Class I Div. I Intrinsically Safe Conduit Run

[sanders11]

I have an application where there is a conduit run between an Class I Div. I XP enclosure and an intrinsically safe device. The XP enclosure has an appropriate XP seal-off. Can I use a liquidtite flexible metal conduit to run to the intrinsically safe device?

I know that article 50.10 (2) lists only flexible metal conduit as the only option, but does it still apply when the circuit is intrinsically safe and has the appropriate seal-off on the other end of the conduit run?

 

[rbalex]

When people start talking about "intrinsically safe" installations, I want to hear about their Control Drawing(s).

500.2 Definitions ...
Control Drawing. A drawing or other document provided by the manufacturer of the intrinsically safe or associated apparatus, or of the nonincendive field wiring apparatus or associated nonincendive field wiring apparatus, that details the allowed interconnections between the intrinsically safe and associated apparatus or between the nonincendive field wiring apparatus or associated nonincendive field wiring apparatus.

If the installation is compliant with the Control Drawing(s) then you may refer to 504.20 for appropriate wiring methods.

 

[sanders11]

The only drawings that came with the device show where the wires are to be terminated and also a drawing showing the conduit connection between the intrinsically safe device and the nonintrinsically safe device (pretty generic drawings). There is no description of what is allowed and what is not.

The drawing shows the interconnection between the two using RGC with a seal-off at the nonintrinsically safe device.

What I am wondering is if the connection between the two can be made with liquidtite flexible metal conduit since there is a seal-off at the nonintrinsically safe device and the outgoing circuit is intrinsically safe?

Here is a link to the product that I am referring to.
http://www.srbrowne.com/brochures/ER_Plus_SRB_web.pdf[/url]

 

[rbalex]

504.4 Equipment
All intrinsically safe apparatus and associated apparatus shall be listed.
Exception: Simple apparatus, as described on the control drawing, shall not be required to be listed.
504.10 Equipment Installation
(A) Control Drawing Intrinsically safe apparatus, associated apparatus, and other equipment shall be installed in accordance with the control drawing(s).
Exception: A simple apparatus that does not interconnect intrinsically safe circuits.

I reviewed the link and a fair amount of the rest of the website. It claims the equipment is UL listed. UL (or any other NRTL) requires the manufacturer to provide a Control Drawing as a condition of listing. The drawing you refered to may well be a Control Drawing and should state it somewhere. Without seeing it, I can't tell.

I would contact the manufacturer and request one or confirmation that what you already have is one.

 

[sanders11]

Thanks for the advice.