Copper vs Aluminum conductor (Pros & Cons)
- Thread starter MO EE
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bdarnell
Senior Member
- Location
- Indianapolis, IN
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- Retired Engineer
Re: Copper vs Aluminum conductor (Pros & Cons)
We use literally TONS of alum MC cable for feeders all the way up to and including 750 kcmil. It's lighter and more cost effective. We always use MAC-ADAPTS at both ends and follow the maunf. instructions on handling and terminating.
More and more specifying engineers are changing job specs to permit the use of large size MC feeders, so we can be more competitive in the market.
Of course, copper will always have a place in the industry and it's use is almost required in some situations.
We use literally TONS of alum MC cable for feeders all the way up to and including 750 kcmil. It's lighter and more cost effective. We always use MAC-ADAPTS at both ends and follow the maunf. instructions on handling and terminating.
More and more specifying engineers are changing job specs to permit the use of large size MC feeders, so we can be more competitive in the market.
Of course, copper will always have a place in the industry and it's use is almost required in some situations.
JohnE
Senior Member
- Location
- Milford, MA
Re: Copper vs Aluminum conductor (Pros & Cons)
On a side note, (I'll guess it's been discussed in previous posts), does everyone realize that oxide inhibiting compound is not required, and I believe prohibited, on aluminum terminations? I received this information in a letter from an aluminum manufacturer at a recent inspector's meeting. MA had an amendment requiring it's use until I believe the 1993 code.
On a side note, (I'll guess it's been discussed in previous posts), does everyone realize that oxide inhibiting compound is not required, and I believe prohibited, on aluminum terminations? I received this information in a letter from an aluminum manufacturer at a recent inspector's meeting. MA had an amendment requiring it's use until I believe the 1993 code.
bdarnell
Senior Member
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- Indianapolis, IN
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- Retired Engineer
Re: Copper vs Aluminum conductor (Pros & Cons)
John -
I'm not sure I understand your post. Do you mean that oxide inhibiting compound is not to be applied to an aluminum termination such as a mechanical lug ? Every compression connector that we use is filled with this stuff. If this is something that the aluminum industry is recommending against, somebody better tell T&B, Burndy, et.al.
John -
I'm not sure I understand your post. Do you mean that oxide inhibiting compound is not to be applied to an aluminum termination such as a mechanical lug ? Every compression connector that we use is filled with this stuff. If this is something that the aluminum industry is recommending against, somebody better tell T&B, Burndy, et.al.
bphgravity
Senior Member
- Location
- Florida
Re: Copper vs Aluminum conductor (Pros & Cons)
I don't think that statement is exactly accurate. Most aluminum conductor products no longer require the use of an antioxident compound, however most still recommend its use.
Here is a comment by UL,
I don't think that statement is exactly accurate. Most aluminum conductor products no longer require the use of an antioxident compound, however most still recommend its use.
Here is a comment by UL,
JohnE
Senior Member
- Location
- Milford, MA
Re: Copper vs Aluminum conductor (Pros & Cons)
The memo we were given states in part:" Al/Cu connectors are tested to UL 486B:
a. UL 486B (par 7.5, p.12) "If specific instructions for assembling the conector to the conductor are furnished with the connector by the manufacturer such instructions are to be followed in the preparation of the samples, except the conductor is not to be brushed or abraded and an antioxidant is used only if the connector is pre-filled with the antioxidant.""
My point was just that I think a lot of people are under the false impression that oxide inhibiting compound must always be used when terminating aluminum conductors.
The memo we were given states in part:" Al/Cu connectors are tested to UL 486B:
a. UL 486B (par 7.5, p.12) "If specific instructions for assembling the conector to the conductor are furnished with the connector by the manufacturer such instructions are to be followed in the preparation of the samples, except the conductor is not to be brushed or abraded and an antioxidant is used only if the connector is pre-filled with the antioxidant.""
My point was just that I think a lot of people are under the false impression that oxide inhibiting compound must always be used when terminating aluminum conductors.
gettingstarted
Member
Re: Copper vs Aluminum conductor (Pros & Cons)
Why would you not want to use "contact paste" as we call it, on aluminum terminations. I have replaced old panels fed by aluminum SE cable where the previous installer did not use cantact paste, and there was serious oxidation on the conductors. Just the same, I have replaced old panels where the previous installer used contact paste and the conductors looked just fine. Or does oxidation not affect the integrity of the termination over its life span?
Why would you not want to use "contact paste" as we call it, on aluminum terminations. I have replaced old panels fed by aluminum SE cable where the previous installer did not use cantact paste, and there was serious oxidation on the conductors. Just the same, I have replaced old panels where the previous installer used contact paste and the conductors looked just fine. Or does oxidation not affect the integrity of the termination over its life span?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Copper vs Aluminum conductor (Pros & Cons)
I'm not sure when the newer aluminum alloy wire was developed but it supposed to resist corrosion. As you stated
With that said I'll keep using Anti-oxidant along with pressure spring type connections as even the newer alloy will still expand and contract which was one of the bigger problems with aluminum.
[ January 13, 2006, 08:41 PM: Message edited by: hurk27 ]
I'm not sure when the newer aluminum alloy wire was developed but it supposed to resist corrosion. As you stated
The aluminum used in this old installation was probably not of the newer alloy type.
With that said I'll keep using Anti-oxidant along with pressure spring type connections as even the newer alloy will still expand and contract which was one of the bigger problems with aluminum.
[ January 13, 2006, 08:41 PM: Message edited by: hurk27 ]
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