The size of the capacitor to the fan motor have to be the exact capacitor as written in the fan motor, if not your motor will overheat and will eventually will overheat and burn. Great explanation, i am a licensed retired 68 yo HVAC, still working to pay my bills. I love this young man way of explaining his videos. It doesn't matter how long i been in this trade, we never stop learning.
Wish I had seen this before when I was younger. I changed a Copeland compressor with a Bristol compressor for a friend of mine since the Bristol compressor was cheaper and he didn't have much money. I think they have since gone out of business. I installed compressor and had correct capacitor for it but I kept getting a higher start winding current than the run winding. Capacitor checked out ok. I ohmmed windings and start winding had higher resistance. It just didn't make sense that run winding was pulling lower amperage. I called Bristol tech support and they asked if amperage was within specifications on compressor. I told them all the readings I had and that I triple checked everything. Even changed capacitors a couple times. I checked charge also to make sure nothing off there. Voltage was within range and guy on tech support said they don't really check the start winding amperage at the factory and everything seemed fine to him. I told my buddy I didn't feel good about it but he had a year warranty. It lasted 10 months and burnt up. Changed it for a Copeland because I didn't trust the Bristol compressor (supply house just charged me difference between Copeland and Bristol cost) and it ran fine and within normal amperage for both run and start. Copeland compressor was still running years later. It was oddest thing I had come across.
Great video. I've had coworkers tell me that you can put in a different size capacitor for the compressor or fan and I've always said that I go back with what's supposed to be there. They'd laugh at me an call me a "by the book" guy but I wear that label with pride. What happens when someone puts in the wrong size and another guy comes in and changes it. If each guy bumps up the mfd by 5 then we aren't anywhere close to what was originally there. Is the second guy going to look at the rating on the compressor and the fan motor? I wouldn't bet a penny on it! If you do it "by the book" then you don't have to worry about burning up motors or compressors.
TO BE FAIR, the compressor has more "wiggle" room with it. I do the same thing, if i see a "non-manufacturer from install" capacitor on a system i'll look at the compressor capacitor rating and put that one on. BUT, compressors can easily handle the "50mfd and use 55mfd" swap as the numbers are way more forgiving than the outdoor fan motors' "5mfd to 7.5mfd." I 100% agree you should put what it calls for, but just wanna point out on compressors the small changes from 45 to 50, 60 to 65, or 65 to 70, etc on those higher ends arent a big deal at all and I'll do it in a heart beat if I just don't have the 60 when it calls for that and i'll use a 65. What I can't stand is when I hear a fellow service tech mention they put a 80 on a 65, etc because THAT is very bad. keep doing it right though my guy EDIT: never put on a lower number though. that's a hands down rule i've learned, even hearing it from the techs that put on those atrocities.
@@Wilsontrax I agree about the difference between the fan and compressor. The difference in percentage on the fan vs. the compressor is much greater but I'm a stickler for correct. I've heard it said that an increase in the mfd on a compressor is the equivalent of leaving the key turned in the start position while starting your car.and it's already started. I just sleep better knowing that I've done it properly. There's so many times I've seen the results of lazy, rigging and not knowing or caring work that I can't bring myself to do it. Once you start cutting corners, where do you draw the line? Be safe.
@@bill944 Haha no I agree. Line is drawn at 5mfd difference (UP!) and ONLY if I don't have the correct match on my van. But that's only me-- I know there are terrible people out there that don't care/don't know I do agree with you though and you be safe my guy. Stay true! :)
@@Wilsontrax No , Just Put the Right One In, He Clearly Stated The Problem With Changing The Size Thats how it Should be Done . That Is More Than FAIR It's The TRUTH .Keeping a Couple Rescue Capacitors Are Well Worth The Extra Cost .
Another fantastic video. It is all about the percentage of being correct with the capacitors. They need to be within 10% of nameplate (using a 55 in place of a 50 is at the limit of that, and acceptable but using 7.5 in place of a 5 is way off (50%) and not at all).
The run capacitor on a PSC motor is selected to give the best power factor at the design load for the motor. Increase or lower the capacitance, at the same design load, the motor is less efficient and the difference ends up as heat that will eventually burn the windings. It is possible to use a meter with power factor to swap in caps till you find the best power factor value. But easier to read the label or contact the mfr. I believe there is a way to calculate a new capacitance value if you were to say use a PSC motor for an application with a different operating load, but it gets down into the motor design black magic.
Great video, Craig. My company has a tendency of going a size larger in a pinch but I won't do that anymore. I'll just stay on top of my inventory and make sure to have a 440V capacitor to be safe.
A friend of mine is a motor rebuilder, and accidentally plugged a 220v motor in to 110v, and couldn't get it to come up to speed. He asked me what I thought might be wrong. I wasn't sure, but He was using a higher mfd capacitor than the motor needed to get it to run faster. I began by reading the label and then realized he had it under powered. The motor was dutch made, so I was aware that in all likelihood, they didn't have any 110v motors. After changing the capacitor, and plugging it into 220, he was able to get it up to speed.
Go to Amrad and get the right capacitor Made in USA and the quality is second to none, Just get one and lift it.. its 2 times heavier and the construction /oil is superior
Thanks for this explanation because I didn’t know about capacitors before this video. The only thing that I knew was that they can store a fatal amount of current. I guess that is true?
The largest determining factor for the lethality of a capacitor is voltage. Anything above 40 volts DC or AC RMS is considered potentially fatal. For HVAC units, all will be above this voltage. The next largest contributing factor is the path the current takes throughout your body. Aside from arc flash situations, after those two, every other factor, including available current is pretty much irrelevant.
This video is 100% correct. I have made the mistake of not double checking the existing capacitor and burned up a new motor in under 15 minutes! I will never make that mistake again.
@@KyleWithStyle7 Did hard start get the compressor to run? I was wondering if it did what damage to the start winding it could do if not noticed right away.
@@officerkrupke4966 it was running normal after replacing the cap, pulling normal amps. 2021 m#… 🤦♂️system was running like that for who knows how long
I always knew the capacitor was required to adequately charge the starter winding. I just now learned that the replacement capacitor needs to match the factory specifications for optimal running and potentially preventing destructive heating.
Dear sir this is good information.however most technician who doesn't know capillary tube restrictions and what is set pressure . could please let me know or post video . 🙏
TY! Nice vid. Was wondering, if you don't know what size cap you need for a motor, how could you calculate what size is most appropriate for any motor?
Don't hold your breathe on getting an answer from him 🤣 I'd love to see him post a video on that because I'm guessing that's way above his pay grade because that involves electrical engineering.
I don't know the answer to your specific question but if I'm not sure what size capacitor is needed I'll use the Copeland Mobile app for Copeland compressors ,and will look up model and serial for fan motor cap or check on rating sticker on motor.
Not sure there is a calculation for us in the field, but if you have a meter that will read power factor, you can swap caps till you get the best power factor reading…I’m guessing, since I’ve not done it!
Are you sure your multimeter is able to properly measure amps with the likely phase shift in voltage and current? The power factor shift of induction motors can be significant. So your calculations of kw could actually be kva (reactive power).
A EE would say that a capacitor controls voltage, not current. But of course, Ohm's Law says that if the load resistance (motor windings) is constant than current changes proportionally with voltage ! The important thing to remember is, a fully discharged capacitor "looks like" a dead short and will draw a HUGE amount of current for a fraction of a second as it charges up. Generators and inverters don't like this. Any "true" soft starter must LIMIT this instantaneous current draw so the capacitor charges slower. Yes, the compressor and fan motors will take a split second longer to start up.
When a lot of these hacks come out they want to just put anything into replace it the problem is the next guy comes along and has no real idea what belonged in it and the saga continues yes I had that happen to me they tried it I overwrote it went down the supply house and got the right part problem solved the right way Godspeed
Wow! This is weird. I'm William Brown also and the reply that you made sounds like my own statements since I've been in the HVAC business. Hacks are a dime a dozen and they give ALL of us a bad reputation. Takes a little effort to do it right but I sleep well at night.
@@bill944 too funny when I was a kid I went to school with three other William Brown's then I was in the Navy with a couple some of them were black and some of them were white it's a very common name most of the black rounds that I know her name Willie they were so funny Willie and Billy that was me and my black friends Aunt Jemima used to laugh her ass off till they took her off the syrup now I don't have any more syrup no more silly willy let's go Brandon F Joe Biden God bless you and your family good friend
@@WilliamBrown-dw3fz Yep. When I was in high school there were two other William Browns. I was constantly called to the principal's office being asked "why haven't you been in on campus isolation?" I'd say "you're looking for the other William E. Brown, the preacher's kid". Too funny. Take care.
Thank you for all the valuable Great Videos I wish you all the best I have a question regarding the UEI clamp meter, I see it can read Amps and Volts at the same time. Is that a special feature for the UEI Clamp meter ? I Have Testo 770-3 clamp meter. Please can you Detail us about the UEI . Thank you
No because the start winding stays in circuit all the time with a PSC motor and the run capacitor is what creates the 90 degree phase shift where the voltage lags the current which is what creates a rotating magnetic field for the rotor to chase around 😉 Since the capacitor causes the voltage to lag the current, the vector diagram will visually show why the back EMF is greater in value than the input source voltage. Also, the start winding has a higher reactance than the run winding hence most of your current will want to pass through the run winding instead. The start winding is wired in PARALLEL with the run winding and the capacitor is in series with the start winding. The start capacitor, assuming it has one, is wired in parallel with the run capacitor to increase starting torque and then is disengaged via a potential relay for HVAC units. Parallel capacitors ---> C(total) = C1 + C2 Series capacitors ---> C(total) = 1/C1 + 1/C2 Hopefully that answers your question.
Thus might sound crazy but I've heard several technicians that you could go up 10% higher on run capacitor on the compressor? I'm assuming that is not true.
I believe they may be referring to VOLTAGE but not the required mfd. You can replace a capacitor with one having a higher operating voltage. But as Chris said the mfd must be correct.
@@d.c.hammond130 You are getting confused, big no-no to put higher CURRENT rated fuses in, but higher VOLTAGE rated wont change they way they operate (for fuses or capacitors). Putting a lower current rated fuse in is safe, but can cause nuisance trips, but putting a lower voltage rated component in could cause it to fail.
Well he showed what happens in his video. Understand you can’t play with the absolute laws of electricity and HOPE it will be ok. The miter and or the new capacitor are going to fail sooner or later. The question is: Are we “hacks” or professionals? Our salaries are dependent on people being able to trust us. When the customers believe we are all “hacks” they will just go with the lowest price option because they see no value in spending any more money. ( please save your corrections, I know there are cheapskates out there who always go by price) that’s not what I’m saying here.
@@renecuevas4128 Don't say "we". Speak for yourself because I'll have no part in hackery. I carry 3, 4, and 5 mfd on the van. If you don't prepare for success, you've prepared for failure. YOU are the cause of the apprehension and the lack of trust that I deal with in customers.
It seems to me that the nameplate capacitor rating is the value that will closely balance the currents between the running winding and the starting winding. What are the components of the “2650” constant in your formula?
Have a 4 ton house AC system a tech is telling it has a bad secondary motor control valve. I’m not seeing any videos on this. Could you please direct me?
The capacitor on my indoor air handler unit keeps burning out. The 1st failure I had replaced by my HVAC company- happened when the system was 8 years old. A year later it died and I replaced that one myself, and today, a year after that, it's dead again! Obviously there's no compressor on this, just the fan motor. I don't have the original capacitor, just the one my HVAC company (that I use for oil burner cleaning) replaced (for $350!) I replaced that one with one of the same rating- 10 uF 10 MFD 370V/440V. What do I need to look at at on the fan motor to determine if this is the correct size capacitor? Many thanks!
Prizm inverter ac unit beeping once the power bottom is pressed from the Universal remote nothing is happening to the unit no lights nothing what could cause this??
I just bought brand new dual capacitor 40/12.5uf +/- 6% 440v, but im getting a reading of 42 uf when I test the herm and common terminals. Do you think the cap is defective ? Thanks
Reread what you just typed out about what it says on the capacitor and then you’ll find your answer. Diagnosing skills also come from learning to read the fine print
will the current always be balanced with the correct capacitor, or will it sometimes be designed to have more current in the run windings? I'm thinking that some motors (especially those made to run in either direction) will have windings the same resistance but others wont
The fan terminal (watched a second time) is connected and the common terminal is connected. Does the common go to ONE SIDE of the CONTACTOR for 120 volts! If so which side? Which terminal on the FAN does the fan wire connect to? A Lot Of Questions.
No, if you look at most outdoor condensing units, they use a cheap relay that only switches one side of the split phase power system, so common is connected to one leg of the 240VAC, and the other leg is switched through the relay contact. Either one of these legs is 120VAC to neutral or ground. But 240VAC leg to leg (L1, L2). When that relay closes, it applies power to the compressor and fan. The common terminal on the capacitor is connected to one of the legs of the power input, and then other terminals on the capacitor are connected to the start winding of fan and compressor (depending on the capacitor size terminal). The capacitor is in series with the start windings on the fan or compressor. Note that the common terminal on the capacitor is not connected to the common terminal of the fan or compressor motor. They are connected to opposite legs of the power. Common here means the point where the parallel connection is made from either L1 or L2. For the motor, that's the common connection to the run and start winding, for the capacitor, that's the common connection that gets connected to the start windings of each motor. Hope this makes sense. Do a google search on "simple wire diagram for outdoor condensing unit", and look at the diagrams.
@@f.hababorbitz “For the capacitor, that’s the common connection that gets connected to the START winding of each motor.” When it comes to the capacitor common connection, I thought it is connected to the RUN connection of each motor? Thank you for the help.
You really need a meter that can test capacitors to make sure its good, but symptoms of going bad are physically bulging, or the motor taking longer to get up to speed.
You said it! And to add... +-10% is clearly labeled on the loads and capacitors. This is due to voltage spikes from different demographics from the power company. Also... A motor such as the one in the video, is aged. Very aged. A larger capacitor will allow it to give up what ever useful work it has left to give. Something like a hard start kit to a gremlin compressor. Schools did teach this. It was part of the basics of electricity and then the basics of electronics. The fact is, that today, schools have abridged the curriculum in favor of class size numbers. This is why the hire and fire rate is outstanding! For all the video is worth, the above should have been included. Lastly... If the technician wanted to be a good one.. and the client was proactive with the financial resources to be... The technician should have replaced the motor and capacitor. Because, the trip to the supply house would be once and done. But, many new techs... 15 years or less, are told to create more work. This too is a fact. Shame on the mess.
Did not see or hear the logic behind the title indicated ---"Does a CAPACITOR Control Electrical Current to the Motor?" as you demonstrated the laboratory work which is good but incomplete. From the title, I take it you are talking in terms of coulombs? But I feel you are looking realistically at "resonance" with respect to the applied frequency to enable the rotating frequency. Let's not forget the other characteristics of BEMF and mutual inductance which influence the outcome.
The caps doesn't control the current...it's a battery that assists the current when the voltage cycle starts going back to zero. It provides the extra push or voltage needed for the motor to continue turning. Smaller cap = smaller push and the motor still needs a push from somewhere so it gets it from the lower voltage times the current needed. Thus the heat from the higher current. E x I = Power or Wok needing to be done. Just replace with the same size cap from the factory and it'll be fine. A larger cap will just have voltage leftover after discharging what the motor needs.
When u are on the field with 8 hrs to do 16 calls u ll figure this quick. Remember AC co are high paced ..field situations are like this. U on the 10 stories Roof...u only 7.5 mfd. U need 4 mfd. Truck is parked 3 or 4 blocks away. 93 degrees plus 10 in roofs...now What would u do or would u procede....time is money specially when u are in Miami area..parking here is 10 to 13 an hour😏.
If you can look yourself in the mirror and not look away in shame, that's on you. You're making a quick fix that will only lead to problems later. Do it right or don't do it at all. Half assed is never acceptable no matter how you can justify it.
The size of the capacitor to the fan motor have to be the exact capacitor as written in the fan motor, if not your motor will overheat and will eventually will overheat and burn. Great explanation, i am a licensed retired 68 yo HVAC, still working to pay my bills. I love this young man way of explaining his videos. It doesn't matter how long i been in this trade, we never stop learning.
No one I work with cares about details like this, I love this stuff, and this channel, keep it up!
Wish I had seen this before when I was younger. I changed a Copeland compressor with a Bristol compressor for a friend of mine since the Bristol compressor was cheaper and he didn't have much money. I think they have since gone out of business. I installed compressor and had correct capacitor for it but I kept getting a higher start winding current than the run winding. Capacitor checked out ok. I ohmmed windings and start winding had higher resistance. It just didn't make sense that run winding was pulling lower amperage. I called Bristol tech support and they asked if amperage was within specifications on compressor. I told them all the readings I had and that I triple checked everything. Even changed capacitors a couple times. I checked charge also to make sure nothing off there. Voltage was within range and guy on tech support said they don't really check the start winding amperage at the factory and everything seemed fine to him. I told my buddy I didn't feel good about it but he had a year warranty. It lasted 10 months and burnt up. Changed it for a Copeland because I didn't trust the Bristol compressor (supply house just charged me difference between Copeland and Bristol cost) and it ran fine and within normal amperage for both run and start. Copeland compressor was still running years later. It was oddest thing I had come across.
Great video. I've had coworkers tell me that you can put in a different size capacitor for the compressor or fan and I've always said that I go back with what's supposed to be there. They'd laugh at me an call me a "by the book" guy but I wear that label with pride. What happens when someone puts in the wrong size and another guy comes in and changes it. If each guy bumps up the mfd by 5 then we aren't anywhere close to what was originally there. Is the second guy going to look at the rating on the compressor and the fan motor? I wouldn't bet a penny on it! If you do it "by the book" then you don't have to worry about burning up motors or compressors.
TO BE FAIR, the compressor has more "wiggle" room with it.
I do the same thing, if i see a "non-manufacturer from install" capacitor on a system i'll look at the compressor capacitor rating and put that one on.
BUT, compressors can easily handle the "50mfd and use 55mfd" swap as the numbers are way more forgiving than the outdoor fan motors' "5mfd to 7.5mfd."
I 100% agree you should put what it calls for, but just wanna point out on compressors the small changes from 45 to 50, 60 to 65, or 65 to 70, etc on those higher ends arent a big deal at all and I'll do it in a heart beat if I just don't have the 60 when it calls for that and i'll use a 65.
What I can't stand is when I hear a fellow service tech mention they put a 80 on a 65, etc because THAT is very bad.
keep doing it right though my guy
EDIT: never put on a lower number though. that's a hands down rule i've learned, even hearing it from the techs that put on those atrocities.
@@Wilsontrax I agree about the difference between the fan and compressor. The difference in percentage on the fan vs. the compressor is much greater but I'm a stickler for correct. I've heard it said that an increase in the mfd on a compressor is the equivalent of leaving the key turned in the start position while starting your car.and it's already started. I just sleep better knowing that I've done it properly. There's so many times I've seen the results of lazy, rigging and not knowing or caring work that I can't bring myself to do it. Once you start cutting corners, where do you draw the line? Be safe.
@@bill944 Haha no I agree. Line is drawn at 5mfd difference (UP!) and ONLY if I don't have the correct match on my van. But that's only me-- I know there are terrible people out there that don't care/don't know
I do agree with you though and you be safe my guy. Stay true! :)
@@Wilsontrax No , Just Put the Right One In, He Clearly Stated The Problem With Changing The Size Thats how it Should be Done . That Is More Than FAIR It's The TRUTH .Keeping a Couple Rescue Capacitors Are Well Worth The Extra Cost .
@@Gcanno I keep 5 of every size basically imagined on my truck. sometimes that doesn't cut it. :) have a good day
Another fantastic video ! Great theory / demonstration of everyday field conditions .
HVAC Knowledge is off the charts !
Thanks for the comparison graphic at the end. Great video to refer to when coworkers want to act like it's okay to install the wrong size lol
Excellent video! I wish schools teach new techs this way.
Another fantastic video. It is all about the percentage of being correct with the capacitors. They need to be within 10% of nameplate (using a 55 in place of a 50 is at the limit of that, and acceptable but using 7.5 in place of a 5 is way off (50%) and not at all).
The run capacitor on a PSC motor is selected to give the best power factor at the design load for the motor. Increase or lower the capacitance, at the same design load, the motor is less efficient and the difference ends up as heat that will eventually burn the windings.
It is possible to use a meter with power factor to swap in caps till you find the best power factor value. But easier to read the label or contact the mfr.
I believe there is a way to calculate a new capacitance value if you were to say use a PSC motor for an application with a different operating load, but it gets down into the motor design black magic.
Great video, Craig. My company has a tendency of going a size larger in a pinch but I won't do that anymore. I'll just stay on top of my inventory and make sure to have a 440V capacitor to be safe.
A friend of mine is a motor rebuilder, and accidentally plugged a 220v motor in to 110v, and couldn't get it to come up to speed. He asked me what I thought might be wrong. I wasn't sure, but He was using a higher mfd capacitor than the motor needed to get it to run faster. I began by reading the label and then realized he had it under powered. The motor was dutch made, so I was aware that in all likelihood, they didn't have any 110v motors. After changing the capacitor, and plugging it into 220, he was able to get it up to speed.
Go to Amrad and get the right capacitor Made in USA and the quality is second to none, Just get one and lift it.. its 2 times heavier and the construction /oil is superior
Thanks for this explanation because I didn’t know about capacitors before this video. The only thing that I knew was that they can store a fatal amount of current. I guess that is true?
The largest determining factor for the lethality of a capacitor is voltage. Anything above 40 volts DC or AC RMS is considered potentially fatal. For HVAC units, all will be above this voltage. The next largest contributing factor is the path the current takes throughout your body. Aside from arc flash situations, after those two, every other factor, including available current is pretty much irrelevant.
Nice demo and explanation ... Thx for posting ...
Excellent display of the issue. Thank you for the practical education.
Thank you, Sir! You learn people a lot. Listening to you! Fixed my problem. Thank you for your Info
This video is 100% correct. I have made the mistake of not double checking the existing capacitor and burned up a new motor in under 15 minutes! I will never make that mistake again.
Thank you Craig
Very interesting and valuable! Thanks.
Needed a separate video on the effect of having a run capacitor fail on a outside unit that had a hard start installed.
Hell ya
Yes indeed ran into that today
@@KyleWithStyle7 Did hard start get the compressor to run? I was wondering if it did what damage to the start winding it could do if not noticed right away.
@@KyleWithStyle7 What did the compressor behave like?
@@officerkrupke4966 it was running normal after replacing the cap, pulling normal amps. 2021 m#… 🤦♂️system was running like that for who knows how long
Very good explanation. Makes sense for both higher and lower capacitor
Thanks for sharing
A good practical channel ... thanks.
Excellently explained 👍
Great job, thank you brother. You are so talented
80% agreed ...
What about the other 20
What’s the 20 % you don’t agree with?
Great job & a great video explaining cause & effect.
That answered a question I have wondered about.
I always knew the capacitor was required to adequately charge the starter winding. I just now learned that the replacement capacitor needs to match the factory specifications for optimal running and potentially preventing destructive heating.
Great video, thanks for sharing.
Thank you for slowing down!
Look forward to seeing you at Kalos
I will be there, sounds good!!!
Dear sir this is good information.however most technician who doesn't know capillary tube restrictions and what is set pressure . could please let me know or post video . 🙏
TY! Nice vid. Was wondering, if you don't know what size cap you need for a motor, how could you calculate what size is most appropriate for any motor?
Don't hold your breathe on getting an answer from him 🤣
I'd love to see him post a video on that because I'm guessing that's way above his pay grade because that involves electrical engineering.
I don't know the answer to your specific question but if I'm not sure what size capacitor is needed I'll use the Copeland Mobile app for Copeland compressors ,and will look up model and serial for fan motor cap or check on rating sticker on motor.
Not sure there is a calculation for us in the field, but if you have a meter that will read power factor, you can swap caps till you get the best power factor reading…I’m guessing, since I’ve not done it!
@@marconantel7735 Thanks Marco.
Looks like my notifications was turned off.
I guess what perplexes me is what is the amp draw tolerance that brought / brings you to the conclusion anything will overheat...
Yup,Yes Sir🧐, Thanks 👌🏻🙌🏻😎.
Great information…Thanks a million !!!
Are you sure your multimeter is able to properly measure amps with the likely phase shift in voltage and current? The power factor shift of induction motors can be significant. So your calculations of kw could actually be kva (reactive power).
A EE would say that a capacitor controls voltage, not current. But of course, Ohm's Law says that if the load resistance (motor windings) is constant than current changes proportionally with voltage !
The important thing to remember is, a fully discharged capacitor "looks like" a dead short and will draw a HUGE amount of current for a fraction of a second as it charges up. Generators and inverters don't like this. Any "true" soft starter must LIMIT this instantaneous current draw so the capacitor charges slower. Yes, the compressor and fan motors will take a split second longer to start up.
When a lot of these hacks come out they want to just put anything into replace it the problem is the next guy comes along and has no real idea what belonged in it and the saga continues yes I had that happen to me they tried it I overwrote it went down the supply house and got the right part problem solved the right way Godspeed
Wow! This is weird. I'm William Brown also and the reply that you made sounds like my own statements since I've been in the HVAC business. Hacks are a dime a dozen and they give ALL of us a bad reputation. Takes a little effort to do it right but I sleep well at night.
@@bill944 too funny when I was a kid I went to school with three other William Brown's then I was in the Navy with a couple some of them were black and some of them were white it's a very common name most of the black rounds that I know her name Willie they were so funny Willie and Billy that was me and my black friends Aunt Jemima used to laugh her ass off till they took her off the syrup now I don't have any more syrup no more silly willy let's go Brandon F Joe Biden God bless you and your family good friend
@@WilliamBrown-dw3fz Yep. When I was in high school there were two other William Browns. I was constantly called to the principal's office being asked "why haven't you been in on campus isolation?" I'd say "you're looking for the other William E. Brown, the preacher's kid". Too funny. Take care.
great work
What happens if you oversized the capacitor rating for the compressor?
Same than the motor. The difference ends up as heat that will eventually burn the windings.
Thank you for all the valuable Great Videos I wish you all the best
I have a question regarding the UEI clamp meter, I see it can read Amps and Volts at the same time.
Is that a special feature for the UEI Clamp meter ?
I Have Testo 770-3 clamp meter.
Please can you Detail us about the UEI .
Thank you
thanks for your tutorial sir👍👍👍👍
Thanks.
Another great video thank you very much
if you're a hvac tech and can't change capacitor, you might want to consider a different line of work.
Excellent video
Same thing with a microwave oven high voltage cap, a higher rated cap will over drive the magnetron and it will burn and overheat.
Good demonstration. I enjoyed it. Question, shouldnt there be 0 amps on the start winding after the motor is running full speed.
No because the start winding stays in circuit all the time with a PSC motor and the run capacitor is what creates the 90 degree phase shift where the voltage lags the current which is what creates a rotating magnetic field for the rotor to chase around 😉
Since the capacitor causes the voltage to lag the current, the vector diagram will visually show why the back EMF is greater in value than the input source voltage.
Also, the start winding has a higher reactance than the run winding hence most of your current will want to pass through the run winding instead.
The start winding is wired in PARALLEL with the run winding and the capacitor is in series with the start winding. The start capacitor, assuming it has one, is wired in parallel with the run capacitor to increase starting torque and then is disengaged via a potential relay for HVAC units.
Parallel capacitors ---> C(total) = C1 + C2
Series capacitors ---> C(total) = 1/C1 + 1/C2
Hopefully that answers your question.
@@weavercattlecompany Yes it does. Thanks for the thorough explanation. I remember that now from school.
Thus might sound crazy but I've heard several technicians that you could go up 10% higher on run capacitor on the compressor? I'm assuming that is not true.
I believe they may be referring to VOLTAGE but not the required mfd.
You can replace a capacitor with one having a higher operating voltage.
But as Chris said the mfd must be correct.
I've seen on videos that almost anything can be higher voltage rating (not fuses).
@@d.c.hammond130 You are getting confused, big no-no to put higher CURRENT rated fuses in, but higher VOLTAGE rated wont change they way they operate (for fuses or capacitors). Putting a lower current rated fuse in is safe, but can cause nuisance trips, but putting a lower voltage rated component in could cause it to fail.
The need start capacitors is why I prefer 3-phase motors that don't need them. All you need to check is the direction of rotation.
What if the rating plate is gone in the compressor and can’t find the unit number?
Is using a 5 mfd on fan/blower instead of a 4 mfd (because who the heck has a 4 on them) a major deal ?
We do all the time on the field
Well he showed what happens in his video.
Understand you can’t play with the absolute laws of electricity and HOPE it will be ok.
The miter and or the new capacitor are going to fail sooner or later.
The question is: Are we “hacks” or professionals?
Our salaries are dependent on people being able to trust us. When the customers believe we are all “hacks” they will just go with the lowest price option because they see no value in spending any more money. ( please save your corrections, I know there are cheapskates out there who always go by price) that’s not what I’m saying here.
@@renecuevas4128 Don't say "we". Speak for yourself because I'll have no part in hackery. I carry 3, 4, and 5 mfd on the van. If you don't prepare for success, you've prepared for failure. YOU are the cause of the apprehension and the lack of trust that I deal with in customers.
good information
Hard to find information. Thank you.
Glad it was helpful!
as always great demo
It seems to me that the nameplate capacitor rating is the value that will closely balance the currents between the running winding and the starting winding. What are the components of the “2650” constant in your formula?
Have a 4 ton house AC system a tech is telling it has a bad secondary motor control valve. I’m not seeing any videos on this. Could you please direct me?
Good video. What is "herm" in capacitor?
Thanks.
I can’t find the one I need I found one that’s .5uf more
Mines is 50/12uf 5% 270v
Found one that is 50/12.5uf 6% 370-440v will it work
What about if u add a kick start to ease inrush on compressor
It’s a good thing they make the data plates with invisible ink instead of stamping them into the motor.
So whatever the Amps is multiply by 2650 devided by the voltage that’s is the size of the capacitor MUST take !? Anybody help!?
The capacitor on my indoor air handler unit keeps burning out. The 1st failure I had replaced by my HVAC company- happened when the system was 8 years old. A year later it died and I replaced that one myself, and today, a year after that, it's dead again! Obviously there's no compressor on this, just the fan motor. I don't have the original capacitor, just the one my HVAC company (that I use for oil burner cleaning) replaced (for $350!) I replaced that one with one of the same rating- 10 uF 10 MFD 370V/440V. What do I need to look at at on the fan motor to determine if this is the correct size capacitor? Many thanks!
Prizm inverter ac unit beeping once the power bottom is pressed from the Universal remote nothing is happening to the unit no lights nothing what could cause this??
I just bought brand new dual capacitor 40/12.5uf +/- 6% 440v, but im getting a reading of 42 uf when I test the herm and common terminals. Do you think the cap is defective ? Thanks
Reread what you just typed out about what it says on the capacitor and then you’ll find your answer. Diagnosing skills also come from learning to read the fine print
What you are measuring is because of the +/- 6%. 40 + 6% = 42.4, 40 - 6% = 37.6,. So on that cap, you might see anywhere from 38 to 42 uf
No. Check ur meter battery first
Hey Craig, do you have any opinion of the EASYSTART soft starters I see for the AC units?
Is that fan motor a split phase motor?
Nice
will the current always be balanced with the correct capacitor, or will it sometimes be designed to have more current in the run windings? I'm thinking that some motors (especially those made to run in either direction) will have windings the same resistance but others wont
The fan terminal (watched a second time) is connected and the common terminal is connected. Does the common go to ONE SIDE of the CONTACTOR for 120 volts! If so which side? Which terminal on the FAN does the fan wire connect to? A Lot Of Questions.
No, if you look at most outdoor condensing units, they use a cheap relay that only switches one side of the split phase power system, so common is connected to one leg of the 240VAC, and the other leg is switched through the relay contact. Either one of these legs is 120VAC to neutral or ground. But 240VAC leg to leg (L1, L2). When that relay closes, it applies power to the compressor and fan. The common terminal on the capacitor is connected to one of the legs of the power input, and then other terminals on the capacitor are connected to the start winding of fan and compressor (depending on the capacitor size terminal). The capacitor is in series with the start windings on the fan or compressor. Note that the common terminal on the capacitor is not connected to the common terminal of the fan or compressor motor. They are connected to opposite legs of the power. Common here means the point where the parallel connection is made from either L1 or L2. For the motor, that's the common connection to the run and start winding, for the capacitor, that's the common connection that gets connected to the start windings of each motor. Hope this makes sense. Do a google search on "simple wire diagram for outdoor condensing unit", and look at the diagrams.
@@f.hababorbitz “For the capacitor, that’s the common connection that gets connected to the START winding of each motor.”
When it comes to the capacitor common connection, I thought it is connected to
the RUN connection of each motor? Thank you for the help.
Using the wrong capacitor can send you to the wrong year and time
Most capacitor burn out due on and off too much the comp and control by thermomstate too much on and off without time delay
For a layman, how do you know when a capacitor goes bad. Also I noticed on my capacitor the top is bulging.
From other videos, bulging means going bad.
You really need a meter that can test capacitors to make sure its good, but symptoms of going bad are physically bulging, or the motor taking longer to get up to speed.
sorry to ask those 5% or 6% makes difference all other information matches
Is it correct that as long as the Capacitances are correct you can replace a 370 volt with a 370/440?
Yes.
Fuckn GENIUS. thank u❤❤❤
👍
capacitors don't change current.
they change phase split thus affecting rpm
torque and amp draw.
You said it! And to add... +-10% is clearly labeled on the loads and capacitors. This is due to voltage spikes from different demographics from the power company. Also... A motor such as the one in the video, is aged. Very aged. A larger capacitor will allow it to give up what ever useful work it has left to give. Something like a hard start kit to a gremlin compressor.
Schools did teach this. It was part of the basics of electricity and then the basics of electronics.
The fact is, that today, schools have abridged the curriculum in favor of class size numbers. This is why the hire and fire rate is outstanding!
For all the video is worth, the above should have been included.
Lastly... If the technician wanted to be a good one.. and the client was proactive with the financial resources to be... The technician should have replaced the motor and capacitor. Because, the trip to the supply house would be once and done. But, many new techs... 15 years or less, are told to create more work. This too is a fact. Shame on the mess.
How to know what capacitor to use if the motor name plate don't have rated capacitor reading?
You will have a over heated fan motor that will go out intermittently and eventually dying
Did not see or hear the logic behind the title indicated ---"Does a CAPACITOR Control Electrical Current to the Motor?" as you demonstrated the laboratory work which is good but incomplete. From the title, I take it you are talking in terms of coulombs? But I feel you are looking realistically at "resonance" with respect to the applied frequency to enable the rotating frequency. Let's not forget the other characteristics of BEMF and mutual inductance which influence the outcome.
The caps doesn't control the current...it's a battery that assists the current when the voltage cycle starts going back to zero. It provides the extra push or voltage needed for the motor to continue turning. Smaller cap = smaller push and the motor still needs a push from somewhere so it gets it from the lower voltage times the current needed. Thus the heat from the higher current. E x I = Power or Wok needing to be done. Just replace with the same size cap from the factory and it'll be fine. A larger cap will just have voltage leftover after discharging what the motor needs.
When u are on the field with 8 hrs to do 16 calls u ll figure this quick. Remember AC co are high paced ..field situations are like this. U on the 10 stories Roof...u only 7.5 mfd. U need 4 mfd. Truck is parked 3 or 4 blocks away. 93 degrees plus 10 in roofs...now What would u do or would u procede....time is money specially when u are in Miami area..parking here is 10 to 13 an hour😏.
That depends on your professionalism.
If you can look yourself in the mirror and not look away in shame, that's on you. You're making a quick fix that will only lead to problems later. Do it right or don't do it at all. Half assed is never acceptable no matter how you can justify it.
I cringed every time you said “start winding”.