Have you, like me...and many other electricians, been using NOALOX on your aluminum wires for years? We're going to go over why it's not necessary except in specific situations - 4 of them evidently.
I'm guilty of this too...so let me just get that out there right now. For years I've been dunking conductors in this bottle and getting a fat layer of goop on the ends of my terminations without reading the bottle (manufacturer's specs) about how it's supposed to be used. I've just gone by whatever my boss had told me to do. Most of our bosses, though, have been wiring shit since the beginning of time and if the didn't hear any different, they've just been doing what they've always done.
NOALOX is an anti-oxidizing compound that helps prevent the formation of oxides on the outside of a conductor. No. Aluminum. Oxidization - NO.AL.OX. Before the 60's we'd been using actual aluminum wire for conductors, and the very nature of aluminum is that it's a very reactive material - especially when introduced to air or moisture. It wasn't until the 80's that manufacturers perfected a few alloys to use in wire, that started to curb this issue.
Galvanic action occurs when two dissimilar metals come in contact with one another for an extended period of time. It more refers to when an ACTIVE metal comes in contact with a REACTIVE metal. What happens is, over time, these conductors start to "eat away" at one another. Using an anti-oxidizing compound around the conductors helps to minimize this "rusting out" of the conductors where contact is made. This is why a lot of these No-ox brands say "for use with aluminum to copper, and aluminum to aluminum terminations."
AA8800 aluminum is what's used in MOST of today's aluminum conductors. I did say most, not all. There are some conductors and cables on the market that this is not true for, so you do need to use caution when deciding whether or not your conductor requires the use of a no-ox or de-ox compound. But most conductors used are now made of an alloy (a mixture of metals into a new type of metal) that doesn't react to galvanic action or air and water corrosion like standard aluminum does.
HOW TO APPLY IT
Another thing MOST people do is install this stuff incorrectly to the conductor. There are manufacturer instructions that must be followed when installing almost everything in the electrical trade, because there are codes and standards that require it. The instructions for a lot of these compounds require you to:
1) clean the conductor off with a wire brush or emory cloth
2) apply noalox freely to both the conductor and the connector
3) assemble joint and wipe off the excess
I bet if you did a poll out there and asked all electricians about this method, at least 75% of them have no clue this is required, nor do they do it. The reason for this is that there's no NEC code article that talks about using it or not using it. It's just a commonly-used method, or "rule of thumb." But 110.14 states (paraphrasing here) "where a compound is employed, it must be used correctly," and 110.3(B) says (again...paraphrasing) - any materials used must be used to manufacturer specs/instructions.
WHERE TO USE IT
There are still places where it’s a good idea to use NOALOX, so I’m not saying DON’T EVER USE IT AGAIN. There are places where corrosion is highly likely, for instance near the ocean. Water and air mixed with salt can corrode many types of metal near the ocean, so using this compound does not hurt - and probably helps quite a bit. The problem in these locales is often that all of the rest of the metal inside the panel - lugs, bolts, bus-bars, all of it - are still going to oxidize…so at least protecting the terminations you make is a wise plan.
Also when an AHJ (Authority Having Jurisdiction) like a city inspector calls for it, or has a code written that requires it - you have to do what they want unless you can argue your way out of it with logic…but you may have better luck growing a third hand. Lastly there are pieces of equipment that are made which call for the use of these compounds. Not many these days, but they do exist. In this case you do need to install the equipment to spec per code.
Lastly, certain conductors are not made of aa8800 aluminum alloy so you need to watch what kind of conductors you’re installing to make sure you shouldn’t be using a compound like this. NEC 110.14 still does say that since dissimilar metals degrade one another, using the correct materials to ensure they’re not intermixing, must be adhered to.
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**Disclaimer - These videos are for training purposes alone, all work done on electrical systems should be done by a licensed and insured electrical contractor. If you are not an electrician, do not attempt any of the work you are seeing in these videos.**