MEP-002A quit generating under full load. Where to start

[rustystud]

Haha. I got it out and the windings are fried. The potted side of transformer is all burned up, swollen and cracked by the iris marked "C". I will see what a new one costs tomorrow. Might be easier to do the Flight Systems regulator if this cost much at all.

After all this I'm not a big fan of the current/ volt transducer for voltage regulation. It's just so over complicated for someone like me that just wants single phase 240vac (it's really the reconnect switch that makes it complicated). I could basically gut that box and use TB2 to connect the gen head windings in the 240 single phase configuration permanently.

It all depends on if new CVT-1's are available and how much they are. Seems that and the ac voltage regulator are the common fail points on these gensets. I hate to use another even older used part.

Thanks again for all the help.

Dave

I'm having the same problem too Dave. I already bought a SX460 AVR . Today I'm finishing up gutting the control boxes. This is the third CVT-1 that has taken a dump on me and I'm done with it.

 

[Chainbreaker]

I'm having the same problem too Dave. I already bought a SX460 AVR . Today I'm finishing up gutting the control boxes. This is the third CVT-1 that has taken a dump on me and I'm done with it.

These SX460 AVR's appear quite robust (potted) and affordable. I see it is used on the Newage Stamford units. So other than the AC voltage regulator what else does it replace in our units?

 

[CrzyDave]

The diode board, the voltage/phase selector switch, cvt-1, reactor, and it would make t-1 and t-2, and the current transducer for the amp gauge of no further value. I think I'll just get some little ct's and some 4-20mA gauges for current draw. Seems like it will be a fun project. I was wondering how the sx460 would hold up to the vibration of these MEP's. You can remove everything except the engine controls, outlet and the breaker.

There is a great schematic here:

http://www.steelsoldiers.com/attachment.php?attachmentid=445209&d=1376101278

 

[CrzyDave]

Basically your hooking it up to only be 240 VAC. You won't have three phase anymore. All details here:

http://www.steelsoldiers.com/showthread.php?109940-Civilizing-the-MEP-002A

 

[Chainbreaker]

That's the answer I was hoping for! Sounds like a great mod that can save $ in the long run and increase reliability (KISS factor). I don't need 3 phase (just household 120/240) and if I were to ever need 3 phase I could keep my backup unit OEM standard original setup for that.

I will review the link and schematic. Thanks for that!

 

[rustystud]

I've been following Craigs plan for a while now. I was actually in the process of converting my first MEP-002A when my second MEP-002A took a dump. At first I hoped it was just the voltage regulator so I bought a new one from Triple Jim. But alas it is the stupid CVT-1 again ! That makes 3 for me ! So after my conversion (I will post pictures ) I plan on modifying all my MEP-002A and MEP-003A and MEP-016D generators. I will keep my MEP-500 generators stock though. Craigs plans are not very specific though, so it is taking some time. He just gutted the whole thing. I plan on keeping all the engine controls and safety features intact. By the way, does anyone know what happened to "Craig Tull" ?

 

[CrzyDave]

I plan to keep my ac output box, the voltage selector switch and all for now. I will just remove the knob. I just need to get this thing back up and running.

I am concerned about if and how this will flash the field, but I can do something with the existing start switch flashing circuit if I have to. That would either be in parallel with the field wires or isolated during flashing and starting with a relay. I haven't seen a schematic for the new regulator, so I don't know if it's safe to wire in parallel.

CVT-1 and the existing regulator will be entirely removed.

 

[Triple Jim]

As I understand the Flight Systems regulator, there's enough residual magnetism in the generator to get things going without having to flash the field, so you don't bother with that feature.

 

[Chainbreaker]

Rustystud, CrzyDave - I look forward to seeing your implementations of the SX460, etc. I probably wont do this right away and will most likely wait until a CVT-1 fails in one of my units or I get bored, have the time and need a new project on my plate. It would be terrific if you guys can document your implementations with pictures so that anyone who chooses to go this route has something of a road map on how its done successfully.

The only thing better is if someone were to offer a complete retrofit kit: including the SX460, wiring harnesses, terminal block(s), and perhaps a set of digital gauges, etc. with step-by-step instructions of what to remove and replace in control box/load distribution box. Essentially a drop in kit without all the parts scrounging and wiring issues compared to attempting on an a-la-carte basis. Perhaps a couple of kit model variations depending on the desired objective/functionality of how civilized one wants to make it. Of course it would need to be reasonably priced but my time is worth something. I would be willing to pay a premium over parts costs knowing that an installation using included instructions/components would yield a safe working configuration (no trial and blue flaming errors).

 

[rustystud]

This is where I'm at today. I've finished the distribution box and have started removing wires in the control box. The small coils on L1 and L3 are for my Amp gauges I bought from "Jimc" .

 

[Jimc]

sorry i havent been around much lately. figured i would drop in today to say hello and see what cool stuff rusty has done to his 002. man that looks sooo empty in there lol. nice job.

 

[dangier]

Nice! Any thoughts about replacing the main breaker with a standard (thermal) one? I have one 002 that I have used as a parts horse. Good engine and gen head. Some thoughts of gutting that one in the near future and doing the same. With the sx460's as cheap as they are it's tempting.
Good Job!
David

 

[Ray70]

Rusty, I haven't seen or heard from Craig Tull in at least a year or more. I had an 002 with a bad CVT-1 and he hooked me up with the one he removed from his machine that fried the AC box harness. It was quite a pain to swap out, but it worked good when I was done. If I ever have another one die on me I'd like to try the regulator conversion myself.
I really like originality on these green machines, but... repair prices and reliability are more important sometimes. Once frequency transducers, voltage regulators and CVT's start going bad, originality has to take a back seat to newer technology.
Good luck with your build... I'll be tuned in.

 

[Triple Jim]

It's really not newer technology as much as different technology. Most or all civilian generators of the period had straightforward systems like you get with the SX460. As far as I've been able to gather, the 002A and 003A were designed so that if the electronics failed, you'd still be likely to have output power, even it the voltage isn't quite to spec.

 

[CrzyDave]

I just ordered my sx460. I was discussing field flashing with tech support at Flight Systems. He was saying that it is probably a good idea to keep it hooked up, but to use a diode on the output of the regulators F+ and on the generators field flash circuit so as not to back feed either circuit. The sx460 will go up in smoke without it when the generator is started unless it is disconnected.


I will try it without the original flashing circuit first like Craig Tull, but if it requires periodic reflashing, I plan to repurpose the rectifier board for this.

I plan to reuse my main breaker. I might put a four prong receptacle where the selector switch lives now.

 

[rustystud]

I just ordered my sx460. I was discussing field flashing with tech support at Flight Systems. He was saying that it is probably a good idea to keep it hooked up, but to use a diode on the output of the regulators F+ and on the generators field flash circuit so as not to back feed either circuit. The sx460 will go up in smoke without it when the generator is started unless it is disconnected.


I will try it without the original flashing circuit first like Craig Tull, but if it requires periodic reflashing, I plan to repurpose the rectifier board for this.

I plan to reuse my main breaker. I might put a four prong receptacle where the selector switch lives now.

There is no reason NOT to use the systems diode. I was removing and rewiring wires today in the control box and the flash circuit is easy to keep. In fact after you remove one unneeded wire from "TB5" to the diode you just reinstall the flash circuit wire. Almost as if it was designed this way (maybe a field repair) . I will be posting pictures and wire numbers later after it is all done and tested.

 

[rustystud]

It's really not newer technology as much as different technology. Most or all civilian generators of the period had straightforward systems like you get with the SX460. As far as I've been able to gather, the 002A and 003A were designed so that if the electronics failed, you'd still be likely to have output power, even it the voltage isn't quite to spec.

That is what I have found when my generators went wonky ! I would get 150 volts at each leg, total of 300Volts . The lights where really bright though !

 

[CrzyDave]

It's fixed!!!!!! I will post a pic later. You can leave all old parts intact. It just requires two wires to the field terminals, and two wires to get L1 and L3 wherever. I landed mine on the reconnection switch. I mounted the new regulator in the ac output box. Literally 4 wires. No need for field flashing either.

Maybe someday I will rip more parts out, but as I see it, there is just no point. My hz and voltage gauges still work. My amp gauge never worked, so everything is the same. I don't plan to use three phase.

I am so happy!!

 

[Triple Jim]

I'm glad you found a way to get it working, Dave. It's also good to get confirmation that you don't have to flash the field when using the SX460 regulator.

 

[CrzyDave]

As far as I can tell, 3 phase will still work too. I'll test it soon.