Need help with MEP 701A!!

[Gunwriter]

Hey, need some help from the group.

I have a MEP 701A 3kw diesel gen set with Yanmar engine.
Oil level good, fuel tank is half full, battery is dead as a door nail.

When I try to jump it off my Deuce it instantly starts runs for a second and
then the DC Control Circuit breaker pops and kills the engine. Most of the time
the breaker will pop as soon as I start to turn the knob.....

What is up? The whole unit is in excellent shape with about 500 hours.

Could it just be the dead battery?

I know nothing about gen sets and got no help from the manual...

 

[Gunwriter]

Nobody?

 

[abh3]

I'm a newb to these mil gensets but if it were a simple DC short it seems like it would trip the breaker when you turned on the master switch. But if it starts and then throws the breaker it might be the AC field causing problems. Looks like that's run off of terminal 27 on the master switch, I'd try disconnecting that one and seeing if it runs. If it does then the fun begins, maybe the field is shorted, maybe ???

 

[Gunwriter]

Well, if I turn the switch slow, it will kick as soon as I move it.

If I move the switch quick like a bunny, the gen will try to start, or actually fire and run for a split second before it kicks.......

 

[Avn-Tech]

gunwriter,

As a military generator mech, I should be able to work through your problem.
But right now I do not have time.

Please post on:
Military MEP and Aircraft Gen-Sets - SmokStak

This is a form for generator collectors and mechanics (steel soldiers for generators).

Good Luck
Avn-Tech

 

[Avn-Tech]

gunwriter,

Sorry, just looked at the smokestak page and saw your post there.
I would try two 12V batteries in series and see if that cures your problem.

LAterrrrrr
Avn-Tech

 

[Gunwriter]

THANKS!!!
Greatly appreciated!

 

[abh3]

It took me a bit to realize my MEP701a was 24v (duh) but it would start and run by 'jumping' the starter, just turning the master switch wouldn't do it. But neither did the DC breaker trip w/ 12v battery in it... I now temporarily have two 12v bats in series and it all works as it should.

I'll be putting two 12N12 motorcycle bats (in series) that I got a good deal on in the battery tray eventually, that 24v battery busine$$ was just too much...