Shield ungrounded, what about armour?

[Eclair]

Hi

I have a lenght of 3C 25kV TECK power cable in a substation.

If I decide to do not ground the shield on one side of the cable what do I do with the aluminum armour with the connector?

It should remain ungrounded as well isn't it?

Someone can confirm what is the right way to do it?

Thanks

 

[tinfoil]

a) Consult an expert familiar with regulations in your area.

b) They will likely tell you to bond the shield and the armor together and to ground to earth at one end only.

c) Depending on GPR in your substn and fault currents that may exist on the cable, you MAY require an arrestor/shunt at the UNGROUNDED end to dissipate transient overvoltages.

 

[7anoter4]

According to IEEE-575-1993 the armor [like the shield] should be solidly grounded at one or more points:.
"Cable shields and metallic sheath/armor should be solidly grounded at one or more points so that they operate at or near ground voltage at all times".
See IEEE-575-1993 ch.6.2 High-voltage power cable 6.2.4 Grounding practices.
A 3 core cable shield or armor losses are negligible if it is both ends grounded.
So, if there is not any other reason to avoid armor grounding you have to ground it.......