Borehole Cable Install

[rob52]

Borehole Cable Install

11kV 300mm2 & 400mm2......ish... Anaconda!

Old MMCables 9/95 Cat lists
300mm2 PIL Screened Cable 11/11kV @2160kg per 100m, OD 83.1mm
400mm2 PIL Screened Cable 11/11kV @2590kg per 100m, OD 91.8mm

300mm2 XLPE 12.7/22kV Close Duty Screened at 1917kg per 100m OD 92.7mm

Pre 1999 120mm2 11/11kV PIL @1180kg per 100m was the biggest CSA in wide use UG, didn't think XLPE was allowed in NSW because there was no real way to test it other than AC Soak Test (DC Hi Pot not permitted on XLPE due to space charge & water trees), maybe XLPE has gained acceptance in UG Coal with the advent of VLFAC Testing ?

Re XLPE, used 12.7.22kV XLPE on 11kV 10A EFL Systems.
=>> Is 6.35/11kV now widely accepted per pg48?
"If the time of fault duration is up to 8Hr (but not exceeding 125hr per year), then AS/NZS1429.1 & IEC 60502.2 allow the standard rated cables to be used."

Rob

[John]

The problems I see with cables in boreholes are, how can they be examined to comply with mining regulations??? Second problem, although it doesn't happen often, but still happens, a blow out due to a fault developing, the very reason we were forbidden to run telephone and signalling low voltage lines along medium and high voltage cable runs. I see they run telephone lines with them.....Asking for problems based on past experience, hence the rules forbidding telephone cables to be run with hv cables..

[rob52]

"how can they be examined?"
=>>Agreed, reliance on electrical testing and maybe bore hole fibre optic camera.

"the very reason we were forbidden to run telephone and signalling low voltage lines along medium and high voltage cable runs. I see they run telephone lines with them.....Asking for problems based on past experience, hence the rules forbidding telephone cables to be run with HV cables."
=>> Hmmm…uncertain whether the accompanying comm's and signalling are deemed "Critical Infrastructure".....BUT if they are....practice the saying "My mission in life is to work for a company with a technical memory beyond the last corporate restructure!"

Rob.