MEP-831a Troubleshooting

[DieselAddict]

Unfortunately not. I bought that second generator for my neighbor and it's turned out to need much more work so I had to sell the first one so I can fix the other one for the neighbor. I'm not happy about having to do that but I had no choice. Until I get the next one running and have a working governor module I can't make a video to show how to set it up.

 

[Cord]

Got the generator head back together today. I couldn't get the mylar trick to work. After 7 tries I ended up using a couple feeler gauges to get the gap between the stator and rotor. The plastic sheets were getting bunched up when I tried to remove them and I'd have to pull the rotor to retreive them. Working in -5 weather probably didn't helps things either.

I definetly need to adjust the electronic throttle as I have the exact same problem you were describing. Upon shut down, the magnet tried to power the engine down, but it releases and you just get a low idle. I refered to the TM and it says to "notify unit level maintenance", in otherwords it's over the tech's skill level. Makes sense if it was factory set. I tried to download the advanced TM you linked previously, but either the website is down or the link is bad. Wondering if Dewie could send me the procedure?

 

[DieselAddict]

You can get it here.
http://www.steelsoldiers.com/showthread.php?135020-TM-for-MEP831

 

[DieselAddict]

Does it run smoothly otherwise? Do you have a volt meter with a frequency readout?

 

[Cord]

Interestingly that manual is significantly similar to the manual that I have, but it's arranged differently. In my manual the actuator maintenance starts on page 4-42 (don't know why another section refers you to somebody else) and in your manual it starts on page 19-1. The data is the same though.

I have not gotten so far as to be reading the hertz, for the moment I'm happy just to get it running. Based on the sound, I'm going to guess that it's turning slow. I'm also getting a lot of white smoke, but I can't tell if that's just because the engine is cold (it's below zero right now) or if it's a indication of another problem. I sure hope I don't have to touch the timing. Tonight I'll drag the set outside and let it run for a while to see if the exhaust clears up. For the short time that I've run the unit (maybe a minute) the engine has been very smooth with no hunting or misses.

 

[DieselAddict]

We bottomed out about zero which is not at all typical for central NC. I've been working with neighbors already this morning to get pipes thawed.

One of the things you can do once its running is to give the governor arm a little shove and see if the controller responds to keep the RPM at setpoint. See if you can get an estimate of the gap while the unit is running without load.

 

[Cord]

I'd say the running gap is around 5/16" with the engine running. The large gap I saw previously must have been the unit trying to shut down because of the low oil pressure. The engine is holding a very stable rpm and does speed up when a load is applied. My multi meter won't allow me to read hertz, but I did get voltage readings:


(spec) no load (spec) 1500watt load
F-G (24) 27.6 (24) 27
J-H (5.3) 5.5 (11) 9.2
D-E (0) 0 (0) 2.8
A-B, B-C, C-A (178+/-2) 172 (193+/-2) 178

 

[DieselAddict]

All that seems good.

Can you describe how the governor acts when you shut it down? Does the actuator close against the magnet?

 

[Cord]

Really? I thought that almost all the values were out of range?

The the target hits the magnet and holds there until the engine slows. At that time the magnet releases and the rpms rise to a idle. Pushing down on the arm will shut the engine down but the magnet won't hold. Seems to take a fair amount of pressure to hold the arm down.

 

[DieselAddict]

Sorry, I totally read that wrong. You are right. Its not in spec.

What is the mechanical governor set for?

 

[Cord]

Well, I just got a new multimeter so I could read the Hz. The low speed was set correctly, but high speed was low. I adjusted high speed and then checked low and it was off. Went back and forth a couple of times so both settings were at spec. I then went back and reread the voltage readings:

F-G: 27 27
J-H: 5.8 11
D-E: 0 2.8
A-B: 177 196
B-C: 177 196
C-A: 177 196

The interesting thing is that the circuit breaker does not open the circuit, only the light turns off. Earlier today the load gauge was working, but now it has quit.

 

[Cord]

Bump. Not sure if I continue to invest in this unit or if I should just bail on it. It's making power and all, but some of the voltage readings are out of spec, the unit won't power down, the circuit breaker won't open and the load gauge readings occasionally go wacky. I'm guessing all the complaints could be related to the voltage readings being out of spec, but I honestly don't know where to turn from here.

 

[R Racing]

Did you find anything helpful in here ? http://www.steelsoldiers.com/showthread.php?135020-TM-for-MEP831

 

[DieselAddict]

Don't worry about it not shutting down. That one will be pretty easy to solve. The solution for that isn't in the book.

Also don't worry so much about the breaker.

I'm more interested with the voltages. Which voltages are out of whack? From the PMA or output voltage? The PMA voltages you list a couple posts up aren't off enough to worry about.

 

[R Racing]

I'm picking mine up next week. Cant wait to tinker on them . Tried to win 2 more today locally. but they went way out of budget !

 

[Cord]

I'm more interested with the voltages. Which voltages are out of whack? From the PMA or output voltage? The PMA voltages you list a couple posts up aren't off enough to worry about.

F-G no load: 27 (spec 24)
F-G 1500w load: 27 (spec 24)
J-H no load: 5.8 (spec 5.3)
J-H 1500w load: 11 (spec 9.2)
D-E no load: 0 (spec 0)
D-E 1500w load: 2.8 (spec 0)
A-B no load: 177 (spec 178 +/- 2)
A-B 1500w load: 196 (spec 178 +/- 2)
B-C no load: 177 (spec 178 +/- 2)
B-C 1500w load: 196 (spec 178 +/- 2)
C-A no load: 177 (spec 178 +/- 2)
C-A 1500w load: 196 (spec 178 +/- 2)

As you can see, almost all of the values are out of spec. Not by a lot, but definetly out of spec non-the-less. Frequency is rock solid and there is only a slight dip in voltage when switching from 0 load to a 1500watt load. I was thinking maybe all of my complaints are related to each other? An incorrect voltage certainly could throw the load meter off.

I was thinking of bidding on some of the units today for their parts, but the need to put tires on the truck took precedence. The one unit looked like somebody tried to modify into their own personal boom box. For the amount of damage, I can't believe what it was going for with hours remaining.

 

[DieselAddict]

Are you running with no batteries?

The ABC voltages are not a problem in my opinion.

The JH voltage depends on the actuator setup. Don't worry about that right now.

What is the no load full speed frequency?

Have you loaded it more than 1500w?

 

[Cord]

Load and no load frequency is 60hz. Nice and stable. I have not tried more than 1500 watts because the outlet is labeled for 10 amps max. Ultimately this unit will be mounted on a atv trailer, but I'm waiting for the frame to come back from the powdercoater. I found a local company that is going to put it on their CARC line. Once I get the trailer back I was going to hard wire up some convenience outlets to the split bolts and then I'll be able to supply a full 15 amps.

Yes, I have a pair of batteries installed.

 

[DieselAddict]

Does the power meter indicate the 1500w correctly?

 

[Dewie38]

If you're loading it from the outlet, the contactor does not remove load from the outlet.
The outlet is before the load contactor, the load contactor only removes load from the split load terminals.
If your voltage from the PMA, A,B,C on the controller are out of whack, that means the speed is not set up properly.
PMA voltage is directly proportional to engine speed.