Q: three-wire/single-phase/240v??

Old 04-20-01, 07:49 PM
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1. thanks for earlier response to my Q. about
making an Al to Cu connection !

2. Now, I'm wondering if I've done things right with
regards to the power to a new Stove-Range top.
The install docs call out for:
"three-wire, single-phase supply line" that
is 120v/240v.

The existing wire to the old appliance has
3-"tentacles" ... 2 of them are insulated and have
a voltage of 240v between them(measured it) and
the 3rd on is bare(I'm pretty sure it's the ground)....

Q: from what I've described of the existing wire, does
this sound like it's a 'three-wire, single phase' line??
... and what is a 'phase' ??

Any info would be appreciated.
TIA - kennetht.

Old 04-20-01, 08:44 PM
Join Date: Sep 2000
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No, you have two-wire, single phase. You only get to count the insulated wires. The bare grounding wire must be there, but it doesn't count. This installation requires black, red, white, and bare wires.

The word "phase" refers to the fact that A/C voltages are a sine wave. All sine waves have a "phase", which is determined by the points where it crosses the X axis. The two hot wires in a home have phases that are 180 degrees out of phase. This means that they cross the X axis at the same points, but one phase is ascending when the other phase is descending.

Some people call this two-phase and some call it single-phase. It really doesn't matter what you call it. We're really only trying to differentiate it from three-phase, which is not normally provided to homes.

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