Power cable

[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.