glene77is
Senior Member
- Location
- Memphis, TN
Anyone had personal experience with Aluminum Wiring Hazards,
or have any horror stories?
or have any horror stories?
Aluminum Wiring Hazards
- Thread starter glene77is
- Start date
- Status
Brady Electric
Senior Member
- Location
- Asheville, N. C.
Aluminum Wiring Hazards
Not these days. Back when I started some electricians used Aluminum wiring in houses before they stopped selling Aluminum #12 and #14 , I always found wire tighten to much to flatten it, wire backed stabbed in outlets which has always been a no no, wire not made good in joints and mixing Al and Copper together not using the proper wire nut or split bolt, and most of all not tighten under screws.
Now days using Al wire in its proper place on services I don't run into many problems. Mostly I find that some don't tighten Al or copper properly and it arch's and burns into or messes up the panel board.
The best thing they ever done is to outlaw Al wire smaller than #8 in N.C.
Personally I only use Al wire except for some services 4/0 or larger but I prefer copper if its in the jobs budget.
Like everything else by the time we are allowed to use wire, outlets, and so on its been tested to be OK when used like the manufacture suggest.
There again I'm talking about N.C.
Semper Fi Buddy
Not these days. Back when I started some electricians used Aluminum wiring in houses before they stopped selling Aluminum #12 and #14 , I always found wire tighten to much to flatten it, wire backed stabbed in outlets which has always been a no no, wire not made good in joints and mixing Al and Copper together not using the proper wire nut or split bolt, and most of all not tighten under screws.
Now days using Al wire in its proper place on services I don't run into many problems. Mostly I find that some don't tighten Al or copper properly and it arch's and burns into or messes up the panel board.
The best thing they ever done is to outlaw Al wire smaller than #8 in N.C.
Personally I only use Al wire except for some services 4/0 or larger but I prefer copper if its in the jobs budget.
Like everything else by the time we are allowed to use wire, outlets, and so on its been tested to be OK when used like the manufacture suggest.
There again I'm talking about N.C.
Semper Fi Buddy
electricguy61
Senior Member
The problem is seldom the wire, its the connections.
I've seen panels that have caught on fire, receptacles that burned at the backstabs and burned up the wall and melted the fiberglass SG box.
We charge $35 to replace devices wired with aluminum (typically 3 purple nurples @ $2 a piece)((Ideal 65)). Always carefully re-strip the wire and don't over tighten the connector.
You can search this forum for an in depth discussion of this topic and these connectors, but I've had no problems with them when installed per instructions.
I've seen panels that have caught on fire, receptacles that burned at the backstabs and burned up the wall and melted the fiberglass SG box.
We charge $35 to replace devices wired with aluminum (typically 3 purple nurples @ $2 a piece)((Ideal 65)). Always carefully re-strip the wire and don't over tighten the connector.
You can search this forum for an in depth discussion of this topic and these connectors, but I've had no problems with them when installed per instructions.
Friday's pricing for -
Aluminum per LB (ingot) $.7428
Copper per LB $1.38 to $1.46
Depending on the time of day.
All the commodities are tanking hard. Aluminum is still a better buy per pound, per foot of wire, in cost calculation. Best check them job specs.
Aluminum per LB (ingot) $.7428
Copper per LB $1.38 to $1.46
Depending on the time of day.
All the commodities are tanking hard. Aluminum is still a better buy per pound, per foot of wire, in cost calculation. Best check them job specs.
glene77is
Senior Member
- Location
- Memphis, TN
Brady,
Obviously you have had some experience with Alum,
and had to solve some problems with it.
I just repaired an Alum/Copper joint set, #10's, where the original electrician had made use of split-bolts, with an wedge between the wires. The electrolysis had set in ( Alum to Brass in this case ),
so the heat built up, and the Alum wire broke off.
Grease was all over the joint, under the tape, over the tape!
with the older aluminum.
I understand that newer Alum is a better alloy,
and larger Alum 4/0 and up is used / crimp connected
all the time by the POCO.
Here is the reason for my opinion about smaller devices,
based on using what I call '1960 Alum Alloy':
The co-efficient of restitution of Alum is much less than copper.
That is to say, if you flatten it, it will stay flattened!
The 'creep' of the metal is such that it tends to take the shape
of the compressing metal screw head.
Then, with thermal expansion/contraction,
a very thin opening (non gas-tight contact) can occur
where the oxidation begins.
Alum oxide is used on computer chips for insulation,
so you can imagine that Alum oxide in a connection
will generate more heat, more expansion/contraction,
more oxidation, more heat again.
I have lived through some of this,
and found Inspect-NY to be a real eye-opener.
See www.inspect-ny.com/aluminum/aluminum.htm
for 40 pages of good experimental info, good pictures,
thermal pics, recommendations, etc.
I have avoided use of any physics equations,
to be clear and general in my comments.
Obviously you have had some experience with Alum,
and had to solve some problems with it.
Your comments are welcome!
...
Obviously you have had some experience with Alum,
and had to solve some problems with it.
I just repaired an Alum/Copper joint set, #10's, where the original electrician had made use of split-bolts, with an wedge between the wires. The electrolysis had set in ( Alum to Brass in this case ),
so the heat built up, and the Alum wire broke off.
Grease was all over the joint, under the tape, over the tape!
I don't think there is a proper 'torqued' spec for small device screws
with the older aluminum.
I understand that newer Alum is a better alloy,
and larger Alum 4/0 and up is used / crimp connected
all the time by the POCO.
Here is the reason for my opinion about smaller devices,
based on using what I call '1960 Alum Alloy':
The co-efficient of restitution of Alum is much less than copper.
That is to say, if you flatten it, it will stay flattened!
The 'creep' of the metal is such that it tends to take the shape
of the compressing metal screw head.
Then, with thermal expansion/contraction,
a very thin opening (non gas-tight contact) can occur
where the oxidation begins.
Alum oxide is used on computer chips for insulation,
so you can imagine that Alum oxide in a connection
will generate more heat, more expansion/contraction,
more oxidation, more heat again.
I have lived through some of this,
and found Inspect-NY to be a real eye-opener.
See www.inspect-ny.com/aluminum/aluminum.htm
for 40 pages of good experimental info, good pictures,
thermal pics, recommendations, etc.
I have avoided use of any physics equations,
to be clear and general in my comments.
Obviously you have had some experience with Alum,
and had to solve some problems with it.
Your comments are welcome!
...
glene77is
Senior Member
- Location
- Memphis, TN
You see right through it all,
right to the problem!
You will find www.Inspect-NY has some very interesting test results
concerning the 'UL' approval of 'Purples', and why there are no other sizes than the original. They have tests and photographs comparing several wire-nuts alongside the 'Purples'.
Having used 'Purples' since their introduction several years back,
I found it interesting that they ALL fall into the same category.
Being an 'engineering' type, I like to test for myself, just to see.
So, I set out a set of experiments to see for myself,
and I was reasonably able to get the similar results.
Not the exact same test, mind you,
and not so controlled and exact as Aronstein's tests,
but my simple experiments obtained interestingly similar results.
Your Comments are welcome.
We all learn something from each other.
...
glene77is
Senior Member
- Location
- Memphis, TN
Rock,
I hope Alum does not become the romex of choice!
The problem things became more interesting than ever
when I lived in a 3000 house area,
all wired with Alum,
and every month another house burned to the ground !!!
Mine could have been next (horrors).
So, I checked around, here in Memphis, and found several 'old timers' who knew eactly what the problem was, and exactly how to 'fix' the joints. None of the younger (fine) master electricians understood the problem, but several 'old timers' had been through it.
F. Baker uses his stock of Alum Romex to make Alum to Alum connections via pig-tail into UL approved Alum recepticals. He also volunteered that he dips the wire, abrades the surface (dragging the grease into the cuts), then puts the wire under the screw.
He figured it out for himself, but I had to search the iNet.
Check www.Inspect-NY for a very good set of pages and photos on this subject.
We used splice blocks (similar to Polaris), alloy material (non steel),
with set-screws and embedded silicon grease, and plastic covers.
That was while they were available locally, now they must be ordered iNet.
I hate to think that I might be spending more time fixing Alum fire damage.
It is not the way I really want to make a living!
Hope you find this forum useful,
and your comments are welcome.
...
I hope Alum does not become the romex of choice!
The problem things became more interesting than ever
when I lived in a 3000 house area,
all wired with Alum,
and every month another house burned to the ground !!!
Mine could have been next (horrors).
So, I checked around, here in Memphis, and found several 'old timers' who knew eactly what the problem was, and exactly how to 'fix' the joints. None of the younger (fine) master electricians understood the problem, but several 'old timers' had been through it.
F. Baker uses his stock of Alum Romex to make Alum to Alum connections via pig-tail into UL approved Alum recepticals. He also volunteered that he dips the wire, abrades the surface (dragging the grease into the cuts), then puts the wire under the screw.
He figured it out for himself, but I had to search the iNet.
Check www.Inspect-NY for a very good set of pages and photos on this subject.
We used splice blocks (similar to Polaris), alloy material (non steel),
with set-screws and embedded silicon grease, and plastic covers.
That was while they were available locally, now they must be ordered iNet.
I hate to think that I might be spending more time fixing Alum fire damage.
It is not the way I really want to make a living!
Hope you find this forum useful,
and your comments are welcome.
...
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