cold creep - aluminum wiring
cold creep - aluminum wiring
(OP)
Hi,
I would like to hook up my new (actually used, but new for me) arc welder in my garage. I need a 50 amp 230 V outlet and am considering Al-wiring since it is about half as expensive as copper wiring. Did some research and found out about the cold creep. Found different opinions, from the suggestion to not use AL to it is fine to use but you have to check the connections every two years.
I am almost at the point where I decided to use the AL wire. Any final suggestions?
Thanks for any input on the subject.
I would like to hook up my new (actually used, but new for me) arc welder in my garage. I need a 50 amp 230 V outlet and am considering Al-wiring since it is about half as expensive as copper wiring. Did some research and found out about the cold creep. Found different opinions, from the suggestion to not use AL to it is fine to use but you have to check the connections every two years.
I am almost at the point where I decided to use the AL wire. Any final suggestions?
Thanks for any input on the subject.






RE: cold creep - aluminum wiring
Do an Internet search regarding termination of Al wire, follow the instructions, and it should not be a major concern with new equipment.
David Castor
www.cvoes.com
RE: cold creep - aluminum wiring
As long as you KNOW that you are going to have to retighten the connections periodically, then you can make the decision on that basis. It is those who don't know to check and/or retighten that get in trouble.
Not that I liked them, the Power Company brought their service in with AL wire and I had to get them out every couple of years to take the transformer out so I could retighten their connection.
During a 12 day outage due to a hurricane in our area, I went around and retighened all the AL connections at my home.
Since you know to do it, you shouldn't have any problem.
I hate AL wire, by the way.
rmw
RE: cold creep - aluminum wiring
If this is a long run and a lot of dollars are involved, consider copper pigtails on the ends of the aluminum conductors. There are a number of crimp type connectors on the market that have enough contact area to connect a copper cable to an aluminum conductor without cold flow issues. Then your connections to the breaker and to the receptacle will be made with copper conductors.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: cold creep - aluminum wiring
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: cold creep - aluminum wiring
We finally invented a solution which was based on spring steel that we cut in pieces, bent and put inside the terminal clamp so that contact pressure was maintained. That, combined with some kind of grease that they probably also used for their Kalashnikovs, made the situation somewhat better.
But, given that experience, I would never use Al for control cables and light gauge power cables. For heavier gauge, there are special terminals that work well. No problems there.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: cold creep - aluminum wiring
The following is from an ABB document.
RE: cold creep - aluminum wiring
http:
While the article is aimed and the use of fine stranded conductors with standard wire terminations, this part is a general comment.
RE: cold creep - aluminum wiring
If anyone wants to get their hands dirty try this:
Install a #6 AWG seven strand cable in a set screw terminal. Use recommended torque.
Give the cable a slight twist in the direction to unlay the stranding.
Drop the cable out of the terminal.
Test two:
Install a new piece of cable and over torque it to a ridiculous extreme.
Give the cable a slight twist and drop it out of the terminal.
The manufacturers torque recommendation is great if the cable is never touched in any way forever after installation.
Don't think of moving the cable so as to be able to measure the current with a clamp on ammeter.
I have encountered many installations where heat damage of one type or another was done as a result of a connection that was probably up to spec when installed but then became loose.
One instance was a 1200 amp switch that was destroyed due to heating that started in the connections.
Recommendations:
1> Tighten the terminal.
2> Twist the cable back and forth as much as possible.
3> Retighten. The screw will now turn easily from 1/4 to 1/2 turn.
Repeat until the screw stays tight.
Exceptions:
Some compacted strand cables will stay tight the first time.
This is for copper. For aluminum conductors in sizes from #14 AWG to about # 8 AWG don't try to put the conductor under a screw type terminal. Use a suitable connector to connect a copper pigtail to the end of the aluminum and connect the copper as you would do normally.
How to connect the pigtail?
There are some excelent connectors on this page for smaller sizes.
http:/
There appears to be only one connector still listed for cu/al. and it may not be large enough.
The Twister Al/Cu
In years past I have had excellent results using either Wing Nuts or B-Caps with aluminum. Unfortunately these are no longer listed for Al. If you do use them, fill them with a corrosion inhibitor such as Penetrox or No-Alox. After connecting the wire wipe off the excess grease and tape well to prevent the grease from weeping.
For aluminum (and copper connections that may be subject to load cycling) look for:
in the specs.
Avoid connectors with for aluminum use.
For larger sizes consider a butt splice. Burndy has a good selection of Cu/Al rated butt spices.
Go here and drill down:
http://w
Search on this number for an example:
YSU4W8W
Good luck.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: cold creep - aluminum wiring
Alumiconn apparently works better using set screws: http://www.alcopstore.com/
Used with 10-12 solid aluminum and 18-10 stranded or solid copper.
RE: cold creep - aluminum wiring
I don't know about the rest of the world, but in the US, the cost savings of using Al wire in this size can be dramatic - often 50% cost savings or more for the same current capacity. Virtually all service entrance cable into residential panels in my part of the world is aluminum and most dryer and range circuits are aluminum.
David Castor
www.cvoes.com
RE: cold creep - aluminum wiring
Your method of tighting the connecton, wiggling or twisting the wires, and tighting again is a common installation method and one that I normally use. I just wish I could find a written statement from a connector manufacturer or NRTL that tells me this is the correct way to make a mechanical lug termination.
RE: cold creep - aluminum wiring
Material cost is certainly getting higher but our labour rates are higher in whatever country-neutral measurement you use so I can imagine that materials are a greater percentage of total cost in the US. A 50A circuit shouldn't be bigger than 10mm²unless it's a very long run, so in this case I wouldn't expect a large cost difference but certainly on big cables copper is becoming ludicrously expensive.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: cold creep - aluminum wiring
Alan
RE: cold creep - aluminum wiring
Here are a couple of interesting reads for you:
http://ww
http://copperrod.ca/egy/tecdoc/6.htm
Good luck with your welder.
rmw