How to Find Common, Start, and Run on a PSC Compressor Motor

In this HVACR Training Video, I show how to Measure Resistance Readings on the PSC Compressor Terminals in order to determine which tab is Common, Start, and Run for Electrical Wiring when a Diagram is not available. I also explain how the Ohm Readings add up and how to Check for a Short in the Windings to Ground. A UEI Digital Multi-meter is used for testing. PSC Motor means Permanent Split Capacitor Motor. This type of electrical motor needs to have a capacitor wired connected in order to start and run when powered. This method can be used to Ohm out a Compressor, Blower Fan, Inducer, or any other type of PSC Motor.
Tools Used In The Video
UEI DL479 Multimeter with temp sensor- amzn.to/2jtsUbJ
Alligator Jumpers- amzn.to/2PxqJXn
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Our Related Videos/Articles
• Refrigerant Compressor...
• Testing if an HVACR Co...
• Refrigerator Compresso...
• Recovering Refrigerant...
• Compressor Overload Pr...
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Our HVACR Educational Books, E-Books, Workbooks, Cards, Posters, and PowerPoints:
All Our Educational Products on Our Site: www.acservicetech.com/store
All Our Educational Products on Amazon: amzn.to/48pDd82
Mini Split Book and E-Book on Our Site- www.acservicetech.com/mini-sp...
Mini Split Paperback on Amazon- amzn.to/3ytHJSs
Mini Split Paperback on TruTech Tools- www.trutechtools.com/BooksGui...
Refrigerant Charging Book and E-Book: www.acservicetech.com/ac-book
Refrigerant Charging Paperback on Amazon: amzn.to/46xTeHf
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Our HVACR Online Resources!
Our HVAC Calculators: www.acservicetech.com/hvac-ca...
Our Newest Articles: www.acservicetech.com/articles
Try our HVAC/R Quizzes! www.acservicetech.com/quizzes
Our Other Resources: www.acservicetech.com/resources
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Tools Used in Our Videos!
Tool Links on Our Site: www.acservicetech.com/tools
Our Tool List on Amazon: www.amazon.com/shop/acservice...
Support the Channel by purchasing tools through TruTech Tools!
Use this link www.trutechtools.com/?aff=8
Save 8% at checkout using code "acservicetech"
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Follow Us On Our Social Media & Podcasting Channels!
Patreon: / acservicetech
Facebook: / acservicetech
Instagram: / acservicetech
X: / acservicetech
LinkedIn: / ac-service-tech-llc
Tiktok: / acservicetech
Spotify: open.spotify.com/show/74KXLz5...
Apple Podcasts: podcasts.apple.com/us/podcast...
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
⚠️ Disclaimer:
Information in this video is intended for educational purposes only. Any work related to the topics in this video should be performed by licensed technicians or by apprentices under the supervision of licensed technicians. AC Service Tech LLC is not responsible for any possible damages or injuries caused by the use or misuse of any information provided. ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
#hvacr #hvacr #hvactrainingvideos #hvactraining #hvactraining101 #acservice #acservicetech #compressor #resistance #terminal #start #electrical #wiring #diagram #ohm #UEI #multimeter #PSC #capacitor #motor
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Shop through Amazon! Your Purchases through Amazon provide a means for channels such as mine to earn advertising fees from all purchases after clicking through. Prices are the same as normal.

[@acservicetechchannel]

Tool List- www.amazon.com/shop/acservicetech Support- www.patreon.com/acservicetech For those that are looking for the tools used in the videos: (Linked Below) Here is the Link for the newer UEI DL479 Multimeter with temp sensor- amzn.to/2jtsUbJ Here is a link to Refrigerant hoses with valves used in the videos amzn.to/2aBumVI Here is the Link for the Yellow Jacket Refrigerant Manifold Gauge Set used in the videos amzn.to/2aenwTq Here is the Yellow Jacket Manifold Gauge Set including standard hoses- amzn.to/2vLVkV9 Here is the link for the Imperial Kwik Charge 535-C- amzn.to/2uipEI6 Here is the link to the Fieldpiece ST4 Dual Temp Meter- amzn.to/2wc1ME3 Here is a link to the Digital Refrigerant Scale used amzn.to/2b9oXYl Here is the Yellow Jacket 4 Port Brute Manifold with Hoses- amzn.to/2BkuGIq Here is the Fieldpiece SMAN460 Digital Manifold Set- amzn.to/2nB4Fe6 Here is the Fieldpiece SMAN360 Digital Manifold Set- amzn.to/2BdoaD4 Here is the Compact Ball Valve Attachment for the end of the Refrigerant Hose- amzn.to/2KUisW8 Here is the Quick Disconnect 90 degree attachment for the end of the refrigerant hose- amzn.to/2MMtVcg Here is the link to the Appion Valve Core Removal Tool- amzn.to/2uYr8WL Here is a link to the JB 6 CFM Vacuum Pump amzn.to/2nqbvo8 Here is the Link to the Appion Blue 3/8" to 1/4" Vacuum Hose- amzn.to/2uYlVyc Here is the Link to the Appion Red 3/8" to 1/4" Vacuum Hose- amzn.to/2uYg6Ro Here is the link to the Yellow Jacket 1/4" by 1/4" heavy duty hose straight- amzn.to/2umtcod Here is the link to the CPS Vacuum Micron Gauge- amzn.to/2v1nM3O Here is a link for RectorSeal Bubble Gas Leak Detector amzn.to/2ckWACn Here is a link the Nitrogen Regulator amzn.to/2bXdR5f Here is a link to the Nitrogen Flow Meter amzn.to/2brvoBg Other tool links can be found in the video description section. Shop through Amazon! Your Purchases through Amazon provide a means for channels such as mine to earn advertising fees from all purchases after clicking through. Prices are the same as normal- www.amazon.com/shop/acservicetech All of the ACSERVICETECH Playlists- kzbin.info/door/OZR-1IqsAer9wzlvFgb4mAplaylists?view_as=public

[@raymondcornielle8263]

What does OL stand for?

[@joeteejoetee]

@@raymondcornielle8263 OL= "Out of Limit" = an open circuit with infinity resistance = The test leads are not connected to anything conductive between them.

[@jollyscaria1922]

Thw lowest ressistance is indicatwd . When the poods are connectwd to twrminals R and s total ..resiatance of both wind is indicated qhwn rhw terminals c and s ..are connected to the metar the resistance of starting wind is indicated or the value will br weenthe trminal e and rhe lowest r and s...the resstinec bet qeen c ans s..will be bwt qeen these tqo the sum of the resttance of ruing qindi g..bet ween r and c and starting qinding bet ween c and s is in dicated when the metar ia connctedr s rs numbwr exples 1.2.3 restanc checking exples 1-2 2-3identiiwd as followea for selald compwrssor the resistance bet qeen 1-2 2-3 1-3found as exples 50ohms 30 ohms and 29 ohms respectivetely .identify the rhree terminala resistance betqeen 1 and 2=50 ohma (hifhhest resiattance between 1-and 2 =50ohms highest resistance bet ween 2and =30 ohms medium resistance bet ween 1 and 3 =20 ohms lowest 1-2=rs 2-3cs .1-3cr..terminal 1=r 2=s .3=c...3teminal poin testing find oit methad hight low mediom conformed wind 3trminal poined ok jolly engring sake gruoping .....ok sir.. thankto somuch redi g sllowing ok

[@zesty2023]

You just explained this better in 3 minutes then my college class explained it in a week.. Thank you.

[@acservicetechchannel]

Ha ha thanks Ian!

[@kennethchristensen7457]

I went to the US Navy HVACR school back in 1960 the instructor told us to remember this for terminal identification .CAN-SHE-RUN common start run . It still works today.

[@Asadhometech365]

how to find compressor common running & starting | csr

[@splagyetsi3287]

I live in a rural areas of Asia and many so called technicians have turned up to fix our commercial fridge. When they see a foreigner the repair price is tripled. You sir have given me all I need to get the fridge running again (excluding a faulty compressor motor) and you have even shown me how to figure that out. Many thanks.

[@drifter436]

Everytime i get in over my head, I pull out my phone and go right to your video's. I can't say thank you enough for all the help that you have given me learning this trade. You sir are the best on youtube.

[@acservicetechchannel]

Thank you very much drifter436! I appreciate your comments very much!

[@iancourter7291]

Second that thought!

[@deanmartin1966]

Once again great info. Thanks for sharing your knowledge. Everyone appreciates the time you take to make these videos. It helps out a lot of people.

[@acservicetechchannel]

Thank you very much Dean Martin1966!

[@Asadhometech365]

how to find compressor common running & starting | csr

[@DanO181919]

Your short, to the point videos are awesome. Well.... all of your videos are awesome😁, but the short videos I’m able to retain the information easier. 👍 Great Job!!

[@acservicetechchannel]

Thanks Danny L!

[@hansmyers7495]

Wow. I have been looking for a video explaining this and yours is by far the best! Thank you!

[@acservicetechchannel]

Glad it was helpful!

[@stuzman52]

Very well explained! Keep up the good work! 😀👍

[@acservicetechchannel]

Thanks Stuzman!

[@missionuluna5837]

Thanks brother, fromHvac technicians in papua new guinea 💪👍power full brother thanks for sharing your videos

[@douglieberman6406]

Just to let you know my credentials - DeVry University was where I attended 2 year school for digital classes in ( and, or, nand and nor ) gates and truth tables, Boolean algebra and Karnaugh mapping. Middlesex County College is where I attended 2 years in Electrical Engineering technology for power supplies in 120 vac step down transformers, half wave, full wave and full wave bridge ( diode) rectifiers , electrolytic capacitors, all resistors, voltage regulators, Direct current circuit analysis. I learned to use a volt ohm meter and an oscilloscope. These circuits really were conversions from alternating current to direct current just to let you know where I am coming from. I did use a taps to tap into the hi pressure refrigerant lines of window or apartment air conditioners to fill them up with coolant working for a TV cable installation company who also did apartment air conditioners. YOUR EXPLAINATIONS ARE REALLY GREAT! I work for Duct-man Mechanical now in Eustis, FL in the scrap yard!

[@rogerf3622]

Another great easy to understand video. Thx.

[@acservicetechchannel]

Thanks Roger F!

[@zenonsiczek1162]

Awesome video!!!!!, I like your videos, very detailed. Do you have a video showing how you would charge the system if for instance you had to repair a condenser coil, or compressor and you would have to charge from a tank.

[@acservicetechchannel]

Thanks Zenon! Here are two videos on that- kzbin.info/www/bejne/iHKac4xtmc6rf8k --- kzbin.info/www/bejne/iHKac4xtmc6rf8k

[@ravanabrahmarakshas4263]

great. simple. short video. accurate. thanks.

[@georgewandwasi4646]

Nice explanation

[@jhundyskitchenvlogs2109]

Nice,very explained..thanks for information

[@acservicetechchannel]

So nice of you

[@treynewawlins4478]

Excellent video

[@acservicetechchannel]

Thank you very much!

[@obaidish]

Best explained in the this video sir....

[@acservicetechchannel]

Glad to hear that

[@wasimedoo1506]

Very good information thanks

[@acservicetechchannel]

So nice of you

[@jhundyskitchenvlogs2109]

Thank you,very informative..

[@acservicetechchannel]

Glad it was helpful!

[@ovetotarwoe9334]

Thanks a lot for making me to understand.

[@acservicetechchannel]

Glad to hear that

[@souhachalhoub2240]

Hi, the capacitor wires should be both placed in one side on the relay (where there is 2 pins) and the white wire (i guess the neuter wire) in the other side from the relay (where there is 1 pin)? Please advise it is an old whirlpool fridge thank u so much in advance 4 ur reply 🙏

[@abrahamvaro5482]

Super very nice video ,thanks.

[@acservicetechchannel]

So nice of you

[@droquesteni]

Thanks my friend!

[@acservicetechchannel]

Any time!

[@yusudong1174]

Thank you Sir.

[@markcarpenter3600]

I love your work and appreciate all you do. I hate to point this out but at 2:40 you said "We should have no resistance whatsoever with the ground." No resistance to ground would be a short to ground. When the meter read "OL" or "Out of Limit" indicates there is more resistance than the meter can measure. For all intensive purposes, infinite resistance. I think I noticed this on one other video about start components as well.

[@skasev]

Mark Carpenter, intents and purposes

[@rolliebca]

I noticed this too. It's dangerous to assume people will understand his intent. As a training video they should at least pop up a text to correct this or do a quick voice over to make this otherwise excellent video correct.

[@anthonytran98290]

Wow great thank you sir.

[@acservicetechchannel]

So nice of you

[@geojor]

very good, thank you ...

[@acservicetechchannel]

Glad to Help!

[@delvirodriguez2182]

Hey thank you, When I went to school I learned it but we forget things sometimes, thank you for refreshing my memory.

[@ooCHICOoo]

great 👍 video.

[@acservicetechchannel]

Thank you 👍

[@jacksonv1ll836]

is it normal that i could get a reading of something about 16ohms when i took the reading on the plug of the refrigerator? cs reads 14.1 cm is 23.2 the sm 36.5..

[@user-mk8wf7bx6e]

Nice sir

[@replayreviews6339]

What do you think about using a megaohm meter to test compressors? What is a scenario where you would actually use one and what is it really for?

[@acservicetechchannel]

You certainly can use a megger instead of just the value from the multimeter. The megger gives you a deeper look into the resistance value of the windings. This would be done to determine if a compressor is on its way out from loosing insulation resin on the windings.

[@replayreviews6339]

I think I’m still confused and here’s why: I’ve only been in the industry maybe 2.5-3 years outside of a year in trade school. I started in residential appliance repair and eventually moved into commercial refrigeration. Now I’m doing residential heating and cooling. Worked in install and have been doing maintenance and service now for maybe 8 months. The current company I’m at keeps pushing everyone to go out buy a megger saying it’s a vital tool. But I don’t see it. It honestly seems gimmicky and kinda redundant. If you can check your compressor with your trusty multimeter why would you ever use a megger?

[@acservicetechchannel]

A megger would certainly be used much more on larger compressors than small residential and appliance repair, thanks

[@nurfetalic205]

Craig there was the question in reference about commercial work yes only in a small scale in the reference to small tonnage range from 5 to 15 Tons the company that I work and HVAC department guys that work on the units ranging from 30 tons 250 tons including Chillers and that's total totally different animals when comes to the service and repair it's not the same when you work in the residential and Light commercial units it is mind-boggling when it comes to the service and repair. Computer-controlled program that's including Electronics sensors pressure switches high voltage 480 3.phase and 2100 volts ac three phases feeds the chillers over 150 tons . My electrical department we work only on install service and troubleshooting It is challenge and adventure. Craig good work and nice video.

[@elgallo0823]

Great info

[@acservicetechchannel]

Yes they are different animals, ha ha. I still think that the basics need to be known first and that large companies that do commercial work still need to give applicants the chance to step into that and learn and work in that environment too. A lot of techs are told they don't know enough or that the existing knowledge doesn't apply. I am not a fan of that since techs still need to start somewhere, that's all. So when someone asks me if they are similar, they are typically asking with the question in the back of their head" should I even apply for that position?" I say yes, go for it and take the knowledge that you do have and build on it. Thanks Nurfet Alic, always a pleasure!

[@superdau]

Ahh, looks like I have a broken dehumidifier compressor. Or is there any other internal construction that would not give the R_start + R_run = R_total? I am very sure that the terminals are in the same location as on the compressor you are showing, because of the external components connected to them (PTC-thermistor with "M" and "S" marking, overload protector on common, capacitor going to M and S). I am measuring 6.6 Ohms on the start winding, 8.1 Ohms total, but the run winding measures 10.3 Ohms. The first two values would fit with your example, and 8.1 - 6.6 Ohms would give nice 1.5 Ohms, but that's not what I measure. The compressor runs for about 15 seconds (the heat exchanger pipes even start to cool), but then the overload protector trips.

[@raymondcornielle8263]

What does OL stand for?

[@OmelaSamuels]

On the supply side,is the common same as the supply or it's the run?

[@LawMtetwa]

Hie my common to starting has less resistance and common to run has big resistance ,does that mean the compressor is not workn have to replace it

[@blanka2711]

Dziękuję

[@balachandarj4245]

Thankyou

[@acservicetechchannel]

Glad to help!

[@Jiggywithfacts]

Hey Craig. Do you ever do commercial work ? Can you do a video on that ? Same thing you with residential hvac problems. Do same for commercial hvac problems. Thanks.

[@acservicetechchannel]

I do some but not very large, just light commercial with my company, thanks for letting me know what you would like to see!

[@Jiggywithfacts]

AC Service Tech LLC so basically it’s the same principle apply to commercial work as to residential work. Like charging, capacitor, motor fan. Etc. it’s all the same ? Or different complex. ?

[@acservicetechchannel]

Yeah same principles, 3 phase motors, multiple compressors and evaporators, belts attached to blower motors instead of direct drive but same refrigerant procedures until you get very large, thanks

[@acservicetechchannel]

JiggyPatel, did you see Nurfet Alic's post under the same video for you?

[@Jiggywithfacts]

AC Service Tech LLC thanks. I will check it out.

[@curlyelp7530]

Hey , So I have a compressor that is not only blowing my "overload" but I also have continuity between "ALL" three pins and the copper tubing right next to the compressor. So Is this compressor Bad for sure then??

[@joeteejoetee]

Resistance between "ALL" three pins is normal. A short between any of the 3 pins, or any of them to ground/chassis/copper means it is bad because it is shorted to the compressor body internally.

[@FlextheJuvat]

You could also use continuity to check against the ground, right?

[@acservicetechchannel]

Absolutely!

[@FlextheJuvat]

@@acservicetechchannel Forgot to ask .. is Common to Run *always* lower than Common to Start??

[@lesliedaisley7846]

Bro do you guys do apprenticeship programs

[@irbytime]

When I try to test any of the terminals on the compressor from my old freezer the resistance number jumps around and never settles. Is there some reason for that?

[@throttlebottle5906]

only thing I didn't hear is, why the start winding has higher resistance and the run has lower resistance. guess that could be a video of it's own :)

[@acservicetechchannel]

Ha ha yeah this was just mean't to be a quick review, thanks

[@joeteejoetee]

@@acservicetechchannel The question was: "why the start winding has higher resistance and the run has lower resistance" This Start and Run label on the schematic in the video seems backwards to me. It would surely burn out a compressor if it was connected backwards.

[@gabrielsansar6187]

@@acservicetechchannel uve ben asked and no answer to it.. um.... slow clap

[@edsecce5685]

My reading is off by 0.6, 1.5 plus 3.2 gives me 4.1 instead of 4.7, it's my compressor broken?

[@runningcoyote3897]

The psc has a run capacitor which is in series with start winding and a centrifugal switch right?

[@acservicetechchannel]

There is no centrifugal switch on this. This would have an externally mounted relay if there is a start cap mounted, thanks

[@ejohnfall]

Thanks well done

[@acservicetechchannel]

Thanks ejohnfall!

[@bobsanford6061]

I just watched another guy do this, and he didn’t explain to the people what the difference between the poles out of the motor.🎉 I was trained by Frigidaire.

[@sah_shrawan]

❤❤

[@jacobmcentire8790]

Is it free to have a hvac company remove refrigerant just wondering?

[@acservicetechchannel]

That would be up to how the company charges for services but certainly wouldn't be free unless it was a warranty thing, thanks.

[@jacobmcentire8790]

AC Service Tech LLC thanks

[@shripalahlawat8516]

Sir DC volts ka batao

[@andranika6203]

👍👍

[@girlthatseasythadon9783]

Scenario 1: The compressor is not running, but the condenser fan is running and the compressor is hot to the touch. What may prevent the compressor from coming on? Scenario 2: Name the compressor terminals, identify the color of each wire, and name the component to which each wire connects. Scenario 3: How do you identify the compressor terminals if there is no diagram? How do you identify the terminals on a capacitor if the name is not visible?

[@3niknicholson]

go ahead

[@alizimam5809]

Ok

[@acservicetechchannel]

Thanks

[@SBE3000]

F me. I hear the infromation but my brain can not digest it, even with moving pictures and pointing.😂 *internal screams* "This is this and that means this is this is that is this-that..." is all my brain is getting. Its like Charlie Brown's teacher talking. 😢 why cant i just be normal? Why couldnt this fridge have the schematic!? 😅 Okay. I slowed it down and used crayons. Now to find out the other end of my plug. Thanks

[@gabrielsansar6187]

and fails to spend ten seconds explaining how the start and run feeds function.... slow clap