Cables screen & drain wires. Collective or individual screen?

[zrzr]

Good day everyone,

I came across this cable specification which is coded I2 and I4. These cables are pair cables having the same materials. Then, I noticed that for I2 cables, the screen of the cables are collective screen while I4 cable are having individual screen for each pair.

My question is, what are the difference between using collective screen and individual screen? When should I use collective or individual screen?

Thank you, hope someone can point me to the right direction here.

Regards,
zr

 

[roydm]

I take it you are talking 4-20 mA loops it's normal practice to shield each pair individualy. I have never seen the paired cable with overall shield used. Not to say it wouldn't work.
Roy

 

[NWBeaver]

Like roydm says, if you are using separate pairs for 4-20 mA loops, I would use the individually shielded pairs.
The overall shield cable works for something like an encoder, which uses more than one pair for a single device.

 

[zrzr]

Alright, thanks for the info guys.