Intrinsically Safe wiring
Intrinsically Safe wiring
(OP)
I have a sump in C1D1 area. Need to install a accelerometer onto a pump to monitor vibrations. The pump shaft is 8ft long. Motor is in C1D2 area. This is where I would read vibe reading.
Accelermeter is I.S. rated. I have matching I.S. barrier.
My question is wiring between accelerometer and I.S. barrier. The clerance around shaft is very tiny. Would need to route cable alongside of the pump shaft. What is permitted? How to protect it from damage? Does it have to be in conduit? I know NEC states "Any of the wiring methods suitable for unclassified locations, including those covered by Chapter 7 and Chapter 8, shall be permitted for installing intrinsically safe apparatus"
Can someone clarify?
Thank you for any response.
Accelermeter is I.S. rated. I have matching I.S. barrier.
My question is wiring between accelerometer and I.S. barrier. The clerance around shaft is very tiny. Would need to route cable alongside of the pump shaft. What is permitted? How to protect it from damage? Does it have to be in conduit? I know NEC states "Any of the wiring methods suitable for unclassified locations, including those covered by Chapter 7 and Chapter 8, shall be permitted for installing intrinsically safe apparatus"
Can someone clarify?
Thank you for any response.





RE: Intrinsically Safe wiring
You're allowed virtually anything by the code. Just a cable with a twisted pair is OK. That's because on the hazardous side of the barrier there isn't sufficient energy available to ignite anything, no matter what happens to your wires.
It's up to you to decide how much physical protection is needed to keep your system in service. As long as your cable is OK by itself, you can also run it through metal tubing of whatever type too.
Let us know how you decide to proceed!
Good on ya,
Goober Dave
RE: Intrinsically Safe wiring
Keith Cress
kcress - http://www.flaminsystems.com
RE: Intrinsically Safe wiring
John D