Domestic-Power in USA

Most USA residences have both 110V and 220V circuits. Standard wall outlets, however, are 110V. Kitchens often have 220V for the stove. Laundry rooms usually have 220V for clothes dryers. Garage areas often come equipped with 220V outlets for a welder or other use. People often have special circuits installed for various purposes by qualified electricians, unqualified electricians (bad idea) etc.

Most USA residences have both 110V and 220V circuits

Here in this area it's 120 and 240. Some parts do have 110 and 220 but thats limited. then there is all so 120 and 208. All so seen 208 3Ø with a grounded leg locally.

Thank you,

My son is always correcting me on that. I guess it's something I picked up and never saw the need to revise.

Domestic power in the USA out of a regular wall outlet is 120VAC like the other person commented. Some appliances in your house run on 208VAC (like washer) due to it's higher current needs. The 208VAC is the voltage between phases and 120VAC is the voltage between a phase and the neutral.

I have a feeling you're asking to run 220VAC appliances that would normally run in Europe. Besides the voltage differences, European electronics and appliances are made to run at 50Hz frequency and the US frequency is kept at 60Hz. While you can get a transformer to step down the voltage the frequency might cause a problem mostly if what you're using something that has a motor in it. The motor would run faster as a result of the increased frequency and it might not be designed for that.

Look,

I don't want to quibble. I let the 110 - 120 thing slide and I agree with the 50Hz vs. 60Hz scenario but let's get real folks. The voltage you get is a 'range' as is the Hz. The reason for that is the varying voltage that comes down the power lines. The power suppliers do a pretty good job of keeping it between the ditches of 110V to 120V. It's higher in some parts and lower in others. It can even be different at my house than the neighbors due to differences in the transformer on my pole vs. thiers. I just went around with a meter in my house and got voltages between 114.4V and 115.1V.

In a 220 -240V circuit there are two legs of 110 -120V which together make up the 220 - 240V. If you are getting just 208V from your 220V circuit it's time to let someone check it out. This is very simple math.

The original question was about "voltage in the USA".

shadetree; many apt building have 120/208 volts 3 phase,with each apt being served with the neutral and 2 phases of the 3. most electronic equipment wouldn't know the difference between 50/60 cycles , ac clocks & motors would run slower. perry

The official ANSI / IEEE standard is 120/240V. There used to be no official standard, so some areas had 110/220, some 115/230 and others 120/240. Some time ago, ANSI set the official standard to be 120/240V. The official voltage tolerance is supposed to be +-10%, so that covers 108-132 / 216-264V.

120/208 is NOT normal for residential service. It is derived from 120Y208V 3 phase 4 wire systems by running 2 legs of the 3 phase to the residential load center plus a neutral (bonded to ground). Utilities do NOT, under normal circumstances, want to deliver 3 phase power to residential users. Maybe the odd apartment complex might have it, but that is definitely the exception to the rule. This is, unfortunately, too low on the 208V side for properly designed appliances using 240V. If it is a stove or dryer however, where most of the power is resistive, all that happens is that food takes longer to cook or clothes take longer to dry (240V dryers usually use 120V motors or VFD driven motors, so the 208V is not an issue there).

Equipment and appliance manufacturers are supposed to make their equipment conform to this ANSI standard, but many of them "didn't read the memo" and instead, rely upon outdated or local anecdotal information to end up with improperly rated equipment. I have seen many engineers in foreign countries post messages such as this one in internet fora asking this question, rather than looking at established standards authorities and doing it right. They end up getting erroneous information, as is evidenced herein.

So if they end up designing for 220V +-10% it will cover down to 208V but then if the line climbs to 264V at night, it is almost 30% over design! That's what happens when, instead of properly engineering something from scratch, all you do is copy someone else's design and do it cheaper. You end up copying their mistakes or outdated information as well.

Regards & thanks all for their kind replies.