MEP-005A voltage regulator trouble

[generatorshawn]

hello guys!

so finally got a new engine for this unit and after rebuilding the injection pump on a CRATE motor lol finally got it to start and run the unit itself has sat for roughly 4 or 5 years after the previous owner threw a rod out the side of the block. on start up and ran the unit up to around 1800 rpms runs great but no voltage or hurts readings on the gauges was able to close the breaker and same also tried with the volt meter and it confirms nothing. tried to filed flash the generator by holding the start switch while running voltage climbs to about ~120 volts and the hertz go up in about 2 or 3 seconds but as soon as i let off the start switch the voltage drops away in about the same time. at this point im stuck on what to check next i assume its a issue with the voltage regulator but don't know what to check or what likely culprits turn up on these units.

cheers! shawn

 

[Guyfang]

Its normally the Volt reg. and that's in the static exciter box. Open it up. See if its even there. Look for damage and burn marks.

 

[generatorshawn]

Its normally the Volt reg. and that's in the static exciter box. Open it up. See if its even there. Look for damage and burn marks.

its the box with 2 plugs on the starter side of the engine?

 

[Guyfang]

Yep. Here is a picture.

 

[generatorshawn]

Yep. Here is a picture. View attachment 819353

ok ill have to get it out tomorrow and take a look at it.

 

[generatorshawn]

its the box with 2 plugs on the starter side of the engine?

ok so opened it up today and was expecting to see a burnt transformer instead burnt resisters on the vr now i need to see if i can find a schematic of the vr board and the values of these think ill replace all these diodes while I'm at it they look ruff

 

[Guyfang]

Have you downloaded the -34 TM? All the info you need is in the -34.

 

[generatorshawn]

Have you downloaded the -34 TM? All the info you need is in the -34.

yes indeed found it this is what i found for further reference
CR12 TO CR23 orginal part number is 1n4246 updated part number is 1n4004
CR7 & CR8 original part number 1n4247 updated part number is 1n4005
R20 is a 39 ohm .25 watt
R19 & R20 are 10 ohm .25 watt
I ordered everything from www.mouser.com with shipping was $11.

 

[Guyfang]

Good luck!

 

[generatorshawn]

yes indeed found it this is what i found for further reference
CR12 TO CR23 orginal part number is 1n4246 updated part number is 1n4004
CR7 & CR8 original part number 1n4247 updated part number is 1n4005
R20 is a 39 ohm .25 watt
R19 & R20 are 10 ohm .25 watt
I ordered everything from www.mouser.com with shipping was $11.

so update repaired the circuit and it worked for 30 seconds after flashing the field then in burned R20 and went back to the old behavior right now i have a tech that works on industrial electronics looking at it but would like to have a back up plan i keep hear that people have adapted modern day AVR'S to this unit but no real notes on how they did it especially the field flash part any pointers there?

 

[Guyfang]

Mods are something I stay away from. Send a PM to: Peapvp in the forum. Ask him if he has an idea about why R20 might burn up.

 

[generatorshawn]

Mods are something I stay away from. Send a PM to: Peapvp in the forum. Ask him if he has an idea about why R20 might burn up.

im with you but this is something i have limited knowledge on at this point thanks ill send them a tell

 

[Guyfang]

If all else fails, this fella has Exciters to sell, I have been told. Do not know anything more about how much or where he is.

His name is: Dave Anderson
His phone # is: 209-404-5226

 

[generatorshawn]

If all else fails, this fella has Exciters to sell, I have been told. Do not know anything more about how much or where he is.

His name is: Dave Anderson
His phone # is: 209-404-5226

Thanks I messaged the guy that you suggested I’ve seen a couple of his other post he seems to be pretty knowledgeable he did reply back and say he’s really busy right now so just patiently waiting to hear back from him I’ve also dropped off the regulator with a friend of mine that works on MRI machines for hospitals to see if he can figure anything out on it

 

[Guyfang]

Did you give him the test procedures for the WHOLE static exciter? The problem could be in the volt reg, or in the exciton. Its all in the -34 TM.

 

[generatorshawn]

Did you give him the test procedures for the WHOLE static exciter? The problem could be in the volt reg, or in the exciton. Its all in the -34 TM.

Yes I gave him that whole section of the manual

 

[Guyfang]

 

[generatorshawn]

so update so far found q4 to be bad and several other components to be just outside tolerances we have decided to replace every component on the board and possibly designing and reproducing a new regulator with updated components as they seem to be so rare to find for sale we make make a few extra for others in my spot that wont be way over priced.

 

[leedawg]

so update so far found q4 to be bad and several other components to be just outside tolerances we have decided to replace every component on the board and possibly designing and reproducing a new regulator with updated components as they seem to be so rare to find for sale we make make a few extra for others in my spot that wont be way over priced.

So mine burned up during the wildfires here in ca, I bought an AVR voltage regulator and popped it in under 30 minitrs and it works great have never looked back. Lefy everything else there so somebody really motivated could make it stock if they really wanted to. If you want more details on model and install instructions let me know.

Lee

 

[generatorshawn]

So mine burned up during the wildfires here in ca, I bought an AVR voltage regulator and popped it in under 30 minitrs and it works great have never looked back. Lefy everything else there so somebody really motivated could make it stock if they really wanted to. If you want more details on model and install instructions let me know.

Lee

Yes I would be very interested in what voltage regulator you ended up using and what you connected especially if you figured out a way to have it flash the coil for generators like mine they don’t have enough residual magnetism