Fiber Optic & 770.52

[palmeris]

Hello, This site is a great resource, I have found previos information via search functions but I am not sure if this should be in low voltage or NEC so please move if needed.

Would like to make sure my design is allowed under 770.52 where we have a 3 wire 20 amp cirucit routed in a 1 inch pvc conduit underground with 600 volt #12 rated for underground wet locations would be in same conduit as a OFNP fiber optic cable that is rated for indoor / outdoor use.

My belief is that since this is a non conductive optical assembly that it is allowed to share the conduit with the 20 amp ckt. however I am being told by the site sparky that ....no low voltage can share same pipe with high voltage....

Thanks for any input.

 

[TOOL_5150]

Hello, This site is a great resource, I have found previos information via search functions but I am not sure if this should be in low voltage or NEC so please move if needed.

Would like to make sure my design is allowed under 770.52 where we have a 3 wire 20 amp cirucit routed in a 1 inch pvc conduit underground with 600 volt #12 rated for underground wet locations would be in same conduit as a OFNP fiber optic cable that is rated for indoor / outdoor use.

My belief is that since this is a non conductive optical assembly that it is allowed to share the conduit with the 20 amp ckt. however I am being told by the site sparky that ....no low voltage can share same pipe with high voltage....

Thanks for any input.

Well, Fiber is not low voltage - its no voltage. GLass and plastic. Ofcourse unless it has a shield or protective armor.

I would personally rather run it in its own conduit though.

~Matt

 

[palmeris]

It is listed as an OFNP inddoor / outdoor type which means it is Optical Fiber Non conductive Plenum. There are no metal shield or armour in it. I have tried explaning this to the site sparky but think he just blows me off as us low voltage guys dont know anything once we get over 70 volts.....

I would rather it be in it's own conduit but alas the pipe is an existing underground run of 325 feet that runs under asphalt driveways and i think said sparky just wants to charge for conduits, trenching, and ashphalt work instead of letting us share the existing pipe.

 

[mikeames]

It can share the conduit. I do not have my 08 book with me no to give you the Art and sec.

 

[jumper]

I think 770.12(A) and 770.133(A) 2005 NEC apply to this install. 325 ft for #12 at 120v? 2.8 amps due to VD?

 

[don_resqcapt19]

It is my opinion that 300.8 is modified by 770.133(A)

300.8 Installation of Conductors with Other Systems.
Raceways or cable trays containing electrical conductors shall not contain any pipe, tube, or equal for steam, water, air, gas, drainage, or any service other than electrical.

770.133 Installation of Optical Fibers and Electrical Conductors.
(A) With Conductors for Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm, or Medium Power Network-Powered Broadband Communications Circuits. When optical fibers are within the same composite cable for electric light, power, Class 1, non–power-limited fire alarm, or medium-power network-powered broadband communications circuits operating at 600 volts or less, they shall be permitted to be installed only where the functions of the optical fibers and the electrical conductors are associated.
Nonconductive optical fiber cables shall be permitted to occupy the same cable tray or raceway with conductors for electric light, power, Class 1, non–power-limited fire alarm, Type ITC, or medium-power network-powered broadband communications circuits, operating at 600 volts or less. Conductive optical fiber cables shall not be permitted to occupy the same cable tray or raceway with conductors for electric light, power, Class 1, non–power-limited fire alarm, Type ITC, or medium-power network-powered broadband communications circuits.
Optical fibers in composite optical fiber cables containing only current-carrying conductors for electric light, power, Class 1 circuits rated 600 volts or less shall be permitted to occupy the same cabinet, cable tray, outlet box, panel, raceway, or other termination enclosure with conductors for electric light, power, or Class 1 circuits operating at 600 volts or less.
Nonconductive optical fiber cables shall not be permitted to occupy the same cabinet, outlet box, panel, or similar enclosure housing the electrical terminations of an electric light, power, Class 1, non–power-limited fire alarm, or medium-power network-powered broadband communications circuit.