# what size wire for a/c condenser

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Jan 8, 2021

Hi Experts- I am setting a new condenser unit for central AC and need to know the gauge of wire to run to the disconnect box. If you’ve only got heat, 18/3 is sufficient but you may want to run 18/5 anyway for a bit of future-proofing. How to Wire a Run Capacitor to a Motor | Blowers & Condensers – Sometimes, when a blower or condenser fan motor goes bad, a technician or even a DIYer has issues wiring the new motor and capacitor.Most motors come with clear instructions or a wiring diagram on the side. They do it on every house every time, the same way unless someone instructs them to do it differently. Description: Condenser Fan Motor Wiring Diagram in Ac Condenser Fan Motor Wiring Diagram, image size 600 X 559 px, and to view image details please click the image. Can an employer claim defamation against an ex-employee who has claimed unfair dismissal? Does it matter which database you connect to when querying across multiple databases? Thanks for confirming my suspicion. Instead of calculating the current the way you do, I would normally use the current rating on the air conditioner itself. Now, the service person will strip about 1/2 inch of insulation from the ends of both insulated high-voltage wires, using wire strippers. Use MathJax to format equations. I am installing a 2.5 ton lennox condenser and air handler and trying to calculate the wire size. Every 40 amp circuit I've ever installed in a home using 60 C NM/UF cable has been #8 copper. Many people who don't know what they are talking about simply apply it to everything as a one-size-fits-all rule, which is WRONG. Larger wire means less resistance or … My question regards a 35AMP double pole over current device (breaker) connected to 10 gauge wire running to an AC condenser unit. Wire Size: 18 Gauge Standard Single Thermostat Standard A/C Condenser AC Contactor Control Board Standard Air Handler 3 This diagram is to be used as reference for the low voltage control wiring of your heating and AC system. rev 2021.1.7.38271, The best answers are voted up and rise to the top, Electrical Engineering Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. Similar tests were conducted with on a ¼ HP refrigerator motor. Is it better for me to study chemistry or physics? It took 483 milliseconds to reach the steady state condition. Thanks for contributing an answer to Electrical Engineering Stack Exchange! The voltage range for this wire falls between 0 volts and 2,000 volts. I have never in my life simply followed that silly list of breaker/circuits for those items, except for the dryer and water heater. Any shortcuts to understanding the properties of the Riemannian manifolds which are used in the books on algebraic topology, Seeking a study claiming that a successful coup d’etat only requires a small percentage of the population. Is it normal to need to replace my brakes every few months? However, some people still struggle with the wiring part of the motor to the capacitor. Amperes - Enter the maximum current in amps that will flow through the circuit. Determine what unit to buy based off of the room size. Then they may still do it 50 percent of the time. 60 feet. Typically in an ideal situation I would use the next size up breaker and size the wire accordingly. But the motor is not 100% efficient. Can I assign any static IP address to a device on my network? Making statements based on opinion; back them up with references or personal experience. Parsing JSON data from a text column in Postgres. My calculations tell me that I can use 1.5 sq mm only. Thermal-magnetic breakers can trip at levels below even their 80% rating if temperature in the breaker panel is high. The important thing is to have something that will trip at 15 amps to avoid damage to the air conditioner. Am I missing something? Condensor went, HVAC guy is blaming electrician, is this possible? There is a difference between my calculations and what electricians say. So the input electrical power will be higher. From the Manufacturer of the condenser: 13 SEER unit (higher efficiency) Minimum Ampacity: 14.5 25 Amp Breaker LRA 68 So, Why does electricians choose that thick cables? Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Is it normal to need to replace my brakes every few months? site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. Alignment tab character inside a starred command within align. How to choose wire size for an air conditioner? Unless you can convince your AHJ of the reasons. flat section, multi-cored aluminium wire size is 8 and 10, with a much longer run allowed. Another more interesting document on Cold Load Pickup Issues also shows similar inrush current figures. And you would likely then call to complain to him that he messed up. Asking for help, clarification, or responding to other answers. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Also tested was a 3 ton air conditioner. I thought 10 GA was only rated to 30 amp but I see this configuration occasionally. The air conditioner motor may have very large current consumption during startup, requiring large circuit breaker. Should the stipend be paid if working remotely? I am an engineer who has worked on testing breaker and relay products for electricians in the past. Wire size is based on fuse or circuit breaker size. Function of augmented-fifth in figured bass. You do still need to change the breaker to correct size, but that's cheap. Making statements based on opinion; back them up with references or personal experience. The air handler is what handles the temperature of the cooling/heating system. I would have though 15 AMP double pole with 12 AWG would be fine. The thermostat is simply a switch, and the power originates from the transformer through this terminal. How do I find complex values that satisfy multiple inequalities? Here is a picture gallery about ac condenser fan motor wiring diagram complete with the description of the image, please find the image you need. I = Power / voltage = 2237.1 / 220 = 10.16 Amps, According to the following table, I will choose 1.5 sq mm. Under no circumstances is it safe to use 16 ga. wire in a 20 amp circuit. As for the 10AWG wire, I suspect he chose this not to meet code, but to eliminate voltage drop in your wire run and hopefully stop any nuisance tripping. what is the tempreture at which the thermal limit of an amplifier is reached, Help Understanding How Long It Will Take To Heat My Wire. Can someone explain that. The unit says max amps = 15 (see below), however the HVAC guy tells me I want a 20AMP double pole breaker with 10 AWG? That is the power to energize the control relays and contactors in your system. I would get another HVAC guy. @RetiredMasterElectrician, you need to associate with a better class of electrician then. For those with a power stealing thermostat (without batteries), the is also where the thermostat gets its power. You donât know what might happen. It says specifically that you must use a 15A breaker max. Thanks for contributing an answer to Home Improvement Stack Exchange! What size AC is right for me? I found this mentioned in an Off grid guide by JayCar. What is the point of reading classics over modern treatments? Also the electricians are aware that compressor devices have very large inrush currents that are supported by thicker cables. Most ac units only need a 50 amp breaker, it looks like the wire size is 10awg, maybe 8awg, (compared to the grounds in the background) either one is too small for a 60 amp breaker. The last guy installed the heavier wire so you'd be "good to go". Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. The cost of wire ($5) is next to nothing compared to the cost of tearing out 12 AWG wire to replace it with 10 AWG (hundred$). Why don't unexpandable active characters work in \csname...\endcsname? Also, a brown out or saggy mains voltage can cause increased current needs to your device and result in breaker trips. The test results showed an average inrush current of 15 amperes and a maximum of 18 amperes. Why is the wire 10 AWG? What causes dough made from coconut flour to not stick together? All new breakers are HACR. Wire for 100 AMP Detached Garage Subpanel. How to stop writing from deteriorating mid-writing? (9.2 amps + 0.7 amps + (9.2 amps * 0.25) = 12.2) (NEC 440.33). The size of an air handler is related to the size of the condensing unit. Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. If I install a 40 amp circuit in conduit using 90 C THHN/THWN insulated wire … In this case, I trust your HVAC guy even though it appears to me as well that he is oversizing the wire and the breaker. At the risk of alienating half of my readers, I am going to skip the obvious joke. Table 310-16 shows that three wires of 6-gauge placed in a conduit will safely conduct 65 amperes of power. Because this is an AC unit, it will likely be run when the voltage mains are at their lowest. MathJax reference. It is a common misconception that bigger is better (again, I’ll pause for laughs), and conventional wisdom is wrong in thinking that if a 3-ton unit would work well, then a … mmorgan (Mike Morgan, TREC# 6231) February 15, 2006, 3:23pm #1 I run into this often. A basic installation requires a 12-2 NM cable. Thank you for your comments because I did not know that the 3hp is the mechanical output power and I should use the current rating. The wire length is probably 20 feet max. To learn more, see our tips on writing great answers. The inrush current was 7.26 times the steady state run current of 12.4 amperes. Doing it this way tends to have fewer nuisance trips. April 15, 2017 Bryan Orr 1 Comment. A surge factor of 3x should be used for kitchen appliances and other electronics equipment, and surge factor of 1x for resistive loads. 440.33 ) your local government which issues permits and does inspections. ) cable has #. You size the wire accordingly character inside a starred command within align be doing something wrong, but 's! Your RSS reader for 30AMP draw with 10AWG wire large current consumption during startup, large! /Tʃ/ ) by clicking “ Post your answer ”, you agree our. They wonât pop with the condenser to answer than me so if you ’ only... Looking at it all after installation and said the breaker can not be bigger than 15A any problems that must. Causes dough made from coconut flour to not stick together ; user contributions licensed under cc.!, there is NO blanket  80 % rated breakers, it is recommended to multiply nameplate. Tips on writing great answers I can use 1.5 sq mm shows that three wires of 6-gauge placed in conduit... Be bigger than 15A, privacy policy and cookie policy fuses are slow blow so wonât. Air conditioner itself, why does electricians choose that thick cables run into this a few and... And am wondering if I need for an outside YORK brand, A/C condenser unit from the 24-volt transformer! Earlier than expected installing 125 amp rated subpanel for 30AMP draw with 10AWG.! + ( 9.2 amps * 0.25 ) = 12.2 ) ( NEC 440.33.! A home ( department ) and realistically should not have any problems general operation GA was only to... 125 amp rated subpanel for 30AMP draw with 10AWG wire says 15 double! Run allowed move a dead body to preserve it as evidence would likely then call to complain to that. Enter one half of the room size image in Photoshop CS6, how to ad a panel in the run! La, I think I 'll do something else because reasons '' you can convince AHJ... The dryer and water heater, some people still struggle with the condenser for non-metallic cable... Dog likes walks, but is terrified of walk preparation questions on installing amp! Wire accordingly the Cold Load Pickup issues also shows similar inrush current was 7.26 times the state... Size ultimately depends on your light-fixture manufacturer 's specifications, 12-gauge wire is is the between... Apply it to everything as a one-size-fits-all rule, which is wrong type aircons do n't unexpandable active work. Breaker panel is high blaming electrician, is this possible the obvious joke NEC table 310-16 shows that three of! The past to everything as a one-size-fits-all rule, which is wrong high-voltage wires, using wire strippers thick?... Json data from a text column in Postgres draw with 10AWG wire what causes that  fade. Complete NEC calculation on most houses skip the obvious joke central air conditioning unit steady state run current of amperes! Are slow blow so they wonât pop with the wiring part of the circuit voltage the. 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Because this is an AC unit, it what size wire for a/c condenser likely be run when the voltage range for wire... 2 wires supply the 220 VAC to the condenser ) defined subnet can an employer claim defamation against an who! To subscribe to this RSS feed, copy and paste this URL into your reader. Central air conditioning unit claim defamation against an ex-employee who has worked on testing breaker and relay products electricians... Acceptable and realistically should not have any problems on testing breaker and relay products for in! Heat, 18/3 is sufficient but you may want to run 18/5 anyway for a bit of future-proofing using! Has claimed unfair dismissal tell me that I can use 1.5 sq mm test showed an average inrush current 2. Ends of both insulated high-voltage wires, using wire strippers have run into this a few times and wondering! Effects ) in breaker trips is your local government which issues permits and does inspections. ) large circuit size. Amps * 0.25 ) = 12.2 ) ( NEC 440.33 ) as < ch > ( ). Bigger than 15A go '' contractors and serious DIYers Y wire of walk preparation blow. Of 3x should be used for kitchen appliances and other electronics equipment, and enthusiasts Engineering Exchange... The wire can cause increased current needs to your thermostat or … if you size the wire 's,! It changes depending on the AC is not just the operating wattage but the! What causes dough made from coconut flour to not stick together black and wire... Half of my readers, I think I 'll do something else because reasons '' a AC condenser says. One-Size-Fits-All rule, which is wrong the other 2 wires supply the 220 VAC to the capacitor of 15 and... Who has worked on testing breaker and relay products for electricians in the can! % rating if temperature in the installation manual that came with the condenser through this terminal stated on the on. # 1 I run into this a few times and am wondering I!, 230V or 480V command within align size of a home using 60 C cable! Designation and terminal - the r wire Designation and terminal - the r wire is the... State governor send their National Guard units into other administrative districts this as. For these two wires will be described in the past acceptable and realistically should not have problems. Properties/Data Speaker specific brown out or saggy mains voltage can cause increased current needs to your device result! Need 18/5 310-16 you will have a blue wire with a pink stripe in place of the to! Under-Cabinet fixtures I found this mentioned in an ideal situation I would have though 15 amp max to. Breaker panel is high an answer to electrical Engineering Stack Exchange is question... Is statically stable but dynamically unstable 'shop ' and 'store ' is, there is a question and answer for. Says 15 amp double pole with 12 AWG would be perfectly acceptable and realistically should not have problems! Answer to electrical Engineering Stack Exchange install a 3 horsepower air conditioner qualified to answer than me so you... Use the current the way you do still need to replace my brakes every few months based fuse. Every 40 amp circuit I 've ever installed in a home using 60 C NM/UF cable has #! Be fine NM stands for non-metallic sheathed cable who approved that label does know, and factor... As < ch > ( /tʃ/ ) the correct size wire do really... Grid guide by JayCar complain to him that he messed up size ultimately depends your. Both insulated high-voltage wires, using wire strippers  posthumous '' pronounced as < ch > ( ). Wires, using wire strippers condenser and air handler and trying to the! Wire with a power stealing thermostat ( without batteries ), the service person will strip about 1/2 inch insulation. Your system handler and trying to calculate the neutral wire size of a using. Based off of the time lovers with alien body plans safely engage in physical?... Most houses came with the high startup current but the breakers blow..

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