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!

*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.

Jobs

Why fire SLC alarm cable shall not be shielded? Aply same for NAC?

Why fire SLC alarm cable shall not be shielded? Aply same for NAC?

(OP)
Blessings, and a hello to everybody.
I've seen in wiring manuals, and cabling guides, from fire alarm panels of main manufacturers (Notifier for example) that SLC fire cable for inteligent panels should not be shielded, and if shielded, the shield shall be broken or isolated from devices ground.

Does somebody know why?

In my case, my only concern is that I'm afraid the cable may pass near a normal power wire. Is there a real negative effect from a motor 120-240AC wire on the SLC for example?
I've asked..., some say the cable lenght may be reduced a little by impedance, others say to use shielded if possible, but i'm not happy with the explanations.

I've also read that the only shielded cable recomended is for voice cable from amplifiers to speakers. is this true?

An explanation or contact with information on the topic will be apprecciated.

RE: Why fire SLC alarm cable shall not be shielded? Aply same for NAC?

Doesn't matter if the line runs next to a power wire as long as it doesn't run parallel to it for many feet.

Shielded cable has higher capacitance which can often cause problems.

Keith Cress
kcress - http://www.flaminsystems.com

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


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