Opinions on MEP-831A

[Dwnorton1]

The capacitors have a dielectric compound in them that degrades over time and will start by losing efficiency then can fail. These units have a shelf life and I'm just trying to figure out what that is. Its not a liquid more like a fibrous compound in the ones that I cut apart on my failed unit. Polypropylene capacitors are what failed.


Im not saying these are bad units just want to gather experiences other than mine. So we can all make informed decisions.

 

[Cord]

Got 140 hours on mine and no problems other than it being moisture sensitive and a bear to set the magnet correct.

 

[DieselAddict]

I've not had an inverter failure in one yet but I have had multiple governor module failures and one PMA failure.

 

[Dwnorton1]

I will take responsibility for at least part of the damage on inverter. I was load testing and may have gotten carried away in testing its capabilities. Load was under rating of gen, so it should have survived me.
OverkillTASF has a thread talking about inverter issues so hopefully he will chime in as well.

 

[Dwnorton1]

I've not had an inverter failure in one yet but I have had multiple governor module failures and one PMA failure.

PMA failure. Don't remember that thread, but I have read so much on this site. Lol. Do you mind sending link or elaborating? Thank you for your response.
I read some early threads from a guy that worked for Fermont, is he still on site?

 

[DieselAddict]

I didn't post about the PMA failure because it arrived to me that way from auction. One of those cases where I should have looked more closely before bidding. Luckily it wasn't a big money mistake. It had a shorted winding from overheating.

 

[Dwnorton1]

http://www.steelsoldiers.com/showthread.php?137698-Generator-set-durability-testing

Interesting read and attached conclusion

View attachment failres mep.pdf

 

[Dewie38]

What does any of that mean?
It says nothing to the reliability of the TQG's, it's a fuel blend test.

 

[Dwnorton1]

The way I interpreted it is that the 802-805's are a more reliable unit. The smaller and more complex units such as the 831's and 531's had mechanical and electrical failures. Nothing to do with fuel other than them testing these units side by side was for testing a blend. It is merely a data point. KISS principle seems to prevail. I love the principle of the 831. But I'd wager that in 10 years time a great deal of the 831's are going to have failed at least more than the 802's for example, that are built with less components that degrade over time. Also the fact that they run at 1800rpm will also help with their longevity. I just wanted to try and establish how reliable 831's are going to be long term as many of these are going to be hitting the market soon from the stockpile I saw in OKC. I just want to share information so anyone reading this can make informed decisions. I hope the 831's that I have last 20 more years. I just don't have experience enough to say one one way or another. Hence this post to try and get more people's experience. More data,better conclusions can be made.

 

[Guyfang]

PMA failure. Don't remember that thread, but I have read so much on this site. Lol. Do you mind sending link or elaborating? Thank you for your response.
I read some early threads from a guy that worked for Fermont, is he still on site?

You are speaking about Dewie38

 

[Guyfang]

What you would find interesting is a MTBF report. Mean Time Between Failure Report.

Raytheon, (and the military in general) used to collect data on the Improved HAWK and Patriot missile systems. ANY failure, on ANY piece of missile system related equipment, was supposed to generate a form, (we called it a Bitc* sheet) with information on the who, what, when, where and why of a system failure. It produced VERY a interesting analysis of how long a compleat system could run between a failure that prevented the system from being FMC, Fully Mission Capable, and WHAT were the least and most reliable pieces of equipment in a missile system.

But naturally, people lied. No one wanted to tell the truth, from the mechanics, to the unit officers, no one wanted to report being NMC, Non Mission Capable. Could hurt you promotion potential. And then it was a PITA to fill out the dam* forms. Like who wants to do that crap, at 03:15, when you could be getting back in bed? Or playing spades? And some unlucky SP/5 had to keep control of all the paperwork. Log in all the failures, by date and time. Collect the forms from other people who HATE him, because he is bothering you about BS paperwork that the normal person never sees again, and cant see how its going to help him at 03:15 in the morning.

When I was in Patriot, I kept the MTBF report for Power Generation, in Germany. It was VERY informative. And a great tool for a manufacturer, to improve its equipment, if that's what they want to do. Sometimes you cant be so sure.

 

[Dwnorton1]

What you would find interesting is a MTBF report. Mean Time Between Failure Report.
When I was in Patriot, I kept the MTBF report for Power Generation, in Germany. It was VERY informative. And a great tool for a manufacturer, to improve its equipment, if that's what they want to do. Sometimes you cant be so sure.

You are most correct. I would be very interested in that data. We do similar in my industry RCA (root cause analysis). People accuse me of over analysis all the time. I just say yeah, so what. Lol
Pretty simple concept, if you know what to expect from a piece of equipment, you might might be able to correct a problem before it becomes a catastrophic failure that interrupts your sleep or your game of spades at 0300.

 

[DieselAddict]

My seat of the pants MTBF report is that the 831 is much less reliable than the 802s and 803s that I've worked on. Every one I've gotten from auction except one (which was brand new) has needed a repair that would have kept it from being mission ready. And yet I kept buying them. And fixing them. I must have an illness.

 

[Dwnorton1]

And yet I kept buying them. And fixing them. I must have an illness.

I have same affliction. Glutton for punishment, bordering on sadistic sometimes I think. If you enjoy troubleshooting then these units are for you. At least in my experience. I have no doubt I will test this hypothesis again and again, in the future, as soon as the next candidate comes across the auction block when I have some extra jingle in my pocket. On bright side I do have a parts unit and my understanding of these units is improving with help from this forum and the gremlins and the kilowatts that seem to inhabit these units teachings.

 

[Another Ahab]

I have same affliction. Glutton for punishment, bordering on sadistic sometimes I think. If you enjoy troubleshooting then these units are for you. At least in my experience. I have no doubt I will test this hypothesis again and again, in the future, as soon as the next candidate comes across the auction block when I have some extra jingle in my pocket. On bright side I do have a parts unit and my understanding of these units is improving with help from this forum and the gremlins and the kilowatts that seem to inhabit these units teachings.

That statement has a funny kind of "ring" to it.

 

[Another Ahab]

What you would find interesting is a MTBF report. Mean Time Between Failure Report.

When I was in Patriot, I kept the MTBF report for Power Generation, in Germany. It was VERY informative. And a great tool for a manufacturer, to improve its equipment, if that's what they want to do. Sometimes you cant be so sure.

You are most correct. I would be very interested in that data. We do similar in my industry RCA (root cause analysis). People accuse me of over analysis all the time. I just say yeah, so what. Lol
Pretty simple concept, if you know what to expect from a piece of equipment, you might might be able to correct a problem before it becomes a catastrophic failure that interrupts your sleep or your game of spades at 0300.

Funny you mention that. When I was a construction project manager the corporate "flavor of the month" was something called CQI (Continuous Quality Improvement), great concept but it was all lip service.

It likely got somebody promoted to VP for advancing the concept, but in the field you real quick were made to understand that nobody wanted to hear anybody's "good idea", and instead it was:

- "This is the way we've always done it; and that's always been good enough"

In some industries it's hard to teach an old dog new tricks.

 

[Guyfang]

With us, it was all about the unit Chief Warrant officer. When you had a good one, he made sure we filled out the Bitc* cards. When you had a lazy one, he didnt manage it or care about it. He drove the train. I learned a lot from both types. Which is why I took over the data sampling program for Patriot Power Generation, later on in life.

For me, my great love, will always be the 15,30 and 60 KD, DED sets. I don't need a light to work on them. I know what is where. I still remember lots of the places to measure voltage, jump relays, how to cheat components that are belly up. They were fun.

 

[Dwnorton1]

That statement has a funny kind of "ring" to it.

That is exactly what one of my tests looked like when I let the magic smoke out.


Have been thinking that I need to clarify. The MEP-831A is a brilliant piece of engineering and fit a very nice niche in the military gen sets. The are and have been on frontline protecting us and the warriors in the field and I truly appreciate the engineering that went into these units. I am not trying to down them in any way. I just want to ensure that I don't upset anyone with the perception than don't think these are really cool units.

The point I intended to make is that the units we have access to are not frontline units. They are on GL because they were more than likely pulled back out of service because of the issues we see when we get them. I have one particular unit that I have been chasing an issue for past 3 weeks. The little gremlin than resides in this unit evidently is afraid of a Fluke DVM. Every time I go to try and diagnose the issue, the unit will fire up a work flawlessly. Put the meter up, back comes the problem, makes a real PIA to try and diagnose. I understand why the military would dump a flakey unit like this because when one of fails in service people can get hurt or worse, when it fails me my ice cream might melt. Lol

I can imagine a 20 something kid trying to chase down the issue with this set, I imagine he would say the same choice words that I have, but having a bigger supply of backups, would eventually say screw it. I have a more vested interest in getting it working. $$$$$$ invested.
In summary if you want one of these units by all means join band wagon, just be prepared for a very complex piece of gear.

 

[Dewie38]

I can tell you that they don't always have another one to swap out and have to fix what they have been given.
I had a soldier call me once that was the fourth soldier to troubleshoot this particular set, and he said he was given 8 hours to figure it out and he never worked on generators before.
The issue was the primary fuel pump was not working but it had 24 volts going to it.
He tried another known good pump and it still didn't work.
The ground for the pump comes through the harness by way of the K1 contactor and the contactor at some point got miswired, you want to blow a guys mind that never
worked on gensets before, tell him the problem with his pump is the K1 contactor

 

[Dewie38]

Sorry guys, I must have a littles case of Old Timers Disease.
The 24 volts for the fuel pump comes from the K1 contactor, the contactor wires #31 AND #13 (hot and ground) had been swapped at some point and caused the soldiers problem with his inoperable fuel pump.
The lesson here is, you never know what may have happened to these sets before we by them at surplus.