Cross bonding HV cable

[hooman17]

Hi
I am very happy to find this good forum and joined it to have useful and scientific conversation with the member.
I am working in a wire and cable factory. and I have a project about HV cable installation.

My problem is about cross bonding a cable like N2XRYBY 1000MM2 132KV THAT HAVE COPPER WIRE SCREEN AND ALUMINIUM WIRE ARMOUR:
If the cable just have shields/sheaths layer,the shields/sheaths are cross-bonded at the end of each minor section and can be earthed or connected to SVL.For the cable have two layers and have induced voltage and current how we should install
armour and the screen to the SVL and linkbox? should they connect together or seperate and which of them should install at linkbox (armour or screen or both)?

 

[Marmite]

Normally cable screens are bonded to armours at joints and terminations. I don't see that this situation is any different. Cross bonding is applied to insulated sheath single core cable systems. By design you have a standing voltage to earth at the end of every minor section. If you don't bond the screen to the armour you will have a voltage between them, which would be bad for the cable, particularly during a fault. Also, if you somehow earthed the armour separately to the cable wire screen, you would effectively defeat the cross bonding by introducing a parallel end to end solidly bonded arrangement via the armours.

Regards
Marmite

 

[7anoter4]

At first I agree with Marmite, of course. More details are in IEEE-575/2014 section 6.5 Cross bonding.

 

[cuky2000]

See if the enclosed example could help

 

[hooman17]

@Marmite; @7anoter4; @cuky2000
Dear Friend
Tnx for your reply, The problem is solved and my question is answered.
Some days ago I was simulating a cable with two single point bonding at CYMCAP and I relized that for a flat cable if you increase the space between cable,The current rating is decreased.It was interesting for me and I would like to share with you this subject.