MEP-006A Voltage Regulator Failure / Questions

[cbrTodd]

I am working with the same MEP-006A generator at the local Christian camp, that I have tinkered with for many years now. For the last year and a half, it has done great, has been used regularly, and has been load banked by a local company for testing / clean out. It has behaved well and got a clean bill of health from the load bank test...

...Until it had an electrical issue during a recent outage and spiked some kind of voltage surge through the camp. It melted a couple breakers and fried several circuit boards in air conditioners, fried the juice machine transformer, etc. They had the company that did the load bank come out and check it and they said the voltage regulator had failed. I don't know who took what apart, but when I saw it the top case to the exciter was removed. The only damage that I can see is a broken wire on transformer NSN 5950-00-101-2387, item number 29 in figure 55 of TM 9-6115-545-24p. One tab was pulled out from the core and the tiny winding was broken. I don't see any signs of damage on the voltage regulator card or any 'toasty' components anywhere in the exciter assembly.

If that failed transformer could cause it to go high voltage (or something else that would have damaged a bunch of downstream equipment), does anyone have a good source to get a new one? They have been calling sources listed from part target and so far the best price they have found is $500 each, minimum order quantity of 2...

One idea I had was if a 400 Hz exciter would have this transformer in it, and could be swapped over to the 60 Hz exciter module they need? Oshkosh has a used 400 hz one in stock that would cost less than just the new transformer, and my look at the parts manual makes me think this is common to both excites, but I was wondering if anyone here could confirm that. They are out of stock of the correct exciter module.

Thanks in advance for any assistance you can provide!

 

[cbrTodd]

The failed lead into the transformer is at the bottom right of the picture, just behind the vertical aluminum extrusion.

 

[Guyfang]

If that is all that's wrong, then yes, the Transformer from the 400 hertz Static Exciter will work in the 60 Hertz machine. But I think you need to be real sure that's all that's wrong.




That's what the UOC, (Usable On Code) is for. It tells you what part fits what model.

 

[cbrTodd]

Thanks Guyfang, I thought that is how the UOC worked, but I wasn't 100% sure. There were specific sections labeled 50/60 hz and one labeled 400 hz too and this was in neither of those, but I wanted to be sure.

Any guidance on how / what to test to confirm that 'only' the transformer broke? I don't have access to the 100 volt variable AC power supply called out in the -34 to test the voltage regulator card (instruction 8-12 of the -34), but that test appears to be directed at the card only and not the rest of the components in the exciter module. The card itself looks fine.

I am tempted to try soldering the lead back on the transformer, verify that voltage is good when the set is run that way, and if so, order a 400 Hz exciter module to rob the transformer from as a more permanent fix.