I might be wrong but I do not think your application would permit two
feeders under the different voltages provision since the 120 volts is
derived as one leg of the 240 volts and thereby CAN be provided from one
feeder. Such a provision would apply if you were supplying 480 and 120
volts, where two panels would be required. You might be more comfortable
with two feeders but that is not the normal way it's done. I think the
primary consideration is that in a fire or other emergency it is possible
for emergency personnel to shut off all power to a structure by killing the
feed without having to figure out if there might be others.
Don Young
"chester" wrote in message
...
SQLit wrote:
"chester" wrote in message
...
OK complicasted question, maybe...
I am wiring my (large) shed now, and have decided to do two dedicated
circuits.
1 Circuit will be a single 20A/120V for all the outlets and lighting. It
will be GFCI-protected at the house-when the wiring exits the house, I
simply added an outdoor GFCI outlet, and put the shed load out of this
outlet. So all the outlets, and lighting in the shed will run off this
circuit. Easy enough...
I think that this is a mistake. I run some pretty heavy loads in my
garage.
Sharing the circuitry with god only know what else could cause tripping
of
the gfci
Well, the circuitry to the shed running the outlets and lighting is to be
a dedicated 20a/120v circuit. the only other outlet outside the shed on
this circuit will be the one outside at the house, which will rarely be in
use for anything.
BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric
heater. I am assuming I need to GFCI-protect this line as well, but
maybe I don't. I know the heater itself has a breaker in it (dunno if
that is GFCI or not?),but do I need to protect the line from the house
(buried 12-24" down in the ground)? I would think I need to, but maybe
in-wall heaters do not need to be on GFCI circuits, and/or maybe the
buried cable does not need to be protected with GFCI? Thanks for the help
c
There are several critical pieces of this puzzle that are not included.
What is the distance to the new loads? My calculations say that your new
load (heater) must be less than 145 feet total wire length. Fixed pieces
of
equipment are not required to be gfci protected. That does not mean that
it
is not a good idea. Any flammable liquids out in the new area?
The distance is about 70-80 feet. Ther ewill be no flammable liquids kept
in the area. finished shed for storage/excercise, TV etc.
Other threads seem to indicate that you already bought the wire. Was the
wire UF cable? NM as far as I know is not rated for direct burial.
The wire I bought was UF cable 12/2 w/g
Not knowing the path of the electrical run and the use of the area. 12
inches could be to shallow. 24 would be fine in all situations.
I am going for 18-24, with PVC conduit.
Thanks for you input/questions. I was concerned with the two separate
circuits, but I found NEC code online, and found there are exceptions to
the rule of one circuit (including multi-branch) to an external structure.
One exception is when different voltages are supplied with the two lines.
This appears to apply to my situation. i feel a whole lot more comfortable
with two circuits, than running one multi-brnach circuit with a 240V and
120V running off of it.
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