Anti oxidizing for AL wire?

Status
Not open for further replies.
stickboy1375 said:
I use nolox on exterior screws, lightbulbs, etc, makes for a great anti-seize.... can't say I use in on AL. though, the newer alloys just don't require it.
Click to expand...
It makes a great anti-seize because it seals out oxygen so they don't rust. Not sure if it is a good idea on lightbulbs because of the heat and because it is conductive and may help cause "flashover" in a lamp socket.
 
kwired said:
It makes a great anti-seize because it seals out oxygen so they don't rust. Not sure if it is a good idea on lightbulbs because of the heat and because it is conductive and may help cause "flashover" in a lamp socket.
Click to expand...

I always put a light coating on all exterior lamps, sometimes you just can't get them out...
 
Fulthrotl said:
...Seems to be more of a waterproofing grease than an antioxidant....
Click to expand...
There's probably a lot to be said for that. We refer to it as an "environmental seal" rather than an antioxidant, because while I don't know if grease is chemically preventing oxidation, I do know that if you coat the conductive mating surfaces you will significantly improve the life of that connection.

We have pulled apart very deteriorated bus connections in very destructive environments where reactive gasses like H2S where present, and found that the greased mating surfaces were still clean bright metal.

To that end we use a lot of Mobil 28 as a general-purpose environmental seal, but if it has to withstand outdoor conditions we'll use No-Ox ID simply because it's much thicker and harder to wash out.
 
big john said:
There's probably a lot to be said for that. We refer to it as an "environmental seal" rather than an antioxidant, because while I don't know if grease is chemically preventing oxidation, I do know that if you coat the conductive mating surfaces you will significantly improve the life of that connection.

We have pulled apart very deteriorated bus connections in very destructive environments where reactive gasses like H2S where present, and found that the greased mating surfaces were still clean bright metal.

To that end we use a lot of Mobil 28 as a general-purpose environmental seal, but if it has to withstand outdoor conditions we'll use No-Ox ID simply because it's much thicker and harder to wash out.
Click to expand...

I didn't look up properties of Mobil 28, but most general purpose lubricant greases and oils are not considered conductive, where products marketed for anti-oxidation for electrical components are conductive in nature.
 
:rant:
kwired said:
I didn't look up properties of Mobil 28, but most general purpose lubricant greases and oils are not considered conductive, where products marketed for anti-oxidation for electrical components are conductive in nature.
Click to expand...
I know that is the prevailing wisdom, I'm just not sure how much I agree with it.

There is an argument that sandwiching solids like zinc and graphite in the connection actually reduces conductivity. Because while those materials are conductive, they get in the way of metal-to-metal contact between copper/aluminum, which are far better conductors. It's also interesting to me that nobody seems to publish conductivity values for their antioxidant, it makes me wonder how critical that actually is?

I have done many good DLRO tests on connections made with Mobil 28, so I am comfortable with it.

EDIT: I don't know how that angry face got in there, nor how to remove it. Stupid phones.
 
stickboy1375 said:
Unless this has actually been amended to be required, he can't make you use it...
Click to expand...
Sure he can require it, depending on his authority. There's a municipality here in the KCMO area which gives carte blanche to the two inspectors they have. One is by the book, technical wording, etc...the other sees things his own way, sometimes regardless of the book.

I actually prefer the latter because he can be reasoned with from a practical standpoint, and he has actual experience which factors in.
 
iwire said:
Many power companies have very strange habits.

From not grounding light poles to not allowing or requireing a ground rod connection at a meter.

I will not base my views on power company traditions. :)
Click to expand...

Should I be offended?:p We as one of the evil POCO's do use it on aluminum because aluminum oxide is not conductive, unlike copper oxide. Manufacturers do not recommend it for plated copper bus connections, such as CT primary busbars. But I've been on many callouts for flickering lights only to find mucho corrosion on aluminum connections, both crimp type and bolted. Even when Insulink sleeves were used, which contain factory installed grease. I never have been a fan of aluminum, unless it's plated, even though it's cheaper. But then again, we as a POCO get to spend as much as we want and bill the customer.:rant: Remember all of the trailer fires there used to be when they used aluminum wire? I think the key is to use it sparingly, not like frosting on a wedding cake.

If the customer chooses to use it or not is not our concern. We get enough grief from contractors as it is.
 
meternerd said:
Remember all of the trailer fires there used to be when they used aluminum wire? I think the key is to use it sparingly, not like frosting on a wedding cake.
Click to expand...

Those fires mostly started in 15 - 20 amp branch circuits using solid single strand conductors under a "screw terminal"

I would like to think there is a very significant number less of fires started by failed terminations of multi-strand conductors in better designed "lug" terminals whether they be set screw or compression varieties.
 
kwired said:
Those fires mostly started in 15 - 20 amp branch circuits using solid single strand conductors under a "screw terminal"

I would like to think there is a very significant number less of fires started by failed terminations of multi-strand conductors in better designed "lug" terminals whether they be set screw or compression varieties.
Click to expand...

Also, aluminum conductors are now made from an alloy whose thermal expansion coefficient much more closely matches that of copper.
 
From SOUTHWIRE installation guide

From SOUTHWIRE installation guide

When terminating aluminum conductors, there are several practices one should be aware of to ensure a
quality connection that will remain trouble free.
1) Always use a connector that is listed for use with aluminum wire.
2) The following is recommended but not required. Always follow the connector manufacturer’s
instructions
a. The surface of the conductor should be wire-brushed to break any aluminum oxide
barrier leaving a clean surface for the connection.
b. The use of anti-oxidant compound, joint compound, is not required unless the
connector’s manufacturer requires it. However, the use of a listed joint compound is
always a good practice.
3) Always tighten set-screw type connectors to the manufacturer’s recommended torque.
4) Most importantly, do not re-torque the terminations as part of routine maintenance. As
with copper conductors, repeated tightening of any set-screw connections can result in the
eventual “biting” through the conductor causing the termination to fail.
 
iwire said:
That is called a an opinion not a fact. ;)
Click to expand...

It’s a fact, not an opinion.

Joint%20compounds_zpsgpjhyzuf.jpg


http://www.usbr.gov/power/data/fist/fist3_3/vol3-3.pdf
 
klineelectric said:
When terminating aluminum conductors, there are several practices one should be aware of to ensure a
quality connection that will remain trouble free.
1) Always use a connector that is listed for use with aluminum wire.
2) The following is recommended but not required. Always follow the connector manufacturer’s
instructions
a. The surface of the conductor should be wire-brushed to break any aluminum oxide
barrier leaving a clean surface for the connection.
b. The use of anti-oxidant compound, joint compound, is not required unless the
connector’s manufacturer requires it. However, the use of a listed joint compound is
always a good practice.
3) Always tighten set-screw type connectors to the manufacturer’s recommended torque.
4) Most importantly, do not re-torque the terminations as part of routine maintenance. As
with copper conductors, repeated tightening of any set-screw connections can result in the
eventual “biting” through the conductor causing the termination to fail.
Click to expand...

I'll bet that not very many people that use the anti-oxidant have ever wire brushed the conductor.
 
stickboy1375 said:
I use nolox on exterior screws, lightbulbs, etc, makes for a great anti-seize.... can't say I use in on AL. though, the newer alloys just don't require it.
Click to expand...

It works very well on the threads of aluminum conduit and helps to prevent galling when screwing the pipe into the couplings.

It also works on the threads of steel fittings into aluminum boxes or condulets.
 
Aluminum conductor alloys used for the past 25 -30 years or so do not require antioxidation compounds at terminations.

Older alloys did require use of compounds, you still may find other alloys in conductors that the POCO's sometimes use - those conductors are not approved conductors for NEC applications though.
 
Ok, this is coming straight from macmikeman so all you guys pay close attention. When installing services and using aluminum ser cables in either Hauula, Laie, Kahuku, Sunset Beach, Haleiwa, or Wailua, you better put no-alox on the wire connections or it is going to turn into yellow powder inside of a year and a half. Of course you all know how the salt air is in those towns so don't forget this important tip. Now get back to work.....
 
Status
Not open for further replies.
Top