Dryer Trips Breaker...Except When it Doesn't

[gfretwell]

The number of aluminum house fires compared to copper has dropped to the point of insignificance and most never had any remediation.

I see a lot of line work here in Florida where corrosion is worse than just about anywhere in the country., I never see them use goo on the

1350 alloy wire. The compression sleeve should create a metal to metal gas tight connection where there is no opportunity for corrosion. The sleeves are 1350 too. On a drop, the goo will be gone in a month anyway. Actually the same is true about the connection in a screw binding terminal, as long as the expansion of the screw matches the conductor. The contact should be gas tight The problem was the difference of steel and the 1350 alloy that the first wire used. I have been in a couple of seminars about this with engineers discussing the original failure problems. I think lawyers have more to do with the antioxidant "recommendation" than any real engineering data. (I know of no instructions that say "shall" or "must" use)

Bear in mind CPSC is a political operation, U/L is a pure testing lab. When U/L lists something, I tend to trust them a lot more than some political hack that may be guided by campaign contributions as much as anything else. I feel the same way about classified breakers. When I look at the failure pictures I usually see 3 or more wires in the nut and it makes me wonder what the mix was, how they are joined and that sort of thing. If you have been in the business very long, you have seen plenty of burned up wirenuts with all copper installations. There are also plenty of terminal failures. That is why we put things in boxes.

I think it is just more of the knee jerk reaction. The insurance company tried to cancel me over a pool slide that was 29" tall.

[bud--]

I see no reason to think that is true. Likely the rate is far lower than around the time aluminum was being installed.

Certainly can be.

As I remember, the extensive testing (many thousands of aluminum connections) done for the CPSC showed connections made following the manufacturer's instructions can also fail.

According to the information linked to, based on the research for the CPSC, critical in connections is not just antioxide paste, but abrading the wire to remove the oxide layer. CO/ALR, goo, and abrading can be a good plan.

The new alloy aluminum wire is just as vulnerable to oxide as the old wire. And the new alloy is not better than the old in wire nuts. It is better under binding screws, where extrusion can occur.

Last instructions I saw for Ilsco lugs said to brush aluminum wire and use antioxide. A utility lineman said for the midspan splices on solid aluminum the instruction was to brush the wire and use antioxide.

The recommendations linked to has a lot of information on the Ideal 65 wirenuts. They are not necessarily better than other wirenuts except they have antioxide paste in them. As with other connections you have to abrade the wire for a reliable connection. I would ratner not use Ideal

1. The author would rather use 3M Scotchlocks (which are not UL listed for aluminum).

That would be real interesting to look at. I think larger aluminum wire has few problems because the connection methods, like an allen screw tightening into the side of the wire in a lug, deform the wire and break the insulating oxide surface layer. The Alumicon does the same thing. I wouldn't think a side plate connection would. Or the clamp on 15/20A SquareD QO breakers. And certainly not the binding screws on receptacles and switches.

I would like to see actuarial information from insurance companies on aluminum wire. I am not convinced there is a basis for not insuring. aluminum wire. It gives them a way of not insuring houses 50 years old.

[bob haller]

I quit trusting UL after nearly getting kiled by a machine I repair for a living. the machine has a key lock carring line voltage in in a all plastic cover.

one customer reported the key lock was hard to turn, i happened to be touching the machines frame with one hand while attempting to turn the key.:( I will never ever do that again! 120 volts hand to hand isnt good

next thing i knew i was across the room looking up at the cieling. people came running apparently i screamed...

I called and reported it to UL, the lock should have a ground wire to the machines frame. they werent interested..... the units even today lack a ground for the electric key lock. the manufacturer was informed to but never did anything.......

I also found a machine where the manufacturer fused the neutral side of the power line, UL had inspected the new model and passed the model, fact is I was at the manufacturers plant the same day UL was doing their review, I got to see the new model while the UL reps went to lunch.

UL may try but they are far from perfect:(

[clare]

The new alloy is a LOT less succeptible to corrosion - which is extreme axidation.

If they are not listed, don't use them, regardless WHAT you think. You become liable if and when something goes wrong.

They are NOT approved for aluminum wiring - which says something.

ALL insurance companies in Ontario will insure aluminum wired houses with an inspection - requiring the conversion pigtails (expensive, and in my mind stupid) or coalr outlets

But gives them no "out" on 60 year old houses -

Not sure there are many "decent" home inspectors. Most I have run across are half blind and stupid. They don't see the obvious serious stuff, and pick up on all kinds of stupid little things of no real importance or expense to repair.

Home inspector doesn't notice signs of water damage in ceiling from leak in upstairs tub area - doesn't catch that the overflow is loose and has no gasket, tags a switch as installed upside-down when it is a three-way, complains about no GFCI in the bathroom, and totally misses an owner-installed steel stud wall in the basement wired with NMD wire and no grommets in the studs. Complains about no insulation on the concrete basement wall, but totally misses the fact the attic has barely R14 insulation and only half the vent area it should have, and the eaves troughs are 1/2 inch deep in roof grit off the deteriorated roofing shingles. Then he notes there are nail pops in the drywall, but doesn't notice the front step is crooked and the porch railing is rotted off on 2 of 5 posts and half the anchors to the brick wall areso loose they are holding nothing. And oh, yes - there are 2 cracked switch plates in the garage - where he totally misses the fact the door track is totally rusted away for the bottom 6 inches and the man-door at the back of the garage doesn't close properly because the jam is not square in the framing due to either poor workmanship, damage, or rot.

[clare]

CSA is a LOT more stringent - but if something has NOT been approved by UL there is likely a pretty good case for not using it - since they allow some pretty obvious dangerous defects to pass.

[gfretwell]

It says they don't want to cannibalize the $5 a pop CO/ALR device market with a $2 device and pay U/L $50,000 for the privilege..

[gfretwell]

U/L is basically just testing for the spread of fire

[triple7sss]

Bad breaker. I moved it over to another 30AMP dual breaker and the wire at the breaker never warmed up and never tripped. $15 later I'm in bidness.

Thanks everyone.

[triple7sss]

I kind of noticed that when I took the old breaker out. It is aluminum wire and the contacts on the breaker were...not exactly corroded, but like the wiki article suggests it looked like oxidation had done a number. I cut the wire back an inch or so and put in a new breaker and I'm in good shape.

[gfretwell]

I have never seen anything but the compression sleeve.

A properly torqued termination will deform the wire a little and seal the contact point.

It depends on what it says. If the word "recommend" is used, it is not a requirement.

The ideal 65 is not listed for Al/Al splices.

When you consider hat a properly made Cu/Cu joint should never fail 7x is not that big a number. I still believe most of the aluminum problems are a workmanship problem. The same builders who were cutting costs with aluminum wire, were also taking shortcuts with the quality of the workman. In 1971, I knew guys who were starting as electricians right out of high school and wiring houses by themselves within a week. (Ryan Homes)

[bud--]

The lineman had 2 kinds of midspan splices. One was what you talk about, a sleeve that was compressed onto the wire. The process deforms the wire which breaks the oxide layer. As I understand it, the splice isn't just gas tight, the wire and sleeve are cold-welded together.

The other splice is a sleeve and you just poke the wires into the ends - kinda like a chineese finger torture tube.

I haven't seen "goo" disappear on, for instance, service panel lugs. A major part of the recommendation is to abrade the wire to remove oxide. I never heard that binding screws were a gas tight connection, but if it is gas tight with oxide between the sides the gas tight doesn't help much.

The recommendations I linked to are from a professional engineer who ran testing of many thousands of aluminum connections by an independent lab. He also tested additional copper connections for reference.

I don't remember that instructions for anything say "shall" or "must". IMHO if the installation instructions say to wire brush the wire and use antioxidant it is a UL requirement.

In the linked paper there is a picture of a failing wirenut. Looks like

2 aluminum wires A couple turns of the wirenut spring are red hot. The spring is not intended to carry the current.

Aluminum connections are just more likely to fail. I have heard a number (?like 7x) but I don't remember what it is.

[bud--]

If it is not UL listed for a particular purpose it likely means the manufacturer did not want to spend the money to get it listed for that purpose (like Scotchlocks with aluminum).

True for something like a TV.

For most of the devices we talk about, fuses, circuit breakers, switches, receptacles, etc - UL tests include that the device provides a reasonable function and service life.

[clare]

U/L - Underwriters Labs = insurance issues.

[clare]

Like I said.

[triple7sss]

>

:-)