CL1, DV 2

[dgalenski@glauber.com]

Hello- new to forum here. I have a question regarding RTD's in class 1 div 2 locations and a control panel located in another unclassified room. if a 4-20mA transmitter is used in the connection head, does the loop require a barrier? If the 4-20mA transmitter is moved to the unclassified area, does this change things? Also- does this change the wiring methods? New to C1, D2 requirements and a little guidance would be appreciated. Thanks.

 

[rbalex]

Hello- new to forum here. I have a question regarding RTD's in class 1 div 2 locations and a control panel located in another unclassified room. if a 4-20mA transmitter is used in the connection head, does the loop require a barrier? If the 4-20mA transmitter is moved to the unclassified area, does this change things? Also- does this change the wiring methods? New to C1, D2 requirements and a little guidance would be appreciated. Thanks.

Welcome to the forums.

Unless you are prepared to meet all the requirements of Article 504, including having a manufacturers control drawing, barriers and their locations are irrelevant; i.e., you can add barriers but they won't change the wiring methods unless you go Intrinsically Safe "all the way". Boundary seals, grounding and bonding requirements won't change in any case.

Wiring methods generally permitted for Class I, Division 2 are listed in Section 501.10(B).

 

[petersonra]

at least some RTD xmtrs are already FM certified as non-incendive for use in C1D2 areas. might be the easiest answer if you have not bought them yet just to buy something suitable.

 

[rbalex]

at least some RTD xmtrs are already FM certified as non-incendive for use in C1D2 areas. might be the easiest answer if you have not bought them yet just to buy something suitable.

While the NEC doesn't devote as much text to nonincendive circuits as intrinsic safety, it has virtually all the same issues to comply with; i.e., control drawings, boundary seals, grounding and bonding. I agree that buying the proper equipment in the first place can mitigate the issues, but after-the-fact barriers won't.

 

[petersonra]

While the NEC doesn't devote as much text to nonincendive circuits as intrinsic safety, it has virtually all the same issues to comply with; i.e., control drawings, boundary seals, grounding and bonding. I agree that buying the proper equipment in the first place can mitigate the issues, but after-the-fact barriers won't.

IIRC, the last ones I used were also FM certified (or whatever FM does) as IS and XP too. They just came that way with like 6 pages of certificates.

If you buy the cheapest thing you can find it may turn out that you are out of luck altogether if you want to use something in a classified area.