MEP-831A Governor Controller Voltages. TM Typo?

[kloppk]

Got a MEP-831A that I suspect has a bum governor controller.
Was reading the TM -13&P and I suspect there is a typo regarding voltages that should be seen on the controllers D & E LOAD input terminals.
TM 9-6115-639-13&P dated 30 APRIL 2010 page 19-1 paragraph 3. PDF page 160.
It reads...

3. Close circuit interrupter and apply full load to generator set. Voltage between terminals F and G should be 24
VDC. Voltage between terminals J and H should be 11 VDC. Voltage between terminals D and E should be 0
VDC. Voltage between terminals A and B, B and C, and C and A should be 193+/-2 VAC.

I suspect "Voltage between terminals D and E should be 0 VDC" should read "Voltage between terminals D and E should be 5 VDC".

That is what I measure when it's under full load on both my 831's and 2.5 VDC with 50% load.
Is this a TM typo?

 

[Guyfang]

What TM date? What TM change if any and what page?? My TM is 30 April, 2010, no changes. This sounds like a job for Dewie38!

 

[kloppk]

What TM date? What TM change if any and what page?? My TM is 30 April, 2010, no changes. This sounds like a job for Dewie38!

Same TM issue date as yours.
PDF page 160
TM page 0019-2

 

[Tinstar]

Could you pick a font color that's harder to read?

 

[kloppk]

Could you pick a font color that's harder to read?

Sorry, displays fine on my laptop but may not on other devices.
Fixed it.

 

[Tinstar]

Sorry, displays fine on my laptop but may not on other devices.
Fixed it.

Ah
Much better

Much Appreciated

 

[KE5AFU]

Double check that the molex connectors are fully seated into the governor. Mine appeared to be plugged in, but pulled out easily. I got it to snap in place and no more issues with the 831A.
I'll check my voltages between those terminals this evening and let you know what I read.

Got a MEP-831A that I suspect has a bum governor controller.
Was reading the TM -13&P and I suspect there is a typo regarding voltages that should be seen on the controllers D & E LOAD input terminals.
It reads...
3. Close circuit interrupter and apply full load to generator set. Voltage between terminals F and G should be 24
VDC. Voltage between terminals J and H should be 11 VDC. Voltage between terminals D and E should be 0
VDC. Voltage between terminals A and B, B and C, and C and A should be 193+/-2 VAC.

I suspect "Voltage between terminals D and E should be 0 VDC" should read "Voltage between terminals D and E should be 5 VDC".
That is what I measure when it's under full load on both my 831's and 2.5 VDC with 50% load.

Is this a TM typo?

 

[Guyfang]

For some reason the military went to MOLEX connectors. We had many problems with them not being secured and when ever we got new electric fuel pumps, and had to put new MOLEX plugs on them, no one had the proper crimping gear. Yes, they can be crimped without the right tool, but for some reason, most people screwed it up. Bad connections. Give me a screw on canon plug any day.

 

[kloppk]

...I'll check my voltages between those terminals this evening and let you know what I read.

Thanks, much appreciated!

 

[Dewie38]

A dc voltage signal of 0-5vdc is applied to increase engine speed in proportion to kW load.
0 vdc is no load, 5 vdc is full kw load.

 

[KE5AFU]

I read a voltage of 0.0781 at no load. What Dewie38 says make sense as these are variable speed engines.

 

[kloppk]

Thanks you Dewie and KE5AFU for the info and confirming the TM is incorrect.

 

[kloppk]

Double check that the molex connectors are fully seated into the governor. Mine appeared to be plugged in, but pulled out easily. I got it to snap in place and no more issues with the 831A.
I'll check my voltages between those terminals this evening and let you know what I read.

Checked it and it's seated well. I suspect the control module went south. All voltages going to it are in spec but the voltage to the actuator is pegged at about 25 VDC causing the actuator to fully rotate and allow the engine to stay at WOT. Adjusting the 27 turn SPEED pot has no affect.
This unit had previously randomly surged and now it's just WOT. New controller time...

I suspect there are two (or more) versions of the controller. The one that died has a rectangular sticker on it.
My other 831's good controller has a "U" shaped sticker on it and it has a raised bump in the middle of it from some large potted component that's located in the "U" of the sticker. The SLC100 currently shown on the GAC website also has the "U" shaped sticker. Possibly GAC re-designed the controller somewhere along the line.
Just a thought..

 

[Guyfang]

Checked it and it's seated well. I suspect the control module went south. All voltages going to it are in spec but the voltage to the actuator is pegged at about 25 VDC causing the actuator to fully rotate and allow the engine to stay at WOT. Adjusting the 27 turn SPEED pot has no affect.
This unit had previously randomly surged and now it's just WOT. New controller time...

I suspect there are two (or more) versions of the controller. The one that died has a rectangular sticker on it.
My other 831's good controller has a "U" shaped sticker on it and it has a raised bump in the middle of it from some large potted component that's located in the "U" of the sticker. The SLC100 currently shown on the GAC website also has the "U" shaped sticker. Possibly GAC re-designed the controller somewhere along the line.
Just a thought..

Because I am old and lazy, please give me the part number and NSN for the controller. I can ask someone if there is an updated version, or maybe Dewie38 knows.

Then, why don't you copy the TM passage that is wrong, change the part that is wrong, in RED lettering, and we should post that in the TM Forum, in addition to the manuals already posted. It does no good to just post it in this thread, because lots of folks don't read anyway.

 

[kloppk]

Guy,

The NSN is: 2990-01-477-1371
The PN is: 98-19539

Per your suggestion I updated the initial post to highlight the error in RED and the correction is in GREEN.

Also added exactly what TM, version, section, paragraph the error is in.

 

[NATCAD]

With so many bad controllers around - is it possible to rebuild the controllers? D.A> have you opened one to see what the failure cause is?

 

[Guyfang]

Guy,

The NSN is: 2990-01-477-1371
The PN is: 98-19539

Per your suggestion I updated the initial post to highlight the error in RED and the correction is in GREEN.

Also added exactly what TM, version, section, paragraph the error is in.

Great!

This is how it's supposed to be done. When you find a problem with the TM's, you don't keep the big secret to yourself! This whole forum is built around sharing.

I will ask my rocket scientist son if we can go into the original manual, and change the text. Then reupload the manual. It means everyone needs to redownload the manual, but what can I say? This was one reason I loved my paper manuals. I simply made a pen and ink change, then sent in a Form 2028, to CECOM, explaining the problem/mistake, and suggesting a solution. Over the last 10 years of my army time, I submitted about 75-80 Form 2028's. Not all were accepted, but at least I tried.