Are skirts of termination kits on the same phase allowed to touch?

[kewo]

Say we have cables (two per phase) terminating at a bus, can the skirts of the cable termination kits ON THE SAME PHASE touch?

Would the voltage potential throughout the length of the termination on both cables be equal? Or would there be slight differences of potential between the two terminations that it would cause problems? Any other concerns? If they are not allowed to touch at all, is there a minimum amount of separation recommended? The cables are 15kV.

Thanks.

 

[alehman]

I would say no, but ask the manufacturer about recommended spacing.

 

[bacon4life]

Some of ours older installations have terminations that are smashed together, and we haven't documented an increased failure rate do to the decreased creapage distance or voltage stress. We have however recently updated our construction standards to avoid contact.

 

[busbar]

Raychem {er, Tyco} used to have an application note/drawing for their HVS-series terminations at their site but I can’t seem to find it now.

 

[dpc]

I would think that any deformation of the skirts would reduce the tracking resistance. The creep distance could be reduced quite a bit, I think.

For the indoor type without skirts, it may not be as important.

 

[DanDel]

I would think that it is OK close to the actual connection, but more questionable the closer to the semi-con grounding point. Of course, once the shield in covering the insulation and conductor, there is no problem.

 

[rempman]

As has been brought up previously by allowing the skirts to touch is not the recommended practice.

We avoid this by installing a piece of 4in copper bus drilled to NEMA hole pattern. In an overhead application we also include a bail off one side to hang an arrestor, thereby eliminating any voltage difference between the arrestor and termination.

 

[pwrengrds]

I have seen a few skirts with corona damage, they get a white powder or turn brown. I wouldn't recommend them touching if you are able to avoid it. The closer you are to the neutral the less it is likely to happen.