Power cable

[cytech]

Hi All,

3x 1C cable lay above the ground from substation to substation, 1 week after commission it was found the tray is over heating. what is the cause of the tray over heating, this single core was lay apart.

please advise.

Regards
Cy

[br1x]

Is likely to be due to eddy currents

But explain best the phenomena with a drawing, were are indicate the dimensions and distances, cable type (armour, unarmour) voltage, current, path length, etc.
The cable is in trefoil or laid in flating formation (separate or touching)?

the formulas to understand the problem can be found in IEC 60287

bye

[Rudi Tua]

Wel, overheating means energy, try to look for the energy source, such as :
1. Electro magnet looping from metal cable ties that forming CT.
2. single core cable lays in different tray.
3. ground current from ground "summing" flows through tray to ground
4. Both ground end of cable is grounded so the cable is heated up
5. etc.
But since you mention "single core lay apart", I suppose the magnetic and capacitance is not balance and transfered to tray. Try to implement "INTERPOSING" method.
Hope this will help you.

[cytech]

Hi All,

This cable is single core connected to main substation to sub substation from 22kv to 6.6kv, distance between 1c cable is 300to400mm.

Regards
Cy

[hputters]

Hi All,

This cable is single core connected to main substation to sub substation from 22kv to 6.6kv, distance between 1c cable is 300to400mm.

Regards
Cy

Clear answer. You cannot lay powercables single core segregated.
Trefoil installation with cleats for dynamic forces is the only solution.

[karn2u]

Please check list :
1. Connection all point.
2. Current in grounding. <<< The most of problem.
3. However , if Temperature are not anymore from cable data sheet specification, you 're not serious.