Compression Splices


Staff member
a lot of jobs are specifying witness marks on the crimps to verify UL approval.
the correctly sized die, when swaged, will leave a die mark raised in the swage mark.

these critters are the reason why. not UL listed termination.
So the inspector signs off seeing the witness marks and then you go back and actually activate the heat or cold shrink that you had to put on the wire and tuck out of the way?


~~Please excuse the mess. Sig under construction~~
So the inspector signs off seeing the witness marks and then you go back and actually activate the heat or cold shrink that you had to put on the wire and tuck out of the way?
i asked that question of the engineer as well. the answer was.... yeah.

so i called out the inspector, showed him what i was gonna
do, showed him sample terminations, and asked if he wanted
to see every one.

he looked at the burndy, looked at the dies, said... "damn..."
and said i was good to go.

in the one case i've had to do that, no.
yes, it would be a level ten sucky poo thing to have to do that.
but i have copper and aluminum dies out to 750MCM, and a
full set of grounding dies. why would i cheat after buying all that crap?
any cheat i might do would take longer than doing it right.


Compression Splices

I agree with others in the comments, we typically use Burndy Connectors and Dies.

Looking at your Statement, it looks like you haven’t used Crimps before so to answer your question about length of time; after the first few uses, you could easily use the same time for Crimp or a few minutes more if you are using Long Stem Lugs.

I would like to give a few Pit Fall preventers.
Use the Correct Crimp Lug and the associated Dies, don’t get something close and put extra Crimps or use a Different Die to make it work out.
We have a Manual Hedge Clipper type Crimper, a Hydraulic Hand Crimper, and two Hydraulic 10,000 PSI Power Packs with Crimper Heads. I don’t care for the Manual Hedge Clipper type as it pretty much takes two people to operate. One to hold the Lug and Cable properly positioned and the other to perform the actual Crimp. This type also has the Built in Ratchet that forces you to complete the Crimp. That Ratchet sounds real good but there are times when confined spaces interfere with this feature and make it impractical to use. The Hand Pump Hydraulic works much better in confined spaces and one User can inch up to hold the Lug then the User can properly position the Cable with one hand and use the Pump Handle with the other. With that in mind, the Manual Hedge Clipper type sits in the Box most of the time.

Some of the Crimp Dies don’t have the MCM or Die Size markings that transfer to the Crimp for proof of correct sizing. If you need this feature, be sure the Dies you purchase are marked on the Crimp Rib of the Die.

If you are crimping Bolt Lugs inside Enclosures or Boxes be sure and leave a few extra inches of Waste Cable on both ends to help you with the Bending process. Don’t measure and cut the wire to length and then make the Bends. If you Cut First, the bends will pull Strands back into the Insulation when you make the bends and you end up with a Cable that is too short and start over. This is especially important with 300 MCM and larger Cable size. If you are just making straight end to end Butt Splice, this doesn’t come into play. We use Short Stem Lugs, Long Stem Lugs, and Window / Witness Lugs. The Window / Witness Lugs are usually on the Short Stem Lugs. You usually get two Crimps on a Short Stem and Four Crimps on a Long Stem. Burndy Lugs have Color Coded Bands for proper Die Sizing printed on the Lugs to help you position the Crimps but I have seen Lugs without any Markings and others with Markings not positioned correctly on the Lug.

I like the Cold Shrink but love the Thick Wall Heat Shrink with Glue or Sealer that is activated during the Heat Shrinking process.

There are also Companies out there that have all different Colors of thin wall Heat Shrink Tubing that we use for Cable / Wire Labeling purposes. With a Thermal Printer to create the Label on the Heat Shrink you make a very professional looking Labeling system. You can also place the thin wall Label over the finished Thick Wall Heat Shrink or just behind it on the Cable Insulation.

For the last preventer I would suggest wasting a Zip Tie on Multi Strand Cabling Crimps. Cut then pull the Insulation almost off the end of the Conductors. Before you finish removing the Insulation, place a Zip Tie on the Conductors and pull tight. Pull the Insulation the rest of the way off and let the Zip Tie hold the Strands together while you insert them into the Lug. Once in the lug, cut the Zip Tie and make the Crimp. If you drop the Lug and the Conductors fan out, you can waste another Zip Tie to pull the fan back down but it won’t be as effective as the steps above.