It is mind boggling to me how anyone sitting in front of a computer watching a professional diagnose and repair at the level that you do here for them to give a thumbs down. The amount of value that you give to the world in small engine and generator repair is unprecedented, and I am so thankful that you take the time to teach as you do. Absolutely awesome. Thumbs up for sure brother.
Not sure why you are confused. Some people just look for videos to down vote. Could also be that his videos are largely unedited. Could also be the audio that starts breaking up during the gen operation.
Came here after watching Part 1. Although I;m now retired... from one field technician to another... you are amazing and a credit to the industry. I'd be proud to work along side you any day. I can only hope the folks that have you do their maintenance and or repairs are aware how lucky they are to have you at their service.
I'm probably twice your age, so happy to see a modern technician thinking old school. You need to take on an apprentice or 2 during your lifetime. You have a lot of old world knowledge along with current to offer.
Agreed! I wasn't even a big fan of generators in general before, but have a new-found interest in them, and have plans to clean up and upgrade my 1970-vintage Kohler 3.5KW genny that came in my 1970 "Ute Liner" motorhome. It's a 4-pole unit, so it turns at 1800RPM, meaning it is quieter and longer lasting than the typical 3600RPM "cheapies"
I'm a racing engines , engine, fuel, and elec, system builder, trouble shooter, and repairs/inventafix, Guy. And my take on your trouble shoot, inventafix, and test run. Show a better than factory piece of machinery here . I would just as soon buy this repaired Gen. as a new one !! Good Job Iearned a lot. God Bless
As a kid, I ran a 24 VDC fan off a variable supply. If you looked at a rotating object THROUGH the spinning fan, it had the same effect as a strobe (you could stop apparent motion by adjusting the fan speed).
I have the same Genset at my home in Mexico. The only problem I have ever had was the tiny copper exposed brush wires rotted out. Since finding your channel, I am way more well versed in the operation of the generator. Thanks for showing us all how an expert repairs generators.
Wow, I said this about one other fellow on You Tube: you should be teaching this material at the local Community College or Technical School. Your repair was genius. Thank you for sharing your brillance!!!
What amazes me is the generator can deliver that amount of power out of such a physically small machine. Granted, over here in the UK, we're working on a different system, but we have a couple of 20kW generators in our yard, which by comparison, are huge. Our little 6kW unit is about the same physical size as yours. It has to be said though, they date from about 1963 to about 1978. Maybe that also says something? Come to think of it, we have a little Onan RV2 (I think it is) 2.2kW propane RV generator from about 1962 - Nice machine when it's up and running.
The design of those stupid studs is so incredibly bad. Relying on a connection by pushing that hub on there...really!! Bad engineering!! But...Beautiful fix. Thumbs up!!
Some gen manufacturers rate these home units when run on LP gas. As you figured when on natural gas you must derat. NICE JOB. I have a 30 year old kohler 18 kw. Has a 2.3 l Ford engine, 1800 ram still going. I worked for a Cat dealer as a EPG Technician for 43 years. NIVE JOB
I have painted a lot of Glyptal red enamel on different things. One time we had an arc fault in an incoming feeder which continued into the main breaker on a 480 volt 800 amp service. The breaker was badly carbon tracked, with deep grooves, of course the company that produced the breaker was no longer in business and we needed to get the service back on immediately.. Obviously we had to get the carbon tracks out. I took the breaker to a sand blast cabinet and removed the finish off the breaker and painted the breaker with the Glyptal and put it back in service as soon as the paint had dried. It worked fine and was still in service 10 years later. I also cleaned and painted the inside of the breaker enclosure with the same paint. I painted a lot of 5000 volt bus bar that had been covered with a covering that had no adhesive. It is great stuff. Looks like you have a winner here. Have you checked to see if there is any vibration caused by adding weight to the rotor on two places and possibly not being equal?
Hey Mike, you are a STUD!!!!!!!!!!!!!!!!!!. So nice to see a younger guy who has a real understanding of OLD SCHOOL logic and a full understanding of multi trades and equipment systems. LOVE your old load bank.Good Luck in your work and life.
I'm an engineer myself, but on the computer and networking design architect side working Microsoft and the Fed for years, but i still embrace my mechanical roots, I rebuilt my first car engine at 15 years old, and i took apart every mechanical toy i got my hands on when i was wet behind the ears. I don't get to work hands on with small motors much anymore, too much arthritis and bad eyesight, but your videos are an absolute joy to watch. You are thorough, easy to understand, and meticulous. Your stroboscope trick was excellent, a lot of times that's hard to catch with a camera. Thanks for keeping us entertained!
Surprising that the manufacturer did pot or epoxy those connections on the rotor. A cheap looking assembly for a brand name that really should know better.
The comments below attest to how much anyone of knowledge appreciates you solving the problem. You sir are a top of the line technician. I was in the field for 35 years and I can say without a doubt you rate at the top.
I had a chat with a cell site guy who has lots of sites he and the company he works for maintain. He said the sites with Generac units have the most problems with the generators, I forget his call but he is in the Midland TX area. KØOJ
@@ojjenkins7110 I bet alot of them have that stupid design fault that could be fixed with that solder/epoxy job on the rotor assembly...probably wouldn't hurt to Glyptal the stator windings like he did as well to protect from the environment...sad that that particular design is the weak point...Generac is normally bulletproof!
Nice work Mike, that strobe o scope proves how solid your repair is. It’s a sad state of manufacturing that this one got out of the factory. Hopefully somebody high up will watch your video
Small engine mechanic is an understatement to what you are. I’m blown away at your generator knowledge and your hands on skill. Much respect keep up the good work
Thanks for this video, I understand a little more about generators. I also watched a machinist building a 2-Stroke .60 ci model airplane engine and now understand a little more about machining. YT is a great source of entertainment and information. Respect for your skills.
I'm not sure how I ended up here, but this is amazing work. Great job and thank you for the two part video on your troubleshooting, repair, and testing!
you must really enjoy this field of work, you are into this heart and sole . It is nice to see folk enjoy work this way . Great video on the repair and find of issue. I enjoyed this very much . Thank you .
You are a rear great tech and produce awesome videos. Gen is around 18kw on NG and 20kw on Propane. Also good to verify the settings in the controller is set to NG not Propane. This will through off the controller thinking the rating is low on the display. Your gas reading is below the minimum required. Cummins specs the number at full load. But she ran good under spec. This is why the governor was pushing everything it has and shut down to protect it. I would check the fuel settings.
That generator is in better condition now than what it was when it left the factory. This guy knows his stuff. I would definitely buy used stuff like this from him. He makes them better than new.
Another thing is derating for altitude... which can be significant but probably isnt' the whole picture. I really am impressed with he amount of effort you put in to make this a a solid repair.
The 20 kw rate is surge power for a short duration of time. Mfg's use that number for marketing shine. All gen's true rating (full design load) will be about 15 % less. Always look for full design load rating for the fuel type you are using. Forget about the surge watts. BTW, gasoline and propane fuel will always give more output watts than natural gas, but still lower than short duration surge watts.
I worked for a contractor years ago and he installed a generac version of this at his house. He had the city install a 2lb meter and ran all his other appliances on regulators so he could get propane pressure for the generator.
@@squintin480 Yes and many newer meters can be tweaked for a modest increase in gas flow by the utility. Not always required to install a different meter. Most small residential generators run very well with a steady 6-7 inches of water column at full rated load. Thats about .4 PSI of pressure in the pipe.
Great video... and I have to say I loved the use of the stroboscope.. in addition to measuring the RPM, you can actually inspect the armature while under centrifugal force.
To those people who want a whole house generator should check this video. My town probably like most towns are getting upgraded gas lines and pressure. So this unit can probably get close to its rating. These Natural gas / Propane units are nice but I think fall short on peoples perceptions on ability to run constantly for long hours and possibly at high loads at 3500 RPMS. They should be used for essential equipment and appliances. This is a excellent video tutorial.
@Edgar Miller I like this repair video and since part one I've been looking to find out how long Cummins made propane or CNG engines.... it looks like they're 'lowest bidder' from you-know-where.
Excellent fix...permanent and done right...sad that the design is so weak that causes all those issues...you solder then epoxy is never gonna fail! Keep em coming!
Mike, I'm the former owner of a company that did all the automation for Cummins at the Fridley MN plant (for 17 years) and specifically for the line that this unit was manufactured on. I have intimate knowledge of the manufacturing of this unit. Your assumptions are spot on. Also, I own this same exact unit, it has 150 hours on it. Happy to answer any questions.
You sir are one heck of a great mechanic I’d be honored if you ever worked on anything of mine that was awesome when you showed the gen running with the strobe light wow
Good job! I like your approach to troubleshooting and you do good quality repair work too. I also like your post repair testing. Nothing left to question.
You did a great job of repair. If I had to add a little advice it be to use very high temperature epoxy as the rotating field usually runs quite a bit hotter than the stator., of course you are not directly on the windings. An old Delco generator engineer. Thanks for a very interesting video.
Well actually.... it's not sloppy work, it's an engineering design issue which was implemented to simplify the manufacturing process. In this case, most likely that whole rotor assembly including winding, wire orientation across the press fit slip ring with pin assembly was machine fitted and assembled. That's why the press fit pin electrical wire connection was implemented, easy work for a machine.... unlike solder or wire crimp located in such a small and delicate area.
Diagnostic skills..check / perseverance...check / a clever repair...check. Well done sir. And they said it couldn't be fixed. Yeah right! Good job. A blessed and Merry Christmas to you and your extended family.
That strobe light was pretty darn cool. I'm used to seeing timing lights on engines and stuff so when you fired that thing up at 3600rpm I was surprised how crisp and easy to see everything was. Looks like you've got a good genset there. I hope you're able to make a nice little profit on it now that it's not only repaired but also a little product improvement implimented with the potting on that rotor and the addition of the Glyptal. I've seen that stuff used inside lifter valleys and crank cases to help oil drain faster.
Super video! I came to the conclusion that, at the full load, the engine wasn't getting enough fuel, (low pressure), and the governor was demanding more power. An excellent teaching video. I have a cheap Chinese 5.5 KW unit that has discoloured windings just like what you saw on this unit. I will now be able to have a closer look to determine whether or not the unit was overloaded. My problem is, that I couldn't find the correct resistance for the stator windings.
I would have done the same diagnostics and repair... good job you did more than those cummin guys I love the way you explain the details... You earn my subscription Love from the PH 🇵🇭🇵🇭🇵🇭
Wow what a job you did on this machine. Wished I lived closer to you. You do such a great job of quality work in what ever you do. Great generator now. Thanks for the video. Merry Christmas
Great video. And I love your diagnostic abilities: I don't know if they're natural aptitudes or if you simply have thousands of hours of experience, but I'm impressed regardless.
Solid troubleshooting, diagnostics, and professional repair. The additional weight of the wrap and resin should be negligible as they sit so close to the bearing. 65amps of 1.5hrs. continuous load is an overkill test scenario for a 20kw Natural Gas household standby generator. I agree your gas meter & possibly your gas regulator could limit a full load test. Also residential gas pressures do float a little and most older homes installing a home standby generator will require a meter & prv upgrade. FYI you should setup a Raspberry Pi as a data logger with 3 CT clamps(L1,L2, and battery charging amps), 3 volt clamps(L1,L2, battery), 2 temp probes ( engine water temp & exhaust temp) you can monitor these data points from your cell phone with a terminal server browser connection.
A nice repair, it's clear to see why Cummins have dropped this supply of stators ! Very poor quality. A nice piece of equipment to have if you live in an area where supply suffers regular disruptions.
5:11 Just discovered your channel. Sorry if this is redundant but as convenient as the hypodermic-style epoxy is, I've been using West System marine-grade epoxy and additives for decades, mainly for boat applications. For the rotor repair encapsulation I'd use their 105 resin and 205 (fast) hardener plus their 404 high-density filler. You can mix as much or as little of the filler as you want to achieve the perfect viscosity. Skip the pumps that screw into the cans, they eventually become a huge mess ... just pour it out carefully ... I use a quality kitchen scale to measure the 2 parts accurately 5:1 resin/hardener by weight. Little plastic cups are great for small batches. The resin and hardener last (almost) forever if you store them in a place that doesn't bake in the summer.
That thing is pretty quiet with all the enclosure on. At least you were able to test the overload shutdown, although you didn't expect it initially. Didn't over heat, your repair was excellent and your test came through with flying colors! nice genset!
I like his comment about the noise level and when he said " maybe a bit much in a residential area", first thing I thought was not if everyone is out of power and you are warm because your neighbor with the " noisy generator" is sharing some of his power with you!
When I installed my 33KW genset, I installed an outdoor breaker panel with 6 20A NMEA outlets 120/240V. They buried long dropcords between us. My deal is they keep my 250 gallon #2 fuel tank filled and pay for genset maintenance and I power up the cords when the grid dies. It's a great deal!
The load shutdown was very likely the result of not having the required fuel pressure to allow for the unit to meet the demand. The unit was at 100% throttle for more than 10 seconds which resulted in the shutdown. If you had the required fuel pressure/ volume this would not have happened. I think you got this one fixed. I would be comfortable with it being capable of taking a full 20KW load for short periods at a time and carrying a 16KW load constant. Good job, you get an up vote.
Now, it's had a good break-in period, time to change the oil and filter(if equipped) and adjust the valve clearances. It should last for another decade, as a backup generator for a residence. I would just recommend that the oil level be checked after every black out, to make sure it's ready for the next black out. The problem with natural gas, is that it can be considered an "infinite" fuel source. The generator won't run out of fuel, before it runs out of oil!! With propane, gasoline, or diesel, it's easy to remember to check oil level each time it's refueled. With natural gas, you must be vigilant on maintaining proper oil level. Most of these generators have a low oil cut off, but that is only a safety stop gap, not an intended low oil indicator. A generator like this should be test run periodically, and should run loaded for at least an hour each time, just to evaporate any moisture that has condensed in the oil from prolonged periods of non use. These are a good time to check the oil.(These are my biggest concerns for backup generators)
Even though I didn't understand some of the technical terms used, it's still obvious, at least to me, that you know what you're doing. I have no problem believing your explanation of the diagnosis.
I appreciate repairs that exceed new condition. The customer with the new warranted gen will be dealing with this again someday. But I know you'll be there for them if it does happen. I have this generator, with this fault, although mine was throwing sparks near the oil cooler also. So, more than one issue, I would say. Thanks very much for the video. Great stuff.
YOUR VIDEOS ARE THE BEST !!!!! ❤ I am contemplating buying a 3600 rpm standby home generator. All of these companies really market their engines and do videos on them like the engine is the only thing that matters. Watching you diagnose the Rotor/Stator was fascinating. I wish there were videos where you take apart various Home StandBy Generators and show people what manufacturer is the most robust generator vs the price point. I was shocked to see only 40 hours ! On the generator !! You would think these manufacturers would inspect their parts before assembly. I am currently looking at: Cummins 13Kv Kohler 12Kv Briggs & Stratton 12Kv Champion 12.5 & 14Kv Not sure about B&S because it is a vertical shaft twin. Not sure about the reliability. Anyway, just wanted to say very interesting Thank You.
Spike Mike a few comments back. I like the way you approached the repair. I would be very confident about that. I was talking to the screen at the end of part one to lace up the repair.
Hi Mike, I have really enjoyed this series of repair and testing of this unit. My hats off to your mechanic abilities. I also see that these type repairs are what you do for your living. Well done.👍👍👍👍👍✌🏻🙏🏽🇺🇸
Nice work. Strobescope was a clever idea. I would guess, the 22 fault was fuel supply. The 59 hz indicates to me you were out of motor (throttle wide open, low fuel). The other shots showed the govenor holding 60 hz tight. Maybe an O2 exhaust sensor would show it leaning out from low nat gas pressure if you have one to play with. Just thinking out loud. Keep up the great work.
I have a Generac generator 30kw I had it installed 14 years ago. My house is 6200 sq ft. It runs everything in the house never had one problem with it. It runs off of propane . It starts 1 time a week for 15 mins. It was worth every dime I paid. I have mine mounted away from the house like 75 ft. You can't here it at all but I live out in the country. I did have to put a new battery in it. It has a 4 cly GM motor.
It is mind boggling to me how anyone sitting in front of a computer watching a professional diagnose and repair at the level that you do here for them to give a thumbs down. The amount of value that you give to the world in small engine and generator repair is unprecedented, and I am so thankful that you take the time to teach as you do. Absolutely awesome. Thumbs up for sure brother.
Cummins employees probably.
Not sure why you are confused. Some people just look for videos to down vote. Could also be that his videos are largely unedited. Could also be the audio that starts breaking up during the gen operation.
My thumbs up just pushed him to 5K likes. Hope that helps, LOL.
A thumbs down come from envy.
Came here after watching Part 1. Although I;m now retired... from one field technician to another... you are amazing and a credit to the industry. I'd be proud to work along side you any day. I can only hope the folks that have you do their maintenance and or repairs are aware how lucky they are to have you at their service.
exact same comment, and I was know to pretty good but not at your level
I'm probably twice your age, so happy to see a modern technician thinking old school. You need to take on an apprentice or 2 during your lifetime. You have a lot of old world knowledge along with current to offer.
That thing's in better shape now than it was brand new. Nice little genset.
And guaranteed not to go kaput due to that stupid design that would open the rotor coils
Indeed
Thanks Mike for all of your video's. I rather watch your video's instead of watching the TV. AAA+++++++++😄
Sir, you are one of the most knowledgeable generator guys on RUclips. I have learned an immense amount from you. Outstanding!
I'll second that. Always great videos and I always learn from them. Keep up the good work.
DITTO
You guys should ALSO checkout James Condon.
Agreed!
I wasn't even a big fan of generators in general before, but have a new-found interest in them, and have plans to clean up and upgrade my 1970-vintage Kohler 3.5KW genny that came in my 1970 "Ute Liner" motorhome. It's a 4-pole unit, so it turns at 1800RPM, meaning it is quieter and longer lasting than the typical 3600RPM "cheapies"
I'm a racing engines , engine, fuel, and elec, system builder, trouble shooter, and repairs/inventafix, Guy. And my take on your trouble shoot, inventafix, and test run. Show a better than factory piece of machinery here . I would just as soon buy this repaired Gen. as a new one !! Good Job Iearned a lot. God Bless
Your repairs to the machine are several times more than the O.E.M. build quality.
26:13 He gets a lock on the strobe frequency vs rotor frequency! real cool!
That was really neat, looking with the strobe.
I want one.
@@greengmcrob They are everywhere on mechanics shops and similar, and on amazon no doubt.
I used one all the time when I was in the Navy.
As a kid, I ran a 24 VDC fan off a variable supply. If you looked at a rotating object THROUGH the spinning fan, it had the same effect as a strobe (you could stop apparent motion by adjusting the fan speed).
I have the same Genset at my home in Mexico. The only problem I have ever had was the tiny copper exposed brush wires rotted out. Since finding your channel, I am way more well versed in the operation of the generator. Thanks for showing us all how an expert repairs generators.
Wow, I said this about one other fellow on You Tube: you should be teaching this material at the local Community College or Technical School. Your repair was genius. Thank you for sharing your brillance!!!
What amazes me is the generator can deliver that amount of power out of such a physically small machine. Granted, over here in the UK, we're working on a different system, but we have a couple of 20kW generators in our yard, which by comparison, are huge. Our little 6kW unit is about the same physical size as yours. It has to be said though, they date from about 1963 to about 1978. Maybe that also says something?
Come to think of it, we have a little Onan RV2 (I think it is) 2.2kW propane RV generator from about 1962 - Nice machine when it's up and running.
I find it very hard to believe that the manufacturer’s assembly process is so subpar, especially for Cummins. Great job repairing it.
The design of those stupid studs is so incredibly bad. Relying on a connection by pushing that hub on there...really!! Bad engineering!! But...Beautiful fix. Thumbs up!!
You can see why they changed the generator.
They probably have many more faults.
Some gen manufacturers rate these home units when run on LP gas. As you figured when on natural gas you must derat. NICE JOB. I have a 30 year old kohler 18 kw. Has a 2.3 l Ford engine, 1800 ram still going. I worked for a Cat dealer as a EPG Technician for 43 years. NIVE JOB
I have painted a lot of Glyptal red enamel on different things. One time we had an arc fault in an incoming feeder which continued into the main breaker on a 480 volt 800 amp service. The breaker was badly carbon tracked, with deep grooves, of course the company that produced the breaker was no longer in business and we needed to get the service back on immediately.. Obviously we had to get the carbon tracks out. I took the breaker to a sand blast cabinet and removed the finish off the breaker and painted the breaker with the Glyptal and put it back in service as soon as the paint had dried. It worked fine and was still in service 10 years later. I also cleaned and painted the inside of the breaker enclosure with the same paint. I painted a lot of 5000 volt bus bar that had been covered with a covering that had no adhesive. It is great stuff. Looks like you have a winner here. Have you checked to see if there is any vibration caused by adding weight to the rotor on two places and possibly not being equal?
Hey Mike, you are a STUD!!!!!!!!!!!!!!!!!!. So nice to see a younger guy who has a real understanding of OLD SCHOOL logic and a full understanding of multi trades and equipment systems. LOVE your old load bank.Good Luck in your work and life.
I'm an engineer myself, but on the computer and networking design architect side working Microsoft and the Fed for years, but i still embrace my mechanical roots, I rebuilt my first car engine at 15 years old, and i took apart every mechanical toy i got my hands on when i was wet behind the ears. I don't get to work hands on with small motors much anymore, too much arthritis and bad eyesight, but your videos are an absolute joy to watch. You are thorough, easy to understand, and meticulous. Your stroboscope trick was excellent, a lot of times that's hard to catch with a camera. Thanks for keeping us entertained!
I was wondering if you would epoxy the tails, good to see that you have. You do great work, always good to see your projects.
You're more interested in quality than the manufacturers. Too bad for them, good for your customers. Great videos.
It's Mike, of course he'd epoxy them. :))
Solid as a rock now!
Surprising that the manufacturer did pot or epoxy those connections on the rotor. A cheap looking assembly for a brand name that really should know better.
It is nice to watch a craftsman at work.
The comments below attest to how much anyone of knowledge appreciates you solving the problem. You sir are a top of the line technician. I was in the field for 35 years and I can say without a doubt you rate at the top.
Great job! Darn shame you had to go in and fix all the things that should have been done when it was built.
I had a chat with a cell site guy who has lots of sites he and the company he works for maintain. He said the sites with Generac units have the most problems with the generators, I forget his call but he is in the Midland TX area. KØOJ
@@ojjenkins7110 I bet alot of them have that stupid design fault that could be fixed with that solder/epoxy job on the rotor assembly...probably wouldn't hurt to Glyptal the stator windings like he did as well to protect from the environment...sad that that particular design is the weak point...Generac is normally bulletproof!
Hi, your not concerned with weight for balancing the rotor with all the extra expoxy?That Gyptal is painted on in engine crankcase too,good stuff.
Mabe this one was made in china
Very good repair though 🤓👍
Thank you taking us along for the repair!
Strobe video is awesome!
Nice work Mike, that strobe o scope proves how solid your repair is. It’s a sad state of manufacturing that this one got out of the factory. Hopefully somebody high up will watch your video
China built ? more than likely.
Small engine mechanic is an understatement to what you are. I’m blown away at your generator knowledge and your hands on skill. Much respect keep up the good work
Thanks for this video, I understand a little more about generators. I also watched a machinist building a 2-Stroke .60 ci model airplane engine and now understand a little more about machining. YT is a great source of entertainment and information. Respect for your skills.
I'm not sure how I ended up here, but this is amazing work. Great job and thank you for the two part video on your troubleshooting, repair, and testing!
When any of your things brake down you better hope to get a mechanic like this...amazing job
Great to see the detail of the repair running at 75% load. That's the way to make a correct repair. Well done!
Great repair on that rotor. The rope and epoxy was a nice touch. I was worried about the centrifugal force on the solder fixes until you added that.
Excellent repair, good idea to pot the repair and taking the time to touch up the windings, your repairs will outlast the generator.
you must really enjoy this field of work, you are into this heart and sole . It is nice to see folk enjoy work this way . Great video on the repair and find of issue. I enjoyed this very much . Thank you .
That stroboscopic effect video came out great. That was awesome.
You are a rear great tech and produce awesome videos. Gen is around 18kw on NG and 20kw on Propane. Also good to verify the settings in the controller is set to NG not Propane. This will through off the controller thinking the rating is low on the display. Your gas reading is below the minimum required. Cummins specs the number at full load. But she ran good under spec. This is why the governor was pushing everything it has and shut down to protect it. I would check the fuel settings.
That generator is in better condition now than what it was when it left the factory. This guy knows his stuff. I would definitely buy used stuff like this from him. He makes them better than new.
Outstanding workmanship. Well done.
Another thing is derating for altitude... which can be significant but probably isnt' the whole picture. I really am impressed with he amount of effort you put in to make this a a solid repair.
Strobe tool is awesome.
Awesome fix.
These generators are often de-rated for natural gas. The full rating is for propane. Perhaps that's what you ran into there at 21:00
The 20 kw rate is surge power for a short duration of time. Mfg's use that number for marketing shine. All gen's true rating (full design load) will be about 15 % less. Always look for full design load rating for the fuel type you are using. Forget about the surge watts. BTW, gasoline and propane fuel will always give more output watts than natural gas, but still lower than short duration surge watts.
I worked for a contractor years ago and he installed a generac version of this at his house. He had the city install a 2lb meter and ran all his other appliances on regulators so he could get propane pressure for the generator.
@@squintin480 Yeah..gonna need a bit more oomph to run an engine on natural gas than what is normally fed thru household meters
He said that at the end
@@squintin480 Yes and many newer meters can be tweaked for a modest increase in gas flow by the utility. Not always required to install a different meter. Most small residential generators run very well with a steady 6-7 inches of water column at full rated load. Thats about .4 PSI of pressure in the pipe.
Great video... and I have to say I loved the use of the stroboscope.. in addition to measuring the RPM, you can actually inspect the armature while under centrifugal force.
To those people who want a whole house generator should check this video. My town probably like most towns are getting upgraded gas lines and pressure. So this unit can probably get close to its rating. These Natural gas / Propane units are nice but I think fall short on peoples perceptions on ability to run constantly for long hours and possibly at high loads at 3500 RPMS. They should be used for essential equipment and appliances. This is a excellent video tutorial.
They obviously employ real craftsmen at the factory, who take great pride in their work!
craftsmenship is more small business stuff these days, factories are all about reaching targets and yields
You mean Hung Chow at the grass hut?
It was designed to fail
@Edgar Miller I like this repair video and since part one I've been looking to find out how long Cummins made propane or CNG engines.... it looks like they're 'lowest bidder' from you-know-where.
Excellent fix...permanent and done right...sad that the design is so weak that causes all those issues...you solder then epoxy is never gonna fail!
Keep em coming!
Troubleshoot, locate cause, perform repair, test like you want it to fail, you sir are a professional on every level, period.
Mike, I'm the former owner of a company that did all the automation for Cummins at the Fridley MN plant (for 17 years) and specifically for the line that this unit was manufactured on. I have intimate knowledge of the manufacturing of this unit. Your assumptions are spot on. Also, I own this same exact unit, it has 150 hours on it. Happy to answer any questions.
You sir are one heck of a great mechanic I’d be honored if you ever worked on anything of mine that was awesome when you showed the gen running with the strobe light wow
A true professional.
Good job! I like your approach to troubleshooting and you do good quality repair work too. I also like your post repair testing. Nothing left to question.
Fantastic diagnostics young man. You can consider yourself an expert in my experience.
Nice to see the strobe effect clearly, I was expecting all kinds of rolling shutter shenanigans.
You did a great job of repair. If I had to add a little advice it be to use very high temperature epoxy as the rotating field usually runs quite a bit hotter than the stator., of course you are not directly on the windings. An old Delco generator engineer. Thanks for a very interesting video.
Thumbs down are from the generator employees that did the sloppy work.
Proud union workers
Chances are real slim that the rotor and stator were US made.
Well actually.... it's not sloppy work, it's an engineering design issue which was implemented to simplify the manufacturing process. In this case, most likely that whole rotor assembly including winding, wire orientation across the press fit slip ring with pin assembly was machine fitted and assembled. That's why the press fit pin electrical wire connection was implemented, easy work for a machine.... unlike solder or wire crimp located in such a small and delicate area.
Cool repair! That strobe scope is the coolest thing I've ever seen. Thanks for the vids.
I'm assuming your furnace is gas , it may have come on and dropped your NG supply pressure.
Imagine if manufacturers made videos this practical, detailed and helpful.
Dream on.
Diagnostic skills..check / perseverance...check / a clever repair...check. Well done sir. And they said it couldn't be fixed. Yeah right! Good job. A blessed and Merry Christmas to you and your extended family.
I agree.
That strobe light was pretty darn cool. I'm used to seeing timing lights on engines and stuff so when you fired that thing up at 3600rpm I was surprised how crisp and easy to see everything was. Looks like you've got a good genset there. I hope you're able to make a nice little profit on it now that it's not only repaired but also a little product improvement implimented with the potting on that rotor and the addition of the Glyptal. I've seen that stuff used inside lifter valleys and crank cases to help oil drain faster.
I am so impressed with your vast knowledge and expertise.
Very informative on how a genset can perform.
Nicely presented. I reckon that generator had already been through some repairs hence the scraping on the inside walls of the stator.
that strobascope is really cool ....really neat how it can hold that still .. nice tool great vid!!
Super video! I came to the conclusion that, at the full load, the engine wasn't getting enough fuel, (low pressure), and the governor was demanding more power. An excellent teaching video. I have a cheap Chinese 5.5 KW unit that has discoloured windings just like what you saw on this unit. I will now be able to have a closer look to determine whether or not the unit was overloaded. My problem is, that I couldn't find the correct resistance for the stator windings.
This has some quality to it. It's like an Autoweek for engine repairs.
I would have done the same diagnostics and repair... good job you did more than those cummin guys
I love the way you explain the details...
You earn my subscription
Love from the PH 🇵🇭🇵🇭🇵🇭
The truth is Cummins would have replaced it and no repairs
Wow what a job you did on this machine. Wished I lived closer to you. You do such a great job of quality work in what ever you do. Great generator now. Thanks for the video. Merry Christmas
I was going to say, how much fun it would be just hanging around his shop. Hell, I'll sweep the floor just to be able to watch.
Excellent video. Thanks for sharing your knowledge. I was amazed how well the mic picked up your voice over the gennie
Glad to see that you did secure the solder and #14 solid wire from centrifugal force.
Great video. And I love your diagnostic abilities: I don't know if they're natural aptitudes or if you simply have thousands of hours of experience, but I'm impressed regardless.
I don't want to be misunderstood but, me too.
Solid troubleshooting, diagnostics, and professional repair. The additional weight of the wrap and resin should be negligible as they sit so close to the bearing. 65amps of 1.5hrs. continuous load is an overkill test scenario for a 20kw Natural Gas household standby generator. I agree your gas meter & possibly your gas regulator could limit a full load test. Also residential gas pressures do float a little and most older homes installing a home standby generator will require a meter & prv upgrade. FYI you should setup a Raspberry Pi as a data logger with 3 CT clamps(L1,L2, and battery charging amps), 3 volt clamps(L1,L2, battery), 2 temp probes ( engine water temp & exhaust temp) you can monitor these data points from your cell phone with a terminal server browser connection.
A nice repair, it's clear to see why Cummins have dropped this supply of stators ! Very poor quality.
A nice piece of equipment to have if you live in an area where supply suffers regular disruptions.
Awesome job getting it to run like it should. Always enjoy watching you and learning a lot!
5:11 Just discovered your channel. Sorry if this is redundant but as convenient as the hypodermic-style epoxy is, I've been using West System marine-grade epoxy and additives for decades, mainly for boat applications. For the rotor repair encapsulation I'd use their 105 resin and 205 (fast) hardener plus their 404 high-density filler. You can mix as much or as little of the filler as you want to achieve the perfect viscosity. Skip the pumps that screw into the cans, they eventually become a huge mess ... just pour it out carefully ... I use a quality kitchen scale to measure the 2 parts accurately 5:1 resin/hardener by weight. Little plastic cups are great for small batches. The resin and hardener last (almost) forever if you store them in a place that doesn't bake in the summer.
A very good video. We gave a 16 kw Generac natural gas. More than likely identical.
Really enjoyed the video. Keep up the good work.
That thing is pretty quiet with all the enclosure on.
At least you were able to test the overload shutdown, although you didn't expect it initially.
Didn't over heat, your repair was excellent and your test came through with flying colors!
nice genset!
I like his comment about the noise level and when he said " maybe a bit much in a residential area", first thing I thought was not if everyone is out of power and you are warm because your neighbor with the " noisy generator" is sharing some of his power with you!
When I installed my 33KW genset, I installed an outdoor breaker panel with 6 20A NMEA outlets 120/240V. They buried long dropcords between us. My deal is they keep my 250 gallon #2 fuel tank filled and pay for genset maintenance and I power up the cords when the grid dies. It's a great deal!
The load shutdown was very likely the result of not having the required fuel pressure to allow for the unit to meet the demand. The unit was at 100% throttle for more than 10 seconds which resulted in the shutdown. If you had the required fuel pressure/ volume this would not have happened. I think you got this one fixed. I would be comfortable with it being capable of taking a full 20KW load for short periods at a time and carrying a 16KW load constant. Good job, you get an up vote.
Now, it's had a good break-in period, time to change the oil and filter(if equipped) and adjust the valve clearances. It should last for another decade, as a backup generator for a residence. I would just recommend that the oil level be checked after every black out, to make sure it's ready for the next black out. The problem with natural gas, is that it can be considered an "infinite" fuel source. The generator won't run out of fuel, before it runs out of oil!! With propane, gasoline, or diesel, it's easy to remember to check oil level each time it's refueled. With natural gas, you must be vigilant on maintaining proper oil level. Most of these generators have a low oil cut off, but that is only a safety stop gap, not an intended low oil indicator.
A generator like this should be test run periodically, and should run loaded for at least an hour each time, just to evaporate any moisture that has condensed in the oil from prolonged periods of non use. These are a good time to check the oil.(These are my biggest concerns for backup generators)
awesome job well done!!!, we all knew that you could get it figured out and back up and running again.
I was always fascinated by these stroboscopic lamps. You know its revolving, but it looks like its standing!
Great video. Nice to see it running and not junked for a simple fault.
Even though I didn't understand some of the technical terms used, it's still obvious, at least to me, that you know what you're doing. I have no problem believing your explanation of the diagnosis.
I appreciate repairs that exceed new condition. The customer with the new warranted gen will be dealing with this again someday. But I know you'll be there for them if it does happen. I have this generator, with this fault, although mine was throwing sparks near the oil cooler also. So, more than one issue, I would say. Thanks very much for the video. Great stuff.
It sure is nice to have a strobe, back in the day when I was in the Navy we had one in our arsenal tool diagnostic tools. Well done I must say!
Nice job, nice view with the stroboscope also!
YOUR VIDEOS ARE THE BEST !!!!! ❤
I am contemplating buying a 3600 rpm standby home generator. All of these companies really market their engines and do videos on them like the engine is the only thing that matters.
Watching you diagnose the Rotor/Stator was fascinating.
I wish there were videos where you take apart various Home StandBy Generators and show people what manufacturer is the most robust generator vs the price point. I was shocked to see only 40 hours ! On the generator !! You would think these manufacturers would inspect their parts before assembly.
I am currently looking at:
Cummins 13Kv
Kohler 12Kv
Briggs & Stratton 12Kv
Champion 12.5 & 14Kv
Not sure about B&S because it is a vertical shaft twin. Not sure about the reliability.
Anyway, just wanted to say very interesting Thank You.
DON'T! Buy the 1800 RPM 4 pole diesel genset, even used like mine. 33KVA 4 cyl commercial grade used for $500.
As the comments say ! Better than new ! Great Job ! A true professional! Thanks
I am honestly mystified by how clear and still the strobescope made the rotor... Wow.
After 70 yrs I finally know why the stagecoach wheels stopped turning .
You have the golden touch and knowledge.
Spike Mike a few comments back. I like the way you approached the repair. I would be very confident about that. I was talking to the screen at the end of part one to lace up the repair.
That strobe footage was the bomb…..Awesome!!
what an awesome shot there inspecting the rotor. never heard cummins made these, i guess for good reason
Gary Townsend I am a gen tech nice job, thumbs up. hope more techs watch it.
the stroboscope borders on magic! great video I learned a lot!
Hi Mike, I have really enjoyed this series of repair and testing of this unit. My hats off to your mechanic abilities. I also see that these type repairs are what you do for your living. Well done.👍👍👍👍👍✌🏻🙏🏽🇺🇸
Thanks for checking it out!
The only problem I have is I do not have the money to buy it.
Good job on the repair.
The cowling doesn't look like it's shaking much so nice to see that the epoxy didn't throw the balance on the rotor off much.
Nice work. Strobescope was a clever idea. I would guess, the 22 fault was fuel supply. The 59 hz indicates to me you were out of motor (throttle wide open, low fuel). The other shots showed the govenor holding 60 hz tight.
Maybe an O2 exhaust sensor would show it leaning out from low nat gas pressure if you have one to play with. Just thinking out loud.
Keep up the great work.
Wow! The strobe a scope footage was awesome
Love Glyptol, it will fix a winding with a low meggar reading, it will hold windings in place, it's best stuff .......good for you Mike! Nice job!!!
I watched Part 1 and was wondering about the heavy wire you added and about the it flying out. Nice work!
I have a Generac generator 30kw I had it installed 14 years ago. My house is 6200 sq ft. It runs everything in the house never had one problem with it. It runs off of propane . It starts 1 time a week for 15 mins. It was worth every dime I paid. I have mine mounted away from the house like 75 ft. You can't here it at all but I live out in the country. I did have to put a new battery in it. It has a 4 cly GM motor.