High Voltage Feeder Cable? Revised.?

Question

I need to run 4160V feeds to some power vaults. Yes, 4160V...not 480V or 110V. Each Power vault requires three power feeds, a ground and a control cable. Amperage is 400 Amps. I've got existing 4" conduits.....but I cannot find a cable small enough and think I need to retrench and run new conduit to at least 5", maybe 6" Anyone got a miracle solution ? Or should I say cable....original design calls for 750 KC mil 133% insulation which is a 3.8" OD and wont run in a 4" conduit. Hopeing to find a rated cable that will. I was hoping a salesman would be on here looking at this instead of all you smart a$$e$.

Answer 1

Direct burial cable or cable tray is the best option here.There are many problems running 6 inch conduit mostly pulling the cable if its not a short straight run.Check websites like BICC for cable quotes they will be able to advise.

Answer 2

It seems that you are inexperienced in cable selection and installation......
1. 4160V is NOT High Voltage it "Medium Voltage". Medium voltage is voltages between 2.4 to 34.5kV.
2. Either you need to carefully read NEC or contact an electrical engineer who will properly calculate, size and specify the correct cable for the application, taking into account the following:
a) Voltage drop
b) Temperature rise including mutual heating
c) Insulation level
d) Short time heating calcs
e) Termination requirements
f) Whether the location requires direct burial, conduit or duct bank.

Answer 3

400A @ 4160V is a pretty hefty system!
No miracle solution, but you may be able to run parallel feeds provided that the cables are EXACTLY the same length. This is generally a less expensive solution than running conduits over 4". I'm not sure what termination problems you would run into on 4160.

Answer 4

it sounds like poor or no planning