I had previously pulled a #6 Al SEU cable out of the wall and back down into my crawlspace, so I can replace it with a copper Romex cable. Now I realized I need the SEU back (I had miscalculated the size needed for the Romex, and realized the SEU was grandfathered in). But I'm worried that the pulling and bending on aluminum cable might have damaged it, since I heard that aluminum is more brittle than copper.
Original:
After removal:
I don't see any obvious physical damage to the cable (apart from some light scratches on the outer jacket), but to fish it back up into the wall I'll need to pull it through a small hole and then bend it 90° to go out of the wall.
Can #6 Al SEU typically take being pulled / removed / repulled like this? Would this increase the risk of damage to the conductors and overheating?
Best Answer
"I'm planning to fly commercial. What are the chances of me dying?" "Depends, how are you getting to the airport?" It's like that.
A 3-wire range or dryer connection is inherently dangerous - that's why the "dryer and range exception" was outlawed in 1996. In 1966 (moonshot), when they required grounds for everything else, they allowed dryers and ranges to "bootleg ground" off neutral on the logic that neutral wire failures were unlikely and the socket was rarely disturbed. That didn't work out so well for several Americans a year, many of them children, so it was outlawed in 1996 and true grounds were required.
Aluminum wire was given a reexamination after a spate of problems on 15-20A circuits in the 1970s-80s. The first thing they discovered is AA-1350 alloy is fine for heavy power lines but too brittle for finer wires. Second, they learned 15-20A receptacles were improperly certified for aluminum (not a problem here). And third, they found that screw torque matters on ALL connections and aluminum is not exempt from this.
The old AA-1350 alloy being too brittle? You bet, that's why they got rid of it. Just put an AFCI breaker at the supply. Just kidding.
No, once you removed it, the grandfathering is gone. You say your inspector is giving a nudge and wink, well don't know what to tell you, we give Code answers here. You should not install a 3-wire dryer or range circuit. They are dangerous.
Talk to us about your wire requirements and let's see if there's a way to fit it in the wire you already bought and/or installed. We have several tricks that can save some money, not least understanding range requirements, which are weird.
Alternately, you could retrofit a ground. This corrects the danger in 3-wire connections. This requires going back to the panel, the Grounding Electrode wire, or a box with a large enough ground back to the panel.