installing a 220 volt

Old 07-20-02, 06:04 AM
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installing a 220 volt

I have a air conditioner that I would like to install. However it is a 220 volt a.c.. how can I run a 220 volt from my electrical box to be able to run my a.c.
Old 07-20-02, 08:04 AM
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Running a new 240-volt circuit is pretty much the same procedure as running a new 120-volt circuit. The main differences are that you use a double-pole 240-volt breaker in the panel, and you use 240-volt receptacles.

It is important to remember, however, that 240-volt circuits are not "general purpose" as are most 120-volt circuits. These circuits are typically designed for one specific purpose, such as your air conditioner. So it's important to read and understand the electrical specifications of your air conditioner, and then install the circuit to meet those needs. The specs will tell you what size breaker to use, whether you need two or three insulated conductors (usually just two for an A/C), and what type of receptacle to install.

Let me give you one example, which may or may not apply to your situation. Suppose your A/C requires a 20-amp circuit. So you'd install a 20-amp 240-volt breaker in your panel -- you need two available spaces, one above the other. Assuming your A/C did not need a neutral, and assuming your city allows the use of NM cable (i.e., Romex), you'd run 12/2 NM cable from your panel to the location of your receptacle -- the same cable you'd use for a 120-volt 20-amp circuit. But unlike a 120-volt circuit, both the black and white wires would be connected to the breaker, and both the black and white wires would be hot -- you should mark both ends of the white wire to so identify it. Then you'd install a 240-volt 20-amp receptacle in a standard electrical box.

Remember, that was just an example. Read the specs of your A/C. And of course, all the other codes that apply to any circuit still apply here too, e.g., protecting and securing the cables.
Old 07-20-02, 08:22 AM
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First is the size of the conductor which is #12 or #10. If the cord-plug is 30 amps. you need #10, otherwise use #12 even if the cord-plug fits into a 15 amp receptacle. You'll need a 2-pole circuit breaker,either 15,20,or 30 amps, depending of the full-load current of the unit. The FLC is "listed" on the name-plate.The "make" of the breaker must match the "make" of the panel-Sq. D, G.E., etc. You'll need a Wiring Method, probably Non-Metallic cable ("Romex") which has 2 insulated circuit conductors and a bare Equiptment Grounding Conductor. Next is the structure of your house-what is "between" the service panel and the AC location in terms of installing the cable? Finished walls,finished basement,etc.---

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