×
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

Non-Incendive Wiring Practices - NEC - ISA

Non-Incendive Wiring Practices - NEC - ISA

Non-Incendive Wiring Practices - NEC - ISA

(OP)
All -

There are many forum postings that discuss this topic. I would like to draw on everyone's practical experience as it applies to the NEC 2011 and referenced ISA standards on the subject.

Hypothetical Design:

- AB PLC 5/05 with Analog Input card rated for installation in Cl I Div 2 (no Non-Incendive rating)
- Transmitter rated FM CL I Div 2 Non-Incendive, no XP rating
- Transmitter includes control drawing including entity parameters
- Conduit installation

The analog input card, as I understand, must conform as an associated apparatus to satisfy the equations described on the control drawing. Without a NI rated associated apparatus, there are no parameters for the power source, and thus can not be considered appropriate. I believe I would need an approved Non-Incendive barrier between the PLC and transmitter to satisfy the requirements of NEC and ISA 12.12.01. Another option, would be to use Non-Incendive (also intrinsic) I/O such as the AB Flex Ex 1797.

Please comment with reasoning and feel free to supply white papers you have that discuss this specifically.

Thanks everyone in advance,
Brian, EE

RE: Non-Incendive Wiring Practices - NEC - ISA

If this is still relevant, I have only used NEC for wiring practices.

Years ago, in one plant, I put the controller, I/O, and IS barriers in the non-hazardous area with the IS transmitters in the hazardous area.  That eliminated the need for poured conduit seals on the factory floor.  I've never seen white papers on this topic nor did I look for any.  Since I was the only EE in the plant and I am registered, it was my decision.

I bet if you search A-B's website for IS barrier, you'll find information.

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! Already a Member? Login


Resources

Research Report - What’s the State of Nonlinear Simulation?
Simulation is an increasingly valuable tool across the product design workflow, but not all simulations are equal. We set out to determine how engineers and product designers make use of specialized analyses, how they incorporate nonlinear simulation into their work and how they rate the available software. Download Now
White Paper – Data Security and Know-How Protection
Our data is constantly exposed to the danger of being intercepted or stolen as it wends its way over global data networks. Data security measures and measures for protecting intellectual property should not, however, first be implemented when data is exchanged – companies must lay the foundation for these measures within their own organization. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close