Mixing Intrinsically Safe and Non-incendive field wiring

[ben5446]

I am looking for a standard which outlines how the ratings for intrinsically safe circuits and non-incendive circuits are effected when the field wiring for both types of circuits are routed together in the same cable tray without any separation or metal-sheathed cables.

 

[itsmoked]

Have you seen this article?

http://www.ul.com/regulators/is_circuits.pdf

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[JLSeagull]

ISA 12.06.01 applies to intrinsically safe wiring. Section 504.30 applies to Separation of Intrinsically Safe Conductors.

“(1) Open wiring. Conductors and cables of intrinsically safe circuits not in raceways or cable trays shall be separated at least 50 mm (2 in.) and secured from conductors and cables of any nonintrinsically safe circuits.

Exception: Where either (1) all of the intrinsically safe circuit conductors are in Type MI, or MC cables or (2) all of the nonintrinsically safe circuit conductors are in raceways or
Type MI, or MC cables where the sheathing or cladding is capable of carrying fault current to ground.”
…

 

[ben5446]

Thanks for your replies. They were helpful, but did not address my specific situation. Let me explain... My co-workers seem to think it is common practice to mix intrinsically safe and non-incendive cables (without following the requirements in section 504.30). They simply reclassify the intrinsically safe circuits to non-incendive because non-incendive has the lower rating of the two types. I cannot find a standard which states that this practice is allowable. Can someone tell me which documentation covers this situation?

 

[JLSeagull]

I would assure that none of the former-IS stuff is in a Division 1 location.

 

[ben5446]

Everything (including existing IS circuits )is located in a Class 1 Division 2 location.

 

[JLSeagull]

You may want to search the following standards that mention non-incendive:
CSA Std C22.2
API RP 14F
ISA 12.02.01
ISA 12.06.01
ISA 12.13.01
ISA RP 12.4
NFPA 70
UL 1604