SSLA
Electrical
- Dec 6, 2004
- 37
Folks:
I've got metering at the wrong end of some direct buried concentric neutral XPLE cable, three single phase cables, 1000MCM Cu with 1/3 neutral, XLPE, grounded both ends.
I need to correct for losses. The load is well balanced so I am focusing on positive sequence current.
When I look in the Pirelli tables I see the positive sequence resistance is 47 micro-Ohm/ft or 0.2482 ohm/mile. The manufacturer says R1 is 0.1286 ohm/km or 0.207 ohm/mile under standard spacing etc. When I carry out the calculations in Anders book "Rating of Electric Power Cables", page 125, I get 0.0793 ohm/mile.
Why would there be such a disparity between Anders "AC resistance" (which based on IEC 287) and the R1 value published by the cable manufacturers? Do the manufacurers assume there will be current in the neutral?
I've got metering at the wrong end of some direct buried concentric neutral XPLE cable, three single phase cables, 1000MCM Cu with 1/3 neutral, XLPE, grounded both ends.
I need to correct for losses. The load is well balanced so I am focusing on positive sequence current.
When I look in the Pirelli tables I see the positive sequence resistance is 47 micro-Ohm/ft or 0.2482 ohm/mile. The manufacturer says R1 is 0.1286 ohm/km or 0.207 ohm/mile under standard spacing etc. When I carry out the calculations in Anders book "Rating of Electric Power Cables", page 125, I get 0.0793 ohm/mile.
Why would there be such a disparity between Anders "AC resistance" (which based on IEC 287) and the R1 value published by the cable manufacturers? Do the manufacurers assume there will be current in the neutral?