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Doug Miller

In article om, wrote:
I purchased a thru-the-wall A/C unit that runs 115V to replace an out
A/C and didn't realized the old ran on 230V. Is there an easy way to
convert the 230V outlet to 115V?

Probably, but that depends partly on the amperage rating of the existing
circuit, and that of the new A/C unit. If the new unit is rated at higher
amperage than the existing circuit (e.g. you have a 15A circuit, and a 17A air
conditioner), you'll need to replace everything.

BTW -- it's 120 / 240 now. Hasn't been 115 / 230 for a long, long time.

Assuming that the amperage ratings match up, here's how you can go about it:

First, obtain a 120V receptacle of the proper rating. You might need a 20A
receptacle, depending on what the new A/C requires.

Next, test the outlet with a circuit tester or voltmeter to verify that it's
live. Turn off the circuit breaker and test it again, to verify that it's
dead. (This protects you against the possibility that a faulty tester is
incorrectly showing a live circuit to be dead.)

Then remove the existing receptacle from the box in the wall -- DON'T
disconnect any wires from it yet -- and look at what's connected to it, and
what other wires may be present in the box.

Most likely, there will be three wires connected to the receptacle (black,
white, and bare), and no other wires present. If not, STOP NOW, and post here
again, describing what you *do* have -- and ignore the rest of my reply.

Remove all three wires from the existing 240V receptacle, and connect them to
the new 120V receptacle as follows:
- black to the brass-colored screw
- white to the silver-colored screw
- bare to the green screw
and install the receptacle in the box in the wall.

Take the cover off the circuit breaker panel. Disconnect the white wire from
the circuit breaker for this circuit (leaving the black wire in place).
Connect the white wire to the neutral bus bar in the breaker panel. (This is a
long bar with many screw terminals, that already has numerous white wires
connected to it.)

Turn the breaker back on, and check the new receptacle with one of those
plug-in circuit testers that shows you whether it's wired correctly. Or test
with a voltmeter: you should see 120V between hot and neutral, 120V between
hot and ground, and 0V between neutral and ground.

If everything tests correctly, put a cover plate on the receptacle, plug in
your A/C, and enjoy the cool.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.