Can any one of you explain the following,

A 3 core cable is selected to transmit a resistive load current of around 10 Amps. Even though a 1.5 sq.mm cable is sufficient ,a 6 sq.mm 3 core cable is selected considering several contingencies. The total length of the cable is around 6000 metres and it is supplied wound over a metal drum, the number of layers working out to 40.

The situation is that the cable is connected to the aforesaid 10 amps load with the entire cable in the winded state over the cable drum. There is an anxiety that the cable will not be able to take the load as that the temperature generated due to the heating will not be transmitted outside from the inner layers of the cable winding. Considering the above situation it is planned to impose a limit on the connected load as that the temperature rise in the inner layers is not determinal/harmful to the insulation property and its life.

Can any one of you give an idea in going about with the study of the heat generated in the various layers and the temperature rise?

N.Vedachalam,
Electrical Engineer,
India.
e-mail : [email protected]

 

Responding to NV's query:

Yes, there is a way. But first, what is highest ambient temp?

Regards,
Phil Corso, PE {Boca Raton, FL, USA}
[[email protected]] ([email protected])