Wrapping Split Bolts: Rocket Science?

The Junk Drawer is for those Off Topical discussions where we can ask questions of the community that we feel might have the ability to help out.

Moderators: Harold_V, websterz

Posts: 241
Joined: Sat Jan 11, 2014 12:36 am
Location: Bohemia, NY

Re: Wrapping Split Bolts: Rocket Science?

Post by LIALLEGHENY » Mon Oct 14, 2019 2:43 am

Yes your power requirements will depend on what you plan to do, and what equipment you are going to run. I have a commercial shop with 225 amps, 220v service, 3 phased. I run 2 large CNC mills , a CNC lathe, air compressor and host of manual machines. I can run these all at the same time EXCEPT when am using some of my welding machines. I have a miller Syncro 250, 220v single phase, that is on a 100 amp breaker. Max output is 300 amps, and I have been known to pop the breaker at times when welding heavy aluminum. So when welding I may only run one of the CNC machines. I know of a few people who have the Syncro 250 machines at there homes....and in most places you can't get three phase in residential areas, so the welding might max out your panel. Add lighting, fans , AC, an air compressor that suddenly kicks on.....and you are suddenly in the dark. Again it all depends on what you plan on doing.


User avatar
Posts: 673
Joined: Tue Feb 04, 2003 9:20 am
Location: illinois

Re: Wrapping Split Bolts: Rocket Science?

Post by ALCOSTEAM » Sat Feb 15, 2020 9:32 am

Patio wrote:
Wed Oct 09, 2019 11:23 pm
Split bolts are a pain in the butt, but they are cheap.
This is what I use for splicing in panels and J-boxes.
https://www.homedepot.com/p/Polaris-1-0 ... lsrc=aw.ds
It is easy!
Over the years I have cut many of these polaris connectors out of panels and j-boxes both before and AFTER they burnt up. Ideally they need to be located where every year or two they can be checked for tightness. Myself I do not trust them at all especially if they are in an area subject to movement or vibration as they will loosen and they will burn up. One place I was at was having issues (10 hole mechanical connectors used on incoming service drop- 1200 amp 480v service). The plant maintenance manager run and got their Flir camera and confirmed my suspicion. The connection blocks were showing WHITE thru the Flir camera, and all traces of tape and close wire insulation was gone or falling off in hard semi carbon bits. Another instance was a large grocery store that had been evacuated due to smoke and the fire alarm going off.. the contractor who recently built the store had one short wire going to a rooftop HVAC unit so they set a box and polaris connected that wire, 14 months from when they opened it caught fire. Yes they are expensive fire hazards.
The split bolts (or as we call them Kearney's) while somewhat of a pain are a far better connection and if properly tightened and insulated will last pretty much forever. Another thing to consider if using aluminum wire, special split bolts are needed to splice that. They are rated for both cu/al where as plain copper split bolts against aluminum wire can cause particulation of the aluminum wire, which as a result causes it to decay away, you get a loose connection and burnt up wire or worse a fire.

John Hasler
Posts: 1600
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Wrapping Split Bolts: Rocket Science?

Post by John Hasler » Sat Feb 15, 2020 10:32 am

Were the Polaris connectors that failed tightened to spec with torque wrenches?

Post Reply