220 Volt appliance vs 230 volt

Apr 08, 2019 10 Replies

I had a 20,000 BTU a/c unit installed about 15 years ago. It was plugged into a 220 volt outlet. I see today that these larger a/c units are rated for 230 volts.



Does the difference in voltages really matter?


One more question.

An ad states that an a/c unit is 25.5" in width, yet needs a 29 inch window opening. My window opening is 27". Why won't that 25.5" a/c fit into my 27" window?

What am I not understanding?

Thanks. I did see further down the page that it did say 208 volts to

230 volts.

Now I need an answer to my other question as to why if the a/c unit is

25.5" in width do I need a 29" wide window.

Sorry for the "Max" name change. I had a problem with one news reader and switched to the second without changing the nym.

Generally not. The voltage spec in North America is 240 volt +/- 5% and is most often closer to 234 (117 on each leg) (114 to 126 is allowed)

Bottom line , NO, it does not.

Over the years the power company has raised the nominal voltage comming into the homes. At one time it was called 220 (which I often say because my dad did) then 230, now most often 240. The lower voltage equipment can be half any of those , 110,115,120.

The power company will send anywhere from about 235 to 245 volts to a house depending on how much load is on the power grid. I monitor my power comming into a room in the house and it has varied from 226 to 248 in the last year. This is measured with a voltmeter that is accurate to

1/2 % or better and not the inexpensive China meters.

The one time you do need to pay attention is if the equipment is rated at 208 or the power comming in is 208. Both are seldom seen in homes in most of the country.

That 208 voltage is derived from a 3 phase powe system which I am not going to get into as it will confuse the issue. Just a note to stay away from anything labled that unless you know that is the power comming in to your house.

The "brackets" that mount the unit in the window require a minimum of

4 inches (2 on each side)

The a/c we now have is mounted on the outside from underneath. It has 'L' shaped brackets bolted to the bottom of the a/c. The bottom of the bracket is bolted to the bottom of the window ledge. It's held for

15 years.

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