Spacing Between Two 110 kV Single Core Circuits in a Trench

I'm sure that somebody can tell you this standard, if it exists. A better question for you here will be which IEC standard has this information, so you can buy the correct standard? I do not work with IEC standards. I work with NEC, NFPA standards so I cannot tell you which to purchase.

Where I work I have transformer station 400kV/110kV that is being retrofitted,from air insulated switchgear to gas insulated switchgear 110 kV. The connections for the power lines are made using 500mm2 XLPE cable layed in a trench, 450mm between each power line, 1000 mm between power line and 110 kV transformer connection and 1500 mm between two transformer connections.The cable for transformer is 2000mm2.

These distances were taken from a national norm for power lines, addapted after the IEC standards.

Try this for more info:

http://www05.abb.com/global/scot/scot245.nsf/veritydisplay/ab02245fb5b5ec41c12575c4004a76d0/$file/xlpe%20land%20cable%20systems%202gm5007gb%20rev%205.pdf

and

http://www.nexans.no/eservice/Norway-no_NO/fileLibrary/Download_540199654/Norway/files/Underground_power_cables.pdf

cheers

nikolay

There is no IEC Standards for what you asked.

The Utility/Main Contractor shall decide the formation and bonding method based on the required load, the cable manufacturer shall design the cable based on the received information such as:

a) Transmitted Power (Load) b) Ground temperature (max).

c) Soil Thermal resistivity.
d) Depth of laying
e) Total number of cable/circuit in groups

You may refer to this catalogue for more information:

http://www.nexans.no/eservice/Norway-no_NO/fileLibrary/Download_540199654/Norway/files/Underground_power_cables.pdf