Healy, Rus wrote:
>
> Okay, gang. Put on your thinking toques.
>
> I have a 200 foot run (on the ground) for a 240 V ac power line to the
> tower base. I bought 250 feet of UF-B 12-3 (plus ground) Romex for this
> purpose. Up to now, I've been thinking of running it across the floor of
> the woods, along with the other cables, to the tower base. I need power
> at the tower base to run 13.8- and 28-V power supplies that will run up
> the tower to power a whole bunch of microwave stuff. This will be a
> separate, breaker-protected 20-A circuit with a GFCI.
>
> The path to the tower is thickly wooded, with essentially no foot
> traffic except when Angus, our black Labrador, goes after a poorly
> directed Frisbee or deer, or chasing wildlife. However, the engineer in
> me nags constantly at me (however, not to the extent that I feel the
> need to comply to the letter with the NEC).
I think the NEC would say 24 inches in this case. But I agree about
trenching in the woods, not a lot of fun, and it is hard on trees. I am
also not too happy thinking of just running it on the ground from a
safety stand point.
So my suggestion is to go get some old porcelan insulators with lag
screws and a hole through the porcelan, and screw them into convenient
large tree trunks about 12 feet up. Big tree trunks don't move that
much in the wind in a forest. Space them about every 25 feet. After you
have all the insulators in, unscrew them three turns and run the UF-B
through the hole making sure you have about 3' to 4' of sag in the line
from the last tree. Now screw the insulator back in two turns this will
put a nice strain relief double wrap twist in the UF-B and still leave a
nice 2' droop in the line. The extra turn it to give the tree some space
to grow.
Try to keep it at least 9' off the gorund. If you get it too low, the
deer will get their antlers snagged in it. I was talking to WB8ZRL the
other day and he related how a buck had torn up his Beverages two nights
in a row, so I think higher is better.
Falling tree branches can be a problem, but stuff this crude has
survived for decades around old farmsteads here in Iowa. Just remember
to pull the breaker whenever you are not using it. And a nice big set of
MOV's at each end might help during lightning season.
de n0yvy steve
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