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> are running new electrical circuits Why is this needed? Is it because the electricity in the US is at 120V? Over here (Europe) you can just plug the cable fr

> are running new electrical circuits Why is this needed? Is it because the electricity in the US is at 120V? Over here (Europe) you can just plug the cable from the indoor unit into the electrical outlet.

bluGill 6y ago
Depends, the lower btu units can plug in to any outlet, but even in Europe you can only get so much power. Regardless, ac draws enough power that you want it on a dedicated circuit no matter where you are. Sharing that outlets with anything else is likely to result in annoying breaker trips when you overload the circuit.
troydavis 6y ago
bluGill answered this well. To add a little: the total load of all but the smallest systems (9/12k BTUs/hour) is too large for a typical 15A @ 120V circuit, so most outdoor units need 220V. That means a new circuit. Also, building code in the US typically requires a shut-off box right next to the outdoor unit. At least in the US, many systems power the indoor unit(s) from the outdoor unit. My guess is that since a control wire is required anyway (for central control of fan speed and direction), the manufacturers think it’s easier to power everything from one run.
masklinn 6y ago
I learned recently that US housing generally gets 240V, but most circuits use neutral and a single hot to get 120V which is the standard mains in the country, and you'd run dedicated 240V for large appliances e.g. furnaces, dryers, electric oven, induction cooktop. The AC would not have been planned for when designing the original circuits, so you would need to add a 240V circuit for it unless you put it in a room which already had one. As the others have noted, since it's a high-power unit anyway you'd really want to have it on its own circuit to avoid adding too much load on the circuit. So even in europe you probably want a circuit exclusive to the AC, meaning you may have to run a new one unless an AC circuit had originally been run "just in case" (and even then it might not have been run to the room you wanted it in e.g. maybe the original builders put the circuit for an eventual AC in the living room but you want it in the bedroom you converted to a study).

bluGill 6y ago

Depends, the lower btu units can plug in to any outlet, but even in Europe you can only get so much power. Regardless, ac draws enough power that you want it on a dedicated circuit no matter where you are. Sharing that outlets with anything else is likely to result in annoying breaker trips when you overload the circuit.

troydavis 6y ago

bluGill answered this well. To add a little: the total load of all but the smallest systems (9/12k BTUs/hour) is too large for a typical 15A @ 120V circuit, so most outdoor units need 220V. That means a new circuit. Also, building code in the US typically requires a shut-off box right next to the outdoor unit. At least in the US, many systems power the indoor unit(s) from the outdoor unit. My guess is that since a control wire is required anyway (for central control of fan speed and direction), the manufacturers think it’s easier to power everything from one run.

masklinn 6y ago

I learned recently that US housing generally gets 240V, but most circuits use neutral and a single hot to get 120V which is the standard mains in the country, and you'd run dedicated 240V for large appliances e.g. furnaces, dryers, electric oven, induction cooktop. The AC would not have been planned for when designing the original circuits, so you would need to add a 240V circuit for it unless you put it in a room which already had one. As the others have noted, since it's a high-power unit anyway you'd really want to have it on its own circuit to avoid adding too much load on the circuit. So even in europe you probably want a circuit exclusive to the AC, meaning you may have to run a new one unless an AC circuit had originally been run "just in case" (and even then it might not have been run to the room you wanted it in e.g. maybe the original builders put the circuit for an eventual AC in the living room but you want it in the bedroom you converted to a study).