0

In the process to perform a DIY 400A main panel upgrade,

I have spliced these wires coming from the new main panel to a cable that goes to a sub-panel. This is a pre-existing box where the same cable was spliced to a different one going to my old main panel. The old cable has been removed.

Splice box

I used "polaris" connectors that were very expensive - more than 100 dollars for the three pictured above. Here a detail view:

Polaris ITG3/0

  1. Are these connectors rated for 1/0 aluminum wire? There is NO gel inside the holes nor any marking that suggests it
  2. I looked online and it was surprisingly difficult to find a torque for these. Best I found is 250in*lbs that sounds pretty high for a 3/16 hex driver
  3. Is it OK to ground the box with that copper wire?
2
  • Ilsco PBTS is comparable to the Polaris ITG, but often priced 40% lower and also dual AL/CU rated (at least the one I checked was). And 250 in-lbs isn't so much - maybe you're thinking of ft-lbs? 250 in-lbs = 21 ft-lbs. You can see why connectors tightened to "that feels good" are often under-torqued.
    – Greg Hill
    Commented Feb 11 at 19:10
  • A hex key bolt with 3/16 driver is typically a 1/4" threaded bolt size, which (for a grade 5 steel) typically takes 11ftlbs. I am not sure if this threads into steel or aluminum, in any case a torque of over 20ftlbs seems high to me. Maybe this screw is actually bigger than 1/4" but in my main panel, a screw that takes a much bigger 3/8" hex driver has a listed torque of 250in*lbs Commented Feb 12 at 4:34

1 Answer 1

3

Those are the wrong connectors

Note the "CU9" labeling by itself on the connectors you have -- this means that they are rated for copper and copper only. You need to get connectors rated CU9AL instead, as that means they're rated for both copper and aluminum.

12
  • Oh man this is not the first time the local big electrical distributor gives me something that should work but it's not right, and then they charge 30% restock fee. I remember asking about polaris connectors able to splice 1/0 and 2/0 wire but I may not have specified aluminum, because who uses such big copper wires? :( :( :( Commented Feb 11 at 8:59
  • Is it OK to use that ground connection for the box? Commented Feb 11 at 9:00
  • @AlessioSangalli as to the ground wire, what size is that jumper down to the box? Commented Feb 11 at 14:09
  • I recycled a piece of 12ga wire pulled out of a scrap romex Commented Feb 12 at 0:50
  • @AlessioSangalli -- yeah, that's far too small for bonding a box like that Commented Feb 12 at 3:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.