how to test a RUN or START CAPACITOR the CORRECT way

[Music] well I'm Chris and this is my how to test the capacitor video now these are start and run capacitors for single-phase electric motors 110 220 air conditioners air compressors washers dryers that's what we're doing in this video okay so this is a 110 volt air compressor it has two capacitors one's a start and ones a run so the washing machine motor has a cover and when you take the cover off the capacitor is hiding out back there the point is to locate your capacitor when you find your capacitor this thing is dangerous it can shock you need to take an insulated handle screwdriver touch the two terminals and you'll see them spark if it had a charge we're gonna demonstrate that in test number two but just be careful because this thing can shock you and if you're on a concrete ground AC current is seeking the ground and that's how people die by electrocution or get shocked and burned up real bad so you cannot play games with AC power so once you got it discharged you know it's good then it's safe to take the wires off and get it out so we're going to test this thing three different ways the first way is the right way and the only way really should be testing it the second way is the dangerous way but it actually makes a lot of sense the third way is the pointless way and we'll show them all so first of all your meter has to have that symbol right there so if your meter does not have a symbol like this you have to get one like this because you're not gonna 100% be able to check the capacitor so these three meters this is the only one that has it in this right there so let's go ahead and switch it on now this is combined with the diode sending power in one direction so we need to change it to there now we're measuring the micro farad's that's how you check a capacitor let's do it always discharge it it's good this is the easiest test in the world and of all time all you do is connect the leads to the capacitor and you're looking for a value 236 you can clearly see that flip it around do this about five times to make sure you get consistent numbers let it settle to 36 to 34 let us do it again do it five times 234 233 okay you got a look on your capacitor and hopefully the numbers are still there we're looking for numbers that look like that so we got 233 to 280 MFD that's microfarads so that's given us our range so we have to be in that range for this to be a good capacitor so what did we end up getting if we got 233 to 280 shake it one more time 235 to 34 so capacitor is good this capacitor was giving me trouble and you can see it's on that low range I went ahead and bought a new one anyway just to be on the safe side okay so this is a star capacitor on air compressor 210 to 260 the UF that's the micro farad's okay 247 remember flipping around play with it 247 we're good this is a good capacitor is this is a real capacitor off the same air compressor it's showing a value of 40 micro farad's plus or minus 5% so what does that mean so you take your 40 micro farad's multiplied by a percentage of 5 is going to give you 2 so that means that this capacitor must be in the range of minus 2 which is 38 2 plus 2 so 38 to 42 micro farad's is what we're looking for so let's test it 35.5 flip it play around with it do it a few times this is very interesting because this is off an air compressor I got from work that is bad and it starts up and it trips the breaker and guess what we just found we're looking for 38 to 42 we're getting thirty five point five micro farad's so this run capacitor is actually bad that's why it's very important to test the capacitance with the correct meter because the other two tests we're not going to be able to check that like we did so I've got two good ones and one bad one so the second test is a dangerous test but in emergency situations you may have to do it wear safety glasses wear gloves whatever you got to do to protect yourself do not do this outside on the ground be careful now when this is plugged in we got live power right here so we're not going to be touching anything we're gonna plug it in and charge the capacitor so be very careful you cannot play games with AC power it will shock you it will burn you and it can kill you so we're gonna go ahead and plug that up right there just like that we're not gonna touch it we're gonna plug it in for one second and we're gonna charge a capacitor you'd be very careful if you dare try this and plugging it in for one second and then pulling it back out one that's it take an insulated handle screwdriver you're going to touch the two terminals and it's going to do like a little firecracker showing you that this is holding a charge dangerous test but we can clearly see it's holding the charge now you got to do that really good before you start touching this make sure this thing has no juice in it got this unplugged be very careful when you do this I don't like showing this on my channel be safe with that test this test is really the most pointless test of all time I hate this test it doesn't really show you anything all its gonna do is show you that it's taking a charge that doesn't show you if it's filling all the way up or anything like this so we're on the 200k setting on ohms so whenever you put your probes on there it's gonna start charging up okay let's backwards just switch them that's what you're gonna have to do just switch them if it's reading negative we're gonna read this see it's already went to overload that's why I hate this test let's go to that one nothing just go to that different one okay let's switch them so it's charging up and then it goes to overload or infinite Tony man this is a pointless test it's taking a charge and it's discharging but it does negative scene that means it's discharging switch them he'll be charging up it's just a stupid test doesn't tell us anything but also the problem is this meter we're using so let's go on the fluke we're going to owns same thing these meters are also because they have auto range so we're going to go ahead and do the same test but it's going to put us in the range we want let's see it's showing its charge and on the fluke meter it will charge to infinite it will just keep charging forever showing it it's taking a charge we flip them around it's discharging so this whole meter test is good to tell if you have a straight-up blown one which happens a lot but to tell if you have a capacitor that's not reaching full capacity it could be causing start issues that test does nothing for you so it's still a test that you should see done but like I said it's only going to give you a dead giveaway if this thing is blowing up inside and not working at all so if you enjoy the video please like and subscribe and thanks for watching

Channel: Craft Customs

Views: 666,615

Keywords: DIY, do it yourself, how to, capacitor, testing a capacitor, capacitance, capacitometer, start capacitor, run capacitor, air compressor, washing machine, dryer, air conditioner, fluke, commercial electric, multimeter, diode, single phase, 110V, 220V, tutorial, HVAC

Id: H792xf78loU

Length: 7min 34sec (454 seconds)

Published: Wed Oct 09 2019