Direct burial power cable splicing question.

[waltsuz]

I am running all our power underground with #4-4 aluminum cable/wire. I am using what our local electrical supply and our utility field rep suggested. My problem is that the length of wire I have is about 10' too short to run as I need to. Its about a 100' run. Should I even consider splicing this or bite the bullet and buy a longer piece of wire. Its direct burial, no conduit except for the entrances. Something seems to worry me about splicing this.  Thanks for any opinions, Walt

[MountainDon]

There are special splice kits for underground direct burial use. They have a block with set screws... tighten with a torque screwdriver. The shrink tubing has adhesive that helps seal it when heated.

[Redoverfarm]

Personally I do not like to use Aluminum wire period whether it be underground or above.  I have heard that aluminum moves when put under large loads and heats up.  There is several splice blocks available but splicing in a long run could mean a failure at sometime in the future.  Less likely to fail with one continuous run w/o splices.  Water and corrosion will be your biggest issue.  If you do make sure that you use a special waterproof grease (antioxidant Paste) and a water tight connector.


Here is one.  It says it can be used on Alum but the specifications indicate Copper. 

http://www.homedepot.com/p/Ideal-Thermo-Shrink-AL-CU-Underground-Splice-Kit-46-401/203761582

Here are some others and information to splice

https://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4TSNA_enUS401US438&q=splicing+aluminum+wire+underground

http://www.practicalmachinist.com/vb/general-archive/hoping-some-advice-splicing-4-0-alluminum-200-amp-service-4-4-4-underground-98193/

[rick91351]

I am running all our power underground with #4-4 aluminum cable/wire. I am using what our local electrical supply and our utility field rep suggested. My problem is that the length of wire I have is about 10' too short to run as I need to. Its about a 100' run. Should I even consider splicing this or bite the bullet and buy a longer piece of wire. Its direct burial, no conduit except for the entrances. Something seems to worry me about splicing this.  Thanks for any opinions, Walt

I have done it two ways.  Come up with conduit and an above ground J Box - made my connection there with the good quality bolt clamps.  Wrapped and taped - then back down in a conduit (At that time had to be schedule 80.)  There was a reason for doing this thinking some day i am going to need to ______.  It paid off.   Then there is a few as MD says.....  We did run the mains for this house in Aluminum because I was not comfortable with the cost of copper when Electric Ray my electrician told me he was okay with doing it in Aluminum.  I have been told to kill the power like once a year and re-torque the lugs..... Ray says no need...But I never used it before - and I an not comfortable with it.  But it saved some $$$.  I do not know if I would do it again.     

[waltsuz]

Our power lines coming in to our meter and service entrance is aluminum from our utility company, 200 amp service worth here on our property. Probably millions cheaper for them but it works. I don't have any issue using aluminum if I am confident I have done it correctly, its why I came here to ask about splicing underground power lines. I will ask the supplier we have here about a splicing kit to extend the lines. If it don't feel right to me I'll buy a piece long enuf to make one run of it. I appreciate the reply's, Walt 

[Tickhill]

There are enough headaches and worries with cabin/home ownership, eliminate one of them by not splicing and make it a continuous run of feeder.   

[waltsuz]

There are enough headaches and worries with cabin/home ownership, eliminate one of them by not splicing and make it a continuous run of feeder.   

I agree, Looked at the splicing kits, talked it over a bit and I'll buy another piece of wire. I have plans later on where the short piece will be used. Walt

[Redoverfarm]

Our power lines coming in to our meter and service entrance is aluminum from our utility company, 200 amp service worth here on our property. Probably millions cheaper for them but it works. I don't have any issue using aluminum if I am confident I have done it correctly, its why I came here to ask about splicing underground power lines. I will ask the supplier we have here about a splicing kit to extend the lines. If it don't feel right to me I'll buy a piece long enuf to make one run of it. I appreciate the reply's, Walt

Let me back paddle a little.  I too have underground aluminum wire but that was installed by the power company for my 200 amp service as well.  Not a lot of choice as that is the standard for them.  I think you made a wise decision to run a continuous piece rather than splicing.  Splicing just opens you up to potential trouble down the road.