Member Login
member
passwd
remember me on
this computer.

- join now -
- forgot username or password? -

Search

Sponsored Communities
Cool stuff
Select a topic of interest:
...and press:
Neat Stuff
Control.com Stuff

Visit our shop for nerds in control lifestyle products.

Fortune
In Pocatello, Idaho, a law passed in 1912 provided that "The carrying
of concealed weapons is forbidden, unless same are exhibited to public
view."
RSS Feed
RSS feed Use this link to get an RSS feed of the Control.com article flow, for private, non-commercial use only:
www.control.com/rss/
To get a personalized feed, become a member at no cost.
Select a Page Style
Select one of the following styles:
- BluFu
- Classic
(cookies required)
advertisement
from the Instruments and Controls department...
Earth Fault Detection
PLCs and related questions. topic
Posted by S Janakiraman on 27 November, 2007 - 12:51 am
Please confirm if each channel of an analog or digital input/output module for a PLC is provided with earth fault detection. My understanding is that this is not available with any manufacturer, and this is not required. Generally, each channel is provided with surge protection only.

The above requirement is for a Shell project.

Another query: the same project demands that for the digital output module, the output should be from solid state device and not relay module. Please clarify if this is standard with system suppliers.


Posted by Michael Griffin on 27 November, 2007 - 11:08 pm
Most PLC manufacturers offer both relay and solid state outputs. Many customers prefer 24VDC transistor outputs because they are usually much more reliable than relays.


Posted by S Janakiraman on 29 November, 2007 - 9:50 pm
Thanks Griffin for your kind response. Can you respond to the first part about the earth fault detection for each channel in a module?

Also can you tell me how a Rittal Cabinet suitable for Zone 2 installation is tested to be suitable? My understanding is that a cabinet for Zone 2 is adequate to be EEx'e'. The modules installed inside this cabinet needs to be self-certified for Zone 2 area. The cabinet with all the components are tested to be suitable for Zone 2 area from the point of heat dissipation, energy retainment, etc. Pl. explain.


Posted by Michael Griffin on 1 December, 2007 - 10:37 am
Sorry, but I think you need to get those answers from someone else.

From Control Engineering magazine...
Related articles from Control Engineering magazine
Above articles copyright 2008 Reed Business Information. Subject to its Terms of Use.
Your use of this site is subject to the terms and conditions set forth under Legal Notices and the Privacy Policy. Please read those terms and conditions carefully. Subject to the rights expressly reserved to others under Legal Notices, the content of this site and the compilation thereof is © 1999-2008 Control Technology Corporation. All rights reserved.

Users of this site are benefiting from open source technologies, including PHP, MySQL and Apache. Be happy.

Internet Explorer 6.0 Fix

Advertisement
Our Advertisers
Help keep our servers running...
Patronize our advertisers!