Troubleshooting Generator With No Power Output - AVR and Brush Replacement - Flashing the Field

hey guys welcome back so tonight I brought home this husky generator it was advertised as a good running engine but no power output and generally speaking when there's no power output that's usually pretty bad a lot of times it's a bad stator or bad rotor in which case it's never gonna make power again unless you replace the power head in this case I don't know which it is it might be neither so I'm gonna get you set up and we're gonna run a few tests and see if we can't figure out what is making this generator sick so one test you can do pretty easily most of the time is you can test the resistance of the stator through the outlets now this is a 240 volt generator which means it has to 120 legs so you got to test both to get an idea of what this generator health is and I don't know the reading on this but generally the readings are between 0.3 and 0.5 and if you don't know the reading just compare the two they should be very close if not exact so in this case we get 0.5 let's just check the bottom it should be the same so between four and five actually it's settled on point four and we'll check the other winding same point four that's a good reading since the stator tested good from the outlets really the only thing you can do now is pull this cover off for the next few tests I'm guessing someone already had this off judging by the fact that the boot isn't installed properly the stator actually looks pretty good those are the wires there you see that go around the outside here and it's wrapped with these ropes and if you see any ropes broken that's usually a sign that the stator is overheated and another sign is the color of the wires if you see any that are black or burnt looking then those wires overheated and there's a short somewhere but both the stator and the rotor which is in the middle look pretty healthy the wire color looks good so that's that's good news those are the major components that if they failed you would not fix it just doesn't make sense financially so yeah next I guess we'll pull the brushes pull the AVR and just check out what's going on there okay I'm gonna get this AVR out of the way I already removed this bottom bolt and loosen the top one and I'm gonna unplug it from the brushes as well as this harness here now this one you don't need to pay too much attention to it's keyed so you can only plug it in the right way but the wires going to the brushes you do need to pay attention to in this case positives on the Left negative on the right and that's usually also indicated by something on the wire in this this case it's a little yellow plus on the red I'm gonna test the resistance as well through the brushes you can go direct to the slip rings you'll get the most accurate reading there if you go through the brushes the resistance will be higher but I like doing that first because it's kind of testing two things at once if you don't get a reading through the brushes take them off try on the slip rings but if you start with the brushes and you get a reading then you know the brushes are good and the slip rings good now this generator I know is about 55 ohms or it should be and through the brushes it'll be higher priority or 90 so I'm just gonna hook it up and we get 75.8 that's perfect so I know the brushes are good the rotor is good we previously found out the stator was good so that pretty much rules out everything in here it's good most likely the problem is with the AVR or a loss of residual magnetism and most generators that have an AVR don't lose magnetism because they have permanent magnets on that rotor but I don't know for sure if this does or doesn't so what I'm gonna do is first I'll bring it outside we'll run it with this AVR see what we get so when we get nothing I'm gonna hook up 12 volts to the brushes and check the output here on the stator with 12 volts on the brushes I should get somewhere between fifty and a hundred volts it varies depending upon your generator but if I get that then that kind of validates that everything here is good assuming I get that that'll also restore magnetism if it was lost so I'll reconnect the old AVR test one more time if I still get no output then I'll try a new AVR and I happen to have one right here they are the same brand they look like Zak the same board the only difference is the new one has a metal case and the older plastic let's get this thing outside and see if we can't get some power out of it okay I'm just going to take a minute and validate what I was told about this generator and that is that it the engine runs well starts first or second pull and there's no power output I have the original AVR hooked up kind of dangling precariously I have a light plugged in and a voltmeter hooked up to the stator so I'm gonna start it and we'll just see real quick what it does if anything okay confirmed no power he'll play it was fluctuating between Lake you know one in three volts which is a little odd I would have expected it to stay a little steadier around three somewhere between three and six volts the engine did start well first pull so don't have a problem there so what I want to do now is unplug this AVR and apply twelve volts to the brushes while it's running and see if that powers this thing up okay so I got alligator clips hooked up to the brushes here positives on the left and I'm not going to finish connecting it to the battery until this is running and I do have the meter hooked up to the stator what I want to see is at least fifty volts or higher and I also have a light here if it is 50 volts of higher the light might start to turn on okay I think that's good we got 26 volts lower than I expected but a good result - nonetheless so I'm gonna try the original AVR if it was a loss of magnetism then this should have fixed it and the date code on the say VR is April of 2018 so I'd be surprised if this AVR it didn't work no power out of this AVR so I'm gonna plug in the other one I have see if there's any difference okay unfortunately we might have a bigger problem going on here now I don't know the history on this particular AVR but it should work so one thing I haven't done is tested these blue wires these are what supply power to the AVR and I would expect the ohms to be somewhere around 1 plus or minus probably half an ohm 0.7 that seems fine to me gotta be honest little surprised that this didn't power up given all the ohms readings you know this thing should power up and even with the new AVR did not now when I supplied the 12 volts to the brushes I did get power out of the stator but it wasn't the 50 volt minimum I was expecting it was closer to 25 volts 30 at best so clearly I'm missing something here one test I didn't do which I probably should have is an ohms test to ground and what you want to do is test each coil to ground to make sure that there's no connection whatsoever do you want to make sure that if you have a neutral bonded generator that you disconnect the bond and in a lot of cases there's a wire running from white to green in this case this is not a neutral bonded generator but if you do get continuity you know between the stator and ground potentially the bond is up in this control box up with the outlets are so disconnect these wires if there's any doubt you know do the test again to ground and see what the reading is so I'm going to do is just check each winding to go out and I get nothing for the first winding and nothing for the second winding so stator is good so I'm gonna check the rotor now I got one lead on the brush one of the brushes and the other one on the ground and no continuity so that's good so again stator and rotor test good now I'm going to check the blue wires so I want to do one to the blue and one to ground and again no connections so we're good there the fact that I was only getting 25 to 30 volts out of here tells me that there could be a problem with the power transfer from the brushes to the slip rings so I'm gonna pull off the brushes and inspect them as well as the slip rings brushes do not look worn out but these marks right in the middle look a little bit odd not sure what to make of that but I do have another set of brushes so I'm gonna try those well we got the brushes out I'm gonna try getting a reading directly from the slip rings that's kind of high actually I would expect that reading to be between 50 and 70 and it's kind of right on the edge and that seems a little high I just want to show you a close-up of the slip rings they don't look too bad the resistance reading has me a bit concerned it's on the upper edge of acceptable but with that said it sits right on the upper range of good so let me try to clean those slip rings a little bit put some new brushes on see if we get a different result after a quick cleaning this is what the slip rings look like they weren't bad before but they're a little better now the brushes I'm gonna use are the ones on the right they are more worn out than the ones I took off but they don't have those funny marks right in the middle so I'm hoping that this will produce a better result can I try hooking out 12 volts again the only difference is these are different brushes and the slip rings were cleaned okay no change with the stator output it's around 30 volts this has me stumped honestly readings are all pretty good the only one that's a little bit suspect is the rotor so I'm guessing that that is the problem when hooking up 12 volts I do get 30 volts out but that's not enough that rotor needs to be more taking more current basically to ramp up the voltage and I think it's not doing that so I'm gonna bring this back to the garage get the stator off and get a better look at what's going on inside someone's been in here before me the usually there's washers which are all present and then a lock washer and then the nut and two of the four we're missing the lock washer I think I forgot to hit record anyway I just removed these four bolts going around the stator so now that we have these four bolts out we've got these engine sorry the stator mount bolts out the stator should pull out just like that sometimes you need a puller not seeing anything obvious here the rotor looks pretty good you know the I guess the biggest thing I do notice if you look at the color of the wires they're different you know so this side is darker than that side so yeah maybe there is an issue with this rotor that's what I would suspect the stator this is the other end of it it also looks pretty good the wire color is good yeah at first I thought there was a broken rope but I think that's just where the rope was tied off I don't see any issues here so what I'm thinking I'm gonna do is I have a rotor here which came off a generator that definitely had a bad stator it looks to be the same size so I'm gonna pull that rotor out put these side-by-side take some measurements and if it's the same I'm gonna reassemble it with this rotor and this one I have tested the ohms on it is 55 ohms and that's what it's supposed to be okay this cup is threaded on the Huskies it's an m12 1.75 should I put the bolt back in without screwing it in and that's how long it is before it hits the shaft now I have a couple of pre-cut a couple of pre-cut rods that one's too long that one's just right you can see it leaves it's about a quarter in shy of coming out which is what you want so this rod will go in and then I'll play the m12 in I may not have put enough or open the cylinder and I put this blanket down to catch the rotor if you can kind of hold it to but in this case the engines kind of moving around a lot so I'm gonna hold the engine and torque this down okay so you can't win them all this is the rotor that I just pulled out and I've measured the length and marked it here in this rod this is the one I was hoping to put in and you can see we're short by about half an inch so I can't use this and you know I wish I could say a hundred percent that this rotor is bad but the stator tests absolutely perfectly and this is the only thing that's a little bit off I checked a few other service manuals just to see what the upper limit was and you know I checked three different manuals all of them had the upper limit at 70 ohms and this one is right there you know it's at sixty nine point nine and it pretty much says at 70 ohms it's trash it needs to be replaced and you can see we're at 70 also this reading is supposed to be taken at room temperature it's pretty much freezing in this garage so the resistance is actually lower the colder it is so if I were to bring this inside let it warm up it would be over 70 there for comparison this rotor I know it has a lot of hours on it it came out of a generator where the stator head melted down and you can see the wire color isn't as good on this rotor but when I test it we get a nice 51.6 ohms that one's healthy okay I was pretty much ready to call it in the garage but it's bugging me we know this rotor works because we put 12 volts to it and we got power out of the stator and yeah okay the resistance is high so potentially it won't be able to reach 120 volts if that rotor won't power up enough and the higher the resistance is the less able it will be to create power in the stator but the underlying problem is the AVR is not powering up so why is that you know the rotor although I didn't show you this the rotor had permanent magnets on it and I tested the magnets they work fine that's all this generator needs to start the power generation process and what should be happening is that power is being fed to the AVR from these blue wires which is where I have this middle meter hooked up to that was permanent magnets should be able to produce somewhere between 4 and 8 volts AC and I'm guessing that that is what is not happening and because of that the AVR can't power up so I'm expecting that this will be less than 4 volts obviously we know this is the stator which is like around 2 and a half volts and this one's hooked up to the DC on the brushes and I'm expecting that to stay pretty close to 0 since the AVR is not powering up but let me just start it and see what these gages do that's pretty conclusive it is 0.33 volts on those blue wires and that is why the AVR will power up and unfortunately there's not much I can do about that those windings come from the stator and even though the main windings are good the sub winding providing the power to the AVR is bad and we're not going to get any power unfortunately and yeah so I think this power head is done and for the purposes of this video we're done so I hope this video helped someone thanks for watching I was editing this video together and I realized I missed something really important here and that's the broken ropes on the stator I did notice oh but yeah they didn't look burned to me and I just dismissed them but now looking at it while editing the video I can see better that there's a wire sleeving that starts right about here and runs down and stops right here and that exactly corresponds with with the broken ropes start and stop I'm just gonna advance the video a little bit and you can pretty much see that everywhere the rope is broken is where it was touching that's leaving so I'm confident ultimately whatever is under that sleeving whatever happens is the cause of this generators death and you can see in the last one here does actually look burnt as well so didn't want to end the video without at least calling myself out on that issue

Channel: James Condon

Views: 372,800

Rating: 4.7946672 out of 5

Keywords: AVR Replacement, AVR, Bad AVR, Bad Brushes, Bad DPE Winding, Bad Exciter Winding, Bad Sense Winding, Brush Replacement, DPE, EX30, Flash Generator, Flashing Generator, Generator, HU40500, HU40500G, HU5000, How to Remove a Stator, How to Rename a Rotor, Husky Generator, Low Voltage, Model HU40500G, No Power No Power Output, Small Engine, Subaru, Troubleshooting

Id: NfE7pbm0l7E

Length: 28min 20sec (1700 seconds)

Published: Thu May 14 2020