Too many volts?
May 5, 2014 7:32 AM   Subscribe

I'm moving into a new (to me) NYC apartment, and I need to buy two window-unit air conditioners. The super said that the power there is 110 volts, but the ACs I want are 115 volts. Is that a problem?

If so, can I have some recommendations for window units that will work in my situation?

Here are the 115-volt units I'm currently eyeing:
posted by grumblebee to Home & Garden (7 answers total)
The voltage isn't a problem, but if the outlets they're plugged into are on the same circuit you want to make sure you're not going to trip a breaker if you run them both at the same time. The specs list 7 amps so if both are running at the same time, that's 14 amps. Your circuit is probably a 15 amp (possibly 20) so that's cutting it kind of close. If the two on their own don't trip the breaker, and I'd guess they would, anything else (like an incandescent lamp) added to the circuit would.

You should check with your landlord to make sure the outlets are on separate circuits. He/she might know offhand, or else you can test them if you can get access to the breakers.
posted by bondcliff at 7:40 AM on May 5, 2014 [2 favorites]

For modern household usage, 110V, 115V, and 120V are essentially the same thing. Modern consumer electrical supply is nominally rated for 120 volts, but the power they supply is going to fluctuate based on demand by quite a bit. In the US electrical equipment is rated by NEMA to operate within a certain range - I think it's something like 10% of rated voltage so for a 115V appliance we are talking between 103 and 126 volts.

"110V" is a legacy term used generally to mean "standard American single-phase consumer power," in contrast to 220 volt (which could be anywhere from 220-240 volts) or industrial three-phase power. It's like how we call lumber "2 by 4" even though it doesn't measure 2" x 4", or how an 8" pipe actually measures 8.625." I highly doubt that your actually serviced with exactly 110 V, but even if you were the AC should run fine as long as you have enough current.
posted by muddgirl at 7:44 AM on May 5, 2014 [7 favorites]

I think you want to make sure that the ACs can be plugged into two different circuits. I don't think there would be any way that you could run two them on the same circuit (assuming 15 amp) without almost constantly tripping the circuit breaker. I have the 12000 BTU version of that AC in my apartment, and about 10% of the time when the compressor kicks in, it trips the breaker - and that's with very few additional devices plugged into that circuit... It's super annoying.
posted by Fidel Cashflow at 7:50 AM on May 5, 2014

No. I think standard American range is something like 105-125V, and US electrical things are all designed to operate normally within that range. "110" actually refers to that range, and is just common usage to refer to US standard voltage. Similarly, "220" for UK/European standard or US heavy-duty appliances. "220" also more accurately refers to a range.

Check the breakers or fuses in the apartment, and make sure where you're planning to use these A/C units, the amperage of the circuit matches at least the minimum requirement of the A/C unit. Most outlet circuits are 15 amps or better, so by bondcliff's analysis above you should be fine, but check it anyway.
posted by tckma at 7:52 AM on May 5, 2014

Re different circuits. There are outlets specially intended for the AC units (each with just a single socket), right next to the windows, but is there any reason why I can't use an extension chord and plug one into a further away outlet, so that they're definitely on different circuits?
posted by grumblebee at 7:55 AM on May 5, 2014

If there are dedicated outlets, then those are probably dedicated circuits (if you're lucky the breakers will be well labeled).

Like most large appliances, air conditioners shouldn't be connected to extension cords.
posted by ryanrs at 8:00 AM on May 5, 2014 [6 favorites]

They make heavy gauge, ac-specific extension cords. They're not very cheap, and don't get longer than maybe 6 or 8 feet.

People mostly tell you not to use extension cords because thin gauge ones can melt or cause other problems. There's nothing inherently wrong with it if you're using a properly rated cord.

That said, I've never seen a single outlet for an AC that wasn't on its own circuit. If those were put in, that was always done at the same time in my experience. That's the exact "single outlet circuit" they mention on a lot the packaging for air conditioners...
posted by emptythought at 11:56 AM on May 5, 2014

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