Author	[Modern View]
RMinVa 12-26-2012 13:13:09 67.142.166.23 Report to Moderator	Made a lot of splices over the years and some underground. I'd make the splice connection with split bolts sized for the wire unless you have access to lugs and a crimper. Keep it clean. After each split bolt connection is made use Scotch Varnished Cambric Tape and cover all the exposed area and up the insulation about 2 inches and at least 3 wraps. Keep it clean. Then use Scotch Linerless Rubber Splicing Tape. This tape is made to stretch as it's being applied. Cut each piece about 5 inches long and stretch as applied to cover all the area with at least 2 complete wraps and extend up the insulation past the Cambric about 1 inch. Keep it clean. Then apply Scotch Super 33+ Vinyl Electrical Tape. Tape over the linerless with 3 full wraps and up the insulation another inch past the linerless. Don't settle for other brands of tape. This is the best I know of and have used it for over 25 years. The linerless will become a ball of rubber and seals really good if applied proper. The Cambric is used basically so you can get all that tape off the connection if need be later. If you don't use the Cambric and have to get back in that connection later you'll wish you had used it. The linerless is really hard to cut once it's applied. It has to be cut to be removed. If you have to cut some you can most of the time feel when the blade goes through the Cambric. Then you can use channel lock pliers and roll the tape wad off. Use heat shrink over all that. [Reply]   [No Email]
John T 12-26-2012 13:30:58 216.249.82.117 Report to Moderator	Re: Underground electrical splice in reply to RMinVa, 12-26-2012 13:13:09   Yearssssssss ago I made such a similar splice and had even more coats of epoxy and silicone and tape etc etc and its never went bad yet KNOCK ON WOOD LOL John T [Reply]  [No Email]
showcrop 12-26-2012 14:22:12 75.67.231.80 Report to Moderator	Re: Underground electrical splice in reply to John T, 12-26-2012 13:30:58   I installed a well pump last summer with some friends. The new pump came with crimp connectors and heat shrink tubing. [Reply]  [No Email]
RMinVa 12-26-2012 14:20:00 67.142.166.23 Report to Moderator	Re: Underground electrical splice in reply to John T, 12-26-2012 13:30:58   Many years back I had one to blow out. Guess that was my classroom. Working in heavy industry you throw code out the door at times to get back running. There's some old repairs that we never got back to and are still good today. I wouldn't dare try that with 4160 but have several times on 480. I've always been amazed at the spray paint insulation we use now on 4160. Course that's all in a dry J-box and I still don't trust the stuff completely and use the other wraps with it. But it works and with 4160 I use anything that helps keep that stuff in the insulation. Few years back we upgraded to some mining cable running 1000 hp motors that moved in a aligator tract as the carriage made it's stroke. This cable had an extra layer if graphite inside and the guys on night shift didn't see it printed on that wrap. It was left in there right against the lugs. Started that big boy up and by the 4th stage of the start cycle it blew the door off that 4'x4' 2' deep junction box. Hinges and all. Some more of that true classroom work. LOL 4160 takes time to prep. We don't rush that work at all. [Reply]  [No Email]
Shetland Sheepdog 12-28-2012 13:05:33 72.71.217.243 Report to Moderator	Re: Underground electrical splice in reply to RMinVa, 12-26-2012 14:20:00   Had a 20KV splice fail in an underground vault. Found it after patrolling the overhead. Pulled into an alley on the underground route, and had no trouble spotting the location. Blew the cast manhole cover annd base right up out of the pavement! [Reply]  [No Email]
Dr. Walt 12-28-2012 11:58:01 12.2.223.79 Report to Moderator	Re: Underground electrical splice in reply to RMinVa, 12-26-2012 14:20:00   You're absolutely right about that 4160. I was Senior Underground Top Millwright / Mine Maintenance Mechanic a few years back, in a large Mine. We had several Road-headers that were electric over hydraulic and powered by 4160 Volts at 1000 Amps. I have a VERY healthy respect for that kind of power. I got to witness what happens when a 5 Yard Scoop-Tram pinches a 4160 cable between the bucket and the rib of the drift - It was like a dozen 4th of July fireworks shows all happening within 5 seconds. MAN, WHAT A SHOW, DOWNRIGHT SCARY! [Reply]  [No Email]