Overbuild distribution circuits
Overbuild distribution circuits
(OP)
I wondered if anyone had experience with overbuild distribution circuits like 25 kV on top and 12.5 kV on the bottom. We've had incidents from tree limbs and from vehicle accidents where the upper phase makes contact with the lower phase.
Short of separating the 2 circuits (including putting one underground), the only other solution that comes to mind is to convert the lower voltage to the same voltage as the upper one. I don't know of any other solutions so that's why I'm asking what others do.
Thanks in advance.
Short of separating the 2 circuits (including putting one underground), the only other solution that comes to mind is to convert the lower voltage to the same voltage as the upper one. I don't know of any other solutions so that's why I'm asking what others do.
Thanks in advance.






RE: Overbuild distribution circuits
One option would be to replace the 25kv run, if it is open wire, tangent construction with a spacer cable run.
Not knowing the exact configuration, I would guess the other option is to install surge arresters every few spans on the 12kV to clamp the overvoltage from the 25kV landing on it.
That's not as bad as my overbuild where I had 46kV land on 4160V.
RE: Overbuild distribution circuits
RE: Overbuild distribution circuits
RE: Overbuild distribution circuits
RE: Overbuild distribution circuits
RE: Overbuild distribution circuits
I haven't seen the "broken wire guard" down here along the Gulf of Mexico in Louisiana, at least as you describe it. I used to work for one of the big electrical utilities.
I did hear talk about installing a copper conductor on the crossarms supporting some conductors. This was connected to the grounded conductor running up the pole, and the idea was the same as your broken wire guard, to insure that a falling conductor had a solid, relatively low impedance ground path to achieve reliable ground fault relay operation.
old field guy
RE: Overbuild distribution circuits