Spacing of Concentric Neutral wires

[surenrshah]

In medium voltage 34.5 KV cables, there is a conductor shield, insulation, and insulation shield. On top there are 12-24 copper wires called concentric neutral wires somewhat equally spaced around the insulation shield. The CN wires are grounded about 4 times every mile. The CN wires are in constant electrical contact with the insulation shield which covers 360 degrees of insulation. How important is to have equal spacing of 12-24 wires around the circumference? Does it make any difference in the performance of the cable?

 

[bob]

In medium voltage 34.5 KV cables, there is a conductor shield, insulation, and insulation shield. On top there are 12-24 copper wires called concentric neutral wires somewhat equally spaced around the insulation shield. The CN wires are grounded about 4 times every mile. The CN wires are in constant electrical contact with the insulation shield which covers 360 degrees of insulation. How important is to have equal spacing of 12-24 wires around the circumference? Does it make any difference in the performance of the cable?

Those conductors are just the neutral for the system. I assume they a bare conductors. The shield that is important is the insulation shield. It equalizes the voltage stress on the insulation. Are the conductors
direct burried? If so, I not sure what the "grounding 4 time per mile" does for you.

 

[mbrooke]

In medium voltage 34.5 KV cables, there is a conductor shield, insulation, and insulation shield. On top there are 12-24 copper wires called concentric neutral wires somewhat equally spaced around the insulation shield. The CN wires are grounded about 4 times every mile. The CN wires are in constant electrical contact with the insulation shield which covers 360 degrees of insulation. How important is to have equal spacing of 12-24 wires around the circumference? Does it make any difference in the performance of the cable?

The cable shield ground is normally pre-wound with the concentric cables. The concentric serves several functions. 1 is in the event the cable is dug into it helps detect that a fault is present. 2. being to even out voltage stress on the insulation, similar to why one uses a drain wires on stress cone terminations.