MEP-006A not making more then 50 volts

[Coalrollincummins1]

I just bought a Mep-006a gen set that makes only 50 volts on the 120/240 setup and holding it in the start position is the only way it’s making proper voltage can anyone chime in … any help would be greatly appreciated

 

[Scoobyshep]

Start by getting into the manuals (TM tap at the top of the page)

When you hold the switch to start, you are bypassing the voltage regulator (this is the flash circuit, its what gets the head going to excite the regulator) You might have a bad AVR but that requires testing to confirm.

 

[Guyfang]

99.99% of the time its a Volt reg.

And yes, if you have not downloaded the TM's, you should. I saw a card on flee-bay not long ago.

 

[Light in the Dark]

If its the VR, reach out to SS member @Suprman . He has this item in stock (and can be seen on ebay, but I am sure he would prefer you just reach out direct).

 

[Coalrollincummins1]

If its the VR, reach out to SS member @Suprman . He has this item in stock (and can be seen on ebay, but I am sure he would prefer you just reach out direct).

Thanks y’all I really appreciate the help… I did some testing on the regulator and some capacitors or diodes
had no ohm readings

 

[Guyfang]

Was the card disconnected? Did you un solder one end of the components before testing?

 

[Guyfang]

Also, the listings I saw in epay showed the whole VR. You don't need that. The card alone will fix the problem. Look up the card NSN and part number. Look for just that. Its got to be cheaper then the whole VR.

 

[Coalrollincummins1]

Was the card disconnected? Did you un solder one end of the components before testing?

I didn’t but I was getting open circuit on many of the diode’s

 

[Guyfang]

One side should be un hooked to do it right. And you know how to check diodes right?

 

[Coalrollincummins1]

Ok so I just got a new voltage regulator installed and no change !

 

[Guyfang]

You said that it makes proper voltage when the S2 is held in the start position. That means the man gen is good. That means the S9-1 switch works, in its first position. When the S2 is released, the S9-1 reverses its contacts, and the the Initial excitation is turned off, and the Static Exciter/Volt Regulator takes over. Do you have the Schematics? Can you read schematics? Because something is not telling the Volt reg to take over and you need to go a bit deeper then changing a part.

 

[Coalrollincummins1]

You said that it makes proper voltage when the S2 is held in the start position. That means the man gen is good. That means the S9-1 switch works, in its first position. When the S2 is released, the S9-1 reverses its contacts, and the the Initial excitation is turned off, and the Static Exciter/Volt Regulator takes over. Do you have the Schematics? Can you read schematics? Because something is not telling the Volt reg to take over and you need to go a bit deeper then changing a part.

I am definitely trying to figure out these schematics but I am struggling for sure! Yes I have the -34 downloaded to my phone

 

[Markarons]

Check your voltage adjustment potentiometer, if open will get the same problem.

 

[Coalrollincummins1]

Thank you for the help it’s a little hot here in central Texas at the moment so I’ll check and get back to you

 

[Coalrollincummins1]

0-73ohms on the voltage potentiometer

 

[Coalrollincummins1]

Never mind I just looked up how to test the potentiometer at the j1 connector and I’m getting proper ohm reading so it’s not that! Dang I was hoping it would be something simple

 

[Coalrollincummins1]

Is there supposed to be a bus bar across the top because like I said this is all new to me I just got this and by the diagram it looks like it should have one to convert to 120/240

 

[Guyfang]

You need to read the TM's. The TB1 is changed by taking off the mounting nuts and moving the board. The instructions for moving the board are on the sheet you posted.

Why do you want to move it? Or check it? There is nothing wrong with your main generator.

Get into the -34 TM. Read about how the S9 switch works. It controls the K5 (Field Flash relay). The K5 is in the Special Relay box. See if its there, and if the card its screwed into is damaged.

 

[Coalrollincummins1]

You need to read the TM's. The TB1 is changed by taking off the mounting nuts and moving the board. The instructions for moving the board are on the sheet you posted.

Why do you want to move it? Or check it? There is nothing wrong with your main generator.

Get into the -34 TM. Read about how the S9 switch works. It controls the K5 (Field Flash relay). The K5 is in the Special Relay box. See if its there, and if the card its screwed into is damaged.

I just opened the relay box yesterday and it was filthy so I have some cleaning to do first! The only reason I was asking about the bus bar is because I do not see one on this unit but in the diagram it looks like there is a bus bar that goes across the top 4 lugs!

 

[Guyfang]

Look at the A5 card. It has the K5 mounted on it. Look at the back side of the card also. Burn spots are not good. Often the are traces that have been burnt in half. Burned up components are not good. Sometimes you can fix them. Some times buy a new/used card in ebay, or Forum member KLOPPK makes a new one.