In a message dated 1/30/07 9:02:21 PM Eastern Standard Time,
dconnitt@fuse.net writes:
<< I was fully intending to use 6-2 cable but here in Cincinnati, the electric
code says I need to have a separate, insulated neutral wire for 220 single
phase. So... I need the 6-3 cable. It has a red, black, and white conductor,
plus an uninsulated ground wire. The code here further states that I need a
separate, uninsulated ground wire too. The 6-3 wire I saw at Home Depot
would do what I need at $2.39/foot! Too bad I need about 100'..
>>
That requirement is only for loads that use 220 and 110 from the same run.
Like a clothes drier where you need 220 for the heating element and 110 to
power the drum motor or a oven that uses 110 for lighting. These will have a 4
prong plug. If you are using a straight 220 load, the neutral ( white ) will
go nowhere. Many welders use a 3 prong plug that is 2X the size of a 110 V
plug. The two blades attach to the black and red wires and the pin attaches to
the bare ground. Only at the main breaker box do the neutrals and grounds
get tied together. I'd really get the code officer to clarify the hookup and
draw the 3 prong 220V socket connection out.
<<The oven I have is an old electric range/stove. The plate on the back says
it needs a 220 VAC 50 amp service. I never thought about not considering the
burners on the top of the stove. I don't plan on using them. >>
I don't know how many watts the oven elements take, but assume that they are
greater than the range elements. 4 range elements, 2 for the oven into 50 A ,
that is 8.3A / 1826 watts. Assume each oven element takes 2500 W , that is
11.3 per, if you are running 2 that would be 22.6A , well under the limit. To
make this "fit" code the range elements/controls/wiring would need to be
removed so there is no chance the connected load could exceed your wiring.
The double cavity oven sounds problematic for space therefor making the other
oven more attractive, but less useful and potentially more dangerous. For
equal wattage, a 110 oven must draw 2X the current of the 220 unit. 110
heaters are generally limited to 1500 W about 13A as this is within the limits
of
the common household 15 A circuit. A 2000 W element will need a special 110
20A plug and 12G wiring.
Any chance you could move the oven closer to the main box or even poke the
wire through the house where the heat pump was and do your baking outside?
Sounds like the project is on the edge of being worth buying wire that won't be
used very much.
Harold
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