A
> > The next decision isn't quite as easy to make. I can use a standard 110
> > VAC
> > light that costs about $120 or a 12 VDC light that costs $223 (Dialight
> > model 860-1R03-001 from www.unimar.com). Either option only requires a
> > couple of amps.
>
>Even with a couple of amps at 12 volts you wouldn't want to go far.
>
> >
> > I will have mast mounted preamps for 6m, 2m, and 70cm mounted at the top
> > of
> > the tower, so I need 12 VDC there anyway. I could run 110 VAC to a NEMA
> > box
>
>You are probably going to want the 12 volt supply up there any way which
>means running the 110VAC up there as well.
Just because it's low voltage doesn't necessarily mean you don't need
permits etc. The low voltage thing in the code is for energy limited
systems (doorbells, garden lights, etc.) that have current limited
transformers. The voltage is limited to <50 V (shock hazard), but the
energy is also limited (no fires possible). You'll see this described as
"Class II" wiring.
I would imagine that running 100 Amps at 12V would raise the local
electrical inspector's eyebrows.
Something else to consider is that if you run both 110V and 12V, they'll
have to be in separate raceways (conduits), except in certain circumstances.
What you might contemplate is not wiring your tower as an electrical
system. That is, have the electrical service terminate at a GFI receptacle
with appropriate overcurrent protection at the base. Then, everything else
on the tower (12V power supplies, lighting supplies, etc.) is "installed
equipment" all connected with a flexible cord and plug. I'm not sure
exactly how you'd want to present this, and it may be fundamentally
incompatible with the FAA's need to have reliable obstruction lighting.
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|