Class I Div II Requirements

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bnewport

bnewport

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Indiana
I need clarification on NEC 501.10 (B). I have a Class I Div 2 location containing various 4-20mA 24V sensors. The factory cables from these need to be joined in a box, and new shielded cables run in conduit.

According to the NEC Handbook "Any wiring method suitable for ordinary locations may be used for nonincendive field wiring" and 501.10 (B)(4) states that "Boxes and fittings shall not be required to be explosion proof except as required by 501.105(B)(1), 501.115(B)(1), and 501.150(B)(1). There are no arcing parts, transformers, etc in this location. I have to check if these circuits are considered "nonincendive" or not, but if they are, does this mean that a regular junction box (such as a bell box with screw cover) can be installed in this area?

My questions are these:
- Is the raceway required to be rigid, or could it be EMT?
- Is it acceptable to use bell boxes with a standard cord grip (to install the sensor cable into the bell box.)

Thanks-
 
bnewport said:
I need clarification on NEC 501.10 (B). I have a Class I Div 2 location containing various 4-20mA 24V sensors. The factory cables from these need to be joined in a box, and new shielded cables run in conduit.

According to the NEC Handbook "Any wiring method suitable for ordinary locations may be used for nonincendive field wiring" and 501.10 (B)(4) states that "Boxes and fittings shall not be required to be explosion proof except as required by 501.105(B)(1), 501.115(B)(1), and 501.150(B)(1). There are no arcing parts, transformers, etc in this location. I have to check if these circuits are considered "nonincendive" or not, but if they are, does this mean that a regular junction box (such as a bell box with screw cover) can be installed in this area?

My questions are these:
- Is the raceway required to be rigid, or could it be EMT?
- Is it acceptable to use bell boxes with a standard cord grip (to install the sensor cable into the bell box.)

Thanks-
Click to expand...

Most of this kind of stuff is now UL listed for use in Div 2 areas.

Generally for nonicendive circuits you can use any wiring method from chapter 3, including EMT.

I am not sure what you are calling a bell box, but a regular old junction box is fine.
 
Thanks Bob!

What if the circuit is not "nonincendive?" Would EMT and "regular" (welded steel) boxes still be ok? From what I read, as long as there are no parts that could arc, or reach temperatures above what is listed in the code, even if not "nonincendive", that EMT and "regular" boxes were approved. 510.4 (B)(4).

Here is what I mean by a "Bell box."
http://www.drillspot.com/pimages/12/1260_300.jpg

Thanks-
Bryan
 
bnewport said:
Thanks Bob!

What if the circuit is not "nonincendive?" Would EMT and "regular" (welded steel) boxes still be ok? From what I read, as long as there are no parts that could arc, or reach temperatures above what is listed in the code, even if not "nonincendive", that EMT and "regular" boxes were approved. 510.4 (B)(4).

Here is what I mean by a "Bell box."
http://www.drillspot.com/pimages/12/1260_300.jpg

Thanks-
Bryan
Click to expand...

I don't have a 510.4 in my 2005 code. maybe it is in 2008. Someone with a new book will have to answer your question about that one.
 
bnewport said:
Thanks Bob!

What if the circuit is not "nonincendive?" Would EMT and "regular" (welded steel) boxes still be ok? From what I read, as long as there are no parts that could arc, or reach temperatures above what is listed in the code, even if not "nonincendive", that EMT and "regular" boxes were approved. 510.4 (B)(4).

Here is what I mean by a "Bell box."
http://www.drillspot.com/pimages/12/1260_300.jpg

Thanks-
Bryan
Click to expand...
Any enclosure that is suitable for the environment (wet locations, ect) can be used in a Class I, Division 2 area, assuming the equipment is non arc producing, but you are limited to the wiring methods in 510.4(B)(1) and (2) if the circuit is not non-incentive. EMT is not one of the permitted wiring methods.
 
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