It does need to stay "low voltage" because there is no practical/economical way to get an electrical permit to run 600-700 meters of code-compliant 240VAC through this particular section of forest.
Interestingly, looking at $/ft prices for cable I have found that 3-conductor 14 gauge UF-NMC (2 + bare copper ground) is less costly per foot than 18 gauge SJOOW. That sort of helps on the voltage drop problem. It's intended for direct burial but in this case would go through a forest taped to an armored fiber cable. In a few years falling leaves and such will cover it. On Tue, Jul 5, 2016 at 5:00 PM, Chris Fabien <[email protected]> wrote: > I would also run 240V AC out there, not DC. Unless you are needing to stay > "low voltage" for permit/licensing reasons. > > On Tue, Jul 5, 2016 at 7:59 PM, Chris Fabien <[email protected]> wrote: > >> I would use 14-2 UF cable, direct buried next to the fiber, or pulled >> into conduit with the fiber if you are doing conduit. That's going to be >> much cheaper than SOOW type rubber jacket cable, or pretty much any other >> options. 1000ft spool costs us about $250, and there are direct bury splice >> kits for it to make a waterproof buried splice. >> >> On Tue, Jul 5, 2016 at 7:25 PM, Eric Kuhnke <[email protected]> >> wrote: >> >>> Due to terrain I'm helping somebody design a network link where a PTP >>> radio will go on the side of a tree on the opposite side of a mountain from >>> where AC power, a router and other network equipment is located. >>> >>> We're looking at 600 to 700 meters of singlemode fiber and a small >>> NEMA4X junction box with the radio on the far side of the hill, containing >>> a SC-SC patch cable bulkhead and a meanwell DC-DC converter. >>> >>> It looks like based on the wattage of the radio and voltage drop >>> calculations for 18-2 cable that we can get away with a 56VDC power supply >>> at the power source, dropping to not lower than 35VDC at the receiving end, >>> which will be fed into a DC-DC converter to bring the output back up to >>> 52.5VDC for the radio. >>> >>> If you had to run 600-700m of 18AWG cable outdoors through a forest, how >>> would you do it? SJOOW type cable may not hold up over a long enough time. >>> Ideally something that is more armored than SJOOW (it can be much less >>> flexible if needed). Cost is somewhat of a factor. >>> >>> >>> >> >
