Aluminum antioxidant paste on Copper ?

[Ron Bibler]

Why would sparky put Aluminum antioxidant paste on Copper ?

Would you call this out? He has this in all the panels on a commercial building.

Best

Ron

[Rick Cantrell]

I do not see the paste on the aluminum connector though.
Strange.???

[Jim Port]

You may not see the paste because it is not required.

[Rick Cantrell]

I said "Strange" because the paste IS on the copper but NOT on the aluminum.

[Corn Walker]

Why would sparky put Aluminum antioxidant paste on Copper ?

Would you call this out? He has this in all the panels on a commercial building.

How do you know it's "aluminum" antioxidant paste and not a copper or multi-purpose antioxidant paste?

The purpose of antioxidant paste on aluminum is because aluminum oxide is an insulator. The antioxidant is applied to aluminum conductors to ensure optimal electrical conductance and reduce overheating.

Some electricians also apply it to copper, particularly with aluminum lugs.

[Philip]

So it is the aluminum lugs which mandates the paste. Would not need it al to al. Looks like the Sparky knew what he was doing.:)

[Corn Walker]

So it is the aluminum lugs which mandates the paste. Would not need it al to al. Looks like the Sparky knew what he was doing.:)

While some local jurisdictions may require its use, the NEC does not require anti-oxidant compound, except so far as it defers to the manufacturer's instructions. It does mention its use however. Whether the Al lugs require the compound or not would therefore depend on the manufacturer and locality.

All the same, it is probably a good idea to use the anti-oxidant compound when working with aluminum to minimize oxidation and the potential thermal problems that accompany it.

[John Steinke]

Keep in mind that lugs often come with some manner of compound already in them. The amounts of the compound vary, as does the final appearance of the connection.

[Robert Mattison]

Has anyone on this site, ever done inspection where they might have
seen a copper wire corroded at its terminal connections? Any yes some
lug come pre - load with a corrosion resistance compond.

[Jerry Peck]

Has anyone on this site, ever done inspection where they might have seen a copper wire corroded at its terminal connections?


Yes.

In corrosive environments, such as along the beach (thinking Atlantic Ocean and Intra Coastal Waterway here, both saltwater - and, where I inspect, we are between the two, and the two are less than 1/2 mile apart, we are on a barrier island).

[Mitchell Toelle]

Has anyone on this site, ever done inspection where they might have
seen a copper wire corroded at its terminal connections? Any yes some
lug come pre - load with a corrosion resistance compond.

Bakersfield...120+ miles inland...no obvious reason for finding this, but we do occasionally.

[Christel Hunter]

I've done a little research on oxide inhibitor, here's an excerpt from an article I authored that was published in IAEI News in 2006:

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.

[Bert de Haan]

Yes.

In corrosive environments, such as along the beach (thinking Atlantic Ocean and Intra Coastal Waterway here, both saltwater - and, where I inspect, we are between the two, and the two are less than 1/2 mile apart, we are on a barrier island).
And in sub panels. (You let the opportunity slide so I took it. :))

[Denny Waters]

I believe I read in Doug Hansen's book "Electical Inspection of Existing Dwellings" that it helps with torquing down the lugs as well.

[Bill Nolte]

Has anyone on this site, ever done inspection where they might have seen a copper wire corroded at its terminal connections? And yes some lugs come pre-loaded with a corrosion resistance compound.

You will always see corrosion on copper terminations in residential or commercial swimming pool equipment rooms, Waste Water Treatment Plants and Water Treatment Plants. Correct oxide inhibitor is always a good idea whether required or not. I have seen copper corrode where exposed at the terminations in less than a week in Waste Water Treatment Plants on new installs. It's a shame the engineers didn't know to require oxide inhibitor in their project specifications.
Always remember NFPA70 the National Electrical Code is the minimum for safety and not necessarily the best design criteria.

[H.G. Watson, Sr.]

You will always see corrosion on copper terminations in residential or commercial swimming pool equipment rooms, Waste Water Treatment Plants and Water Treatment Plants. Correct oxide inhibitor is always a good idea whether required or not. I have seen copper corrode where exposed at the terminations in less than a week in Waste Water Treatment Plants on new installs. It's a shame the engineers didn't know to require oxide inhibitor in their project specifications.
Always remember NFPA70 the National Electrical Code is the minimum for safety and not necessarily the best design criteria.

I disagree. You will see when the installation and area is violative of the code in either its use, maintenance, or design.

It is an indication that the system has not been designed or maintained (and the area not designed and/or maintained) correctly.

Equipment must be designed and maintained (and area) so as to protect equipment from the effects of corrosion and chemicals. Storing disinfecting chemicals in the area and/or not properly designing the area and zone for the correct CATEGORY of hazardous conditions.

The code is not a design/engineering manual.

[Bill Nolte]

I disagree. You will see when the installation and area is violative of the code in either its use, maintenance, or design.

It is an indication that the system has not been designed or maintained (and the area not designed and/or maintained) correctly.

Equipment must be designed and maintained (and area) so as to protect equipment from the effects of corrosion and chemicals. Storing disinfecting chemicals in the area and/or not properly designing the area and zone for the correct CATEGORY of hazardous conditions.

The code is not a design/engineering manual.

The simplistic view related above shows a potential lack of real world experience and forethought. NFPA 70 “The National Electrical Code” is a design manual! It is the minimum for safety design allowable by law, as stated previously. The code also states that compliant designs may not be the best or most efficient design. If the NEC were not a design manual it could not be quoted for corrections to non-compliant installations.
Waste water treatment plants have many corrosive elements, some atmospheric, that are impossible to keep out of the equipment; the equipment can only be designed to mitigate the intrusion of these corrosive elements into the enclosure. Similarly the electrical terminations within a pool equipment room are exposed to chlorine vapors by the very nature of the location of the pumps. Although the load center or panel board and related controls do not have to be located adjacent to the motors, a disconnect should be so located for safety reasons and by such location the disconnect is also exposed to corrosive vapors. NEMA 4X stainless steel or fiberglass enclosures help to mitigate the corrosive effects but they do not eliminate such effects.
Per your statements design and maintenance would also eliminate the need for hazardous locations sections of the code. Nothing could be further from the truth. Hazardous location requirements are also designed to mitigate (the effects of an explosion), not to prevent one.
I stand by my statement that anti-oxidant compounds are a good idea. All metals corrode over time, some just faster than others and frequently due to atmospheric contaminants. The anti-oxidant is a cheap, simple, safe way to extend the life of terminations, especially those exposed to damp or corrosive atmospheres!

[Jerry Peck]

You will always see corrosion on copper terminations in residential or commercial swimming pool equipment rooms, Waste Water Treatment Plants and Water Treatment Plants.


I disagree. You will see when the installation and area is violative of the code in either its use, maintenance, or design.

It is an indication that the system has not been designed or maintained (and the area not designed and/or maintained) correctly.

Equipment must be designed and maintained (and area) so as to protect equipment from the effects of corrosion and chemicals. Storing disinfecting chemicals in the area and/or not properly designing the area and zone for the correct CATEGORY of hazardous conditions.

The code is not a design/engineering manual.


The simplistic view related above shows a potential lack of real world experience and forethought. NFPA 70 “The National Electrical Code” is a design manual!

Let's start here: (underlining and bold are mine)
- From the 2008 NEC.
- - ARTICLE 90 Introduction
- - - 90.1 Purpose.
- - - - (C) Intention. This Code is not intended as a design specification or an instruction manual for untrained persons.

I.e., the code IS NOT a design manual. The simply stated MINIMUM REQUIREMENTS which are to be incorporated into the design of electrical systems.

Now let's go to the other comment regarding location for the electrical equipment:
- 110.11 Deteriorating Agents.
- - Unless identified for use in the operating environment, no conductors or equipment shall be located in damp or wet locations; where exposed to gases, fumes, vapors, liquids, or other agents that have a deteriorating effect on the conductors or equipment; or where exposed to excessive temperatures.
- - - FPN No. 1: See 300.6 for protection against corrosion.
- - - FPN No. 2: Some cleaning and lubricating compounds can cause severe deterioration of many plastic materials used for insulating and structural applications in equipment.