×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Laying of IS and nonIS circuit cables

Laying of IS and nonIS circuit cables

Laying of IS and nonIS circuit cables

(OP)
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.

RE: Laying of IS and nonIS circuit cables

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>

RE: Laying of IS and nonIS circuit cables

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.

RE: Laying of IS and nonIS circuit cables

(OP)
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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources