U/G PVC in Hazardous Location

[MEP Guy]

We need to run underground coax, twisted pair, or fiber on a site that is a landfill and is classified as a hazardous location . The cable is for security cameras mounted to site lighting poles.

Could PVC conduit be run between splice boxes at the base of each pole, then transition to RMC extending to seal off fittings 2' above grade to feed each pole, since the PVC is not passing through a Hazardous Location ?

Any help is appreciated.

Thanks.

 

[bobgorno]

Fiber for the comms, but how are you powering your cameras?

Try PVC U/G, transition to long radius, RMC 90 U/G, XP seal at grade for power. Use a good, sturdy OFNC, there are some durable mil spec varieties to allow for long pulls.

I don't think an XP seal is needed for non conductive fiber. Your fiber may be in the same raceway as power for related equipment, so it may go thru the seal anyway. Transition your fiber to copper as required for your camera system above the classifed area to avoid any issues with the fiber to copper converter.

 

[weressl]

Firstly, you must be clear about the area classification. Class, Division, Group, T-group. Second, you must insist on a graphical/pictorial representation of the extent of each different hazardous areas, plan and elevation views. Then you can review in the NEC of what wiring methods would be acceptable.

NEC 770 will detail your requirements for optical fiber installations. Shooting from the hip: fiber does not transmit energy, therefore you can direct bury it if it is listed to do so. PVC Counduit may be used as raceway. Firestops at building entry and proper grounding of the conductive armor, if any, may be required.

Are the cameras stationary or do you have to provide remote pan/tilt/zoom control? That would require another set of wiring in addition to the power cable that was previously mentioned. If so your fiber installation is not your main concern, because it will have the least stringent requirements. Of course you can install wireless camera with a solar power supply that would require no wiring connection whatsoever and would be of no concern from the Area Classification point of view IF it can be installed high enough to be outside of the classified area.