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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: enter image description here After removal: enter image description here

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?

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"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.

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  • The state inspector who looked at this asked me to put it back and assured me it was still grandfathered in (also see our chat on diy.stackexchange.com/a/273262/128465). FWIW the homerun is mostly all still there (up till the panel), I just pulled it out of that vertical wall and left it directly under it.
    – peter
    Commented Jun 9, 2023 at 17:04
  • FWIW, personally I'd much prefer sticking to copper Romex, but I have little appetite for fishing another 100' of 8/3 through my crawlspace and attic (and paying $350 for it), and since my inspector asked me to just put this one back I'd rather just do that. I was just wondering if it's safe to do so, or if I'd damaged the conductors by pulling it out and putting it back. I would still consider running new 8/3 romex if the Al SEU was unsafe (e.g. fire risk).
    – peter
    Commented Jun 9, 2023 at 17:06
  • The suggestion to retrofit a ground is a good one, and I'm likely to do that by borrowing ground from another nearby circuit that terminates in a box 2" away from this one. But my main concern in this question is "is this existing SEU cable safe to re-use, or should I consider it totally damaged"? (Code aside, since the inspector allowed it. I'm just concerned about material safety)
    – peter
    Commented Jun 9, 2023 at 18:05
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    @peter Just a note that any ground you "borrow" needs to be sized large enough to handle your circuit. Ground on a 15A circuit might be too small for a 30A circuit.
    – Armand
    Commented Jun 10, 2023 at 1:19
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    Thanks for the responses folks. I found another electric supply store that sells 8/3 copper NM for half that price and bought a roll of 125'. Will try to run a new home-run tonight so I can avoid the AA-1350 stuff.
    – peter
    Commented Jun 10, 2023 at 1:30

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