Anyone know what this VR board fits?

[storeman]

A few weeks ago I posted pics of a VR board asking if there was a way to tell if it was functional. No one noticed anything unusual about it. This board came out of my parts MEP-003a but was in there loose when I got it.

Today I pulled a board from my parts 002a and they are nothing alike. No wonder I couldn't get the 003a running! I believe the 003a and 002a use the same board. Having looked closely at some of the board components, I suspect this came from a DC generator but I don't know how to start with an item number and find out what if fits. The one on the right is the mystery board. The info inscribed on it is 30554 ASSY 72-5020. I can't figure out how to go from a manufacturer's part number to a NSN.

Any help out there?

Jerry

 

[DieselBob]

The board labeled 72-5338 is listed for a 400hz unit.

REGULATOR,VOLTAGE - 400 HZ
72-5338 (30554)
332-2285 (44940)


The 72-5020 is for a 60hz unit.

REGULATOR, VOLTAGE-60 HZ
72-5020 (30554)

Both are AC vr's and are the same for the 003 and 002.

 

[storeman]

HUH? I checked my other working 002a's and they both have the 72-5338 board in them.

Wonder why they work?

 

[DieselBob]

Not sure how that would work to be honest. I know my 003 has the 72-5020 and a WebFLIS search on the 72-5338 came up with

NSN: 6110010957440 [FONT=Verdana, Arial, Helvetica, sans-serif] Item Name:[/FONT] REGULATOR,VOLTAGE Query Type: PUBLIC Date of query: 12/11/2011 10:07:53 PM
SPECIAL FEATURESUSE ON ENGINE MODEL MEP-112A,DED GENERATOR SET,NSN6115-00-465-1027

 

[bmwsyc]

If you look in the -34 for the 002a (which is for 60hz and looks like it does not cover the 400hz model) it has diagrams for both the 72-5020 and the 72-5338. If you look at the components, they appear to be mostly the same...just maybe a beefier version/update. Might be possible that the 24P for the 003a might have an error in it?

 

[Keith_J]

The -24P shows the regulator part number 72-5338 corresponds to NSN 6110-01-095-7440 made by FSC 30554 (MEP-DoD)or part 332-2285 made by FSC 44940 (Onan).

If the generator's data plate is other than Onan, the original regulator was probably the 72-5338.

The 003 uses 72-5020 by FSC 30554, NSN 6115-01-037-9650. The 112 (400 Hz) uses 72-5338 by FSC 30554 or 332-2285 by FSC 44940.

Why? Because the exciter systems of the 112 and 002 are nearly the same. The field of the 003 is longer, meaning more current while the 112's field has 24 poles (002 and 003 have 4).

The -24P TMs tell all.

 

[storeman]

Thanks all. So I guess all 4 of my boards are correct for their intended applications. I'm glad I happened to notice the difference in them and didn't send out an inappropriate board. Because the board was loose in the 003a when I got it last year, I suspected someone stuck something inappropriate in there.
Jerry