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older houses and Alum wire

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Just figured I would give you guys a heads up if you have alum wire in your older houses, you might want to look at changing your 220 volt stuff over to Copper. over the years alum deteriorates via the heat and the heat from the amps causing it to get weak, when it gets weak it , and or connections loose up it over AMPS and Poof up in flames. our house we bought in 1982.

2nd time in 2-3 years, Luckly NO damage other than wires burnt to a crisp and some burn marks on drywall and some wood.

Once A year I always made sure of the wires being tight in the Breakers. but never checked any other connections like wire nuts on the water heater connections or other appliances.

Also if you have a alum wire burn at a connection replace the whole wire from where it starts at the BOX  not cut off a foot cause the damage is already done to the wire.

I ended up putting all the Garage 220 stuff on a separate sub panel (in the garage) then conduit to the dryer and Water heater today. Next couple of weeks A/c and Stove but those will be a little more labor intensive.

 

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Ouch! My boy's house in Havasu burned down in '06 due to a remodel/addition done by a previous owner and they didn't replace the AL wiring in the existing part of the house. His house was a total loss.

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my first house I had built was in 2003. I had a welding receptacle added to the garage. They did it in aluminum and i fought them on it. They left it aluminum because they said it was up to code. I bet all my 220 in my current house(built in 2000) is aluminum. 

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The problem is not the aluminum wire, it the connection.  Pig tail with copper properly will suffice.

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Great topic and timing...I am in the process of running power to a shop that we just had built. The electrician gave me a price to run copper and an alternate to run aluminum. There was a pretty big cost difference between the two. I thought about going with the aluminum but would like to hear your thoughts on that. This would not be it the walls, just from service to the new sub panel. The run from the service to the shop is 250'. Not sure if it matters but we are on flood irrigation also. 

Any input that you or anyone else may have on this subject would be greatly appreciated!

 

 

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Aluminum is a big no no for house wiring of any type it is a fire waiting to happen not a matter of when but how bad it will be. Not worth the savings in the long run. Copper takes the load better than aluminum plus the electric wave vibration of current running through the wire copper doesn’t loosen the connections as bad as aluminum. Granted ever year or two at the most connections should be checked for being tight.

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2 hours ago, briant_az said:

Great topic and timing...I am in the process of running power to a shop that we just had built. The electrician gave me a price to run copper and an alternate to run aluminum. There was a pretty big cost difference between the two. I thought about going with the aluminum but would like to hear your thoughts on that. This would not be it the walls, just from service to the new sub panel. The run from the service to the shop is 250'. Not sure if it matters but we are on flood irrigation also. 

Any input that you or anyone else may have on this subject would be greatly appreciated!

 

 

I worked for 3 years as an engineer at a power plant & another 4 years as a shop supervisor at a power circuit breaker rebuild shop. In both jobs we owned / maintained a large amount of low voltage power equipment (low voltage is 600v 3 phase, 480v 3 phase and under). That said, we never, ever used aluminum wire for anything and in the power plant it was forbidden, even for non-critical loads like lighting. 

There are many reasons why copper is better, from conductivity, tarnish resistance and wire flexibility. If it were up to me, I would pay extra for the copper (and I did when running a 60A, 220v circuit for the welder / plasma cutter outlet & a 50A circuit for my air compressor in my current garage).

Another good data point is to take a look at what is used where. Even on the cheapest AWM wire used in appliances in your house, it's copper. The step up to MTW (machine / tool), it's better copper with a higher strand count and better insulation. The highest reliability wire (THHN, THHW, XHHW or Welding / specialty) is high strand count, tinned copper, sometimes with PTFE jacket or other high temp insulators with specific solvent resistance. *EDIT* Many wires carry multiple ratings today so it's not as straight forward as I alluded to here, but there is an order of quality / reliability that you pay for and aluminum is bottom shelf on any list of electrical wire types.

If you were to use aluminum, it would be the weak link in your system from the service box. It would normally be: Service box (copper bus / breakers normally, sometimes aluminum) -> aluminum wire -> brass/copper outlet -> full copper in the welder / motor / etc. tool.

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That MTW wire is the best, because its flexable as well as multi strands and one fo the best features the insulation they use is actually resistance to almost every type of oil, degreaser etc etc. but the UV sucks so its not good with any sunlight. as its made for machine use plus you can solder it and it holds. Thats what I used because I have a shoot pot of it. wire nuts work well on it too

I have spools of #4 and #6 Thhn for runs in conduit from our main fuse box to the machines we have at the shop. that stuff is great BUT sucks with wire nut connections.

I'm pretty much against wire nuts unless a emergency  I use screw in lugs on almost everything.

That all being said I guy I knew in Canada was building a new manufacturing plant, he has over 200 cnc mills and lathes. it was about 15 years or so ago when copper was real high. the looked into Alum wire and the cost savings was around a 1/4 million dollars just using alum vs copper for his runs. he went with the alum. the 1st year they had to go in and retitghted every lug the wires plugged into. after that he gave an update and hadnt had any issues. He also got the contractor to warranty the alum wire for either 5 or 10 years.

if I remember correctly he used 2 sizes up for alum than for copper.

 

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12 hours ago, briant_az said:

Great topic and timing...I am in the process of running power to a shop that we just had built. The electrician gave me a price to run copper and an alternate to run aluminum. There was a pretty big cost difference between the two. I thought about going with the aluminum but would like to hear your thoughts on that. This would not be it the walls, just from service to the new sub panel. The run from the service to the shop is 250'. Not sure if it matters but we are on flood irrigation also. 

Any input that you or anyone else may have on this subject would be greatly appreciated!

 

 

Aluminum for the feed is ok.  SRP and APS both use aluminum triplex to feed residential houses on the incoming service.  Where Aluminum has it's problems is where it connects to outlets or switches.  

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