MV Cable Termination

[E Torres]

I have a 5kv load break switch feeding a 150kva,3ph, 5kv/480/277V xfmr. My dilemma is that we are using MV cable and according to art. 300.40 I need to provide stress cones on all terminations, but I don't have enough room in the xfmr to install the stress cones. Anyone have any suggestions?

 

[jtester]

What kind of termination is in the transformer, live front? Most stress cones are only a couple of times the cable diameter, and not very long. It would seem uncommon for there to be no room in a primary compartment. You might set the transformer over a vault and enter from the bottom, that would give you a lot of room below the bushings.

Jim T

 

[E Torres]

Xfmr

Xfmr

The xfmr terminations, both X and H, are at the front. X terminations are at the bottom and the H terminations are at the top of the core. The transformer is totally enclosed and is only 36" in height. We are running the MV cable up into a cable tray from the load break switch and into the transformer. I would think that the manufacturer would have known about this problem and would size the xfmr enclosure accordingly. :-?

 

[KarlS]

Forum

Forum

Ed,

I am clad to see you use this forum. I have used it from time to time have and found it very useful. Let me know when you have worked out your problem.

Karl

 

[mkgrady]

Are the terminations deadfront (elbow connections required) or live front (stress cones required)? An elbow can be made up in a pretty small space. In either case if you do not have enough room you need a hand hole or a spacer under the transformer. The transformer manufacturer should offer a spacer that can bolt to the bottom to raise the terminals up enough to terminate the MV cables