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Joined: Nov 2004
Posts: 7
New Member

Is there a proper way (as determined by NEC, manufacturer or some other body)for split bolt connectors to be installed for LV applications (208V)? Should tape be used? What kind?

I have heard that duct tape should not be used.

I have also heard from other sources that no tape should be used.

Tammy Gammon

Joined: Sep 2006
Posts: 58
I've always done the taping with 3 layers. First the varnished cambric tape, then rubber, then plastic. When I first started in the trade we used friction tape instead of the plastic on the top layers.

Joined: Jan 2001
Posts: 1,044
Tom Offline
2005 NEC 110.14 (B) "...shall be covered with insulation equivalent to that of the conductors or with an insulating device identified for the purpose."

I usually use a few layers of glass cloth tape (varnished cambric is good too) which helps prevent sharp edges from poking through the tape, next a layer or two of self fusing rubber, followed by at least one layer of vinyl electricians tape. The glass cloth or cambric will also make it easier to remove all the tape should the connection ever need to be taken apart.

Few things are harder to put up with than the annoyance of a good example.
Joined: Mar 2001
Posts: 2,056
Try these. Much easier to make up, and to take apart:

As far as duct tape -- what would be it's dielectric strength? It's not listed for insulating electrical connections.

Joined: Sep 2005
Posts: 421
FIRST, duct tape ain't what it used to be...if you tried wrapping some splices with "real" duct tape you would get a small fireworks show...but regardless forget about using something non-electrical to cover your splices.

SECOND, where are these splices that you can just leave them uninsulated ?

and C, if you don't have either glass cloth or cambric , try wrappng them first with vinyl but wrap it with the sticky side out, then rubber or 130C , then more vinyl, but this time wrap it the regular way...and don't forget to twist the tail so the next gal, or guy doesn't have to use an electron microsocope to find the end....

BTW ....when you are assembling your splice, do you whack the bolt and re-tighten... after... you have snugged it up ????

Joined: Nov 2004
Posts: 7
New Member
I am not an electrician. I think it is great that some women are electricians. I just do office work for an electrical engineer -trying to find an answer to a question he had.

Joined: Jan 2007
Posts: 22
Junior Member
split bolts are becomming obsolete. there are many other devices that don't require any tape.

Joined: Jul 2006
Posts: 272
Originally Posted by togol
and don't forget to twist the tail so the next gal, or guy doesn't have to use an electron microsocope to find the end....

always be sure to leave a buddy tail!

Luke Clarke
Electrical Planner for TVA.

Joined: Jan 2005
Posts: 5,370
Likes: 1
Cat Servant
The method, as taught by the Union - so it's likely buried in the NECA standards somewhere - is:

1) 'round out' projections with electrical insulating putty;
2) Wrap several times with self-fusing rubber tape; and,
3) Finish with a two layer wrap of ordinary electrical tape.

The inner tape, and putty, fuse together into a solid rubber block, so you're not going to ever be able to unwrap this assembly; it's time for a sharp knife - and patience.

Some will start off with a layer of 'glue side up' electrical tape, with the idea that this will make taking the thing apart easier .... but I worry that this practice will result in the final assembly not being as waterproof as it should be.

Joined: Oct 2002
Posts: 482
Polaris makes a nice, although pricey, line of insulated connectors in a variety of configurations. I've been using them for years with no problems.

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