Regarding grounds: You will _require_ a ground. The wiring nomenclature
we use below (eg: "14/2") is wire size/current-carrying-conductor-count.
Which does NOT include ground.
In Canada, you ALWAYS have a ground wire. Ie: in Canada a 14/2 will
actually have three strands of copper - two insulated (the "/2") and
one uninsulated (not mentioned explicitly). In the US, the ground
isn't always assumed, so there is such things as 14/2 with only two
conductors and no ground. To be sure of things, we're using the
Canadian convention, and in the US, tack on "with ground" to the wire
designation to be sure.
Well in the US, most wiring is labeled 12/2 with ground. 12/3 witll have
3 insulated wires, with a bare gound, "in my experience". I am sure
there are exceptions.
Combinations of more circuits: go with a sub panel in the shed; the home
run consisting of three conductors plus ground wired
to a double pole breaker, and rated to hande 125% of
your worst-case load (i.e.: a 10 ga home run should be
protected by a 30 A breaker, but should only be loaded
to 80% of this value, or 24 A).
This will be a single cable "wiresize/3". Ie: "10/3" for Henry's 30A example.
Note as well, detached outbuildings with a subpanel USUALLY need their own
grounding system (ground rods etc), and do NOT need a ground wire in the
panel feed. You will need to consult a local inspector to be sure.
Note: Generally speaking, the third option (A "240V" or "240V/120V" circuit)
is rarely useful. Neither of which permit 120V devices (outlets or lighting),
they're really only useful if the shed will contain ONLY 240V or 240V/120V
devices (can't even mix 240V-only and 240V/120V devices), and usually only
one at that (ie: a shed containing only your 240V water pump, and you plan on
using flashlights for maintenance... ;-).
[Strictly speaking, while hanging 240V-only or 120V-only devices off a
240V/120V circuit _can_ be made to work, it's almost always a code violation,
sometimes potentially hazardous or dangerously confusing, and should be avoided.]
Generally speaking, if the shed only needs lights and a few outlets,
a single 120V circuit (first example) is the best approach. This
is more-or-less the minimum (and most common) "Garage arrangement".
If you plan on anything more substantial, a subpanel (last example)
is usually the best approach. Unless you know that you need only
two circuits, will never exceed it, and don't need 240V.
Well, I need two circuits, and that is it I would anticipate. I need one
for ruunnning lighting (one over head flourescent, and one other
probably incandenscent). Probably also a TV and /or a cumputer. The only
big draw I could imagine adding to this circuit is a excercise tredmill.
I have no idea what the draw is on those, so I guess I will need to
check. The other circuit will be a dedicated circuit to run an in wall
electric space heater, set to run at 15A/120V. I have two in the house,
in added-on rooms, and they work well.
I will look into the 30A subpanel, but would lean on just running two
12/2 w/ground out through some pvc conduit as the easiest option.
Thanks for the input.
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