Noalox on Aluminum

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mbrooke

mbrooke

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Is there any risk in not using it? Around here there are plenty of installations without it showing no signs of overheating.
 
Compression connections usually already have it in the connector, where mechanical lugs in panels and disconnects do not. As Steve said, oxidization can take a while. That’s what gave aluminum a bad name, improper installation. They are bad around here to lug a #10 copper in a lug with 4/0 aluminum on MH disconnects. They use it as a tap for the well pump. Takes about 4-5 years for the connection to fail, Noalox or not. ( dissimilar metals, a different subject)
 
mbrooke said:
Is there any risk in not using it? Around here there are plenty of installations without it showing no signs of overheating.
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Over time the connections will oxidize. It will take longer that a week, a month or year to see the results. Most of the meter enclosures that I use (usually Milbank) have a dab of some sort of anti-oxident inserted in the lug cavities. That said,, if you've ever seen the commercial for Frank's Hot Sauce - "I put that $#@& on everything" :cool: Copper or aluminum. (especially if it's in a damp or wet location or exposed to elements.
 
It's not required so I'm not sure why the termination would deteriorate over time if properly installed in the first place. IMO it's cheap insurance but you are not required to use it.
 
The older aluminum alloy was as issue but the new alloy does not require noalox.. Of course, old school here we use it anyway
 
I generally do not use it indoor, but do outdoor. How about the H Taps typically used my POCO at the weather head though? I don't think that has it and those sit out in the rain for decades without problems :unsure: I suppose a crimped connection turns most of the joint into essentially a solid mass so there is much less area exposed to potential corrosion, unlike a mechanical connector.
 
infinity said:
It's not required so I'm not sure why the termination would deteriorate over time if properly installed in the first place. IMO it's cheap insurance but you are not required to use it.
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Thats what I'm thinking- but I'm being told that manufacturer instructions require it. I'm not finding which instructions call for it though. Not NEMA receptacles, not breakers and not enclosures. I could be wrong on one of those.
 
mbrooke said:
Thats what I'm thinking- but I'm being told that manufacturer instructions require it. I'm not finding which instructions call for it though. Not NEMA receptacles, not breakers and not enclosures. I could be wrong on one of those.
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That is common BS inspector call, 110.3(B). I have not checked every one, but have found statements from several AL conductor mfgs saying noalox is optional not required.
 
There is also this info below. Aluminum wire was 99.5% aluminum. It no long is-- see below. In all it seems the best deal is to use anti oxidants on both copper and aluminum but you must be careful not to use the incorrect compound.

Oxide Inhibitor Oxide inhibitor use is considered good workmanship for all 600-volt terminations, whether wired with copper or aluminum conductors. The oxide inhibitor provides a barrier at the connection point that excludes moisture and other potentially damaging environmental substances. Oxide inhibitor must be compatible with the conductor type. Different manufacturers make compounds that can be used with copper only, aluminum only, or both copper and aluminum. Be sure to choose the compound listed for the application. Compression connectors often come pre-filled with the appropriate oxide inhibitor. When connectors are tested for compliance with UL 486B, the conductor is prohibited to be wire brushed or abraded, and oxide inhibitor may only be used if the connector is pre-filled with the antioxidant. Therefore, mechanical set-screw terminations are tested without wire brushing and oxide inhibitor. According to the UL GuideInfo (UL White Book) for wire connectors (ZMVV), oxide inhibitor for aluminum or copper wire may be used if the connector manufacturer recommends its use on the connector documentation. Oxide inhibitor is of the most value when making connections between uncoated copper and aluminum. This type of connection is subject to galvanic corrosion when in the presence of an electrolyte. Since most lugs today are made of tin-plated aluminum, galvanic corrosion is limited except in the case of severe electrolytic environment or significant damage to the connector plating.
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Aluminum wire was 99.5% aluminum. It no long is

The EC grade wire then available was 99.5% pure aluminum, hard-temper and was more notch sensitive than copper building wire. This is no longer true since AA-8000 aluminum alloy building wire is a fully annealed aluminum alloy conductor that is very strong and flexible.
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Dennis Alwon said:
There is also this info below. Aluminum wire was 99.5% aluminum. It no long is-- see below. In all it seems the best deal is to use anti oxidants on both copper and aluminum but you must be careful not to use the incorrect compound.




Aluminum wire was 99.5% aluminum. It no long is
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What do they mean by annealing? I always thought that was from when metal was overheated.
 
Annealing is generally the process of heating alloy or pure metal to a critical temperature and then cooling it slowly. The result is a more pliable crystal structure in the metal which is both more flexible and less subject to cracking from stress propagation.
In some cases repeated thermal cycling is used.

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hillbilly1 said:
As Steve said, oxidization can take a while. That’s what gave aluminum a bad name, improper installation.
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Allow myself to add more personal observation to the mix. Previously I did not believe the Noalox "hype". Then I ran into an application that made me a believer.

Application was a high current power supply for melting glass (3 PH 5,500 amp). Original equipment designed for 1.6 MW but process demanded 1.85 MW. (obviously overloaded). 36 total SCRs switching the transformer secondaries from parallel to series 120 times a second. Manufacturer out of business 20 years ago (no factory support),

One particular connection type, (mirrored 12 times in the machine) consisted of 1/4 X 2 1/2 aluminum bussbar (water cooled) to a copper single hole strap soldered to a copper 1/2 OD copper tubing (the copper tubing was water cooled). The amps through this connection were just short of 3,000 amps. Under these conditions bad connections showed up very rapidly, thus allowing observations by a trouble shooting type of electrician the opportunity to solve issues, by using thermal imaging equipment.

What I observed was:
1. The single hole strap (.045" thick) needed backup support, a Grade 8 washer and Bellevue washer (No idea what the original fasteners were).
2. If the connection was ever taken apart, the mating faces needed to be wire brushed and Noalox (or equivalent) applied.
 
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