Reinstalling Aluminum Wire

[Strathead]

The original termination has already crushed the conductor and it should not be re-terminated without trimming it back. The original torque specifications accounts for the cold flow that will occur over time as the pressure extrudes the conductor out from under the screw. There is no way to account for that when you re-terminate it as that cold flow happened with the original termination.

Can you back that up with a manufacturer's recommendation? I would assume either the wire or the lug manufacturer would publish this if it is an issue. Otherwise, there would be nothing "wrong" with reterminating. I am not trying to be argumentative here. I have never contemplated this issue and I want to log it in the back of my mind for future consideration.

 

[electrofelon]

The original termination has already crushed the conductor and it should not be re-terminated without trimming it back. The original torque specifications accounts for the cold flow that will occur over time as the pressure extrudes the conductor out from under the screw. There is no way to account for that when you re-terminate it as that cold flow happened with the original termination.

I am quite skeptical that much study was put into these torque specs, when you consider it'd the same for CU and AL, compact or not, and a broad range of sizes. Do you know anything about how and who comes up with torque specs? I think it's typically just based on the size of the setscrew.

 

[letgomywago]

I am quite skeptical that much study was put into these torque specs, when you consider it'd the same for CU and AL, compact or not, and a broad range of sizes. Do you know anything about how and who comes up with torque specs? I think it's typically just based on the size of the setscrew.

Often they are straight from the engineering recommendation for the lug size. I'm sure there was some testing done one ones that spec different numbers for different sizes of wire. Ones that say 20inlbs are fairly conservative and I understand why AL and CU at the 14-10awg size be well connected at that torque

 

[ptonsparky]

Terminal boxes are relatively new. Multiple conductors, mixed Al & Cu, 12 to 250 all under one lug torqued to anything from that's good enough to stripped, and everything still works, pretty common. I've seen a bunch of it. Sometimes we worry too much.

 

[letgomywago]

Terminal boxes are relatively new. Multiple conductors, mixed Al & Cu, 12 to 250 all under one lug torqued to anything from that's good enough to stripped, and everything still works, pretty common. I've seen a bunch of it. Sometimes we worry too much.

But then again I've seen over torque damage and then overheat a lug in a car charger and I've seen under also do the same in panels. It's interesting for sure

 

[acin]

any problem with copper and al together at the ' splice'

 

[letgomywago]

any problem with copper and al together at the ' splice'

Those inline splice reducers don't physically touch the wires together there's a barrier in the middle

 

[electrofelon]

Those inline splice reducers don't physically touch the wires together there's a barrier in the middle

Actually many I see do not have the barrier. I have never thought to check if they require both conductors to be the same material, but I doubt that is a restriction.

 

[letgomywago]

Actually many I see do not have the barrier. I have never thought to check if they require both conductors to be the same material, but I doubt that is a restriction.

I just used some 14 to 2 awg ones today they had the barrier. They are badge engineered Home Depot ones so idk who they get them from.

 

[MD Automation]

If I really couldn't make it reach, either by pulling the cable down or moving the panel up, I would use these:

View attachment 2569927

fwiw... I have a pair of those inline splices handy that Larry posted about - as a "just in case" for a main breaker swap in my house.

As Letgomywago says above, these also have a barrier in the middle. So a copper conductor on one end could not come in contact with an aluminum one at the other. Southwire product, on the shelf at Lowes.