Laying of IS and nonIS circuit cables

[RajT]

We have an application of a 6.6kV feeder to a motor on a offshore platform. The motor is located in (div 2) Zone 2 area.
The main motor cable is a 3c laid in ladder rack.
Along side this cable we have a cable ( 7c screened) also going to the motor RTDs. The cables are not touching and have an approx separation dist of 100mm between them.
Also the cable to the RTDs are of IS circuitry ( ie the motor RTDs are connected to a IS barrier forming part of the protection relay on the switcboard.

The questions are.
1.Is the cable installation correct.
2.If not why not.
3.Are there any published guidence notes (someone can direct me to) which defines installation of IS and non IS circuitry cables.

 

[itsmoked]

Don't you have to have the cable mechanically protected inside rigid conduit? What if something falls on the cable or the cable has a defect and decides to explode?

Also I would want the RTDs running some other route or thru metallic conduit for more shielding.

Someone with a better grip of the code's will be along momentarily.

Keith Cress
Flamin Systems, Inc.- <

http://www.flaminsystems.com>

 

[djs]

The IS cable does not have be run in a conduit, however it must be run in a seperate duct or rack by NEC. You can not have different voltages run in the same via.

 

[RajT]

Thank you gentleman.
The RTD cable is infact screened and armoured. The main motor cable is armoured as well. Because of this armouring, the cables need not be aforded with additional mech protection unless one does so out of choice.
Talking to other engs it appears that there must be some sort of a barrier ( if installed in the same cable rack) between the two types of cables.