Kara Zorn on May 12, 2014 71 Comments Before purchasing a window air conditioner, it is important to note the electrical requirements as window A/C units are typically more powerful than standard household appliances. Most common voltage ratings for AC units are 115, 125 and 220 volts, and amperage rating can run from 15 to 20 amps. The lower two voltage ratings are common in smaller units, while units with a rating higher than 15,000 BTUs will require a 220-volt circuit. Smaller units with a 115 volt and 15 amp requirement will be able to operate off a standard household outlet. However, larger units that have higher energy requirements need a committed outlet to handle the electrical current required for operation. If you already have a committed outlet for your AC unit, you’ll want to try to select a replacement with the same ratings and plug type to eliminate the need of having a new outlet professionally installed by an electrician. If you’re installing a new unit, take note of the wattage, voltage and plug type indicated. Plug types are listed by their NEMA (National Electrical Manufacturers Association) classification and will often include a picture of the plug receptacle for your reference. Some of the most common examples include: Note: Extension cords can be used when needed but only cords rated specifically for window air conditioners or other similar gauge home appliances should be used. See packaging for certification, voltage and amperage ratings prior to use.
Gabriel Lim says February 5, 2016 at 5:15 pm I just purchased a Koldfront 18,500 BTU . It requires a 25 Amp electric source. I only have a 20 Amp circuit breaker and it works well with the cooling of the air conditioner. However when using the heater the demand for more electric power trips the circuit breaker and shuts off. If I decide to just use the air conditioner and not the heater, is a 20 Amp circuit breaker sufficient to power the air conditioner. If I upgrade my circuit breaker what would be the recommended amperage 25 – 30 amp? Reply
andy says June 20, 2016 at 2:14 pm 16000 BTU heating – 20.0A/4800W Input voltage: 220 V/60 Hz 18500 BTU cooling – 7.7A/1730W The way I read it, if you only use the AC, I would use it too. IF I have the correct Amps used in your model. Reply
Deric says September 12, 2017 at 1:58 am Circuit breakers protect the size of the cable in the circuit. 15 amp breaker for 14 gauge cable and 20 amp for 12 gauge. You cannot increase the breaker without replacing the wiring. 10 gauge cable is good for 30 amps. Reply
Joseph Alexander Tate says May 8, 2018 at 8:10 pm switching out the breakers are really easy , turn the main breaker off ,then just pull out your old breaker ,look at wires ,they will be two ,just pull a little on the old breaker and the two wire ,that give you some room , you have two wires ,remember them , unscrew them and screw the wires in new breaker, but the new breaker back in angel ,and push in ,and all finished ,flip the main breaker and you are all good Reply
Edvardas Vitkauskas says July 5, 2019 at 5:39 pm The breaker should never be increased in ampacity. It protects the wiring and your house from catching fire. Reply
Donald McMillan says September 5, 2019 at 6:13 pm Absolutely don’t do it! Unless you are trying to burn your house down! Reply
Josh says June 19, 2018 at 4:54 pm Joseph — That is horrible advice. If someone takes your advice they are going to be running more amperage through the circuit than the *wire* is rated for. The new breaker won’t trip because it’s been “upgraded”. This is a recipe for a house fire. Reply
david says July 22, 2018 at 2:37 pm its a good way to burn down your house. the fuse is supposed to melt and breakers release before the wire catches the house on fire. if its not a dedicated line to a range, dryer or water tank its probably only 12 ga or 20 amp max wire. 12 ga with 25 amps will get warm. connections will get hot. connectors and wire nuts get very hot and poof …. fire. Reply
Larry Noyes says April 10, 2020 at 1:39 pm In addition, circuit breaker ratings – e.g. 15A or 20A – are the maximum peak ratings for the circuits. For continuous duty, the suggested maximum is around 80% of the peak rating. That is why a standard water heater with 4800 watts on a 240 volt circuit, using 20 amps, requires a 30 amp circuit. Reply
bobpop says September 4, 2019 at 4:14 pm If you change your breaker and not the wire be shure to have bergers and dogs ready you will start your house on fire. The breaker trips to save the wire, connectors and what ever is on the circut from overheating Reply
stefan kong says September 14, 2020 at 7:24 pm you would have go with the 30 because of start up current. you all so have to increase your conductor size awg 10 wire. Reply
Donald Porter says July 6, 2016 at 9:38 am I have an Window AC unit with 220 Volt and the plug is tandem 6-15P. However, the wall outlet is for a perpendicular 5-20P. Is there an adaptor that can convert from one to the other or will I need to change the wall outlet. Reply
Owen says October 13, 2019 at 8:19 am What size house wire and breaker for a window unit with 6-15P plug? Reply
Kara says August 24, 2016 at 6:25 pm Can a 18,000 BTU AC safely and efficiently run on a single 20AMP breaker ? Reply
khalid says June 28, 2017 at 5:14 am no u uses 40 AMP braker bcs urs single phase capacity is about to 30 APM,,,but if u uses three phase suply so its enoughf,,bcs in three phase its rating upto 15 Amp,,so u can,,,and u can use 10 mm sq cable with 4 mm or 2.4 sq mm eart cable Reply
Jeanette says August 23, 2016 at 7:25 pm I have a window unit 220,it just stop working don’t know what to do I unplug it for awhile though that would work but it didn’t HELP Reply
Nancy says July 20, 2017 at 11:02 pm Sometimes a dirty air filter will make it stop working/r over heating. Clean the filter no less than once every 10 days. Use a gal. of Water and 1/2 cup of bleach – rinse good Reply
asim says August 25, 2016 at 12:31 am please help me in this issue my ac is 2 ton window ac so how much ampere should i require to put in fuse box because when i turn on my ac the wire start burning Reply
Michael Winkler says November 15, 2016 at 9:29 am No it needs at least a 25 amp breaker and 10 gauge wire Reply
Michael Winkler says November 15, 2016 at 9:31 am You need to change a wall outlet and if you’re unsure of wire and breaker size consult an electrician, in fact consult an electrician Reply
Abayomi says December 31, 2016 at 7:36 pm I have a window AC which make noise when i on it, a friend advice me to get 5000vt stabilizer to power it and i don’t know how true is that to be the course of the noise. Plz advice me, thanks Reply
Michael says March 3, 2017 at 8:01 am I have a window unit(A.C.) Its 15.500 B.T.U WHAT GAUGE WIRE DO I NEED? AND SINCE IT IS A COMMITTED BREAKER. WHAT SIZE BREAKER? 20,30,40 AMP? PLZ LET ME KNOW? THANK YOU. Reply
Bill Berry says June 15, 2017 at 5:09 pm You will need a 20 amp breaker and 12/3 wire. Remember that 120 volts times 20 amps is 2400 watts max, then 80% of that is 1920 watts; anything more than 1920 your breaker will flip off. I own a 15,000 BTU unit and the max wattage it ever has used is 1450 watts, but generally between 1300 and 1350 is the norm. It is important to remember that your voltage throughout your house and neighborhood are higher in the morning and much lower in the afternoon. You are to go no lower than a 20 amp breaker and no higher than 12 gauge (the higher the number the thinner the wire). One final note…it is generally known that anything higher than 15,000 BTUs requires 230 volt. Double check your BTUs. Reply
charles wade says July 14, 2017 at 3:51 am i have a 10.5 amp window air conditioner its on a 15 amp breaker also using a 14 gauge extenision cord works good until around 90 degrees then kicks off little confused. Reply
Michael Wascher says October 12, 2017 at 10:17 am Length of wire increases resistance. Extension cords are generally for short term use and 14 to 16 gauge wire which is for 10 to 15 amp. MAX. When temperature increases the wire resistance increases as well, that’s wire radio towers use nitrogen to cool the cables going to the antenna as they couldn’t possibly be lifted due to it’s size. Reply
terri says July 10, 2018 at 7:42 pm I have a 10,000BTU air conditioner , should I use a 15 or 20 amp breaker and 12/3 wire? Reply
Electric slide says March 8, 2017 at 11:14 am 10-2 wire for a 30 amp breaker. 40 amp breaker is too much for the 10-2 wire. The wire will burn before the breaker will kick off. 40 amp breaker will require at minimum an 8 gauge wire. Reply
Deanna says March 20, 2017 at 7:21 pm I am looking to get a a.c. unit for my 30 ft camper. Any recomendations. The only window that will work is at the back end away from the bedroom. Reply
Faraz says May 10, 2017 at 7:21 am my window ac 1.5 Daikin in noon after 12 am not run when i turned on after 10 mints or half hour electric doing fluctuating its breaker get tripped off and some time compressor off and only fan run then electric comes in normal mode no fluctuating. And when i turned ON AC in night then no problem ac running normal whole night. plz solve my problem i will be many thankful to you. Reply
RICK McReynolds says May 16, 2017 at 11:52 am do I need a 10-2 or 10-3 for the 30 amp breaker 10 gauge wire? Reply
Leif says June 23, 2017 at 3:31 pm 10-2 with a 10 ground probably a 6-30R (receptacle) and a DBL 30A breaker Reply
willie says March 25, 2018 at 8:51 am i have a 12000 btu window heat&cooling unit what size wire and braker will i need to use voltage is 208 or 220 Reply
Teresa says June 3, 2017 at 2:53 am The fuse blow out where you test the AC on a window unit because my grandbaby kept push it on over and over. Where can a buy of get a new fuse for the cord. This is a new ac less than 1 yr old. I hate to buy a new one this one cost almost 800 dollars Reply
Rana Aurangzaib says June 6, 2017 at 10:06 am I want an window AC which can work on 115 Voltage. I have a plane to work with 6 to 7 solar panel 150 Watt/solar panel. Is there any possibilities such type? Reply
Jason says June 12, 2017 at 12:54 pm If the wire is burning then it is NOT THE CORRECT GAUGE for the peticular appliance! The current demand for the appliance is exceeding the current rating of the conductor. You need to get a qualified electrician to service that circuit or you will burn down your house! Reply
Luis says July 27, 2017 at 2:46 am We have an AC unit (window) that uses 230 V and it is 18,000 btu and just did buy another one that gives 15,100 btu and uses 115 V both of them are 15 Amps , what needs to be done besides changing the outlet. Reply
patrick sanger says August 3, 2017 at 11:34 am I enjoy the fact that so many questions are asked and many answers given. but I have another one – slightly different scenario… need to put a portable (or window a/c unit in a 15×13 bedroom that has a bath and walkin closet attached (with no air vents !!@$%#. we are in dallas and it gets HOT in the summer. no way to add a third unit or even add duct work. so hence the window/portable solution. problem might be: we do not have a “dedicated outlet” all outlets run in parallel. and no bigger fuse than a 10 amp is available in the bedroom. question is – what is the largest BTU unit can I run without tripping the breaker all the time? (if any) I have looked at 6k-8k btu’s units that say they draw 6.5-10 amps and 10k-15k units that draw upward of 12amps (all w/ 5-15 standard household outlet plugs) whats is my best fix here??/ . or is it electrician time? Reply
ISAACKELLY says August 30, 2017 at 9:04 am Please i need help can a One and half power house window unite works without a stabilizer . Reply
Colleen says September 4, 2017 at 2:41 pm I have an older Eskimo box fan the cord needs to be replaced I am so confused what to replace it with the top of fan read 115 volt 60 cycles ac 2.2 amps. thank you if any one can help. I donot want to repalce it with the wrong cord. Reply
Penny Singletary says March 2, 2018 at 4:10 pm I have 110 voltage what is the highest BTU window unit I can insert in my window? Thank you, Reply
jonn knoile jr. says April 25, 2018 at 1:17 pm I have a 12000 BTU conditioner (No heater), and all my 15 amps switches do not work on it. It constantly jump them off. no fuses, all pro switches breaker. Im calling an electrician right now. North America here, No europe 220 what the hell. Reply
Dan says May 4, 2018 at 5:45 pm i have two 6000 btu air conditioners. Does anybody know if I can I run both on a single 20 amp circuit? Thanks! Reply
Erik says May 19, 2018 at 7:30 pm Yes, two 6k BTU air conditioners can safely run on a 20 amp circuit as that would total to around 1100-1250 watts and a 20 amp circuit max is 2400 watts. Just be mindful of having them both on the same outlet. Reply
Jerry says May 21, 2018 at 7:51 pm I have just got a 18000 btu ac and need to run 230 volt outlet need to know what size breaker I will need. It takes nema tandom 6-15p outlet. 1590 watts, 8.8/7.9 amps. Reply
Lynn says May 27, 2018 at 9:30 pm Whats the largest btu window unit i can use on a 110 outlet with 20 amp breaker of its own Reply
John Petry says June 20, 2018 at 7:27 pm I have a 24000 btu window type AC. What size breaker should it be wired to if using 10 ga. Wire? 12-3 ga. Wire? Reply
Dan Pott says July 1, 2018 at 8:53 am I have a15 amp breaker/110 and I want to run the largest ac window unit I can. I have had a 15,000 BTU for years and it was fine This year the breaker starts to trip daily. I replaced the breakers but it still happens. Just wondering why all of a sudden? Time for a new ac unit? How large a unit should I buy? Thanks Reply
Ree says July 1, 2018 at 8:25 am I have a 8000 btu AC what is the right amount of amps I would need in a surge protector I don’t have outlets close enough to my account so I’ll have to use a surge protector Reply
Dan Pott says July 1, 2018 at 8:56 am I have had a 15,000 BTU ac window unit for years with no issues. This year it has begun to trip my 15/110 amp breaker. I am wondering why this year? Time for a new ac unit? Do I need to downsize my BTU’s? I replaced the breaker with a new 15 amp but it still happens. Any recommendations? Thanks Reply
Jackie says July 3, 2018 at 5:48 pm Can someone help me out with answers I have two portable ac 10,000 btu every time I turn one on with other appliances it shuts down the circuit box the circuit box switch that shuts off says the number 15.i would like to return the 2-10,000 btu ac and purchase 2 more ac but how many btu can pull on the 15 switch? Reply
Mary says July 18, 2018 at 11:37 pm Ok, I don’t think i want to know about amps, what i have is a 115v – 60 hz new portable AC unit. Is it ok to plug in or not? Reply
Michael Cameron says August 4, 2019 at 1:58 am 15 amp breaker is the size recommended for 230volt 18000 btu unit Reply
Juan Hinojosa says February 17, 2020 at 12:19 pm “amps” is what will answer the ” will it work or not” find the amps that AC pulls. Reply
Christine D. says September 25, 2018 at 10:53 pm I have a 10000 btu air-conditioning….when I turn it on…my lights go dim. And my power gets low. What is wrong? Reply
Jim Earl says December 3, 2018 at 6:48 pm I plan a 5000 BTU AC on a 15 AMP Circuit. Should I dedicate that circuit or could it also handle a couple or three outlets for a light, video player and monitor.? (Space heater would not run in tandem with the AC if I could do that.) Reply
Eddy says January 2, 2019 at 2:10 pm I have a frigidaire ac with heat it has a 230 plug on it can I change it out with a 220 plug. They both have a 30 amp breaker on them Reply
WILLIE WEBB says September 13, 2019 at 5:48 pm You’er best bet is to get a good licensed electrician to install what id needed. Reply
Country boy says July 11, 2020 at 12:18 am Hey, you ppl have curious honest questions. Everyone is accepted that 220 v isn’t real. It means you have two 110 separate currents with two neturals. Or negative and ground. You notice two breakers for two “110s”. Not just one (1) breaker at 220. There never was actual 220. Reply
