MEP-831A have to release the governor arm manually

[Mogman]

I picked up a MEP-831 yesterday with only 0.7hrs on the clock, after shutting it down I have to manually release the governor arm from the magnet before I can start it again, otherwise all looks to be working OK, I looked it up in the field manual and it said to refer to field level maint, cannot find it in the other TM I have.
EDIT, now I have to manually move the governor arm to the magnet to shut it down also

 

[Ray70]

KKlop can surely help you with this issue, but it sounds to me like your speed control rod adjustments may be incorrect or more likely the jam nuts may have loosened and the rod adjustment may be vibrating out of position. The TM covers how to adjust the rods for the speed control.
On the manually releasing the magnet to start it I thought that was standard procedure, but maybe mine was just acting the same way?

 

[Mogman]

KKlop can surely help you with this issue, but it sounds to me like your speed control rod adjustments may be incorrect or more likely the jam nuts may have loosened and the rod adjustment may be vibrating out of position. The TM covers how to adjust the rods for the speed control.
On the manually releasing the magnet to start it I thought that was standard procedure, but maybe mine was just acting the same way?

The rods look secure and unmolested of course that may not be the case, one should be able to start and stop it without having to open it up, the governor controller ohms out at 10.9 ohms which is OK as far as I can tell, it may be a bad controller board, seems to be a problem with these.

 

[kloppk]

Do you have good battery(s) in the set?
Try this. Lift the arm off the magnet. Then move S1 from STOP the RUN position and see if the arm twitch's or not.

The Governor Controller (if working properly) sends out a quick pulse of power to the actuator to lift the arm off the magnet prior to cranking.

 

[Mogman]

Do you have good battery(s) in the set?
Try this. Lift the arm off the magnet. Then move S1 from STOP the RUN position and see if the arm twitch's or not.

It fires up nicely on the internal battery and I have had it jumped with a pair of hot 12v batteries, yes to the "twitch", it also slows down but does not fully shut down when turned off.

 

[kloppk]

Could be that the Governor Controller is faulty and isn't putting out enough current to cause the arm to lift off the magnet.
The 10 ohms is correct for the resistance of the actuator.

After you start it does the RPM increase as you apply a load to the generator or does it run at the same RPM regardless of load?

 

[Mogman]

Could be that the Governor Controller is faulty and isn't putting out enough current to cause the arm to lift off the magnet.
The 10 ohms is correct for the resistance of the actuator.

After you start it does the RPM increase as you apply a load to the generator or does it run at the same RPM regardless of load?

It does not change RPM with load, the max load I have had on it is 1.5KW (space heater)

 

[kloppk]

If the RPM doesn't change then it sounds like the Governor Controller is defective. Very common.
I offer replacement Governor Controllers

 

[Mogman]

I am also not getting 24V on terminal F and G in the run position, (not sure I should) I see some kind of change but it is very small
The schematic in the downloaded TM has VERY poor resolution as far as the schematics go.

 

[kloppk]

You won't get 24 volts there until the set is running.
What happens the moment you flip S1 to RUN 24 volt power is there for a split second. Power gets immediately remove since the fault monitor detects a Low Oil Pressure situation and trips the K12 Fault relay. When you start the set with S1 and the engine comes up to speed it clears the fault and K12 and re-enables power to the Governor Controller.

 

[Mogman]

I am getting 24v when running, with no load I have 9V on J-H 0v on E-D and 197VAC on the three phase inputs to the board, one time it shut down normally during the last tests, one time I noticed K12 active and had no voltage on F-G

 

[kloppk]

If K12's LED is ON that means the sets Fault system detected a fault.
When that happens 24 volts is removed from the governor controller. When that happens the arm is suppose to swing all the way back and stick to the magnet causing the engine to stop.
Your J to H voltage is correct
Your 197 volts on A,B,C seems too high at no load. It should be ~178 VAC at no load.

Have you tried to perform the the adjustment procedure where you adjust the 4 blue potentiometers on the governor controller and adjust the rod length to achieve the 5/16" gap?

 

[kloppk]

I forgot to mention, the 197 volts indicates the engine is running way to fast at no load.
197 VAC corresponds to the RPM for ~110% Load.

At no load the voltage should be ~178 VAC which corresponds to ~3,050 RPM
At full load the voltage should be ~193 VAC which corresponds to ~3,450 RPM

 

[Mogman]

I forgot to mention, the 197 volts indicates the engine is running way to fast at no load.
197 VAC corresponds to the RPM for ~110% Load.

At no load the voltage should be ~178 VAC which corresponds to ~3,050 RPM
At full load the voltage should be ~193 VAC which corresponds to ~3,450 RPM

Yes at that time it was running pretty damn fast, with K12 active it is slower, I have not messed with the gov. seems like a TPITA, must also be a POS if so many get out of whack so easily

 

[kloppk]

... the gov. seems like a TPITA, must also be a POS if so many get out of whack so easily

The two 831's I pick up a few years back both had flakey governor controllers. Both were fresh resets with 2 hrs on them.
That's what inspired me to make the replacement governor controllers for the 831's.

 

[Mogman]

I literally hate military TMs, they are organized by folks that quite obviously don't think right....
I can find the procedure for aligning the gov. 0020 but cannot find the illustrations listed, I think they are also confusing pots with rods....

 

[Mogman]

The two 831's I pick up a few years back both had flakey governor controllers. Both were fresh resets with 2 hrs on them.
That's what inspired me to make the replacement governor controllers for the 831's.

Sounds familiar, mine WAS only showing 0.7hr

 

[kloppk]

I literally hate military TMs, they are organized by folks that quite obviously don't think right....
I can find the procedure for aligning the gov. 0020 but cannot find the illustrations listed, I think they are also confusing pots with rods....

PM me your email address. I'll send you the adjustment procedure written by GAC.
Better written than the TM.

 

[Mogman]

I don't think it is necessary, the control board is definitely telling the electric controller to over speed, with the controller unplugged the engine runs what would seem to be about a correct low idle with 137VAC on the three phase input and the gap between the magnet and the plunger is much narrower (did not actually measure it) BUT with the controller plugged in it runs WFO and with considerable force against trying to slow it down.
So we know a couple things, the load voltage to the board is correct (oV with no load) and we know the board is receiving the engine speed (the three phase input), the manual says with no load there should be about 5. something on the controller and I have over 9V so the only conclusion I can see is the board is NFG
Another thing is the symptoms have been changing from the time I first started testing the generator, this would be more consistent with an electronic board failing after being powered down for several years rather than a mechanical alignment issue, God I hope they did not use tantalum caps on that board, the gov. was big on those for years and they love to fail...

 

[Dewie38]

Written by me
LOL