This is one of the best UTube videos I've seen. You explained the capacitors & their uses very well PLUS you blew one up for everybody to see how they fail. Yeah
Very well done! All tutorials should be this easy to understand. I have absolutely no doubt now how to identify a running or start capacitor or how they shouldn't be used. Thank you!
"IF" the clock on the back wall was accurate, you did this in one take. Until you started blowing stuff up, you just kept rolling without a bleep or hiccup. Sometimes people aren't just watching what you do, but how you get it done as well. Very good on both counts. Congratulations.
I can’t tell you how many capacitor videos I’ve watched. This video gave it to you in layman‘s terms it shows you a start capacitor had to run capacitor and how they work. Very good.
Some capacitors are 1000+ mfd, though many have low capacitance ranges as well. In your case, you could easily use a run cap in place of a start cap. Some capacitors are built with a "Pressure Sensitive Interrupter" design that causes them to fail before internal pressures can cause serious injury. The one we showed is designed so that the top of the capacitor expands and breaks internal wiring.
Great video but one thing to note.... When recording the video I think you had the sound levels volume to high for your microphone., that is why the volume is kind of popping up on a lot of you words. thanks.
Your video on differences between run and start capacitors is very good. What you did not mention is the larger capacitance will deliver a certain current for a LONGER (time) as required. One can obtain the same current level with a small capacitance but the time constant is much shorter, and this will not work! In reality, current delivered by a capacitor is determined by I=V/R. Remember there is a time constant! For example a voltage of 100 volts across a capacitor with a 1 ohm resistor across capacitor will deliver 100 amperes (time constant not taken into account,) Capacitors can more or less be inspected on performance by using an ohm meter on the megohm scale, across a discharged capacitor. Reading should be in the megohm or higher, Basically an open circuit. For quality, apply the operating DC voltage across the cap. to charge. Then install a DC Ma meter to view current flow into the capacitor. This determines the number of DC ohms of this capacitor, ( ohms =V/I ) and shows the power factor. The higher the Ma flow into this capacitor, the worse this capacitor is or is rising to 1, power factor. Power factor is PF = R/Z. It should be 0, or almost no current flow indicates a good capacitor! (R is extremely high.). FYI, there should be no heat detected at any time. To increase capacitor life, add parallel capacitors at the same voltage but adding to required capacitance only , not over. For example a 100 uf cap. can be split twice of 2 x 50 uf or more. Splitting the current demanded by the motor capacitor is always easier on a cap. when multi units are in parallel, and this results in added capacitor life! You might need hundreds of amperes for starting and the small R of the capacitor adds up when delivering lots of amperes, resulting in heat in the capacitor, a no, no.
Great Video!!! thanks for explaining the two different types. I know nothing about them. Installed a start capacitor in a run setup by mistake and it blew up right away hahaha. Now I know that it needs a run capacitor to work. Thanks again, saved me from buying a new motor for the bandsaw
I have an older AC motor that is 240v and runs two capacitors. I went to fire it up and one of the capacitors smoked up. The other one was entirely cool and I noticed it doesn't seem to have any juice in it. The smokey one was spraying heck all over the place. My suspicion was that one capacitor went bad and it wasn't able to get up to speed and thus the centrifugal switches weren't able to kick in and it smoked the other one. Does that make sense or am I completely off the mark. Also for replacing these would I need 120v capacitors since it's one capacitor on each 120v circuit or would I need two 240v capacitors? Mine also don't have the bleed down resistor on them, not sure if that's necessary for the newer ones or not. It's an old saw from the 20s but the motor is definitely newer. Stumbled across these videos from your ebay auctions. Figured I'd see what you guys have to say on it.
Great video. If the centrifugal switch is not releasing would this cause for the motor to draw higher current. My motor runs approximately 3amp without load and about 4-6 amp with load. I have found when the switch is not opening the current jumps to 22amps. The problem was a dead capacitor which I feel was the cause from the centrifugal switch not releasing when motor on. I find that the switch only doesn't release when the load is on the motor soon as I put some load after turning the motor on and off eventually the switch doesn’t release and the current jumps higher. The switch looks clean and no damage. Any help to diagnose is appreciated. Cheers
The switch should open just before the motor reaches full speed. Off the top of my head, here are a few common causes: Loose connection. Voltage falling off from undersized or too long supply cables. Bad motor bearings causing increased startup drag. Soot at the point of contact on the switch contacts (look for a small black spot) if yes, clean with file or sandpaper.
Good Video. Very well done. In your demonstration are you just throwing raw AC power across the caps with out any type of a buffer in the circuit? Thanks.
Great video! One question: You mentioned that run capacitors have a 100% duty cycle so they can remain in the circuit. I want to use these capacitors for a pf correction project on an induction motor, but as my pf will be changing, i need to provide nearly constant switching in which the caps are introduced and taken out of the circuit. Is this safe to do for run caps, or should i use a different type of capacitor? Thank you in advance!
Judging from the capacitance, it appears to be a start capacitor. Start capacitors typically have a range of capacitances, while run capacitors give a single number. The values on start caps also tend to be higher than those on run caps.
Awesome video! Thanks alot for taking the time to make this! Funny the background behind you, because this is exactly the info i needed to complete my RPC and get my shop back online!! Thanks again! Awesome!
Is it a good idea to install a start capacitor if compressor run capacitor keeps blowing? Could this keep the unit working for a while until it can be replaced?
How do you know what size compasotor to replace the compasotors with if there's no label or writing on the old compasotors and there's 3 compasotors on this air compressor and how do I find out what one is the start and run on this compressor?
Hi and thank you for your help. I was going to take the motor apart but thought an easier test. I snipped off one of the cap wires then turned on the small band saw. The motor just hummed so I quickly turned the motor but it would not start. I then reconnected the cap, turned the motor on and it ran. While it was running, I removed the jumper from the cap and the motor slowed down a bit. So I think this is a run cap. Have I diagnosed this correctly? Thank you.
I'm impressed and I don't know anything. I am experimenting with running an AC 230volt washing machine motor on DC 12volts and upwards. I am pleased with the results. However I need more start torque. Can I achieve this with capacitors and if so how do I go about it. Many thanks for the video. I learnt something I did not know today.
I wanted to know the power supply voltage you were using we understood it was AC but is that a 120 plug that you hooks to the capacitors directly I want to know it's capability can you put a wall outlet directly to one of those running capacitors?
My AC went out. My intent was to do the electrical checks, but it started out with a dead mouse on top of the capacitor. I cleaned all the debris, then did the checks for the compressor which was fine as was the relay and controller voltage, leaving the capacitor. I couldn't find any shorts on the capacitor but it is the last item to prove out. It did have a bulge on the top. So I ordered it. I get it tomorrow. Question: was it the mouse that may have cause the capacitor to fail?
Run caps could be use for PF correction. It would be important to be sure that the caps that are out of the circuit at any given time are drained before being reintroduced to the circuit.
I have a 240v 3 phase 7.5hp 5.5kw induction motor for a heavy duty mixer and would like to run it on single phase as i do not have 3phase connection at my location. will i be able to convert it to single phase with cap or i wont get the amount speed from the motor?
I have a 110v compressor that killed the start cap i took it apart 4 yrs ago and i dont know which windings are start or run can i determine which is which with an ohmeter and what would those readings be thanks
Is the voltage spec on a Start (or Run) cap an absolute value? In other words, will a 250v rated cap work ok in a 110v circuit, given the µF is correct ?
What we wanted to illustrate with the exploding start cap was that you can't use it as a run cap. Run capacitors do not come with high capacitance ratings as most start capacitors. You'll rarely find run caps larger than 150 mfd. Capacitance ratings for start caps, on the other hand, can go as high as 1200 mfd or more. Like we mentioned in the video, while you could use a bunch of run caps in place of a start capacitors to get up to the required mfd rating, you'd need adequate mounting space.
Have an old Craftsmen 3/4 HP motor. Obsolete parts. It has a capacitor mounted on top. I have to say its a start. Not sure. Its dual voltage. Old cap was 233-280. Old cap part # was 37211 no info available any more. Not sure if that was correct replacement. Having problem finding any information on this saw motor. Old model Craftsman model is 113-12060. Some blogs say it was an old Emerson motor made for Sears. Old cap was shot. Just want to make sure I insert correct size. This was my dads saw , trying to restore it. Any help appreciated.
Just make sure that the new capacitor: 1. Capacitance is roughly the same: 233-280uf 2. Voltage is same or higher than you are powering your machine with. If you are using 120volts. Cap should be at least 120 volt rated. Higher is ok. 3. The new capacitor will fit in the can on top of your motor. Smaller is ok. Outside of that, you should be good to go! Good luck!
Hi I have a small 10" Delta Bandsaw. The capacitor in the motor is a CBB60 SH (16uF 250V). It looks like a starting cap (Black Case) but has low cap value to suggest it is a running cap. The cap is located in the case screwed onto the motor. The motor is a 110V 2.7A. How do I know if this is a running cap or a starting cap. I hope it is a running cap because i want to install a speed control. Any help appreciated.
I always do this, thinking for some reason is still charged before measurin with the multmeter. But i didnt know these capacitor were able to hold DC Voltage when they say is AC voltage. In any case, after a lot of years this is the only method i used. Of course, if is charged and you dont know it prepare for a little spark.
How do I find what value start capacitor to use to replace an unmarked one? The motor is 230vac, 12A, 2hp, 1ph. I can not find any info for the 40 year old motor.
I have a 220 VAC sanding machine motor, replaced Now starts slow and take time to gradually get to proper speed (around 5-8 sec). Is it the wrong replacement mtor or starting capacitor? Should I increase the capacitance? Appreciate your help.
hi im curious i have a shakey fan blade on my ac unit , i had the motor and the capasitator replaced this morninig and now the AC fan blade shakes the whole unit a smidge, will that kill the motor on the AC fan unit?
You said a capacitor should be about 1.5 times the supplied voltage. I had a pump that ran on 120 volts but the capacitor said 300VAC. Does the hp of the motor matter for the necessary VAC ? There are no markings on it but I think this motor is around 1/2 hp. Question 1) Was that capacitor VAC bigger than necessary ? (1.5 x 120v = 180) I messed up and let it run after it pumped out all the water. Once I unplugged it, it would no longer start or run unless I spun the impeller by hand, then it worked fine. Question 2) Can you clarify and explain to me if it was a start or a run capacitor, or combination ? It says only 8 micro farads, so I guess maybe that makes it a run capacitor. So then I guess sometimes a run capacitor is all that's needed to get the motor 'to start' ???? Because...why ?
I have a 2002 Fleetwood Bounder 32' rv. One of the rooftop (Coleman Mach) air conditioners stopped throwing cold air because after getting up there to check it, there was oil everywhere on the wires and it smelled from the wire casing melting. Is it safe to just replace the hard start capacitor, or should I replace all 3. (There is a bundle of 3 there). Thank you for any thoughts and/or responses. (Roger)
I do understand the main differences between a run capacitor and a start capacitor and their purposes but what I don't understand is why did replacing the 5uF run capacitor on my spa circ pump motor fix its problem of not starting?
Hi will a microwave capacitor 1.1uf 2100vac 50/60hz can be charged by 12 volt battery ? Can it be used to between the battery bank and inverter to not let the battery bank take the brunt of electric initial draw. Saving battery. ?
Thats all good, but how to identify a run verses start cap. Say you have and you don't know where it came from, how do you tell if it is a run or a start by just looking at the cap.
can u help me find these videos on how to test a DC motor, slipring motor and a single phase motor..its for my trade test that am writing monday..Or explain to me how to do these test
I need a lil help.. I am trying to get a pool pump motor to run off of my dc to ac inverter and just hums and then the inverter shuts down. I think if I add a start run capacitor to the circuit it should work fine. I am hoping .. it’s a 120 volt 12 amp 60 hrtz motor. Which start/run capacitor do you recommend. I am thinking a CBB 65 will work. But don’t want to blow the motor.. any suggestions ?
Both original and replacement run capacitor are same 12.5 MFD 440/370 VAC but new replaced blower motor has 7.5 MFD listed . Still good ? Seems fine , it working
@TEMCo Industrial Power My start up capacitor on my compressor is only 31.5uF at 400v (2 terminal) if i buy a much bigger uF rating ie (400uF) would it make my compressor start easier. Mine at present doesn't always start up every time, sometimes it buzzes upon start up and freezes,if i spin the motor by hand it will start up, is my start up capacitor faulty and would it cause these start up problems??
I have a 10hp 230v three phase air compressor I am wanting to run on 230v single phase what start capacitor and run capacitors would you recommend to generate the third field?
I was looking at Baldor 6" Bench Grinders. They have approx. 14 different models! One of the descriptions says: Built for heavy duty grinding, powered by 1/3 hp Baldor PSC type motor (except 612E & 662E which are split phase) What would be better for that type of bench grinder, a (PSC) Permanent Split Capacitor or a Split Phase motor? Is one harder or take longer to start? Do you have to spin the wheels to get it going?
What capacitors should I connect to the 400Watt generator, any suggestion please . I am using capacitors 8 micro farad and as soon as I plug in the light. the power is gon generator is 650 watts
Hey man.. Great video, my motor is humming, I swapped over a capacitor I had in shop, it started motor but cap exploded hahaha after a minute, I will drop a link for my problem, it is a pdf file with all parts listed, I think it is a run capacitor I need, it's the the 66uf 50Hz.. One on the list thanks you my good man
I have a dual run cap (herm, fan, c) that came off a window ac that I want to repurpose. Are all dual run caps running caps (ie will this thing blow up if I hook it up wrong like a start cap will) ? I want to hook it up in parallel with an ac motor to improve the pf. Do I just use the C and fan terminals or X and fan+herm? The specs of the cap are "7.5/40uf 240vac amc-24h07400b hpf ms 10000afc Sam wha... ". But I'll be darned if I can find anything on Google on it. What would the temco replacement part be?
I’m confused about you usage of “duty cycle”. I’ve only been exposed to the term regarding a DC square wave signal at a fixed frequency and duty cycle refers to how much of the wave is “high” vs “low”. Never heard it used discussing AC signals. I would appreciate any feedback.
so the capacitors do not have polarity? my air compressor has similar capacitors like the black run one you have and don't see any signs of showing what side is negative or positive (one blue wire and one white wire).
am using a schultz angle grinder, it has two capacitors, now I have a problem with a big capacitor from it which has some drums inside(capacitor with drums inside), what type of capacitor can I repress it and can a capacitors from a capacitors Bosch grinder work in it ????
Quick question, Im building a AC circuit with an AC motor, and i was planning to use a motor start capacitor. The power supply would not be able to supply the current needed to start the motor, so i was going to use a capacitor to give the motor the higher current surge it needs to start. am i thinking of this correctly? or do caps not supply current surges in AC like they can in DC. Thanks
Start capacitors in an AC motor circuit don't handle surge current like in DC, rather, they delay the AC wave form as it enters into another winding in the motor. This gives you a different phase in the magnetic field to allow the rotor to begin turning.
This is a great video. I have a question about capacitors in parallel, specifically for a well pump. I have not opened my control box yet to see if my well pump controller uses a start capacitor or a run capacitor. Is there any danger in paralleling that capacitor (provided it is the same type) ? I’m in the northeast and we recently had a tornado that left us without power for a week, my generator was struggling with the peak inrush current for our well pump when there were other loads drawing on it at the same time. I wanted to see if I could alleviate some of that stress with an additional capacitor. Any knowledge you have to offer on this would be appreciated. Thanks in advance.
If this is the wrong place/channel for this question, I apologize upfront for not being technical in this area. I have a situation I need help with involving Start-Up and/or Run Capacitor(s). I think..... Situation: When my 6,500 Watt (peak) house back up generator is used to power my home in power outages, my A/C will start slowly and run as the generator slows way down, but the generator recovers after the A/C fully starts up (pump and fans). The A/C will run powered by the generator for whatever time is required for the thermostat setting. The rest of the house circuits can be turned on (Frig, lights, .....) while the A/C is running and all is well and the generator does not sound overloaded or toggle its breaker off. However, once the A/C turns off when the set temperature is achieved, it will not cycle back on without the generator throwing its main 220VAC breaker which shuts everything down. Then, with ALL circuits to the house off (except A/C), and the generator breaker reset, the generator will struggle to restart the A/C and most of the time will throw the 220VAC generator breaker. While during this condition, I can turn on everything/every circuit in the house and the generator will power everything without issue until I try to start the A/C and the cycle repeats. (I know to give the A/C n Generator the best chance to restart is to turn off all the other circuits, my point is to show there is nothing else out of the ordinary while in this condition) I think I need a larger Startup Capacitor for my A/C Condenser (pump and fan). How would I figure out what type/size/capacitance, ......Capacitor to purchase and how would I identify the terminals such that I can swap it out with the existing correctly? Please note: I do not need a lesson in the generator peak/run and house demand (load). I am that technical (for a mechanical guy, but this is Magic Smoke Stuff and so I am in the deep end and barely treading water). For review: 1.) The generator runs the house with no issues with the A/C off. 2.) The generator runs the house with the A/C starting first and the rest of the house load added after the A/C starts the First Time. 3.) The A/C will seldom start the Second Time even if all the house loads are turned off and only the A/C is connected to the generator. 4.) Other than this Second Start (or anything after) failure of the A/C running on the generator, the A/C works flawlessly on-grid power as does the rest of the house. Thank you in advance for any help.
What you are needing to add to your A/C unit is known as a Soft Start capacitor. It reduces inrush capacity needed from your generator upon the startup of the AC's condensing unit, which likely requires a substantial current draw when engaged and until it reaches its normal operating running speed, which likely takes a few seconds. This increased draw happens for large enough of a draw and for long enough that it trips the generators breaker because it overly taxes the generators system to a degree that it would either A; bog it down to a point at which it would stall the engine or B; overload the generating capacity of the core itself and start heating to a degree where the internals could become damaged or fail completely. Just look up "A/C Soft Start Capacitors" or "A/C Soft Start Systems" and there will be a wide array for you to research and choose from. Hope this info helped and good luck with your project
My hvac fan motor runs for about 15 seconds then shuts down. Is that indicative of a bad run capacitor vs a bad start capacitor or did it sound like some other problem altogether? Thanks!
Thanks for the video question got a small 2 amp 120 v motor has drawing on side cap wiring diagram motor has forward and reverse don't know what size cap to install bought one and motor runs in forward but not reverse or sometimes reverse and motor getting hot after it runs like 5 minutes anyways could that have anything to do with he ca
have a single phase century 5 hp 1800 rpm motor, has a 330 volt 408 to 480 mfd cap that blew. it runs with a 220v cap i have in stock, similar mfd range, is that ok to use in an emergency?
I have a 1/6 horsepower 240 volt normal house freezer that is rated at 90 watts, I believe that equates to 124kW motor. I want to help the motor get started/run more efficiently etc. It connects to a 2500 Watts inverter (5000watts surge) though I want to dedicate a much smaller inverter. Can you please suggest what size and type of capacitor I could use and point out where I can get info on clear instructions on installing it? These is NOT already a capacitor in it.
We don't have specific instructions on repairing this, as they can vary depending on motor manufacturers. You might want to just try getting a capacitor of matching values, as they're fairly inexpensive.
i have a 1967 vintage high frequency arc starter that has a leaking mica capacitor inside...is there a modern design capacitor (more effecient) thaT I can use as a replacement?...i think it was 2.0 mfd 5000v 6.amp in a 3in x1 rectangular black box
i have an electric motor but i cannot get it to run. When you turn it on it just hums and does nothing. The odd time it would start but most of the time its just hums. There is a cylinder on the side of it and i think it is a start capacitor but i am not sure. It says 160-200 uf so any idea whether its a run capacitor or a start capacitor?
Can I run a CS Induction Motor for a longer time say a few minutes at low voltage before the Capacitor Switch trips ? Will the start capacitor be able to tolerate low voltage for a longer time ?
Capacitor start induction motors have their speed dictated by frequency, not voltage. So, under-voltaging a CS induction motor will give you reduced torque and increased heating, but the motor will still come up to full speed, thus disengaging the capacitor as normal. At some point in dropping the voltage, the motor won't even produce enough torque to turn, at which point the capacitor will stay engaged, and the motor will burn out. What was your reason for needing to running it at the lower voltage?
I have a 36V forklift with an ailing capacitor rated at 150uf and 250v (250 P.V.W.) The part number on it is FB-887 and it seems to be impossible to find. Would I be able to run an array of smaller run capacitors adding up 150uf?
Replacing a run cap on a bandsaw, the original is a 2 prong and the replacement has the same values but is a 4 pin. If they’re interchangeable does anyone know which pins do I connect to?
Hi I have a air compressor used for painting cars, when its very cold weather the compressor sometimes won't start up. When i pull the red switch up to start it, it buzzes loudly tries to start but doesn't have enough power. If the weather is hot, then most of the time it starts. It has gotten progressively worse at starting now it's about a 50/50 if it's going to fire up or not, when it does start it runs perfect and generates lots of pressure. If i helped the motor along with my hand by spinning the fan blades it does start, sometimes it starts slowly whilst buzzing then gradually build up speed then runs okay after about 10 seconds. Does it sound like the start capacitor at fault? , I do not have a run capacitor on this compressor. Could the start capacitor (faulty) CAUSE ALL THESE ISSUES?
So just to clarify, you can replace a start capacitor with a run capacitor if it has sufficient micro-Farads? For example I have a 8uF start capacitor, I can replace it with a 8uF run capacitor?
hi.. i gota a 1ton AC works on 240v ac. its got 35uf cap for compressor. can i add capacitor bank to reduce amps draw. if so what consequences i have to face. kindly explain.
This is one of the best UTube videos I've seen. You explained the capacitors & their uses very well PLUS you blew one up for everybody to see how they fail. Yeah
Sorry talk very fast with no clear , enough text for explanation
and it's an ad
@@dhidhi1000 uyi
Very well done! All tutorials should be this easy to understand. I have absolutely no doubt now how to identify a running or start capacitor or how they shouldn't be used. Thank you!
"IF" the clock on the back wall was accurate, you did this in one take. Until you started blowing stuff up, you just kept rolling without a bleep or hiccup. Sometimes people aren't just watching what you do, but how you get it done as well. Very good on both counts. Congratulations.
I can’t tell you how many capacitor videos I’ve watched. This video gave it to you in layman‘s terms it shows you a start capacitor had to run capacitor and how they work. Very good.
Some capacitors are 1000+ mfd, though many have low capacitance ranges as well. In your case, you could easily use a run cap in place of a start cap.
Some capacitors are built with a "Pressure Sensitive Interrupter" design that causes them to fail before internal pressures can cause serious injury. The one we showed is designed so that the top of the capacitor expands and breaks internal wiring.
Thanks for the feedback - we'll definitely keep the audio quality in mind for future videos.
Why DC motors does not need these kind of capacitors???
Great video but one thing to note.... When recording the video I think you had the sound levels volume to high for your microphone., that is why the volume is kind of popping up on a lot of you words. thanks.
Your video on differences between run and start capacitors is very good. What you did not mention is the larger capacitance will deliver a certain current for a LONGER (time) as required. One can obtain the same current level with a small capacitance but the time constant is much shorter, and this will not work! In reality, current delivered by a capacitor is determined by I=V/R. Remember there is a time constant! For example a voltage of 100 volts across a capacitor with a 1 ohm resistor across capacitor will deliver 100 amperes (time constant not taken into account,) Capacitors can more or less be inspected on performance by using an ohm meter on the megohm scale, across a discharged capacitor. Reading should be in the megohm or higher, Basically an open circuit. For quality, apply the operating DC voltage across the cap. to charge. Then install a DC Ma meter to view current flow into the capacitor. This determines the number of DC ohms of this capacitor, ( ohms =V/I ) and shows the power factor. The higher the Ma flow into this capacitor, the worse this capacitor is or is rising to 1, power factor. Power factor is PF = R/Z. It should be 0, or almost no current flow indicates a good capacitor! (R is extremely high.). FYI, there should be no heat detected at any time. To increase capacitor life, add parallel capacitors at the same voltage but adding to required capacitance only , not over. For example a 100 uf cap. can be split twice of 2 x 50 uf or more. Splitting the current demanded by the motor capacitor is always easier on a cap. when multi units are in parallel, and this results in added capacitor life! You might need hundreds of amperes for starting and the small R of the capacitor adds up when delivering lots of amperes, resulting in heat in the capacitor, a no, no.
AC capacitors are non-polarity specific, so it doesn't matter which side you connect the wires.
Excellent demonstration. Good info on the differences.
i took hvac class about 8 years ago ,,,thanks for your video ,interesting . love to learn
Great Video!!! thanks for explaining the two different types. I know nothing about them. Installed a start capacitor in a run setup by mistake and it blew up right away hahaha. Now I know that it needs a run capacitor to work. Thanks again, saved me from buying a new motor for the bandsaw
Excellent! Just what I needed to keep from blowing myself up. Got the new "start" cap installed and motor running.
I have an older AC motor that is 240v and runs two capacitors. I went to fire it up and one of the capacitors smoked up. The other one was entirely cool and I noticed it doesn't seem to have any juice in it. The smokey one was spraying heck all over the place.
My suspicion was that one capacitor went bad and it wasn't able to get up to speed and thus the centrifugal switches weren't able to kick in and it smoked the other one. Does that make sense or am I completely off the mark.
Also for replacing these would I need 120v capacitors since it's one capacitor on each 120v circuit or would I need two 240v capacitors? Mine also don't have the bleed down resistor on them, not sure if that's necessary for the newer ones or not. It's an old saw from the 20s but the motor is definitely newer.
Stumbled across these videos from your ebay auctions. Figured I'd see what you guys have to say on it.
Best explanation ive watchd out of 25 vids. Thank u
Okay tell me a bote the run capacitor. How you know the size of capacitor to use on your 3phase motor?
Great video. If the centrifugal switch is not releasing would this cause for the motor to draw higher current. My motor runs approximately 3amp without load and about 4-6 amp with load. I have found when the switch is not opening the current jumps to 22amps. The problem was a dead capacitor which I feel was the cause from the centrifugal switch not releasing when motor on. I find that the switch only doesn't release when the load is on the motor soon as I put some load after turning the motor on and off eventually the switch doesn’t release and the current jumps higher. The switch looks clean and no damage. Any help to diagnose is appreciated. Cheers
The switch should open just before the motor reaches full speed. Off the top of my head, here are a few common causes: Loose connection. Voltage falling off from undersized or too long supply cables. Bad motor bearings causing increased startup drag. Soot at the point of contact on the switch contacts (look for a small black spot) if yes, clean with file or sandpaper.
Good Video. Very well done. In your demonstration are you just throwing raw AC power across the caps with out any type of a buffer in the circuit? Thanks.
Great video! One question: You mentioned that run capacitors have a 100% duty cycle so they can remain in the circuit. I want to use these capacitors for a pf correction project on an induction motor, but as my pf will be changing, i need to provide nearly constant switching in which the caps are introduced and taken out of the circuit. Is this safe to do for run caps, or should i use a different type of capacitor?
Thank you in advance!
Tip ... never use headphones 🎧 in full volume for this video specially starting.
Judging from the capacitance, it appears to be a start capacitor. Start capacitors typically have a range of capacitances, while run capacitors give a single number. The values on start caps also tend to be higher than those on run caps.
Awesome video! Thanks alot for taking the time to make this! Funny the background behind you, because this is exactly the info i needed to complete my RPC and get my shop back online!! Thanks again! Awesome!
Compact and clear yet propper information to get going with, great video which helped me forward
Good day, Sir can Í asked the correct value of capacitor for 10hp motor 3 phase that can run single phase 220vac. Thank you Sir
you have provided me knowledge and one day I will reciprocate by buyimg parts from you. that is how the world should be.
2:41 consider this when considering adding a capacitor to my living room bathroom exhaust blower motor to stop it from getting stuck on start up.
Is it a good idea to install a start capacitor if compressor run capacitor keeps blowing? Could this keep the unit working for a while until it can be replaced?
How do you know what size compasotor to replace the compasotors with if there's no label or writing on the old compasotors and there's 3 compasotors on this air compressor and how do I find out what one is the start and run on this compressor?
Hi and thank you for your help. I was going to take the motor apart but thought an easier test. I snipped off one of the cap wires then turned on the small band saw. The motor just hummed so I quickly turned the motor but it would not start. I then reconnected the cap, turned the motor on and it ran. While it was running, I removed the jumper from the cap and the motor slowed down a bit. So I think this is a run cap. Have I diagnosed this correctly? Thank you.
Can you explain how you are running an AC motor on DC power? This will help us understand more about your set up.
All VFD‘s that run AC motors is actually positive negative DC that mimics ac
This isn't something we specialize in, but you can look up info on power factor correction using capacitors.
Are common and run terminals on single run capacitor interchangeable since there are no markings?
I would like to see the voltage meter readings when you are checking the capacitors in this video. Thank you
I'm impressed and I don't know anything. I am experimenting with running an AC 230volt washing machine motor on DC 12volts and upwards. I am pleased with the results. However I need more start torque. Can I achieve this with capacitors and if so how do I go about it. Many thanks for the video. I learnt something I did not know today.
do you ship to Canada?
I wanted to know the power supply voltage you were using we understood it was AC but is that a 120 plug that you hooks to the capacitors directly I want to know it's capability can you put a wall outlet directly to one of those running capacitors?
My AC went out. My intent was to do the electrical checks, but it started out with a dead mouse on top of the capacitor. I cleaned all the debris, then did the checks for the compressor which was fine as was the relay and controller voltage, leaving the capacitor. I couldn't find any shorts on the capacitor but it is the last item to prove out. It did have a bulge on the top. So I ordered it. I get it tomorrow. Question: was it the mouse that may have cause the capacitor to fail?
Thank for the info sir.how much is prize of running capacitor?
Run caps could be use for PF correction. It would be important to be sure that the caps that are out of the circuit at any given time are drained before being reintroduced to the circuit.
Great video!
What ohm and power is the discharge resistor you used?
I have a 240v 3 phase 7.5hp 5.5kw induction motor for a heavy duty mixer and would like to run it on single phase as i do not have 3phase connection at my location. will i be able to convert it to single phase with cap or i wont get the amount speed from the motor?
I have a 110v compressor that killed the start cap i took it apart 4 yrs ago and i dont know which windings are start or run can i determine which is which with an ohmeter and what would those readings be thanks
Hi there,
I am looking for 6 microfarad x3 capacitor. Could you explain what type 9f capacitor it is? Thanks
Is the voltage spec on a Start (or Run) cap an absolute value?
In other words, will a 250v rated cap work ok in a 110v circuit, given the µF is correct ?
Just what I needed at this moment. Thanks for taking the time to share.
Thanks for the info! Do you sell high voltage pulse capacitors?????
What we wanted to illustrate with the exploding start cap was that you can't use it as a run cap.
Run capacitors do not come with high capacitance ratings as most start capacitors. You'll rarely find run caps larger than 150 mfd. Capacitance ratings for start caps, on the other hand, can go as high as 1200 mfd or more.
Like we mentioned in the video, while you could use a bunch of run caps in place of a start capacitors to get up to the required mfd rating, you'd need adequate mounting space.
What cause that high rating capacitor to burst?
I have a Lakewood floor fan that runs slowly or not at all on low settings.It does not seem to be a lube problem. Any ideas.
Have an old Craftsmen 3/4 HP motor. Obsolete parts. It has a capacitor mounted on top. I have to say its a start. Not sure. Its dual voltage. Old cap was 233-280. Old cap part # was 37211 no info available any more.
Not sure if that was correct replacement. Having problem finding any information on this saw motor.
Old model Craftsman model is 113-12060.
Some blogs say it was an old Emerson motor made for Sears.
Old cap was shot. Just want to make sure I insert correct size.
This was my dads saw , trying to restore it. Any help appreciated.
Just make sure that the new capacitor:
1. Capacitance is roughly the same: 233-280uf
2. Voltage is same or higher than you are powering your machine with. If you are using 120volts. Cap should be at least 120 volt rated. Higher is ok.
3. The new capacitor will fit in the can on top of your motor. Smaller is ok.
Outside of that, you should be good to go! Good luck!
Do you have to change capacitors with exactly the same one or is similar or close capacity ok
Hi I have a small 10" Delta Bandsaw. The capacitor in the motor is a CBB60 SH (16uF 250V). It looks like a starting cap (Black Case) but has low cap value to suggest it is a running cap. The cap is located in the case screwed onto the motor. The motor is a 110V 2.7A. How do I know if this is a running cap or a starting cap. I hope it is a running cap because i want to install a speed control. Any help appreciated.
Do you recommend the screwdriver method for discharging them?
I always do this, thinking for some reason is still charged before measurin with the multmeter. But i didnt know these capacitor were able to hold DC Voltage when they say is AC voltage. In any case, after a lot of years this is the only method i used. Of course, if is charged and you dont know it prepare for a little spark.
How do I find what value start capacitor to use to replace an unmarked one? The motor is 230vac, 12A, 2hp, 1ph. I can not find any info for the 40 year old motor.
I have a 220 VAC sanding machine motor, replaced Now starts slow and take time to gradually get to proper speed (around 5-8 sec). Is it the wrong replacement mtor or starting capacitor? Should I increase the capacitance? Appreciate your help.
You are very well spoken, thanks for the vid!
Matt's Shop was
Alex Bob Network Are you not still well spoken?
An educational promotion; don't see that very often in youtube land - well done :)
hi im curious i have a shakey fan blade on my ac unit , i had the motor and the capasitator replaced this morninig and now the AC fan blade shakes the whole unit a smidge, will that kill the motor on the AC fan unit?
You said a capacitor should be about 1.5 times the supplied voltage.
I had a pump that ran on 120 volts but the capacitor said 300VAC.
Does the hp of the motor matter for the necessary VAC ?
There are no markings on it but I think this motor is around 1/2 hp.
Question 1) Was that capacitor VAC bigger than necessary ? (1.5 x 120v = 180)
I messed up and let it run after it pumped out all the water.
Once I unplugged it, it would no longer start or run unless I spun the impeller by hand, then it worked fine.
Question 2) Can you clarify and explain to me if it was a start or a run capacitor, or combination ?
It says only 8 micro farads, so I guess maybe that makes it a run capacitor.
So then I guess sometimes a run capacitor is all that's needed to get the motor 'to start' ????
Because...why ?
I have a 2002 Fleetwood Bounder 32' rv. One of the rooftop (Coleman Mach) air conditioners stopped throwing cold air because after getting up there to check it, there was oil everywhere on the wires and it smelled from the wire casing melting. Is it safe to just replace the hard start capacitor, or should I replace all 3. (There is a bundle of 3 there). Thank you for any thoughts and/or responses. (Roger)
I do understand the main differences between a run capacitor and a start capacitor and their purposes but what I don't understand is why did replacing the 5uF run capacitor on my spa circ pump motor fix its problem of not starting?
Thank u for the info sir, this is exactly what I need to know for testing a start capacitor.
Hi will a microwave capacitor 1.1uf 2100vac 50/60hz can be charged by 12 volt battery ? Can it be used to between the battery bank and inverter to not let the battery bank take the brunt of electric initial draw. Saving battery. ?
Thats all good, but how to identify a run verses start cap. Say you have and you don't know where it came from, how do you tell if it is a run or a start by just looking at the cap.
can u help me find these videos on how to test a DC motor, slipring motor and a single phase motor..its for my trade test that am writing monday..Or explain to me how to do these test
I need a lil help.. I am trying to get a pool pump motor to run off of my dc to ac inverter and just hums and then the inverter shuts down. I think if I add a start run capacitor to the circuit it should work fine. I am hoping .. it’s a 120 volt 12 amp 60 hrtz motor. Which start/run capacitor do you recommend. I am thinking a CBB 65 will work. But don’t want to blow the motor.. any suggestions ?
Both original and replacement run capacitor are same 12.5 MFD 440/370 VAC but new replaced blower motor has 7.5 MFD listed . Still good ? Seems fine , it working
@TEMCo Industrial Power
My start up capacitor on my compressor is only 31.5uF at 400v (2 terminal) if i buy a much bigger uF rating ie (400uF) would it make my compressor start easier.
Mine at present doesn't always start up every time, sometimes it buzzes upon start up and freezes,if i spin the motor by hand it will start up, is my start up capacitor faulty and would it cause these start up problems??
If a motor calls for a 5mF run CAP will the motor be damaged if you use a 7.5 or 10mF run CAP?
What's the different systems of a single phase motor when the start capacitor goes bad and run capacitor goes bad?
Very informative, kind of a shame the audio is bad quality. Gotta watch those clip levels.
I have a 10hp 230v three phase air compressor I am wanting to run on 230v single phase what start capacitor and run capacitors would you recommend to generate the third field?
I was looking at Baldor 6" Bench Grinders. They have approx. 14 different models! One of the descriptions says: Built for heavy duty grinding, powered by 1/3 hp Baldor PSC type motor (except 612E & 662E which are split phase)
What would be better for that type of bench grinder, a (PSC) Permanent Split Capacitor or a Split Phase motor?
Is one harder or take longer to start? Do you have to spin the wheels to get it going?
What capacitors should I connect to the 400Watt generator, any suggestion please .
I am using capacitors 8 micro farad and as soon as I plug in the light. the power is gon generator is 650 watts
Hey man.. Great video, my motor is humming, I swapped over a capacitor I had in shop, it started motor but cap exploded hahaha after a minute, I will drop a link for my problem, it is a pdf file with all parts listed, I think it is a run capacitor I need, it's the the 66uf 50Hz.. One on the list thanks you my good man
I have a dual run cap (herm, fan, c) that came off a window ac that I want to repurpose. Are all dual run caps running caps (ie will this thing blow up if I hook it up wrong like a start cap will) ? I want to hook it up in parallel with an ac motor to improve the pf. Do I just use the C and fan terminals or X and fan+herm? The specs of the cap are "7.5/40uf 240vac amc-24h07400b hpf ms 10000afc Sam wha... ". But I'll be darned if I can find anything on Google on it. What would the temco replacement part be?
I have a 3/4 hp bench grinder with a PTC relay for the start winding. The PTC relay is bad but I can't find any for a 3/4" hp motor. Any suggestions?
I’m confused about you usage of “duty cycle”. I’ve only been exposed to the term regarding a DC square wave signal at a fixed frequency and duty cycle refers to how much of the wave is “high” vs “low”. Never heard it used discussing AC signals. I would appreciate any feedback.
I have a couple carpet blowers that run off and on. Would this be a capacitor problem. They run for ten minutes and stop for five minutes
so the capacitors do not have polarity? my air compressor has similar capacitors like the black run one you have and don't see any signs of showing what side is negative or positive (one blue wire and one white wire).
am using a schultz angle grinder, it has two capacitors, now I have a problem with a big capacitor from it which has some drums inside(capacitor with drums inside), what type of capacitor can I repress it and can a capacitors from a capacitors Bosch grinder work in it ????
Quick question, Im building a AC circuit with an AC motor, and i was planning to use a motor start capacitor. The power supply would not be able to supply the current needed to start the motor, so i was going to use a capacitor to give the motor the higher current surge it needs to start. am i thinking of this correctly? or do caps not supply current surges in AC like they can in DC. Thanks
Start capacitors in an AC motor circuit don't handle surge current like in DC, rather, they delay the AC wave form as it enters into another winding in the motor. This gives you a different phase in the magnetic field to allow the rotor to begin turning.
This is a great video. I have a question about capacitors in parallel, specifically for a well pump. I have not opened my control box yet to see if my well pump controller uses a start capacitor or a run capacitor. Is there any danger in paralleling that capacitor (provided it is the same type) ? I’m in the northeast and we recently had a tornado that left us without power for a week, my generator was struggling with the peak inrush current for our well pump when there were other loads drawing on it at the same time. I wanted to see if I could alleviate some of that stress with an additional capacitor. Any knowledge you have to offer on this would be appreciated. Thanks in advance.
If this is the wrong place/channel for this question, I apologize upfront for not being technical in this area. I have a situation I need help with involving Start-Up and/or Run Capacitor(s). I think.....
Situation: When my 6,500 Watt (peak) house back up generator is used to power my home in power outages, my A/C will start slowly and run as the generator slows way down, but the generator recovers after the A/C fully starts up (pump and fans). The A/C will run powered by the generator for whatever time is required for the thermostat setting. The rest of the house circuits can be turned on (Frig, lights, .....) while the A/C is running and all is well and the generator does not sound overloaded or toggle its breaker off. However, once the A/C turns off when the set temperature is achieved, it will not cycle back on without the generator throwing its main 220VAC breaker which shuts everything down. Then, with ALL circuits to the house off (except A/C), and the generator breaker reset, the generator will struggle to restart the A/C and most of the time will throw the 220VAC generator breaker. While during this condition, I can turn on everything/every circuit in the house and the generator will power everything without issue until I try to start the A/C and the cycle repeats. (I know to give the A/C n Generator the best chance to restart is to turn off all the other circuits, my point is to show there is nothing else out of the ordinary while in this condition)
I think I need a larger Startup Capacitor for my A/C Condenser (pump and fan). How would I figure out what type/size/capacitance, ......Capacitor to purchase and how would I identify the terminals such that I can swap it out with the existing correctly?
Please note: I do not need a lesson in the generator peak/run and house demand (load). I am that technical (for a mechanical guy, but this is Magic Smoke Stuff and so I am in the deep end and barely treading water). For review: 1.) The generator runs the house with no issues with the A/C off. 2.) The generator runs the house with the A/C starting first and the rest of the house load added after the A/C starts the First Time. 3.) The A/C will seldom start the Second Time even if all the house loads are turned off and only the A/C is connected to the generator. 4.) Other than this Second Start (or anything after) failure of the A/C running on the generator, the A/C works flawlessly on-grid power as does the rest of the house.
Thank you in advance for any help.
What you are needing to add to your A/C unit is known as a Soft Start capacitor. It reduces inrush capacity needed from your generator upon the startup of the AC's condensing unit, which likely requires a substantial current draw when engaged and until it reaches its normal operating running speed, which likely takes a few seconds. This increased draw happens for large enough of a draw and for long enough that it trips the generators breaker because it overly taxes the generators system to a degree that it would either A; bog it down to a point at which it would stall the engine or B; overload the generating capacity of the core itself and start heating to a degree where the internals could become damaged or fail completely. Just look up "A/C Soft Start Capacitors" or "A/C Soft Start Systems" and there will be a wide array for you to research and choose from. Hope this info helped and good luck with your project
My hvac fan motor runs for about 15 seconds then shuts down. Is that indicative of a bad run capacitor vs a bad start capacitor or did it sound like some other problem altogether? Thanks!
Sounds like a run capacitor problem, or there could be a thermostatic switch on the motor that has gone bad.
Thanks for the video question got a small 2 amp 120 v motor has drawing on side cap wiring diagram motor has forward and reverse don't know what size cap to install bought one and motor runs in forward but not reverse or sometimes reverse and motor getting hot after it runs like 5 minutes anyways could that have anything to do with he ca
If the capacitor is the wrong value, that could definitely contribute to your issues. Do you happen to have the specs on the original capacitor?
have a single phase century 5 hp 1800 rpm motor, has a 330 volt 408 to 480 mfd cap that blew.
it runs with a 220v cap i have in stock, similar mfd range, is that ok to use in an emergency?
I have a 1/6 horsepower 240 volt normal house freezer that is rated at 90 watts, I believe that equates to 124kW motor. I want to help the motor get started/run more efficiently etc. It connects to a 2500 Watts inverter (5000watts surge) though I want to dedicate a much smaller inverter. Can you please suggest what size and type of capacitor I could use and point out where I can get info on clear instructions on installing it? These is NOT already a capacitor in it.
We don't have specific instructions on repairing this, as they can vary depending on motor manufacturers.
You might want to just try getting a capacitor of matching values, as they're fairly inexpensive.
i have a 1967 vintage high frequency arc starter that has a leaking mica capacitor inside...is there a modern design capacitor (more effecient) thaT I can use as a replacement?...i think it was 2.0 mfd 5000v 6.amp in a 3in x1 rectangular black box
i have an electric motor but i cannot get it to run. When you turn it on it just hums and does nothing. The odd time it would start but most of the time its just hums. There is a cylinder on the side of it and i think it is a start capacitor but i am not sure. It says 160-200 uf so any idea whether its a run capacitor or a start capacitor?
Can I run a CS Induction Motor for a longer time say a few minutes at low voltage before the Capacitor Switch trips ? Will the start capacitor be able to tolerate low voltage for a longer time ?
Capacitor start induction motors have their speed dictated by frequency, not voltage. So, under-voltaging a CS induction motor will give you reduced torque and increased heating, but the motor will still come up to full speed, thus disengaging the capacitor as normal. At some point in dropping the voltage, the motor won't even produce enough torque to turn, at which point the capacitor will stay engaged, and the motor will burn out. What was your reason for needing to running it at the lower voltage?
TEMCo Industrial Power
Hey thank you for making this video. ;)
100% educational and professional all the way through.
At what temperature do standard motor windings melt?
I have a 36V forklift with an ailing capacitor rated at 150uf and 250v (250 P.V.W.) The part number on it is FB-887 and it seems to be impossible to find. Would I be able to run an array of smaller run capacitors adding up 150uf?
Replacing a run cap on a bandsaw, the original is a 2 prong and the replacement has the same values but is a 4 pin. If they’re interchangeable does anyone know which pins do I connect to?
Hi I have a air compressor used for painting cars, when its very cold weather the compressor sometimes won't start up. When i pull the red switch up to start it, it buzzes loudly tries to start but doesn't have enough power. If the weather is hot, then most of the time it starts.
It has gotten progressively worse at starting now it's about a 50/50 if it's going to fire up or not, when it does start it runs perfect and generates lots of pressure.
If i helped the motor along with my hand by spinning the fan blades it does start, sometimes it starts slowly whilst buzzing then gradually build up speed then runs okay after about 10 seconds.
Does it sound like the start capacitor at fault? , I do not have a run capacitor on this compressor.
Could the start capacitor (faulty) CAUSE ALL THESE ISSUES?
Thank you for the reply. Perhaps I should open the motor and look for an centrifugal switch.
So just to clarify, you can replace a start capacitor with a run capacitor if it has sufficient micro-Farads? For example I have a 8uF start capacitor, I can replace it with a 8uF run capacitor?
hi.. i gota a 1ton AC works on 240v ac. its got 35uf cap for compressor. can i add capacitor bank to reduce amps draw. if so what consequences i have to face. kindly explain.
Thank you for watching! Glad you found it useful.