[TowerTalk] Schedule 40 or 80 PVC Conduit Underground

[Jim Lux]

On 11/12/14, 8:01 AM, Gary J - N5BAA wrote:

>
> What do people think about running a length of direct bury 12 gauge
> romex electrical line with a plug on the shack end and a socket on the
> tower end inside the conduit.  That way one can energize the extension
> cord when needed and have it de-energized at all other times.
>
>

It's not actually romex:NM, but a different kind of cable: UF.

Most places require that you put UF at least 24" below ground surface 
(unless it's under a concrete slab or something).
And you have to have a warning tape that is 12" above the wire. (i.e. 
more than a shovel depth)
And, you have to encase the UF in rigid metal conduit as you bring it up 
from 24" to the surface with a listed bushing where the cable enters the 
conduit.


  A typical code for my area says plastic conduit has to be 18", rigid 
or intermediate metallic conduit can be 6".


My own experience has been that UF is significantly more expensive than 
just buying regular old individual conductors and pulling them through 
plastic conduit.  There are pricing anomalies (copper prices fluctuate, 
and maybe they have a big spool of UF that was made when copper was cheap).

A 500 foot spool of AWG12 is about $50 at Lowes

250 feet of 12-2 UF is $127 at Lowes, so for the same 500 ft of amount 
of copper, you're paying about 2.5 times more.
100 ft is $76


3/4" PVC conduit is $23.50 for 100 feet.  Pulling 3 or 4 12ga wires 
through 3/4" conduit is really easy.

UF is a good solution if you "have it on the work truck" and you only 
need to go a few feet.