Cable crimp types for H.V or L.V. 3

[stu1]

I have been supplied with two types of crimp "lugs" for H.V copper cables. Does any "collar" length suit or do H.V crimps require longer compression areas?
Thanks & All the bst in the New Year.

 

[candu6]

I'm not aware of any minimum collar length as long as the crimp is the correct size for your cable. Depending on the voltage level you will need a stress relieving high voltage termination kit.

 

[busbar]

 
There are short- and long-barrel hydraulic-tooled compression terminals, but use of one or the other for certain voltage levels is more a matter of engineering specification and localized custom. I believe typically they are rated up to 35kV under UL 486A.

A variation has externally beveled at the barrel end to facilitate void-free taping with MV-termination materials. Example 64200-/64800-/64400-series

http://tnbelectricalworld.tnb.com/contractor/docs/colorkeyed_spec.pdf

 

[TMD]

Suppliers (Panduit and T&B (my experience)) will specify in their catalog that their lugs are suitable up to 35 kV.

http://www.panduit.com/products/browse.asp?classid=1047

Greater than 35 kV, I think you're on your own. That is, the market is so small, you're essentially on your own (other than your colleagues here)

 

[tulum]

This will probably sound stupid but...

I have always wondered why lugs come with a voltage rating? I realize there is a reason, however, what is it? How can one piece of copper (lug) have a voltage rating on its own? Excuse my ignorance.



Regards,
TULUM

 

[TMD]

Good question tulum. The only thing I see on the Panduit lugs is that the end of the barrel is tapered toward the conductor, presumably to eliminate that edge. But they also offer a flared end lug (for flex cable) rated 35 kV.

The 35 kV rating has something to do with UL486A, but I don't have the standard.

 

[benlanz]

Sharp edges can lead to partial discharge. Partial discharge is to be avoided around dielectric materials.

-cheers

 

[stevenal]

The Burndy catalog suggests standard length barrels for "limited space applications" while long barrels are "ideal for high voltage terminations and other heavy duty applications requiring high pullout force." Both are UL listed to 35 kV. The way I see it, the long barrel gives you more chances of getting at least one of the crimps right, and the consequences of pullout increase with the voltage.