Aluminum Lugs!

[curt swartz]

I had an interesting inspection today for a new residential service panel. This was for a Square D 200 amp combination service entrance device (load center and meter socket in one box). The inspector asked where the oxide inhibiting compound was on my service conductors. I responded that my service conductors were copper and even if they were aluminum no compound was required unless instruction and listing for the lugs require it. She replied that at a recent seminar a rep from Alcan stated that all aluminum lugs must have an oxide inhibiting compound unless the manufacture of the lug provides instructions stating that it is not necessary. She said it did not mater if the conductors were copper or aluminum the issue is the aluminum lug. I tried to explain this makes no sense since the aluminum lugs are plated during the manufacturing process and are not raw aluminum. If they were raw aluminum the lugs would already be oxidized from being exposed to the air for period of time between manufacturing and actually having wires terminated in them.

I mentioned that I would contact Square D about this issue but she stated that since Square D doesn't manufacture the lugs I would need to contact the lug manufacture. Since these lugs are factory installed as part of a listed device as far as I concerned Square D is responsible for any instructions relating to these lugs. I should not have to figure out who manufactures every part of a listed assembly and contact each of these manufactures for instructions and listing info.

I plan on contacting Alcan to see why they spreading this information.

 

[infinity]

Sounds like she's misinformed. An Al/Cu lug can be used with either conductor without anti-ox. If Alcan is requiring it that's news to many of us on this forum. And what does Alcan have to do with copper conductors?

 

[curt swartz]

And what does Alcan have to do with copper conductors?

Nothing, which my biggest issue. According to her Alcan telling people if a lug is manufactured from aluminum it requires oxide inhibiting compound. Unless Alcan is the lug manufacture it has no business specifying how the lug is used.

 

[infinity]

Did the Sq D equipment have a label that listed the lug specifications?

 

[curt swartz]

Did the Sq D equipment have a label that listed the lug specifications?

She stated that since Square D doesn't manufacture lugs I would need to find the lug manufacturer and contact them. These lugs were factory installed by Square D. I don't even know if there is a manufacture name on the lug.

 

[dana1028]

That sounds like nonsense - Sq. D has their entire panelboard listed, not just parts of it. If UL lists the panelboard, it should meet ULs requirements and the listing instructions from the mfr.

 

[Sierrasparky]

Gotta love these engineer inspector no it alls.
I personally don't think it's an issue to use anti -ox compound. I have a bottle that I have had for years. I have a tub I found on a job left by others. I coat all connections as a rule of thumb. I have never had a call back yet I have done many a call-back on my competitors that don't use the stuff.

by the By SqD uses a some sort of anti-ox on all plug in breakers these days. The POCO coats all meter stabs before inserting the meter. It's just a normal parctice these days.

It's a nice topic for discussion but I would not get the inspectors panties in a bunch over it!

 

[dana1028]

Sierra - I don't disagree with you. I too use the No-Al or whatever just to pacify inspectors. But that said curt is correct as far as I know...if the mfr doesn't spec it, it's not required by code... and I just hate it when inspectors are out there making rules up.

Fortunately we have a UL test site in the area of this write up with an engineer that specializes in panel boards...hopefully we can get something from him in writing to support Curt.

 

[jim dungar]

by the By SqD uses a some sort of anti-ox on all plug in breakers these days

I don't think it is anti-ox, and SqD has been using it for decades.

She stated that since Square D doesn't manufacture lugs I would need to find the lug manufacturer and contact them.

How do you know the lugs were not manufactured by Square D? I do not know about now, but many years ago I saw some lugs being manufactured in a SqD plant.

 

[4SPARKS]

I feel your pain I've been knocked down for not enough de-ox at panel terminations. But a letter from the manufacturer (sq d) is enough to satisfy insp. as long as it states your instal does not void UL listing. I had to do same thing from hubbel on a mud ring as low voltage box.

 

[curt swartz]

I always tell my guys to put compound AL wires just to make the inspectors happy. I have found it takes too much time to fighting with the inspectors for such a small issue so it easier to go allow with the flow. On residential project we are frequently not onsite for the inspections. I NEVER put the stuff on CU wires which is the issue here.

 

[curt swartz]

I don't think it is anti-ox, and SqD has been using it for decades.

How do you know the lugs were not manufactured by Square D? I do not know about now, but many years ago I saw some lugs being manufactured in a SqD plant.

I don't know who made the lugs. The inspector is the one that stated otherwise. I know that panel manufactures frequently use lugs and neutral/ground bars from third parties. I'm sure it is cheaper for them to buy basic items like this from Ilsco or other manufactures than make it in house.

Years ago didn't Square D own one the lug manufactures?

 

[jim dungar]

I don't know who made the lugs. The inspector is the one that stated otherwise. I know that panel manufactures frequently use lugs and neutral/ground bars from third parties. I'm sure it is cheaper for them to buy basic items like this from Ilsco or other manufactures than make it in house.

Years ago didn't Square D own one the lug manufactures?

Yes, Square D once owned Anderson lugs. But, the ones I saw being manufacturered were in a Square D plant (maybe for loadcenters or disconnects, I can't remember).

And what difference does it make if the lugs are custom made for Square D by someone else, it is unlikely that Square D makes the green ground bonding screw, the enclosure paint, or the steel of the box either. Who do we contact to make sure the paint is adequate for the environment or that the steel is 'code' gauge?

 

[kbsparky]

I've heard that some manufacturers are moving away from the oxide inhibiting compound, and in fact are suggesting you not use it.

Why?

Some compounds, like the all-too-familiar sticky gray goop tend to "melt" in the summer, running down from the lugs and into the guts of some of the circuit breakers, either mains or branch breakers as the case may be.

This sticky-gray goop can then clog up the mechanisms of said breakers, making them ineffective and thus a huge liability on the manufacturer. Not a very Ideal condition (pun intended).

When using such compounds, I prefer to use the green "grease" type gunk, that tends to remain in place, regardless of ambient temperature conditions.

 

[jckenner]

Hey Curt -- I never worked there but I heard rumors from other sparkys that City of San Jose used to forbid the use of Noalox type compounds. Does this sound familiar to you? It had something to do with the listing that they took issue with.

I never work with Al wire, though with China driving the price of CU where it is that may change, so when do we need to use oxide inhibitors?

 

[Volta]

...

I never work with Al wire, though with China driving the price of CU where it is that may change, so when do we need to use oxide inhibitors?

Only when the instructions included in the listing or labling require it.

 

[Mgraw]

Found this on Alcan's website. It is from a publication of IAEI

"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."

 

[augie47]

I hate to add confusion to Mgraw's excellent post, but here's a link to ALCAN where they discuss compound. See Pg 32 and 46 in particular:

http://www.cable.alcan.com/NR/rdonlyres/870944E1-1567-4097-B0CA-37193356568B/0/BW0096.pdf

 

[K8MHZ]

Not surprisingly, ALCAN doesn't even mention proper application.

Oxidation resistive compounds are NOT made to waterproof a connection.

Globbing a bunch on and sticking the connection together is not proper application. A big glob can actually act like a heat insulator and when hot will just drip off. Not only that, but how on earth is that glob supposed to get where it's supposed to be, which is in contact with any bare metal that may be exposed to oxygen?

If the compound is properly applied it should be difficult to notice. All the compound should be worked into the conductor with a wire brush making every attempt to brush every surface of every strand. If done correctly, there will be just a thin film of compound on the metal which, if prepped and worked in properly, will be directly on metal that has never been exposed to oxygen. Any extra should be brushed, not wiped, off the conductor. It's nice to wipe down the insulation.

Do not brush the lugs as they are plated. If you get a hankerin' to coat them, use a cotton swab and paint them, don't stuff 'em full.

Now, bear witness that I said difficult, not impossible to notice. Close inspection should reveal enough compound between strands to see, plus the color of the compound tints the sheen of the metal.

Using the least amount needed, there won't be sufficient weight to overcome the adhesive forces and the compound won't drip off when operating at elevated temps.

I don't think it prudent to use any grease type product for waterproofing. Try to blow some cured liquid electrical tape off a joint with a stream of water from a healthy garden hose.

 

[macmikeman]

Engineer turned inspector goes to seminar. Listens to speaker while texting messages to boyfriend/girlfriend. Mixes up what he may or may not be saying,(providing he has his information correct in the first place). Goes home convinced its all true because after all, she heard it in a seminar which had an expert. Methinks this is how 25 ohms would be a good effective level for ground rods got started.