Wiring instruments
Wiring instruments
(OP)
This a a totally simple question for you but I hope I can get your assistance.
I an classified area of a plant (Class I Div. 1), I have instruments with a intrinsically safe installation communicating with the DCS using Profibus PA protocol. The barriers are inside junction boxes.
I need to add a couple of instruments that are intrinsically safe 4-20mA. Is it possible to use the existing junction boxes and barriers or I need to install new for these instruments?
I an classified area of a plant (Class I Div. 1), I have instruments with a intrinsically safe installation communicating with the DCS using Profibus PA protocol. The barriers are inside junction boxes.
I need to add a couple of instruments that are intrinsically safe 4-20mA. Is it possible to use the existing junction boxes and barriers or I need to install new for these instruments?





RE: Wiring instruments
RE: Wiring instruments
Could somebody help me out?
RE: Wiring instruments
Furthermore you would want separate circuits/barriers so a problem with one signal doesn't bring down others.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Wiring instruments
RE: Wiring instruments
I was once asked to come in and upgrade a control system at a huge ETO sterilization facility. The sterilent, ETO, is rabidly flammable, only thing worse is Acetylene. I got there and removed the old control system and installed the new one. The barriers were in a wall mounted box all by themselves, tidily laid out. All the resulting IS wire's exited into an adjacent conduit box<don't recall the name of that type box..> that was about 6"x6" with a cover. Seemed excessive for those IS wires. I pulled the cover.. It was packed with 12AWG wires which I followed back to a 480V panel. They had to change a lot of stuff to fix that.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Wiring instruments
Did you, by any chance, work at the Ontario, CA, where the ETO went boom ! ! ? ?
Chemical Safety Board has a video on the incident at
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Ethylene Oxide Explosion at Sterigenics International, Ontario, California
Dan
RE: Wiring instruments
I can tell you precisely what went wrong but only if you actually care.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com