Al/CU connection


Old 12-20-17, 11:43 AM
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Al/CU connection

I'm replacing an oven. The source cable is 2 conductor 8GA aluminum spliced in a j box to 12GA stranded copper. A split bolt (not copper) was used to splice the oven ground, oven neutral , source ground and the J box ground. Is this acceptable?

I intended to replace the split bolt with purple wire nuts but at $26 a bag (I only need one) I would prefer to reuse the split bolt. However, I do want to make the splice per code.
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Old 12-20-17, 12:14 PM
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The purple Ideal wire nuts will not accept #8. I suggest the Polaris insulated connecotrs.
Old 12-20-17, 01:43 PM
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Old 12-20-17, 02:17 PM
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Various kinds of connectors will work for this -- Polaris is one brand, but there are others. Many tin plated split bolts with a separator plate are OK as long as the package indicates Cu/Al compatibility. A split bolt with direct copper-to-aluminum contact is not OK. Wirenuts are the worst of the available options.
Old 12-20-17, 04:05 PM
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The source cable is 2 conductor 8GA aluminum spliced in a j box to 12GA stranded copper.
Is this a hardwired oven?
Even so 8GA to 12GA doesn't seem right. 10GA stranded is what is usually on the hardwired oven or cook top.
Cheapest solution is using Cu/Al split bolt. This is different from regular split bolt. Cu/Al split bolt has a plate in the middle separating Al and Cu wires.
Wrap this connection with rubber splicing tape, then wrap it again with regular electric tape.
Old 12-20-17, 05:15 PM
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Split bugs are good. Set screws couplers are also good.

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Old 12-20-17, 07:51 PM
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I intended to replace the split bolt with purple wire nuts

There is absolutely NO wire nut approved by the US Consumer Product Safety Commission for directly connecting aluminum and copper wire. The Ideal #65 Twister purple wire nut was never intended for a connection as you want to make and has an extremely high failure rate. Yes, it is UL Listed for aluminum to copper connections, BUT it has never been tested by UL. Other independent labs have, however, tested them and they failed miserably.

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