MEP-806B New To Me: Undervoltage

[KTreece]

I have a new to me MEP-806B that I had picked up a while back online. When received it was defueled, and all the liquids drained. I recently decided to get it going and got all the fluids back in it, and fired it up. The motor fires and runs good, but I am getting a low voltage message. : Contactor Trip - Undervoltage (Generator Voltage was abnormally low. Observe voltage measurements and adjust as necessary to ensure continued operation). The GFI reset switch on the face of the panel also will not reset, I flipped the trip on the back of it as well.

Is there another step during the decommission of these that they have maybe tripped some hidden breaker or switch? When trying to get it to fire up I realized the 50A breaker by the alternator was tripped. I wasn't sure if maybe something else is tucked away that I wasn't aware of.

Also, I didn't know if it mattered that I was running this off of a 24V jump pack as I haven't bought batteries for it yet(but read at 26.9VDC on the readout). I assumed that wouldn't matter but I am not too knowledgable with all the computer sensors it checks through.

Thanks for the help.

 

[Guyfang]

I have a new to me MEP-806B that I had picked up a while back online. When received it was defueled, and all the liquids drained. I recently decided to get it going and got all the fluids back in it, and fired it up. The motor fires and runs good, but I am getting a low voltage message. : Contactor Trip - Undervoltage (Generator Voltage was abnormally low. Observe voltage measurements and adjust as necessary to ensure continued operation). The GFI reset switch on the face of the panel also will not reset, I flipped the trip on the back of it as well. How can it? If there is no AC voltage?

Are you holding the S1 in the start position long enough? If not, the set will not produce voltage.

Is there another step during the decommission of these that they have maybe tripped some hidden breaker or switch? When trying to get it to fire up I realized the 50A breaker by the alternator was tripped. This is not a problem. Someone just opened it before shipping the set out. I wasn't sure if maybe something else is tucked away that I wasn't aware of. No, nothing.

Also, I didn't know if it mattered that I was running this off of a 24V jump pack as I haven't bought batteries for it yet(but read at 26.9VDC on the readout). I assumed that wouldn't matter but I am not too knowledgable with all the computer sensors it checks through.

Volts are good, but your jump pack might not have enough Amps. First hold S1 up longer then you would normally. Hold it up until the AC volt meter comes up to rated voltage.

Thanks for the help.

Open to see comments.

 

[KTreece]

Open to see comments.

Thanks for the response. When you say hold S1 up, what are you referring to? This is where I am failing.

 

[kloppk]

Guy means that you need to hold the Engine Control switch (S1) in the START position until the engine starts AND the Oil Pressure has risen and is stable. Then release S1 the Engine Control Switch.

Holding S1 in START after it starts is OK. The starter automatically cuts out after the engine RPM is > 900 RPM.

S1 needs to be held in start after the engine is up to speed for a few reasons for proper generator startup.
- Allows oil pressure to build so that the fault monitor doesn't shut the engine down immediately upon releasing S1
- Allows the Field Flash function in the set to properly flash the gen head so it starts producing AC voltage. Releasing S1 too soon can cause the gen head to not be flashed resulting in no AC voltage being generated.

 

[loosegravel]

Thanks for the response. When you say hold S1 up, what are you referring to? This is where I am failing.

Guy is saying to hold the S1 in the start position for a few seconds (even after the engine starts) Some faults occur at start-up on these machines and by doing this one simple step it will clear many of these faults, provided there isn't another problem.

 

[loosegravel]

Guy means that you need to hold the Engine Control switch (S1) in the START position until the engine starts AND the Oil Pressure has risen and is stable. Then release S1 the Engine Control Switch.

Holding S1 in START after it starts is OK. The starter automatically cuts out after the engine RPM is > 900 RPM.

S1 needs to be held in start after the engine is up to speed for a few reasons for proper generator startup.
- Allows oil pressure to build so that the fault monitor doesn't shut the engine down immediately upon releasing S1
- Allows the Field Flash function in the set to properly flash the gen head so it starts producing AC voltage. Releasing S1 too soon can cause the gen head to not be flashed resulting in no AC voltage being generated.

Sorry about that Kurt! It looks like I jumped in the same time you did.

 

[kloppk]

No problem at all. Now the OP has his answer.

 

[KTreece]

Guy means that you need to hold the Engine Control switch (S1) in the START position until the engine starts AND the Oil Pressure has risen and is stable. Then release S1 the Engine Control Switch.

Holding S1 in START after it starts is OK. The starter automatically cuts out after the engine RPM is > 900 RPM.

S1 needs to be held in start after the engine is up to speed for a few reasons for proper generator startup.
- Allows oil pressure to build so that the fault monitor doesn't shut the engine down immediately upon releasing S1
- Allows the Field Flash function in the set to properly flash the gen head so it starts producing AC voltage. Releasing S1 too soon can cause the gen head to not be flashed resulting in no AC voltage being generated.

I bet this is it, as soon as it fires i’ve always been conditioned to back off. Headed home now to try. I tried finding a manual for mine but the pdf downloads to just a exploded parts manual.

 

[kloppk]

The manual you want is TM-9-6115-672-14.
You can download a copy of it from ----> 806B Operators Manual
or from here---> 806B Operators Manual

 

[Guyfang]

Once again, Great minds think alike!

 

[KTreece]

The manual you want is TM-9-6115-672-14.
You can download a copy of it from ----> 806B Operators Manual
or from here---> 806B Operators Manual

Got it. Thanks!

No problem at all. Now the OP has his answer.

Update 2: I finally got it to work. I had to go from prime&run to start and as soon as it fired back it off, then toggle back to start and hold until it generated or I would get the starter grind.

Everything is fine except now I have to go back to the motor and tinker as it seems I am losing prime for some reason, and it also seems like I am losing a cylinder during fire up every so often. I'm not sure what that is. I do have a low fuel light on and it reads 22 and I have put about 18 gallons of fuel in it. Perhaps I have a leak of some sort somewhere, I guess we will find out.

 

[Guyfang]

Add fuel. Also, if you have starter grind, you need to check your MPU, (Magnitic Pick Up) for damage, cleanliness and adjustment. Look in the TM, and If no one else tells you where and how to do it, I will when I get back in the house.

 

[jmenende]

Mag pickup should read 2.3 vac.

 

[Guyfang]

First read the procedure.