Stupid AC wiring question (220-ish Volts...)
cclist at sydex.com
Thu Feb 5 22:17:40 CST 2015
On 02/05/2015 08:00 PM, Brent Hilpert wrote:
> In theory, if you have two 20A 120V circuits installed, you could also have 220V 20A from the same circuit(s) at the additional expense of just a 220V socket.
> However, local codes may have something to say about such an arrangement.
Have a peek in the breaker box--you should see the third neutral wire
connected to the common neutral bus, which should also be connected to
the ground bus. At least that's the way it is in my house.
The practice for 240V appliance wiring in the US for many years has been
3-wire, with the third wire used as both a neutral return for 120V
circuits (many cooktops and ovens use this) and also the chassis ground.
Modern code demands that 4 wires be used in that case, with a separate
ground run, but I suspect that the majority of installations for 240V
appliances in the US still use the old 3-wire system.
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