that was the case, we would need to redo every connection in the home using special connectors. I've ordered 150 Alumiconn's for the repairs.

Then I got to thinking: is it necessary to redo the grounding connection? Cost and labor aren't the issue, but I'm wondering if space in the device boxes will be.
Your thoughts forum?

Since you did not look at it first you really don't know if it is wired with aluminum do you?

I have had some of these that are copper wiring and if you lose the circuit at one of the first devices you can have a lot of outlets go down and make it seem like there is a lot of missing power when all it takes is one bad connection near the start of the circuit. They always used back stab devices in these homes and it has been there a long time. The receptacle you find a problem with probably needs replaced even if it was working because it will no longer hold a plug very tight.
 

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
Run as fast as you can away from this one. We dont work on mobiles period, much less the ones wired in aluminum. It is a fire waiting to happen and you will be the last one that worked on it so you will get the blame...

Maybe so but the same could be said about many type jobs, the ones I like because others don't, bidding is not as competetive. I've seen new work go so cheap that I'd have been better off sending GC a check in return for not hiring me, than I would have been if I'd have been low bidder.
 

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
Since you did not look at it first you really don't know if it is wired with aluminum do you?

I have had some of these that are copper wiring and if you lose the circuit at one of the first devices you can have a lot of outlets go down and make it seem like there is a lot of missing power when all it takes is one bad connection near the start of the circuit. They always used back stab devices in these homes and it has been there a long time. The receptacle you find a problem with probably needs replaced even if it was working because it will no longer hold a plug very tight.
yes, and the outlets that go down are often spread out across several rooms, many trailers are wired lengthwise.
 

kwired

Electron manager
Location
NE Nebraska
yes, and the outlets that go down are often spread out across several rooms, many trailers are wired lengthwise.

That is exactly what happened last one I recall working on. They thought they had a major problem someplace, lights and receptacles in two bedrooms, part of living room, hallway, kitchen light did not work. I found a backstab gone bad on first or second outlet on circuit in fairly short time, fixed that and all the rest worked again.
 

dexterg

Member
Maybe so but the same could be said about many type jobs, the ones I like because others don't, bidding is not as competetive. I've seen new work go so cheap that I'd have been better off sending GC a check in return for not hiring me, than I would have been if I'd have been low bidder.


Well, I guess I would have to agree with you there.....(chuckling)
 

Teaspoon

Senior Member
Location
Camden,Tn.
That is exactly what happened last one I recall working on. They thought they had a major problem someplace, lights and receptacles in two bedrooms, part of living room, hallway, kitchen light did not work. I found a backstab gone bad on first or second outlet on circuit in fairly short time, fixed that and all the rest worked again.

I have ran into this same problem with back stabbed receptacles several times,I had one job that really played with my mind.
had lost neutral, I checked every receptacle on the circuit,checked neutral at the panel.I was just about at a loss of what to do next.
I ask the owner if there were in receptacles under the home?
He said yes there is one but I haven't used it since it was under pinned.
Took down a piece of the underpinning, checked this outlet.
There it was plain as day.when I removed the receptacle the neutral wire,
pulled loose. Needless to say it is no longer a receptacle. But a junction box.
 
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