Intrinsic Safety Piping practices 1

[rgonthier]

I am a mechanical engineer so i have a dumb electrical question. i need to connect an intrinsically safe ASCO solenoid to an IS Topworx switch box and want to know if there is anything special that i need to do to connect the two and maintain the IS ratings. We typically connect the two items with a NPT nipple and wire the solenoid to the terminal block in the switch box. from what i understand this is acceptable and i would not need any special sealants or fittings in the conduit. is that true?

 

[ScottyUK]

Under what regulations / in which jurisdiction?

 

[itsmoked]

As intrinsically safe components you can theoretically use bubble gum and staples to install them. The issue is keeping the circuit I.S. by protecting the wiring from ever being able to be cross-connected to non-I.S. wiring even thru a misapplied drill bit! That means the I.S. "space" needs to be isolated from the non-IS space, which typically requires sealed conduits where the IS - nonIS demarcation line exists, and never sharing conduits with nonIS wires.

You also need to supply the switch and the solenoid IS safe energy thru a "safety barrier" device that is outside the IS space.

So, if your switch and solenoid are in the IS space you can use conduit that's non-sealed or special. But if one is outside the space then, again, you need seal the conduit.


Keith Cress
kcress -

http://www.flaminsystems.com

 

[rgonthier]

that is what i understood but just wanted to be sure. Thanks for the help.