We manufacture equipment that has UL/CSA Listed tin plated aluminum set screw connectors that are rated for copper and aluminum up to 250MCM wire size. I have a customer who claims that the screws stripped out on several connectors when he was trying to tighten down on aluminum stranded wire (4/0). I told him that there is a torque limit to the screws and I am sure they are tested by UL and CSA for aluminum wire of that size. He claimed that the screw stripped before it even made a dent in the wire. I could never replicate his claims with the connectors in the factory. Since he is in area with extreme temp fluctuations, (-40 to 90 Degrees) he also insists that he needs to torque more than the label. Has anyone experienced this with aluminum wire before? Perhaps he is not using standard AA-8000 series aluminum wire? If he is correct, or if I can't convince him he's wrong, I thought of suggesting that he use pin type connectors to put on the end of the aluminum wire. Basically, those are UL listed crimp on caps with stranded copper ends. I figure the copper would be much softer and he wouldn't feel the need to torque beyond the limit. I would like to know if anyone has had any experience with anything similar. Thanks.
Aluminum wire and mechanical set screw connectors
- Thread starter teej
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