Old 05-15-07, 05:20 PM
Thread Starter
Join Date: Jul 2005
Posts: 41

Just a quick question. I have a wire connector stamped with the specification Cu9Al. Does that mean it is ok for aluminum and copper connections? Is it ok for aluminum to copper connections? I can't find a definition for that exact designation in any of my books or online.
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Old 05-15-07, 05:51 PM
Join Date: Aug 2005
Location: USA
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Yes. Also signifies 90-degree-C rating as well.
Old 05-16-07, 03:38 AM
Join Date: Apr 2006
Location: New Bern, NC
Posts: 1,623
It is good for aluminum TO copper.

I do not believe it is good for aluminum AND copper.

there are special connectors out there for that.
Old 05-16-07, 02:59 PM
Thread Starter
Join Date: Jul 2005
Posts: 41
Thanks for the info,

Old 05-17-07, 02:45 PM
Join Date: May 2007
Posts: 1

The Cu9Al marking identifies the intended use of the wire connector. For complete details on wire connector markings, you may want to check out, find the online certification directory, and look at the guide information for category ZMVV (Wire Connectors and Soldering Lugs)

Here's a link to this information:

To save you the trouble on this one marking, here's an excerpt from the UL site:
B. General use Connectors rated 75C are intended for use at ampacities not greater than those for 75C rated conductors, and connectors rated 90C are for use at ampacities not greater than those for 90C rated conductors. Connectors may be marked with "75C" or "90C" to represent these levels. Alternatively, these rating levels may be represented by a 7 or 9 associated with the marking "CU,""AL" or "AL-CU," e.g., "AL9,""AL9CU,""AL7CU,""CU7,""CU9." Connectors not marked with an ampacity number 7 or 9 have an assumed level per the following table. Use of higher temperature-rated conductors is not prohibited, provided the ampacity levels continue to be based on the 75 or 90C ratings.
The CU-AL marking means the connector is good for Copper to copper, aluminum to aluminum, and copper to aluminum but not intermixed or in direct physical contact.

A wire connector which is suitable for intermixing aluminum and copper wire would be include an additional marking "intermixed - dry locations only"

Hope this helps!

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