Coating Aluminum Conductors

[mrrf]

Does the NEC require aluminum service entrance conductors at the main circuit breaker to be coated with an anti-oxidizing grease?

 

[ryan_618]

Re: Coating Aluminum Conductors

110.14 would require it if the connection is aluminum to copper

 

[iwire]

Re: Coating Aluminum Conductors

110.14 does not require the use of anti-oxidizing grease.

All it says is if you use such materials they will be listed for the purpose.

Part of 110.14

Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.

 

[rcarroll]

Re: Coating Aluminum Conductors

I had this question from an electrician yesterday so I asked a friend from a supply house to get some info from his wire supplier.I got a copy from EC&M [Electrical construction & maintenance]. 1 item under mechanical screw type connectors says to wire brush the conductor & apply a listed joint compound.

 

[iwire]

Re: Coating Aluminum Conductors

I went to this page at Ilsco to see what they had to say about their connectors with aluminum conductors.

Preparation of wire

When an aluminum cable is installed, certain
procedures should be followed to ensure a good connection.


1. The insulation should be stripped with a whittling motion to prevent the cable from being nicked.

2. The cable should then be cleaned with a wire brush. This removes the oxides from the surface of the conductor.

3. An oxide inhibitor (De-Ox) is recommended to be applied to aluminum conductor immediately prior to installation.

4. For mechanical connectors, the set screw should be tightened. After a few seconds, the set screw should be re-tightened to ensure a good connection. For compression connectors, the lug should be crimped around the conductor using the proper tool.

They say an oxide inhibitor is recommended.

Is a recommendation the same as a requirement that can be enforced by 110.3(B)?

I have never gotten an instruction sheet with the lugs I order.

I do use oxide inhibitors but are we required to?