How to test your Electricity Generator's AVR, Brushes and Alternator on a Brushed Alternator

When your electricity Generator stops producing power or fluctuates, you need to know how to test the Alternator to find what has failed. This video will show you how to do this. Send us your results, and we can tell you which part you need. Contact us via our website generatorguru....
**If your generator has a Brushless Alternator with a Capacitor, please ignore the Brushes step of the testing."
This test was invented by our Founder and is called "The Beagley Testing Technique." With this test you can find out what has failed in the alternator. By default you can discount faults in the alternator allowing you to determine if the AVR or Capacitor has failed. Normally you need an expensive tool to test AVRs and Capacitors at such a high voltage. With this testing technique you can do this with a standard multi-metre!
If you have any questions please email us through your local Generator Guru website.
We are always happy to help. We also sell 1,000,000 generator parts and pro tools on our website with quick shipping.
www.GeneratorGu...
The information contained in our videos and on our websites are designed as a guide only, for assisting Repair Professionals. This does not replace professional training. By using our information you are agreeing to our T&Cs: generatorguru....

[@Generatorguru]

We thank you for your interest in our help videos. Unfortunately, due to limitations in KZbins comment sections, we are unable to quickly answer questions in the comments. Please feel free to contact us directly here: www.generatorguru.com/need-help/ PLEASE NOTE: You cannot test the AVR without a very expensive piece of kit called a Megga meter. This is why you need to do these tests to make sure there is no other problems in the Alternator. This will discount any other problems leaving the only possibility being the AVR.

[@phantomwalker8251]

you need to show,or tell,what happens when certain items blow. . my geni reved up. trying to find out why. the shop said,its chinese,buy another. there not interested. its remote start,key,pull,3.500 w. inverter. i have an old subaru,10 yrs,still going,but noisy as hell. 5kva. need a more portable geni. so bought the inverter.small suitcase size.

[@CodyJohnson-or1sl]

I have never commented on any of the hundreds (if not thousands) of KZbin videos I've watched, but I am beyond grateful for this. I promised a client of mine that I would fix his generator, which I've never done before. More than 5 hours and many YT videos later, I still hadn't figured out the issue. The brushes were shot, everything else had continuity. Replaced the brushes, but still no power. You are the ONLY person I found that pointed out that the positive wire always goes on the left side of the brushes. I just hooked them up how they were before (another shop tried to repair). All of a sudden, IT WORKED!!! So, thank you so much for your help. Very grateful for you.

[@bunnyman6321]

💯

[@Generatorguru]

I am so glad we could help! If you need any other info we have an interactive help centre which can help you fix most generator issues: generatorguru.com/need-help/>Engineering

[@rreatery1960]

Thank you a thousand times!! You were very instructive in every phase of showing how to properly troubleshoot a generator. You even took the time to show the proper settings on the multimeter for anyone who needed help. Your a blessing. GOD bless you.

[@todaywefly4370]

I find it interesting that people who really understand what they are doing make great simple instructors. No complicated garble that the watcher doesn’t understand anyway.

[@Generatorguru]

Thanks! *blush

[@bungalowfeuhler1541]

Thank you so much! This video saved me weeks of ordering parts, dropping them in and finding out they didn’t fix it. You are the best!

[@engineeringdept.generatorg1760]

Thank you so much for your Comment! I have patted my team on the back and passed your thoughtful thanks onto them. We really appreciate you letting us know. Would you be able to leave a review for us on trustpilot? We have recently signed up with them and would like to spread the word and help save more Generators. If you could be so kind, please leave a review via this page uk.trustpilot.com/review/generatorguru.com Thanks again for your feedback!!

[@agentnuget]

this is actually helpful. every other video I've been finding requires jumper cables to test the AVR. didn't think about testing the generator itself.

[@daleslover2771]

Generator Guru back in the early 70s, I was taught by my grandfather, how to rebuild generators, alternators and starters, with the simplest tools available, close to 50 years I've only had to replace one generator to an alternator, switching over a 1960 Ford F-100 Excellent video, really enjoyed it.

[@Generatorguru]

Hi Dale Thank you for the comment, I would love to hear more about it, a lot of people get stuck with the lesser known or unbranded generators as many rewind companies do not want to touch them so charge high prices for repairs to push people away and many people find themselves with a unit that is no use to anyone but not worth the repair costs

[@ovitvchannel]

Thanks brother.. Very well explained.. Great effort.. You saved my generator from selling lol

[@ovitvchannel]

Subscribed your channel 👍

[@michaelwest2608]

Thank You! Finally a video on fixing a generator with brushes that makes sense. I am finally now able to narrow down what the actual problem is. It is the AVR. Thank you again for the awesome video.

[@roberttreadwell3252]

I had a loose terminal on a new duromax 8500 which fried the avr.. They sent a new one but it was only putting out 109 volts on both sides . The avr had an small adjusting screw and I turned it and adjusted it to 120 . Works perfect now.. Thanks for the video

[@Generatorguru]

Ummmm.... you should not be adjusting that screw! They are set at the factory and now you have just changed the hertz output!!! That is not good!!!!! IF IT HAD CORRECT VOLTAGE BEFORE THE AVR BLEW - Run the test in this video and follow relevant steps below. IF GENERATOR IS COMPLETELY BRAND NEW: Best to set it back to 109 then adjust the speed by the top screw on the carb. Use voltmeter to set to the correct voltage. Before you do that. be sure good fuel flow is coming from the tank as the Petcock has a filter behind it which might be blocked. IF GENERATOR HAS RUN FOR MORE THAN 1 HOUR: If you were getting low power and it is NOT totally brand new, but has some running time on it, this is what you need to check: 1) it needs servicing. (1st service best done at 50 hours as loads of metal shaving are produced as it settles in) - see kzbin.info/www/bejne/n6CkmHanhc2InMk 2) The engine has settled in and valves need resetting. This needs doing after about 1st 50 hours - see valve setting on our website and follow this video: kzbin.info/www/bejne/o4rVlaGGi9KUetU If you need more help please contact us on generatorguru.com/need-help/ and we can assign you an engineer. :)

[@roberttreadwell3252]

The generator is running at 60 to 61 hertz. This was tested with an Ideal sure tester

[@bapao83]

Straight to the point and a very good guide for generator troubleshooting. You have earned a sub!

[@TheMills21]

Exactly what I needed and right to the point I wish 99% of the other instructional videos were like this one !

[@Generatorguru]

Aw! Thanks sop much!

[@garyrancilio7184]

This has been the best instructional video I have found on you tube. Thank you for taking the time to demonstrate the testing. Now I have a question not really covered. I have 4.7 v to both the R1R2 and L1 L2 and 0v on R1L1 but I only am getting 1.7v across the brushes. The surface that the brushes are riding on are smooth. I thought these were grooved. I am looking forward to your expertise on this. Gary

[@Generatorguru]

Thanks for the feedback! R1 and L1 should be 0 vac if you have a voltage changeover switch and set it to the lowest setting. These results indicate you need a new AVR. The AVR should bring up the rotor to 5vac also if you run it for 20 mins without load to stabilize the magnetic field. Your brushes will be smooth where they connect to the rotor, but be sure they have enough play in them to make a good connection. If you are still having any trouble please let us know and we will be happy to advise you further. :)

[@garyrancilio7184]

Sorry I should have added that I have already replaced the AVR. This unit has only been used a short time. brushes are not even worn in yet.So are you saying I should run it 20 minutes with the new AVR? one last question. This John Deere 6200 watt runs wide open all the time. Is that normal?

[@FUNFORALL105]

Generator Guru sir i changed the Generator AVR but the voltage is still not stable ..when i start some things on it becomes decreasing voltage from 220 to 195..

[@FUNFORALL105]

i think the AVR frequency is not set... how i set that frequency

[@joebodkin6534]

Followed your tests and ended up replacing AVR .Bingo, fixed it.$17 .Thanks

[@Generatorguru]

Nice work!

[@Generatorguru]

The diodes on your rotor have blown. Check to see if they are accessible (usually on the end of the rotor or the fan end) if so replace them. If they are "in" the rotor you can take the rotor and windings to your local "motor rewind" company and they can rebuild it for you. But worth calling g a few companies as price varies greatly!

[@mojavegold-]

Very good demo. Nice, clear explanation. I thought I might mention though - that the rotor is not "otherwise known as the stator". The part you call "the windings" are the stationary part of the generator - the stator. The rotating part of a generator or a motor is the rotor - whether it has windings, permanent magnets or a squirrel cage structure.

[@Generatorguru]

Hi Ralph Thanks for getting in touch! A few people have pointed it out over the years, a bit of a slip of the tongue we didn't spot until after we had posted the video, it used to have a little tag at that point in the video apologising but youtube seems to have dropped the captions off and won't let us replace them as its convinced they are still there!

[@floydie45]

Hi, Generator is outputting around 3.5- 4V on the brushes and 4 - 5 V on the L1, L2, R1, R2 and when I tested the L1 - R1 I was also getting 4 V but im only getting 8V on the 230V output on the generator. what could this error be?

[@Ubique799]

Thank you, With your help I located the brushes on the Hyundai 7000 and cleaned them so it works again. Genpower were useless and argued over warranty times so much for the platinum warranty! Kind regards Andy

[@engineeringdept.generatorg1760]

Thank you for your feedback! We pride ourselves on "Good old-fashioned customer care!"We strive every day to save generators and other machinery from being scrapped due to parts not being available. It helps every-ones pockets and prevents tons of CO2 being added to our ecosystem!

[@Generatorguru]

We DO want the test in volts (AC. v~). I keep getting emails saying otherwise, but we are doing a different test.

[@jaygatz4529]

Hey man. Thank you. You made my day. I didn't loose magnetism, just had to change the avr (because i mistakenly connect the public power source to my generator. Turned the thing into a motor in a flash ruining my avr in the process. . That's a awesome guy you got there. (the black cutie) Thanks a lot

[@Truthorshit]

nice one

[@Generatorguru]

We thank you for your interest in our help videos. Unfortunately, due to limitations in KZbins comment sections, we are unable to quickly answer questions in the comments. Please feel free to contact us directly here: www.generatorguru.com/need-help/

[@hensonorr9343]

this is the first video i have seen on generators having a problem with mine and youre the best so far fully understand everything

[@Generatorguru]

Thank you for the feedback!

[@CerebralAilment]

What are the symptom of bad brushes? I recently replaced my AVR. I did not replace the brushes as the ones that came with the AVR seemed awful cheap. Now I'm curious if I should have replaced them anyways.

[@Generatorguru]

If you run the test on the Armature (Rotor) with the brushes fitted you should get a constant 5vac. If not replace the brushes. If you have any questions you can contact us via www.GeneratorGuru.com and we will pair you with an Engineer who will work through it with you. :)

[@crocodiledondii]

That was a very well explained and informative video. It removes some of the mystery about what's inside the alternator, and teaches the ordinary lamer some basic troubleshooting tips. Thank you.

[@analiagamarra1715]

hi from argentina, your video was very helpful to me, you explain very well all the trobleshooting, thumb up for you, thanks

[@paperwork1125]

I agree that this is the best instructional video. Might want to do it for companies and get paid for it.

[@ClaymateDesigner]

Generator guru gave me more help with my hyundai generator that the importers of the generator.

[@Generatorguru]

So happy we could help! Thanks for the feedback!

[@ClaymateDesigner]

@@Generatorguru How are you with hyundai diesel engine parts?

[@Generatorguru]

How far have you got? Might be best to chat to a Guru on our website. We are always happy to help! Search "Generator Guru" in google to find us.

[@rasselas36]

Thank you for your excellent and most helpful video. I tested my Firman 4550/3650 and the results were not what I was hoping for. Across the brushes 13.28 L1/2 .38 R1/2 .34 and I didn’t bother measuring L1/R1. Please confirm my worst nightmare about this generator. Thank you again for sharing your time and knowledge.

[@Generatorguru]

Sorry! The rotor diode has blown. If you can see it on the end of the rotor you can remove and replace, or take it to a motor rewind shop and ask if they can change it for you. :)

[@rasselas36]

@@Generatorguru thank you. Have a merry Christmas.

[@Generatorguru]

Was your voltage changeover switch on the lowest setting? If so you windings need replacing. L1 & R1 should = 0v ac

[@stephendullea5307]

What's that you say? Ahhh! Now I can hear you. I have to remember not to test my AVR on a windy day I guess...THANK YOU!! very content rich. Love that.

[@Generatorguru]

Stephen, Thanks for getting in touch. Yes, we find on some computers the sound works perfectly, and on others it is impossible to hear. If you have any questions please contact us www.generatorguru.com/need-help/. We have in planning stage, a new version of this video and a poster for step by step instructions. Thanks for your feedback! Hope it was helpful even with the sound quality. :)

[@habekrats]

Thanks to you and this tutorial my generator works again. Greetings from Holland.

[@vladimirparra1626]

So nice video..thanks teacher..i continue following you from República Dominicana..

[@mickeycruz912]

Great video.. now I’m headed out to the shop to use what I just learned on a generator. Thank You

[@Generatorguru]

Glad we could help

[@jimmyprophet8529]

Excellent video. I learned so much and learned how to diagnose my generator properly... Thanks generatorguru!!

[@Generatorguru]

Can you please clarify what the n v v u represent. Also which generator (make and model) do you have? Your rectifier is reading a bit high. I would suggest replacing it.

[@samgokuo1775]

I am very much curious, how much resistance reading is expected across the slip rings of the rotor, and does it vary, depending on the power rating of the generator? Very informative video by the way, thanks for the clear demonstration.

[@Generatorguru]

Thanks!! Resistance varies from generator to generator, and not all generator companies publish them. Hence needing a better way to test the alternators, and we came up with this! It is called the "Beagley Alternator Testing Technique" and was invented by our company founder many many years ago! :)

[@davids9139]

nice video. The only technicality I see is your explanation of a rotor and stator, two distinctly different parts. Keep up the great work! This was a very informative video!

[@Generatorguru]

Yeah I got nervous during filming. I did add a note over it on youtube, just after I uploaded the video, to say I got them mixed up but over the years it seems to have disappeared with all the updates that KZbin have done. Thanks for pointing it out. I will try to get that reinstated. :)

[@Generatorguru]

+Rick Saffery You cannot test the AVR without a very expensive piece of kit called a Megga meter. This is why you need to do these tests to make sure there is no other problems in the Alternator. This will discount any other problems leaving the only possibility being the AVR.

[@johndavidson8955]

Generator Guru my UST 2300 reads 145-190 vac and HZ reads 75-79 time to scrap it?

[@Generatorguru]

John, These are the results without the AVR attached during testing? If not please test without it attached, if so, then follow the next step. If the hertz are that high then we would be questioning the speed of the engine. First, check the Governor Rod and all springs are in good order (especially the one over the rod to the top of the carb as a little play in the spring will greatly affect this.) Also, service the engine to be sure that nothing has gunked up the governor which sits inside the engine as this adjusts the speed. In North America, you want 60hz (50hz for European or Auz regions) so you need to slow down the engine if neither of the above is the case. On your generator, you can do this with the screw at the top of the carb. Turn slowly anticlockwise until you get the desired Hz. If this does not work you will need to replace the governor inside the engine. If you need parts we hold them for your generator. You can buy online on www.generatorguru.com/

[@atcaleb]

I get 94mv DC from brushes which move and look like new. It's a very steady 94mv too. I get 4.14V AC from tests #2 and #3. I get 0v AC from #4. Unit is 3 years old and only got used when new for a few hours. Looks exactly like the one you are working on. I did have it set to 110V like you said. I know AC from DC and I also had the + wire to brushes marked from the OEM. Is the left one too. The rotor assembly is USD $180. Is that the problem here from the info I am giving you? Rotor is clean and shiny. Very clean unit, stored inside. The brown wire(bottom nut) had a bit of rust and corrosion. Is clean now. Great video, only of it's kind!!

[@Generatorguru]

What are you getting in Volts AC on the brushes? In need this to tell you what the state of your rotor is. The other tests (on the windings) are good, so there is not problem there. Look forward to hearing from you.

[@dudealjero]

Very explicit and concise. You're the best.bless you

[@TheBigmachineman]

Excellent video and obviously you know what your doing and gave great advise. Thanks for sharing.

[@davidsalmon3605]

Very helpfull. I have a DG6, it looks like I have to remove the muffler first to access the end of the Alternator. Thanks for your help. David from NZ

[@Generatorguru]

If you have the super-silent version, You might be able to find the Capacitor (or AVR in some models) from the back panel held on by the 10mm bolts (some models only). If not you will have to remove the exhaust... sorry.

[@Powerstrokemods]

Thanks for the video, this is one of the better, more informative videos on this subject! The service manual for my EB6500SX is about $150, USED, so, you might have saved me that money!

[@Generatorguru]

Glad it helped

[@000001willy]

Excellent video. I would have appreciated better close-up shots but I think it was good enough to give me the general idea.

[@Generatorguru]

Hey thanks for the info We will try to rectify this in future. :) (PS. sorry about the delay in answering, for some reason KZbin sent this question to the "junk" folder. We apologise for the inconvenience.)

[@jaimequintero843]

Very good explanation of the fault, will serve me much thanks

[@engineeringdept.generatorg1760]

Always happy to help!

[@waqariqbal9946]

thankyou very much for your effort and sharing nice video. but i was little bit puzzled during video how can multimeter gives 5,10 volts without any supply. please elucidate this point.

[@Generatorguru]

+wajahat hussain This is a good KZbin video which explains how an Alternator works: kzbin.info/www/bejne/qpqueWduerKagac. There will be a residual voltage which is what we test.

[@markwestaway6173]

Hi, I have a 3KW Suntom single phase diesel generator. It was ok, but now only producing 85Volts AC. I have followed your instructions, I have 1 volt across brushes, brushes ok. 4.8 Volts on L1 L2. 4.9 Volts on R1 R2 0Volts R1 L1. Do I need a new Rotor?.

[@carpetinbathroom]

Good footage and really helpful. I have just tested my generator that wont give power. Across the brushes 4.8 volts. L1 and L2 11.3 volts. R1 and R2 2.2 volts. R1 and L1 7.8 volts. Just need to work out now what that actually does mean 😀

[@Generatorguru]

You alternator has blown. Sorry! You need to either replace it or take it to a motor rewind company to see if they can fix it for you. :(

[@daviddominguez3461]

Usted tiene un excelente canal, muchas gracias por compartir, Saludos desde Veracruz México.

[@engineeringdept.generatorg1760]

Gracias por sus amables comentarios. Thank you for your kind feedback.

[@Generatorguru]

Does it have 2 poles on the windings (i.e. L1 and L2 And R1 and R2). If so then one of your windings sound like they have broken. Test the continuity on each set to see if one has snapped.

[@del80y]

Probably 1 of the most helpful and easy to understand videos I've seen. Especially as I'm trying to diagnose my genny which has stopped producing power. I've tried the drill technique and I've tried the flash with a battery after disconnecting the avr. Neither have worked. Tho the genny did produce power for the few seconds I flashed it with the battery. So now I'm wondering if the avr is fried as we noticed water in the extension lead that was plugged into it. So I'm thinking that has sorted out the avr to protect the alternator like you just mentioned it should!

[@Generatorguru]

For fault finding or technical advice, feel free to contact us using the link below www.generatorguru.com/need-help/ This will allow our engineers to review your query and give you the best possible advice!

[@robertcontreras4636]

hello this video helped me out in a big way thank you... i have a tested brushes and the winding here are my results L1&L2 16.3. R1&R2.099 R1&L1.191 across the brushes 75.4.... if i heard right you said if the brushes read higher then the windings it would be the rotor?

[@engineeringdept.generatorg1760]

Sorry for the delay in responding. We have had a few technical issues on our KZbin and were unable to respond. Yes you are correct the rotor is failing. As your Alternator has failed the tests, you need either replace the rotor, or to contact a local “Motor Rewind Company” to see if they can fix it. These companies can vary in price, so if you have time, it is worth getting a few quotes.

[@usenchristopher9942]

thanks to generator guru. your video is very much educational, please i need your assistance. i bought a working core and armeture and core for 2.5-3.0 kva generator but i am having deficulty on the connection of the core and panel

[@Generatorguru]

Hi! Please contact us on www.generatorguru.com/contact-us/ and we will assign you an Engineer to help. :)

[@malcolm4200]

Hi Thanks for the great Video, after following your great instructions I have come to the conclusion that my AVR is toast, I have an old Colman Powermate 5000 which i can no longer get parts for, my question is, can i fit a substitute of equal output ? thanks for any help.

[@Generatorguru]

Please contact our Engineers by submitting a ticket here: generatorguru.zendesk.com/hc/en-us We will assign you an Engineer to work through the issue with you. We do not charge for this service. :)

[@Generatorguru]

Hi Amber, Are you getting any reading across R1 and L1?

[@SOLOPAMPA]

Excelente explicación, sencillo y concreto

[@Generatorguru]

Thanks! If you need any further help or parts, please visit us at www.generatorguru.com. :)

[@ochaarul786]

Very usefull video, thanks a lot for your teachings.

[@Generatorguru]

You are welcome

[@edlewandowski1867]

Generator Guru, I get 1.7 VAC on all 4 tests R1 to L1 included. Honda EB5000 HELP! Thanks Ed

[@Generatorguru]

Do you have a voltage changeover switch? If so make sure it is set to 110/120v. If you do not have a switch there may be a reading on R1-L1. This means we cannot test if the windings are arcing.

[@edlewandowski1867]

Generator Guru Switch was set for 110v. Thanks for you quick reply. !.7 is low too isn't it?

[@edlewandowski1867]

Ed Lewandowski also should I have the breaker on or off on the control panel?

[@Generatorguru]

Ed Lewandowski Yes it is low but an AVR should rectify it for you. We are much more worried if the voltage is too high. The breaker position does not make a difference to the readings.

[@Generatorguru]

Thanks *Blush.* He is 1/2 German Shepard, 1/4 Lab, and 1/4 Rotti. He is 8 years old now, and accepts that I talk to a tripod... Don't you love dogs, they accept you for who you are without question, even when you look nuts and talk to yourself. Thanks for your feedback

[@jebr6694]

hello, little question for you, if the reading on the brushes is above 10 does it mean the brushes are bad and need to be replaced? also would bad brushes get me bad readings on r1&r2, l1&l2 and so on...? thanks for your answer

[@Generatorguru]

+Jeremie Bricout (FireFrenchy) We think it is best you call us to discuss it with an Engineer. Contact your local office via our website. www.generatorguru.com/ :)

[@drywalller]

thanks for your video helped me alot.I repllace avr on my generator brushes are find but .dont have power .

[@randolphjones7143]

Then how did the video help you at all then I dont understand really

[@josemariacalebgarciayamin5250]

Saludos, excelente tus explicaciones,muy buen video.atentamente José María García Yamin Caracas, Venezuela.

[@engineeringdept.generatorg1760]

Thank you your feedback is greatly appreciated Gracias, sus comentarios son muy apreciados

[@Generatorguru]

Don't cry! Yes you are correct in some countries it is called the Stator. It is also known as the armature and the rotor. We sell all over the world so use all these terms.

[@bradchapman2879]

I have a 4000watt predator generator. Ran great for 2 years but at the end of Hunting season I had an electric heater plugged in I my camper and when it kicked back on it ran wide open all of a sudden and I'm not sure if it was making any electricity or not. I need to get it going so I can run my devices at camp. Could you help me with a starting point? Thank you for your time and educational teachings which by the way are great. Thank you!

[@Generatorguru]

Please contact us for help on our website to open a ticket with a senior engineer. www.generatorguru.com/need-help/ We will require the result from running the tests in this video to help you. Please provide this with your enquiry. kzbin.info/www/bejne/qnTCfaWoj8iraZo&lc=Ugwo15WlXUwe1A7d1kh4AaABAg :)

[@dreadlocksoutdoors492]

Helpful video. Thanks for sharing.

[@Generatorguru]

Glad it was helpful!

[@kenhilson786]

Wish you had indicated if the first voltage test of brushes failed was there any expectation that the next 3 tests be be ok.

[@Generatorguru]

Good point! We are looking at remaking the video soon as this one is very old now, and we will follow your suggestion. Thanks for taking the time and the suggestion, it is much appreciated. :)

[@mark31383]

Hello, Great video, thank you for taking the time for doing this. I would like to get your thoughts on the Harbor Freight generators. I have the 8K one and have had it a couple of years and it has been great, but it is a cheap chinese unit. I recently moved in to a house that looses power alot in the winter. I was thinking of upgrading the brushes and AVR to a US made parts to try to keep the unit reliable, would you recommend doing this? If so, who would you recommend getting parts from? Also, what are your thoughts on propane conversion kit? I have read mixed reviews. Finally, how long would you run a generator for? I just had a power outage for 6 days with an outside temp of 20F, pretty much ran the unit 24/7, only shutting it down for about 20 min every 8hrs to add gas and check the oil. Thank you, Mark

[@Generatorguru]

You can run your generator continuously so long as the engine has good air flow and you do not need to stop it to refuel. The propane conversion kits are very good (not for Natuaral Gas, just propane) and can save money depending on fuel costs in your area. There are not US made brushes or AVRs for this unit but you will find that the brushes and AVR are of a good quality and will last so long as you do not overload the generator or allow it to overheat. Please be aware Harbor Freight is not the generator brand name, it is a shop that sells many different good generator brands. To find grade "A" parts and spares for your generator, please look on the control panel to find the Brand name of the unit and the model code, and look up the name here. www.generatorguru.com/categories/Make-%26-Model/ :)

[@gertrudemartins1317]

I was running my heater off my generator (3000 watts)for about an hour when the heater when off. I checked the generator and it was running and smoking so I shut it off. Would that indicate my windings or alternator is burnt? Great video, very educational.

[@Generatorguru]

Yes, you will need to get the alternator rewound by a Motor Rewind shop. It is arcing and burning the varnish on the windings.

[@Raycr]

I ]'m wondering what the electrical problem is when my Predator 6500 watt genset produces about 20 volts on the rotor when checked running as in the video? Will there be shorted windings then?

[@engineeringdept.generatorg1760]

Can you please contact us with a full set of results here www.generatorguru.com/need-help/ Regards The Generator Guru Team

[@enochsteven307]

Thanks a lot for all of the fault finding techniques. Really appreciate it. I have one query and here it is. What will be the likely conclusion if I don't get any reading(0 Volts) with the brushes and the windings??

[@engineeringdept.generatorg1760]

As your results are showing a low voltage, we suggest you “Flash” your alternator. Follow the steps below: 1. To re-excite your alternator, we suggest you only use this method, as described by Generac Generators on KZbin: kzbin.info/www/bejne/Y321Z2WpopyIibc 2. Run the generator for 20 minutes without load to stabilize the magnetic field in the Alternator. 3. Test with a suitable appliance to make sure the load is stable. If not go to step 4. 4. Repeat our tests: www.generatorguru.com/help-me-fix-my-generator-repair-advice/ If results are below 1 Vac, repeat step 1. If this continues please contact us. If results are between 1-7 Vac, but you are not getting full voltage at the sockets, then you will need to replace your AVR/Capacitor. If results are above 8-10 Vac range, then you will need to replace your AVR/Capacitor. But be warned that the high reading will damage the AVR/Capacitor over time. This could result in it lasting a fraction of the time expected on a stable alternator. If results are above 10 Vac range, be sure you removed the AVR/Capacitor before testing. If you have and are receiving this result, we suggest you take your generator to a “Motor Rewind” company for repair. You can find your local Motor Rewinding company by doing a search on the internet for “Motor Rewind.” It is worth asking for a quote from a few Motor Rewind companies as their prices can vary greatly.

[@rossjackson7130]

I took the dust cover off and there did not appear to be an AVR. Generator is a powermax xpg1301 which is putting out 400vac

[@Generatorguru]

+Ross Jackson We think it is best you call us to discuss it with an Engineer. Can you please contact your local Generator Guru office via our website. www.generatorguru.com/. They will be happy to assist you. :)

[@Bsetzd]

I have a question I got a champion 4 k generator it just started doing this out of the blue when you put a 1100 watt load on the initial startup my window ac unit on the generator makes a buzz like sound coming out of the generator head what is causing this? now if I run my coffee maker that's pulling 1500 watts continuous it's absolutely fine?

[@Generatorguru]

+Brandon Setzenfand We think it is best you call us to discuss it with an Engineer. Contact your local office via our website. www.generatorguru.com/ :)

[@MyBacktrail]

I gave this video a thumbs up but I have to say, the rotor is NOT the stator. The rotor "rotates" and the stator is "stationary"> The stator is the part he calls the windings. The windings are in the stator.

[@Generatorguru]

Yes we had a note on the video but over the years youtube has changed this and we are unable to add it back on. But you are completely correct. I just got nervous in front of the camera and got mixed up. Sorry for the confusion.

[@serpentine1983]

Hi, thank you for the video. Nice of you. My generator has an output of 230[V]. The connectors don't say which one is L1-L2-R-R2, just says 1-2-3-4. 2 and 3 are connected with a wire. So L and R are in series. This are the voltages: Brushes: 8,32 [V] 1-2: 3,5 [V] 1-3: 3,5 [V] 1-4: 7 [V] 2-3: 0 [V] (same electrical point) 2-4: 3,5 [V] 3-4: 3,5 [V] Thank you very much.

[@engineeringdept.generatorg1760]

Dear Sir/Madam, As your Alternator has failed the tests, you need to contact a local “Motor Rewind Company” to see if they can fix it. These companies can vary in price, so if you have time, it is worth getting a few quotes. This is a much cheaper option than replacing the Alternator as the manufacturer charges over ½ the price of a new Generator and we would still need to get it shipped to you from China. Being so heavy, that would be very expensive and outweighs the economy of a new Alternator.

[@serpentine1983]

Thank you for your answer. appreciated.

[@Generatorguru]

Sorry for the late reply. Your message went to our youtube junk box for some reason. (I assume your voltage should be 110-120v where you live. 1st be sure you do not have a 230v socket on the generator, if you do then this is correct.) Your brushes indicate that the rotor diodes are failing as this should be around 5vac. Take the rotor to a "motor rewind" shop to see if they can fix it. This is your cheapest option. You can replace the AVR but the high readings from the rotor guarantee it will blow the replacement sooner rather than later. Hope this helps!

[@serpentine1983]

Where I live, it's 230 V. All sockets outputs in generator are 230V output. (L1-L2 in series with R1-R2) So, my readings are correct then? Got confused with "if you do then this is correct." Thank you a lot! I appreciate it A LOT.

[@Generatorguru]

Then yes this is correct. But the rotor readings are too high. If you replace the AVR it will work but the high VAC (should be 5vac yours is 8.32vac) coming from the rotor will burn it out sooner rather than later (never know how short a time either.) So you need to get the rotor seen to 1st if you can.

[@adriaanwinkelmans139]

Hi, Very clear explanation! I had 210 instead of 230 Vac on my generator output. All values of stator and rotor were fine. So, I raised the output voltage up to 230Vac by adjusting the potentionmeter screw on the AVR. So far so good, but now the 12Vdc 8.3A output is giving me too much voltage: 21Vdc. I assume this is a consequence of adjusting the AVR. Is there a way of to get the voltage back to 12Vdc without lowering also the AC output voltage? (Off course I could solder some resistor in series with the rectifier but that seems like an uneconomic solution...) For your information: I tested the diodes on the rectifier bridge that goes to the 12Vdc output and all 4 diodes seam fine. Generator: GENERMORE, CF6500 Thanks in advance!

[@Generatorguru]

You AVR is failing and needs to be replaced. There is no fix without replacing it for a new one. We do hold AVRs for Genermore Generators and would be happy to help you. You will need to contact our engineer to identify your particular AVR as they made this generator with 3 different alternators over the years. Please contact us on www.generatorguru.com/need-help/

[@Generatorguru]

No the L1 & R1 reading tells me the windings are arcing. Remove the winding and have a look to see if anything has got ground up between the long fins. If so remove carefully and reassemble. DO NOT USE OIL ON THESE PARTS! (you may not but many do, and oil and electric do not mix!) If this is not what has happened take the winding and the rotor to your local motor rewind company to be rewound. Hope this helps! If you need any more help call us. Our website lists our number. :)

[@notchfox6086]

Woow im going to check my Generator !! Thanks for the video!

[@miketh9234]

Thank you for the video. Just a quick question, you say the AVR protects everything, when I used the generator yesterday and it worked fine...although i may have overloaded the machine, so what I am understanding, it is the AVR is probably blown...do I need to do all tests or can I just replace the avr...the machine has not really worked that much, or do you suggest I do all the tests

[@Generatorguru]

Hello! Good question. 99% of the time it is just the AVR as the alternator has been overloaded, but run the test if you think you can smell electrical burning or if you have replaced the AVR recently, or just want to be sure before you replace the AVR. Overloading is the most common issue so be sure that you try to only load the generator 2/3 of max watts stated on the generator (unless it is a GENUINE "Honda Generator" i.e. not just the engine but the whole generator, as they already rate theirs at 2/3 power for you. They rock!) This allows for surges when things like motors start. Whenever you start anything there is a surge, and if it has a motor (like in fridges, freezers, drills, tools) it normally takes about double the running watts to start it. Other stuff takes less and they do not need to move anything, just excite their components. (Honda have an online calculator you can use.) If you calculate that you have not overloaded it, you might need to get your equipment checked for faults. A fault in anything attached can cause an AVR to fail. IF YOU ARE IN THE EU OR AUZ OR NZ- Please also be aware there are many generators being sold on selling sites and "side of road" sales that are mislabelled and a scam. They will do this by putting a model number like 8500w to make it look like they give out that amount, when in fact they only give our about 2.8kw. If you are suspicious as to what your generator gives out and it keeps blowing AVRs or Capacitors, please contact us on our website www.generatorguru.com and we will be happy to identify it for you. (Hint - these are mainly common in EU. Framed versions that have a 3 phase sockets and 3 x 240v plug sockets. There are also Inverter versions that are sold as 2000w but have a capacitor under the side flap (i.e. not an inverter and built to only give out 750w). Please contact us for full info on these units. They can still be used at lower power, but there are safety things you need to know if they have a 3 phase socket!)

[@Generatorguru]

If you have a capacitor then you need to have a look at my video for Brushless Generator Testing. You cannot fit an AVR unit to a brushless alternator without replacing the whole alternator and wiring system. It would be cheaper to buy an new generator, and a lot less hassle! Hope this helps!

[@doilHliob]

Thanks for the informative video. I am an experienced motorcycle mechanic, but wasn't sure what to look for in testing why my xp4400e generator was only producing 40 volts at the outlets. The tests you prescribed here showed all within normal operating parameters, is it your opinion that my AVR has quit? Thanks again!

[@Generatorguru]

Please drop us an email via our online form on the website.

[@Generatorguru]

It could be that the floater in the carb is stuck. I suggest a good clean, and inspection of the whole carb. If there is old or dirty fuel it will allow to much fuel through to the engine. The only other thing it will be is a governor problem, but this is very rare.

[@Generatorguru]

Please call us to discuss as we will need more info. Our number is on our website.

[@alfredkabura]

I will be opening that part of my generator tomorrow hopefully nothing major is wrong.

[@Generatorguru]

Rotor needs attention.. Windings may not but need to fix rotor and re-test. Check the diodes on the rotor and replace if possible. This should fix it for you. Some do not have the diodes showing. If that is the case take the rotor and winding to your local "motor rewind" company and they should be able to rebuild it for you. Hope this helps :)

[@eusebiomunozhumanez7076]

Que bien por la traduccion al español seguire en contacto

[@Moeterboater]

Hi, I've inspected everything and it all looks good. The generator is very new, used only a few times but it's been sitting in the shed for a few years. Does it sound like the AVR is gone? Would that horrible noise I described come from the generator if the AVR was gone?

[@deetee27]

Hi Guru, Thanks for this informative video. I have a generator with 220v and 400v. outlets. No power on the outlets. I measured 2,2 v on the brushes. L1-L2 16,2 v, R1-R2 9,0v R1-L1 16,3v (and R2-L2 8,8v). I understand this readings are a bit high and now I should investigate the windings. Is that right? In your video you said that I must contact you, how I can do that. Can you help me with that? Kind regards Dick Terweij

[@TauCu]

I seem to have a problem, I'm using a gentech 5kw alternator (with a honda 9HP engine) and i noticed that the generators voltage drops to almost 180v~ from 250v~ under 3 kw load, The engine doesn't seem to bog down, however, when i pulled a small bit on the throttle, the voltage rises a fair bit (i didn't want to push it past 260v) I initially thought the Regulator was bad, so i opened it up, however there didn't seem to be a regulator in sight! the only thing i did see was a large capacitor (something you would find on an induction motor for starting) Any ideas? My only answer would be that the regulator is perhaps between the engine and Alternator cooling fan? (also there was no brushes that i could see at the back of the alternator, but there was an exciter winding. Thanks Tau

[@Generatorguru]

Can you call us? We would love to help and talk you through it! Our full contact details can be found on our "Contact Us" page here: www.generatorguru.com/ask-the-guru/

[@jorg7913]

Verry good !!!! thanks s lot , mam

[@Generatorguru]

Always happy to help! FYI... We also have loads more info on repairs and maintenance on your website if you ever need it. :) www.generatorguru.com/need-help/

[@juniortoigin3670]

Good nice explanation, can you please tell me this four wires coming out of avr. Which color wires for? (two blue, one white & one yellow wires)

[@Generatorguru]

Hmmm... Ok lets assign your issue to one of our engineers. Please contact them to set up a ticket on generatorguru.com/need-help/.

[@wyattoneable]

Outstanding video, very helpful Thank you.

[@jamesbarratt593]

So and I couldn't see exactly, but presume when checking brushes for voltage, you were connecting the meters leads to the leads that connected to the brushes, and NOT the terminals of the brushes themselves. My understanding is that volts have to be applied to the rotor and stator to create the magnetic field for the windings to enhance. Id I am right about checking the leads and there's voltage, then I check L1 L2 and R1 and R2 as you have shown. Thanks

[@Generatorguru]

+James Barratt You need to test across the brushes. I.e. the tabs protruding from the brushes. :)

[@FinNote]

Hi. I have Kraftech KT-8500W Power Generator - 6500 Watts / 6.5 hp / 4 stroke / 12V, 220V, 380V. No voltage output my results 1) 5.7 V 2) 7.8 V 3) 7.6 V 4) 11.3 V Please HELP..Thanks

[@Generatorguru]

Please, can you contact us on [e-mail] with these readings and about this generator. We would like to discuss it with you further.

[@gmaster5482]

Thanks for your video. But can you tell me how much the input and output voltages across the AVR. Because i have replaced 2 AVRs but generator has still no power output. What should i do?

[@engineeringdept.generatorg1760]

Thank you for contacting Generator Guru can I please ask What results you are getting from the tests on the video Regards The Generator Guru Team

[@stevengeorgecleator5040]

Top vid , cheers mate . Very informative.

[@Generatorguru]

Glad you enjoyed it

[@Generatorguru]

An inverter AVR is very large (at least 200 x 250 mm) and most of the generator models will have an "i" in it. e.g. kge1000ti Capacitors only have 2 or 4 wire connections. Therefore everything else has an AVR. Hope this helps :)

[@MeltingRubberZ28]

Hey man, have a true life 4500 generator. Runs like a top but I am getting the following voltages: on the 120v receptacle, 20 volts. On the 240v receptacle, 40 volts. On the 12v DC prongs, 2.5 volts. I'll have to see what I can do to get that rear cover off, but when I removed the bolts the cover wouldn't come off. Will try these tests sometime soon.

[@engineeringdept.generatorg1760]

Hi there For fault finding or technical advice, feel free to contact us using the link below www.generatorguru.com/need-help/ This will allow our engineers to review your query and give you the best possible advice!