What are the point of a single core cable to be earthed?

Answer Posted / 7anoter4

The grounded point of a cable shield[or screen] could be :
1)at the supply side-usually is not necessary since the
supply side is enclosed
2)at the far end-is better for receiver security.
3)if the built-up voltage-due to induction produced from
the current flowing in the main conductor-is elevated [more
than 25 V usually limited]then a middle point grounded will
reduce this voltage to a half.
4)Both ends-if the middle point it will not reduce enough
the built-up voltage.
However, the circulating current will produce a
supplementary heating of the main conductor and then a
derating factor should be introduced.
There are also other means to overcome this by cross-
bonding the shield and even the main conductor, also.

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