I need to install a field barrier inside of a class 1 division 1 area. The barrier is installed inside a class 1 division 1 box. The rigid conduit running from the non-safe area shall have a seal off less then 18 inches before it enters the box. All points that leave the box will be intrinsically safe. Do I need seal-offs for all other points that leave the box and enter the class 1 division 1 area? Can I use a cable gland? The wire is instrument tray cable (shielded).
Are seal-offs required?
- Thread starter johnluke
- Start date
- Status
generally if the barrier is not suitable to be mounted in the hazardous area and requires a cl1 div1 box then ALL ins and outs of the box must be sealed (18" C,D 1.5" A,B). You probably do not need a seal at the device if it happens to be farther than 18" from the box seal. However I would check further if there is a large junction box volume at the device.
Note that in Div1 areas even fittings like eajt's need seals. verify you are truly Div1, Div2 is easy
Note that in Div1 areas even fittings like eajt's need seals. verify you are truly Div1, Div2 is easy
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
If the barrier and enclosure are in the Division 1 location, it must be assumed that the external power into the barrier is not itself intrinsically safe. In that case, the enclosure?s integrity requires all exiting raceways to be sealed.
Side note: Is this being installed per a Control Drawing as required by Section 504.10(A)? The Control Drawing should indicate sealing requirements.
Side note: Is this being installed per a Control Drawing as required by Section 504.10(A)? The Control Drawing should indicate sealing requirements.
The area is Class 1 Division 1 Group D. The Division 1 rating applies because methanol (Group D) is pumped through the entire facility and not always confined. The barrier itself is rated EXd [ia] llC T4 (Associated Electrical Apparatus in an explosion-proof enclosure located in hazardous area). The barrier will be placed inside a class 1 div 1 barrier to satisfy 504.10(B). The control drawing states that barriers be located inside an EXd enclosure but does not directly specify seal offs. My question is where does intrinsically safe start? Does it start when it leaves the box at which point my wire type is limited by 501.10 and sealing required by 505.16 (7). Or does it start after the barrier at which point 504.20 applies, and I use blue ITC cable and ATEX cable glands. I am not trying to be a lawyer, I am trying to be safe & economical.
The area classification is Class 1 Div 1 Group D. The area uses methanol and its not always "contained". The barrier is Ex me [ia] llC T4 (Associated Electrical Apparatus in an explosion-proof enclosure located in a hazardous area). My question is where does the intrinsically safe portion start. Does it start inside the box at which point 504.20 applies and I run ITC cable and use cable glands or does it start when it leaves the box at which point 501.10(A), 501.15(A) applies and seal offs are used at each point of entrance. I am not a lawyer, I am just balancing between safe and cost.
Are seal-offs required? More detail
Are seal-offs required? More detail
The area classification is Class 1 Div 1 Group D. The area uses methanol and its not always "contained". The barrier is Ex me [ia] llC T4 (Associated Electrical Apparatus in an explosion-proof enclosure located in a hazardous area). My question is where does the intrinsically safe portion start. Does it start inside the box at which point 504.20 applies and I run ITC cable and use cable glands or does it start when it leaves the box at which point 501.10(A), 501.15(A) applies and seal offs are used at each point of entrance. I am not a lawyer, I am just balancing between safe and cost.
Are seal-offs required? More detail
The area classification is Class 1 Div 1 Group D. The area uses methanol and its not always "contained". The barrier is Ex me [ia] llC T4 (Associated Electrical Apparatus in an explosion-proof enclosure located in a hazardous area). My question is where does the intrinsically safe portion start. Does it start inside the box at which point 504.20 applies and I run ITC cable and use cable glands or does it start when it leaves the box at which point 501.10(A), 501.15(A) applies and seal offs are used at each point of entrance. I am not a lawyer, I am just balancing between safe and cost.
- Status