Powertech generator 20 kw

[Joe Carter]

Having problems with my Power tech generator

1) as soon as the generator fires on with the switch the squirrel cage fan starts up in the next bay to blow air across the radiator, then in 1 second stops and never starts again leading to overheating and shutdown.

2) The generator now for some reason does not start charging or supplying electric power to the coach. In the past I would hear a click and the generator lug slightly and we were charging. Now nothing.

We did just get the generator serviced and hope it could be something stupid.

Joe

Coach is a featherlite xl2 2009

[Pipeliner Prevost]

Hello Joe, welcome to the Group.
In our H345 Featherlite with a 17.5kw Powertec and were experiencing the same problem with Generator Starting normally then immediately Shutting off due to Overheat Protection. The Fan was the culprit due to a Power problem to the Fan. Thinking back, a Fuse blown comes to mind. Good luck Joe.
It looks like you're from Montana, we're just up the Street from you in ol Alberta!
Pipeliner Prevost.

[Fratto]

I have seen serving firms turn off the main breaker on the generator and then forget to turn it back on when they are done.

[Pipeliner Prevost]

Hey Joe,
Powertech has been very helpful in the past. Here's a Contact:
Jeff in the Service Dept. will answer questions and Email Manuals if needed. (352) 435 4416. M-F 8am - 4:30 in Florida.

[No Name]

PTS 17.5KW 2700 hrs. After running the genset for roughly 70 hours continuous, plugged into shore power for over a week, then running continuously for about 80 hours I noticed the genset overheating. Then found in the `97 Royale that there was a generator stop switch that killed the genset then in about 30 seconds it started right up.... No manual stop that I can find. It was a several minutes before we could pull off and get in the generator bay. Just kept holding stop button ever time it started. At the generator there was not manual off switch, only the 3-way momentary stop/preheat & start positions. I finally just hit all the DC disconnects on the coach and disconnected the the generator battery - success. During all of this I immediately noticed no hot air blowing on my feet from genset cooling fans. Also there was now a bigger than pin-hole in mu lower radiator hose about 4-6 inches from the gen.... I opened the control box and noticed the, what look like 27yo factory, 16/3 SO cord was gummy and melting - but only the green & white - the black hots (2 circuits) were hot but not disintegrating. Our guardian angel must have been watching as we contacted Prevost PASS for assistance and were offered to go to Prevost Ft Worth to plug in, troubleshoot and repair for as long as we needed - now the angel part, where we pulled off was only 2.4 miles from Prevost. So after spraying the bulk of the coolant into the bay we closed everything and headed to Prevost. I didn't do too much investigating as Prevost provided me with a service company for Kubota Generators. I called them in the morning, tech was there about 12:30p and the games began. I'll sum up the experience by saying I told the tech/company to jump in the lake and I did the repairs myself. The tech did dive into the generator while I was running to multiple stores around DFW rounding up parts because the tech had no parts, filters, etc. on him after I had to fill out a detailed spreadsheet questionnaire at 8:15am and provide a CC authorization before they would dispatch. During this time he said the water pump was failing - I spun the pump and he was correct.

So what was wrong? I think a domino effect. Fan wires melted/shorted (but 20A breaker never tripped....). Temps hit 240 indicated and old hose blew. No problem. Replaced 16/3 SO with 10/3 and crimp splices vs wire nuts. Added manual kill switch on side of gen control box (in same path shown on PTS manual schematic). Replaced water pump. Belt looked great, but I have an extra. Replaced failed hoses, the long ones - however I will be doing this again in the near future at I could only find 1.25" radiator/heater hose at Napa, not the reinforced with anti-kink wire stuff it had like they use on boats. None the less it lays in there fine, although it is now a multi stage process to push the genset back into the compartment to not kink or have hose laying on a chafing surface - not ideal but will last the summer. Crawling in the generator bay in 105 deg heat...not fun. Did a full service with filters and a conversion to Delvac1 from Shell T4. Took several times to bring to temp, let sit, etc., to bleed air from system via vent on T-stat housing. Ran great for a few hours, even inside the bay. Then while on the road I turned on the water heater and all was well for about 1 hour - then overheating again. No breakers popped. I ran in and bought an amp clamp multi-meter because I thought the 20A breaker was bad. Well it wasn't, there is a time delay module in the control box that, with the transfer switch transfers load after about 20 seconds or so. I had good voltages, fans were running, etc... Off we went again. About an hour down the road, here we go again. Temps climbing, and I noticed that the AC units shut off and show an E7 alarm on the Dometic t-stat. This time I say the white 4A field breaker popped out (it has never been popped out before). Manual has faulty field breaker several times in the troubleshooting flow charts. I figure, they are thermal breakers, it's hot in there, over 27 years... Ok, bad breaker is possible. So I put the amp clamp on, 1A, all 3 roof airs pop on ~2.8A, turn on the water heater ~3.35A, turn on the microwave and I watched it climb to 4.4A then the breaker popped. So why is my field wire from the main AC output breaker to the voltage regulator so high? SO I reset the breaker and said, it shouldn't be this high but let's just not run the water heater and MW (the MW was really for a load test). Then the AC units started shutting off (E7 error) which used to mean the 4A field breaker was tripped. Well not this time. And in the time it took me to go from the driver seat to the gen bay, the load had transferred and the AC were running again. They held for several minutes in the several of the same cycles to the point of only holding for about 20-30 seconds - all the time with no tripped field breaker. In fact the field wire never gets over 2.8A until it shuts off, it sits at 1A until load is transferred back.

My guess is the voltage regulator has completely failed (it’s on the exciter side now?) – thoughts? The manual is giving me just enough info to be frustrating. Maybe there’s something I’m not seeing.

On a side note, I removed the squirl cage blowing into the generator end to get my fat self into the luxury accommodations of an antifreeze soaked gen bay. I noticed the grate was almost fully obstructed with road dirt/grime similar to fan belt dust, but a bit slimy. I’d like to squirt some engine degreaser in the re and spray it out with a hose. I thought about taking the entire end cap off but didn’t want to wind up pulling the generator apart. Curious on thought’s, etc.. My only concern is the degreaser hitting a conventional bearing and removing all the grease from it, yet I’m certain they are sealed bearings, but yet I ask for thoughts.

[No Name]

Hey Joe,
Powertech has been very helpful in the past. Here's a Contact:
Jeff in the Service Dept. will answer questions and Email Manuals if needed. (352) 435 4416. M-F 8am - 4:30 in Florida.

Will be calling them 1st AM. Thx for info.

[Fratto]

Will be calling them 1st AM. Thx for info.

I had Jeff on speed dial for a while. He’s a great guy. You’ll enjoy talking with him.

[No Name]

Spoke with Jeff - VR is bad. When the generator energizes the ATS swings the power over then the voltage drops and the ATS disengages. ATS sees good voltage again and transfers load to genset, voltage drops, ATS transfers to Inverters.... Vicious cycle I saw yesterday. Power Tech is unable to ship a VR today as they are doing inventory, call back Monday and they are almost $500/ea... Apparently the VR has been replaced previously as I have something that looks like an AVC63-6 but it's not (BE350). Also the white wire was on the 50Hz vs 60Hz... (that wouldn't effect the output/operation of the genset but could mess with the loads). So as I couldn't get the Basler AVC63-4 from Power Tech I found Advanced Service and Parts (ASAP) at partsfortechs.com. They had the correct Basler AVC63-4 in stock (55 of them) for $229/ea., a Taiwanese equivalent for $183 and the Chinese for $129. They say they sell so many of the cheaper Chinese models that they have a ton of the Basler in stock. Regardless I ordered 2, as this seems to be a common item with these generators. I bought the Basler's and figured they were 2 for 1 vs Power Tech - hopefully they arrive by noon tomorrow as scheduled.

I did ask Jeff about cleaning the air intake to the generator/alternator where the squirrel cage blows all the road dirt. He said do not put any water in there and certainly not any degreaser as it will remove all the grease from the bearings. So that answers the "are the bearings sealed" question - they are not. He said vacuum it out. I asked if I pulled the plate where the squirrel cage mounts was that the end plate that holds the bearing, he said he thought it was. I looked at the exploded diagrams in the manual and it looks like it's not. I'm probably going to give it a try taking off the end plate - there is so much road grime in there that it looked 95% blocked when I pulled the squirrel cage the 1st time. I like stuff clean. My biggest pet peeve and deterrent for wanting to work on something is dirty areas and systems.

We'll know by 12:30p tomorrow if I'm back in business.

[No Name]

So the generator saga continues. All worked well for several hours then back to intermittent operation as described above then nothing and the overheating began. The 4A field breaker popped again and once it cooled down and I was able to reset it, nothing... a little over 18V across the output/breaker legs. Next morning troubleshooting showed 13.2-13.3 ohms on the exciter stator, supposed to be 23-28 according to manual. Pulled off the end cap - which does NOT support the end bearing of the generator end - so you can pull and blow out and clean out that end cap screen (mine had a few big leaves in it). Found the exciter stator has one of the 2 wires that go between the 6 coils popped off. I'm guessing its a double wound stator as I get 13.2 ohms, half of the 23-28 ohms. Tech support said it's not enough resistance to trigger the voltage regulator soooo... generator no work-y. It makes since looking back at all the problems (different) I was having to this point of complete failure. The insulation was holding the broken wire together then it eventually let go. I bet my old voltage regulator is not bad... At least I have the correct one in there now and 2 spares... LOL.

http://forum.prevostownersgroup.com/attachment.php?attachmentid=18764&stc=1http://forum.prevostownersgroup.com/attachment.php?attachmentid=18763&stc=1

New exciter stator purchased from Power Tech this morning $1215.95 + ridiculous amount for overnight shipping. Parts lady said wow that's an old generator, 1996... It only has 2700 hours on it, engine runs great. Part of buying/owning anything old. The insulation on the wires reminded me of the Vietnam era A4's and F4's i worked on in the military in the early 90's - wire insulation, especially the old varnish/shellac insulation, is cracked and flaky. Well it's just another part. While this initially seems a bit intimidating, it's actually quite easy to get at and swap: Pull the squirl cage, pull the end cap/plate, then the 3 bolts holding the stator. I did have to remove the 4 nuts holding the control box to the generator so I could cut the zip-tie between the control box and generator that has feed/power wires from the main stator to the main breaker and the exciter stator wires (zip-tied in a bundle). I have the "M" style generator, which I'm assuming stands for Marathon which sems to be the manufacturer of the generator end. It's looking like Power Tech is like Lotus cars, they build a chassis then piece together parts from everyone else - in this case, engine from Kubota, generator from marathon, etc..

We'll know tomorrow when the exciter stator arrives - hopefully it's be good for another 27 years.

[Fratto]

Sorry you are going through this but what a learning curve we all get to watch! This is great information and I bet many folks will be using it in the future.

[No Name]

This generator saga is officially turning into a mini-series…. Received the new exciter stator from Power Tech this morning and….. well look for yourself:

http://forum.prevostownersgroup.com/attachment.php?attachmentid=18765&stc=1http://forum.prevostownersgroup.com/attachment.php?attachmentid=18766&stc=1
Not only are there 8 magnets vs 6 but also 4 mounting bolt holes vs 3. It did ohm out at 33 which tech support said was “within range” - manual range is 23-28 and voltage regulator requires 15 or greater to apply voltage. The the “can we make it work” thought process kicked in. Yes a machine shop can punch 3 holes in the correct position but are the ID & OD close/compatible?

Of course not:
6 pads on old 9.485” OD
5.775” ID


8 pads on new
9.050” OD (almost 1/2” smaller)
6.050” ID (1/4” larger)

so after tech support and parts punted me back and forth between the departments a few times the answer was it’s a Marathon generator end (confirming my suspicion above) and it’s discontinued. They are sending me a return ticket and a refund upon receipt.

This is a bit of a vent/rant, I kept having to fend off the, it’s old, I’ll sell you a new one comments…. It’s disheartening to hear the throw it away buy a new argument for absolutely everything… while cramming Chinese products down our throats. You know what the longest lasting thing to ever come out of China is? Covid… (joke for the day)

Then I called around and found a shop that still rewinds these things. If I cared to wait 2-3 weeks it would be less than $500, but because i need it now before my family mutinies on me, $800 and he should be done by Saturday. He will have to hand wind it as his machine is in use, so it’s really an extra labor charge but well worth it. We had to hand wind a starter armature in the military in school just to learn how - that’s some tedious stuff I don’t wish on anyone. Wrap, insulate… rinse and repeat a thousand times. In the meantime I’m going to replace the end bearing as that’s really the one big item that will cash the generator end, bearing fails and drops rotor on stators at 1800rpm with 36hp behind it… think big die grinder… lol

This bearing here:

http://forum.prevostownersgroup.com/attachment.php?attachmentid=18767&stc=1

Our Alaska plans are getting flipped around but still possible… I’m going to tackle the driver AC units (2) in the dash and overhead. I had it blowing 43 degree air then in the morning when we went to leave…nada. I don’t see it cycling at all (pressures, compressor is engaged and spinning) - I hope it’s a clogged orifice tube but probably the expansion valve. Usually these dual unit single compressor systems have one of each. Investigation will tell.

will be rebuilding toilet (Microphor) F210 air as soon as parts arrive. The flapper was broken and glued back together previously and when I tried to replace the flapper seal the flapper started folding along the glue joint so apparently the flapper seal is holding the flapper together…. I’m only taking that bowl off once so even though that is the only problem with the toilet - it’s all getting done regardless. Poopy jobs are no fun. Not nearly as bad as replacing a duck bill valve on the poop tank pump (on top of the tank - vacuum flush) on a boat while in a hole, below water line, bobbing up and down in the ocean with a full tank - all from a curious kid turning the overboard discharge key/switch with the overboard seacock closed - turns the valves inside out every time…. No RV septic work compares to that… I had a 5gal bucket beside me as I was getting seasick at the same time. I remember my father telling me as a kid that a power outage is an inconvenience but running out of TP in the bathroom is an emergency. How true, the poor ladies on board were crossed legs and potty dancing waiting on me. Memories….

[Fratto]

Ha! You are so right about the duck bills :-)

Thanks for keeping us in the loop.

[No Name]

A little longer than expected waiting on the stator rewind. Stator was actually ready Monday but he was waiting on a super hard insulating varnish that came in today (Wednesday) so I picked up the stator at almost 6pm. He explained that he used American wire with #6 insulation vs the cheaper Chinese which only has #2 insulation - I haven't researched what that means yet but I will. Likewise the varnish he used is a super high temp and very hard - perfect to be stuck in a hot generator compartment. He also explained that it was wound in 2 windings so you could have half of the stator fail like the old one did, reason I was getting 13ohms on the old/failed stator. Re-wound stator Ohmed out at 20.2, a little lower than the factory 23-28 but more than the 15 required to trigger the voltage regulator. Install was quick except for a trip to the parts store for 2 ring terminals to connect the stator to the terminal strip with the voltage regulator - it's always the little things. Then I fired it up and had just under 6 VAC, never jumped up to the 240vac (measuring across L1 & L2) which after investigation (RTFM for the VR) and the VR will not fire unless it sees 6VAC or more. Remember i was seeing just over 18vac on working old stator. So I flashed the excitor stator as there probably was little to no residual magnetism in it being basically new. That is a super simple process that is a bit scary to do for 1st timers, me. I've never had to do this before so I did a lot of reading and then took a leap of faith and did it. Basically you take the 2 wires off the exciter stator (the ones that go the F+ and F- on the VR) and touch them to 12vdc for 3 seconds, reconnect and check for AC voltage. You first ohm the leads and make sure you're good there (20.2 ohms in my case). The I ohmed from each lead to ground to make darn sure I was not grounded out (from install or otherwise). For ease sake I simply unplugged the F+ & F- leads from the VR, took 2 pieces of wire about 2" long each, stripped both ends and stuffed one end in the female spade connector and touched the F- lead to ground and the F+ lead to the 12vdc on the starter solenoid in the control box. It makes a small spark when you remove the lead (for me I removed the +12vdc lead) which makes since as the magnetic field collapsed and well, inductive kickback, just like an ignition coli & spark plug. This time I got just under 10vac when I connected the exciter stator to the VR, over 6VAC to trigger the VR but still no 240vac. So I flashed the field a 2nd time and got just over 18vac (as per the manual for the VR, rinse and repeat on field flashing) - I was happy with that, but still no 240VAC.... So I try the old VR that was in the gen when I bought the RV, no luck. Then I pulled out that one brand new spare AVC63-4 and voila - 198vac (FYI Auto Voltage Controller 63VDC-4A) - Now to buy another $229 spare, apparently they are now bad from the failing stator..... Pulled out the screw driver and turned the voltage pot to 238VAC, turned the stability pot to full clockwise as per the VR manual and centered the under freq pot. Ran it for an hour, turned on every load in the bus and boy do I need to load balance the legs. One leg is hitting 55A and the other barely 15A. If I move just the water heater and insta-hot over that will put it at 25A and 35A which is much better. I didn't get to the bearing with all the other projects on the bus, however it seems pretty straight forward and easy enough to swap.

Summary - $800 and 10 days for a stator rewind at a local shop. AVC63-4 Voltage regulators 3 @ $230/ea - original one was wrong one (Bassler SE350) according to Power Tech but it worked - I bought 2 new ones, failing old stator fried the original and 1 of the new ones. Changing water pump and almost all radiator hoses, new radiator caps, 3 sets of filters (2 spare sets), spare belt, installed manual on/off switch, replaced 40A start circuit CB, changed/upgraded all 3 cooling fan wiring, new antifreeze and synthetic oil roughly $900. Grand total roughly $2200 my labor is of course free but generator should be good for a long while now with plenty of spares with filters for at least 750hrs of run time. Way less than the $6k the generator service wanted to charge and that didn't include VR's, spares or a stator rewind. I encourage anyone to tackle this yourselves, once you're done that generator will no longer me a magical power maker and you'll be very equipped to handle anything it throws at you in the future.


Here's some photos:

http://forum.prevostownersgroup.com/attachment.php?attachmentid=18778&stc=1http://forum.prevostownersgroup.com/attachment.php?attachmentid=18779&stc=1http://forum.prevostownersgroup.com/attachment.php?attachmentid=18780&stc=1

[Fratto]

Wow, thanks for taking the time to document this for all of us. It will come in handy in the future for sure.