Spice THHN in buried handhole enclosure?

[kwired]

Thanks for your thoughts. The size variation across the splices was the main issue. Shrink tube that goes over a #2-wire butt splice I believe isn't sealing down to #12. At least the rubber tape is adhesive and applied carefully is pretty dang well sealing, and protective. The splices are suspended toward the top of the box, the drainage location is gravel/sand hilltop and will never see water accumulation. Imperfect but workable I hope.

Sealed pretty dang well, below grade, and aluminum conductors do not go well together. It must be absolutely sealed, or the aluminum will oxidize and eventually fail.

 

[TimWA]

Sealed pretty dang well, below grade, and aluminum conductors do not go well together. It must be absolutely sealed, or the aluminum will oxidize and eventually fail.

The AL 2-2-4 USE conductors were de-oxed of course before attaching the butt splices.

What would you suggest?

 

[kwired]

The AL 2-2-4 USE conductors were de-oxed of course before attaching the butt splices.

What would you suggest?

I really don't have a specific suggestion, but have repaired many underground aluminum conductors and my experience with those tells me that even a nick in insulation eventually leads to conductor oxidizing and turning into white dust (aluminum oxide). You have to have something that thoroughly seals it and not just pretty good. You can get away with pretty good with copper conductors as oxidation of them is not as catastrophic to the conductor.

I can't recall needing to seal such a connection in a location below grade but if I were I would try to find something that encapsulates the connection I don't trust rubber tape to seal well enough. If you are not in a drainage problem area you may be lucky

 

[John120/240]

The AL 2-2-4 USE conductors were de-oxed of course before attaching the butt splices.

What would you suggest?

It is a major HACK method I know; Cut off the pointy end of a tube of silicone caulk. Make

your connections good-en-tite. Stuff the whole mess in to the tube of caulk. Yes I know it

is a HACK idea.

 

[Strathead]

It is a major HACK method I know; Cut off the pointy end of a tube of silicone caulk. Make

your connections good-en-tite. Stuff the whole mess in to the tube of caulk. Yes I know it

is a HACK idea.

As I stated earlier and someone else reiterated. Use Scothkote. That is what it is for. I worked on Nuclear Submarines. Would anyone like to guess what they used for watertite splices? you got it. Two half lap layers of self fusing rubber tape, two half lap layers of Scoth 33 electrical tape and ScotchKote.

 

[TimWA]

Follow up on this, WA inspector approved complete today. Good to know for future. Thanks all.