On May 11, 8:14*am, Norminn wrote:
Our new-to-us home has a garden and koi pond at the back of the
property. *The pond uses a submersible pump and, in winter, a heater to
melt hole in ice. *Switch for the present wiring is in garage, which
(I'm guessing) is about 70 feet from the pond. *The wire/cable is white,
like two round sections with a flat white section between them. *Outlet
(yikes!!) is an outdoorsy looking thing with a metal back and a plastic
cover....it is not fastened to anything for support, just basking on
some rock near the pump/filter. *No GFCI. *Yike again.

I would like, eventually (fairly soon, like by next spring), install
underground lines for water and for electricity for use at the pond and
the garden. *There is a septic field between the house and garden, so
that is (I think) a consideration. *When I had a chandelier installed by
an electrician, I asked him about installing underground electric, and
he told me it must be 4' down....I haven't found anything online today
that addresses that....several articles that recommend burying line
12-18", using conduit, RF line, etc.

We had an electric line changed from 220 to 120 when we installed gas
range, so need to re-study what breakers control what in the house, as
those marked on the breaker box may be wrong. *Indiana doesn't require
electricians be licensed.... *The garage wiring (and pond) may be on the
same circuit as kitchen. *Have yet to blow a breaker.

Questions: *How deep are gas and electric lines (from utility)
buried..we had 811 mark them, but no idea of the depth. *When we had
cable installed (TV and internet), the guy ran a little thing that put
the cable barely into the sod (and cut my puny little 1/4" water line to
the pond). *Is cable supposed to be a minimum depth? *The cable layout
really screwed my plans for planting shrub and flower beds.

Here in Arizona, we recently installed code approved underground cable
to a well head.
Cost of $5,000 [cheap] to go about 150 feet. including wiring and
metering connection to APS utilities.
The ditch required minimum depth [can't remember] and this caught me
off guard, minimum width! [also can't remember]
But it took some guy with a major piece of equipment to dig the trench
for over half a day. Plus, WE chiseled out the solid boulders hit here
and there. Just to meet the depth/width reuqirements.
However, the wiring looked like standard underground cable you can buy
at HD. That 10 Gauge two conductor stuff with GND.

You're not attaching directly to the AC Utilities, so you should be
able to do your own. Put in proper GFCI breaker setup, get a trencher,
dig the minimum depth and width [going around your septic
requirements], and drop in such a cable to lay in 'once and for all'
power to your pond. Put inside a conduit, or not? *IF* you do, arch
the conduit [like a piece of plumbing pipe] so that at each end water
can run out to a void area underground [upside down plastic 'bubble'.]
Seems like a lot of extra effort, but long run will be worth it. And,
I mean long run. The problem can be seen, just envision a conduit that
goes down, comes back up, as though it were a buried water hose with
wires running through it. Long term collect water and just asking for
trouble.
If me, I'd use heavy pvc conduit to shield the cable [cables cost way
too much to allow accidental nicking] That way, if you forget and
accidentally hit the pvc it's sacrificial.