Considering trading our U295 on a slightly larger used U295. Both coaches are equipped with 10K Powertech gensets. The coach that we are considering has 4400 hours clocked on the generator.
How many hours is too many? I cannot afford to both make the trade and rebuild the genset.
I have over 6600+ so that one has low miles
With 4400 hrs. you need to install a new generator end bearing, it is over due. If you DIY the bearing is about $15. You need to see if the generator has brushes or not. If it is a brushed style generator you need to install a new set of brushes and possibly a brush holder and springs.
Pamela & Mike
Mike what is in yours?
I can't find my notes, Mike, but somewhere I came to understand that PT Generators with brushes vs exciters have different bearings and those with exciters DO NOT require bearing changeout until major overhaul -- which is way out there in hours. I seem to recall that the Leesburg, FL service guys told me that they routinely had PT's with 12,000 hour runtimes between major overhauls. And, they had a few island generators that had twice that runtime, in combination with less than stellar maintenance care, that were still running fine. They emphasized clean fuel, clean air, if brushes - clean commutators and brush sets, keeping the "pieces-parts" tight and then PowerTechs are very dependable.
I know that Paul Yasbeck told me that mine (12 Kw with exciter) is "just broken in" and the bearings in this model are a non issue. I'll update this with my model # and current hours tomorrow.
Neal
Edit:
Oregon Motorcoach told us of a customer that came in to have the power tech geny switched out, Just because it was time. 40,000 hours on it. At 50 mph average, that's ? 2,000,000 miles. With regular service I guess it's possible.
Neal,
By what I understand the 12kw is totally different design than the 8 & 10kw units that are installed in a lot of the coaches. We have never seen a problem with those end bearings in a 12kw or the newer style 10 kw bearings. The 10kw that are brushed are the ones that seem to have the biggest bearing load trouble. As you know if the end bearing fails it can cause the rotor to contact the stator resulting in a major problem. Power Tech in the past recommended end bearing inspection and possible replacement at 1000 hrs. If I went to all the trouble to inspect the bearing I will replace it with a new one as the labor to get to the bearing whey out weighs the cost of the bearing. The OP don't tell how old the unit is so I was just letting them know about the possibility of problems with the older 10kw units.
There are a couple of post on bearing replacement for those unfamiliar with the process and here is a link to one. I understand this one has 4000 hrs. and is a 8kw but this still applies. Important to check generator brushes... & have a good Phoenix generator shop. (http://www.foreforums.com/index.php?topic=28746.msg240715#msg240715)
Pamela & Mike
I contacted PT a few weeks ago and the 1000 hour bearing change for the 8k is the current recommendation.
Is a 2003 brushed or un-brushed?
Call Power Tech with your model number the can tell you if it has brushes.
I called Power Tech with my model and searial number and was told my bearing change was at 3000 hrs.
It appears that there are several different bearing change requirements on these generators.
Do to the expense that can occur this isn't something you want to overlook.
A call to PT will clearly point out the requirement on your generator.
It doesn't matter if it has brushes or is brush less. You still need to know you bearing time change requirement on your generator.
I guess then I will never have to even think of mine (other than oil and coolants etc) as it only has had around 40 hrs in 8 yrs and that was for mainly just keeping it able to run.!!
JohnH
You may want to use the chat function at PTs Webb site. Much quicker for me than trying to get through. The chat can also be printed out. It was fast and very informative. Power Tech Mobile Power Generators (https://www.powertechgenerators.com/)
Might be nice to start a thread/sticky with Power Tech model numbers, and corresponding bearing replacement hours.
That way we have the information as archival info on the site, and we don't wear out goodwill with Power Tech on old generators no longer under warranty.
We have a PTS IDL10EFT 10 KW unit, but the only manual I have is for a PTS 12.5 KW unit. That manual does not mention anything about changing bearings or brushes. I had no idea to plan for bearings until reading on the forum.
My experience with contacting Power Tech hasn't been great. When I called with technical questions I left several messages and never heard back. In addition the parts department gave me incorrect information about several parts I needed to replace.
Chris
Sorry John, I think that you are wrong and you may already be overdue for your bearing change.
Let me explain:
I have always been confused about the generator end bell bearing changeout requirements, due to the lack of definitive guidance in the PowerTech (PT) manuals and the highly conflicting "conventional wisdom" on the street.
This thread stirred up that confusion again. So, I called Jeff, the head of the PT Technical Support Department today, and here is what he said:
- There isn't specific guidance in the PT Owner's manuals because PT doesn't know how you will be using your generator set
- With regard to the generator end bell bearings, the best use is daily and the worst use is exercising a few minutes once every few (insert........weeks/months/years). Low use is the worst killer of the bearing because the bearing lubricant has a chance to "age out" from inactivity/drying out/hardening/stratifying/undergoing lubricant thermal cycle creep and partially exposing bearing surfaces/exposed surfaces then become "tender" because the lubricant film is either thin or non existent, especially on startup and during initial warmup, etc., etc.
- The bearings and internal thrust forces in the 8Kw, 10Kw and 12Kw brush or brushless sets are all different but the sealed bearing lubricants are essentially the same in all of them. Sets with exciters can go longer, because the thrust forces are more balanced, but not forever.
- So year of coach (and PT generator set) manufacture and frequency of operation are the most important factors.
- With infrequent use, 1000 hours of use (or less) in 5 years is a good thumb rule to use for changeout
- With frequent use, each 4,000 to 5,000 hours or 4 to 5 years of use is also a good thumb rule to use for changeout
- With utility, heavy daily use, 10,000 hours or 10 years of use (whichever occurs first) are recommended changeouts
- Jeff was clear that these are PREVENTATIVE MAINTENANCE recommendations and good practices. The bearings and generator sets can operate reliably far beyond these thumb rules. But, if a bearing does start to go bad or fails, and the rotor contacts the stator, the repair bill is in the order of $3,500 to $4,500 plus labor and misc parts.
- Since mine is a 2002 PT unit (so 15 years old), has 1220 hours on it (so low use), is mounted in a quiet box (which means more drastic thermal cycles), I'm overdue when I thought I was OK.
- The service estimate for my no slide-out, quiet box, 12Kw unit is $450 to $500 plus the $58 bearing (made a fall appt.).
- PT themselves no longer have the Leesburg service facility. Jeff himself does these and can recommend others to do it.
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HTH,
Neal
Mine uses a marathon pancake generator end. These are in portable light towers, and nobody ever checks or changes the bearings. They routinely have 30,000+ hrs and never have bearings fail. I have 5000 hrs on my generator and it runs great. If I have to remove it for insulation repaira I might take it apart and replace rear main oil seal and bearings just because its out, but otherwise have no plans to ever touch it. The Marathon manual also recommends "checking" the non servicable bearing every 1000 hrs. I dont think any commercial customer ever does.
http://www.hardydiesel.com/kubota-generators/dl/marathon-pancake-generator.pdf
Neal thank you for the complete outline on bearing maintenance. After Bob raised the issue when I reworked ours, I received inconsistent info on this before contacting PT. Now I understand why this was happening. With 1500 hrs over 20 years and now using solar, this was a very valuable outline of the rationale for when it needs to be done. I am overdue.
Mine was going strong with over 5000 hours. I had a bad regulator installed at mot and they paid for the new end.