15Kw generator Starts but no power output

[Darr]

I was having a problem with my MEP804A 15KW generator. The gen set would start fine but when leaving off on the start switch all the gages would disengage and there would be no power output.
I found the KLK 3A (fast blow) fuse behind the control panel was blown, replaced it and gauges all stay on now after switch comes off start to run and we have power.

 

[Light in the Dark]

That fuse is for your DC circuit, which also is what flashes the generator head... so sounds like an easy fix.

 

[Guyfang]

There could be several reasons that the fuse blew.
1. Someone cranked the engine over for way too long.
2. Bad AC Volt regulator.

If the fuse blows again, you need to see why.

 

[LuckeyD]

Took a chopper ride to a FOB being shot at, to find 6 gens like this. There is a hand pump on the injection pump. Work it a few times if the gen is sitting a while as the fuel pump pop it valves tend to not seal great and it gets air causing hard starting. Holding the start switch too long for what ever reasons causes nuisance blows. The 15-60s use a fast blow fuse on the F+ field wire to protect the main gen. They seemed to work well for 2 decades before this though. An over active A5 and MPU is actually at fault. Set the MPU at 2VAC and this reduces the issue. There is nothing you can do inside the A5 on this circuit.

 

[Darr]

There could be several reasons that the fuse blew.
1. Someone cranked the engine over for way too long.
2. Bad AC Volt regulator.

If the fuse blows again, you need to see why.

After reading your replay, I started the generator every other day or so and all was fine until today when I found the fuse blown again. It doesn’t crank too long before firing up. I am not sure how to check the AC volt regulator but the output AC voltage is correct between legs. Could it be a problem on the DC side? Thanks

 

[kloppk]

Testing of the AC Voltage Regulator is covered in the -24 Generator TM
---> TMs

Be aware the generator was made with 1 of 2 different AC Voltage Regulator systems. One by Libby and one by Technology Research Corporation (TRC). Be sure to use the correct test procedure in the -24 TM.

 

[LuckeyD]

Attached is from a seminar the factory gave us, a while ago. The last page gives some tests. It covers both says the factory engineers. I did not argue but used it for a very long time successfully. Now, recommend checking connections, cannon plugs ensuring all is well and tight. Keep a few extra fuses. If it runs and maintains a stable voltage, chances are the regulator is ok. That's the cheap way. The regulator tries to keep a steady voltage output. This is why I say check the connections. Now the next thing is check your Main Gen. The diode ring attached has the values. yell if you need help testing. I also attached the A5 adjustments so you have that.