MEP 805B won’t stay running except In battle mode

[B8136sx2196]

I’ve gone thought through the TM’s. Replaced the MPU. voltage is +/- 2.7 vac. Wired around the connector at the actuator. ( this action fixed the voltage to the actuator). I’ve cleaned all grounds and all connectors/ bus. the lights on the backplane are correct according to The DCS baseline. I have to hit the fault toggle to get the speed controller dc power light to come on. The engine will crank and run for about 5 seconds then sputter and die. I found once it cranks if I put it in battle short it will stay running. I can turn off the battle short after 20 seconds and it will stay running. The cim will indicate battle short is off and it will run great.
If you crank it, engage the battle short, and then turn of off in less than 20 seconds it will die just like the Normal cranking procedure. I think I’m losing voltage during the first 20 seconds I guess. I just don’t know how to proceed from here.

 

[uniquify]

Are any of the fault lights lit when it dies?

 

[peapvp]

Are any of the fault lights lit when it dies?

This is a Bravo Unit which doesn’t have idiot lights.

Are there any fault or warning codes displayed on the LCD?

 

[B8136sx2196]

This is a Bravo Unit which doesn’t have idiot lights.

No faults when it dies Usually the cim will come back on and show no faults. What is odd is I took a video last night and it cranked up just like it should. Today it was back to engaging the battle short for 20-30 seconds and then Turning the battle short off. The display will show battle short off. Runs fine then.

 

[peapvp]

It sounds you may have a loose wiring connections.

open up every compartment and check:
Fuel, oil, coolant leaks
Loose, frayed or burnt wiring
Missing or loose components

 

[B8136sx2196]

It sounds you may have a loose wiring connections.

open up every compartment and check:
Fuel, oil, coolant leaks
Loose, frayed or burnt wiring
Missing or loose components

I have done that as well. Will do it again.

This is a Bravo Unit which doesn’t have idiot lights.

Are there any fault or warning codes displayed on the LCD?

no fault or warning codes

 

[B8136sx2196]

It sounds you may have a loose wiring connections.

open up every compartment and check:
Fuel, oil, coolant leaks
Loose, frayed or burnt wiring
Missing or loose components

We have done this a few times. But will do it all again. I must have missed something. But I agree

 

[peapvp]

We have done this a few times. But will do it all again. I must have missed something. But I agree

is your CIM turning off as well when the engines goes off?
When does it reboot?
Do you have the panel lights turned on before starting the Genset?

 

[Guyfang]

I’ve gone thought through the TM’s. Replaced the MPU. voltage is +/- 2.7 vac. Wired around the connector at the actuator. ( this action fixed the voltage to the actuator). I’ve cleaned all grounds and all connectors/ bus. the lights on the backplane are correct according to The DCS baseline. I have to hit the fault (What is a fault toggle? S7?) toggle to get the speed controller dc power light to come on. The engine will crank and run for about 5 seconds then sputter and die. I found once it cranks if I put it in battle short (S7) it will stay running. I can turn off the battle short after 20 seconds and it will stay running. The cim will indicate battle short is off and it will run great.
If you crank it, engage the battle short, and then turn of off in less than 20 seconds it will die just like the Normal cranking procedure. I think I’m losing voltage during the first 20 seconds I guess. I just don’t know how to proceed from here.

I think here is the key to the problem. The use of the S7, during, not before, during start up is an old trick. It works on the 004A to the 007A, and the TQG's also. It was a good way to start a set when its cold, and the batteries are not up to snuff. Anyway, Something in the start process is cutting off DC voltage to the actuater and starter, right after Initial start is sensed. It has to do with start up. After the engine hits the right RPM, you can turn the S7 off, and it continues to run. Have you pulled out the plastic relays in the control cube? Looked at them? Looked at the sockets? Looked at the wires to the sockets. AND, the K15. It is the start relay. pull it out, and replace it with one of the other relays. See if this changes what happens on start up. Think now, if the S7 allows the set to start, then there is a good chance that everything S7 bypasses, could be the problem.

Open to read comments.

 

[B8136sx2196]

is your CIM turning off as well when the engines goes off?
When does it reboot?
Do you have the panel lights turned on before starting the Genset?

Yes the cim turns off when it dies. Unsure of when it reboots. I normally turn off the mater switch within 30 seconds.
Yes I turn on the panel lights before starting the genset. As a matter of fact the sun went out at some point when i first started messing with the I it. One day I turned on the panel lights before I started it and the CIM started working. Since then I always turn on the master switch then The panel lights. Then I follow the cranking sequence.

today I had to crank the unit using the battle short method. Left the unit running for a couple of hours. Turned off the unit. Came back to it and it cranked like it was supposed to. I did it twice.

 

[peapvp]

Yes the cim turns off when it dies. Unsure of when it reboots. I normally turn off the mater switch within 30 seconds.
Yes I turn on the panel lights before starting the genset. As a matter of fact the sun went out at some point when i first started messing with the I it. One day I turned on the panel lights before I started it and the CIM started working. Since then I always turn on the master switch then The panel lights. Then I follow the cranking sequence.

today I had to crank the unit using the battle short method. Left the unit running for a couple of hours. Turned off the unit. Came back to it and it cranked like it was supposed to. I did it twice.

I somehow have the strange feeling that this could be a battery issue. Do you have a trickle charger on your batteries or do you disconnect the ground cable from batteries when you are not using the Genset?
On the other hand, the CIM should stay on even if the engine shuts down due to a fault.
This points back to the control cubicle and the Master Control Switch if your batteries are ok and fully charged and are actually holding the charge.

For how long have you had this Genset and does it have any modifications, like different AVR, governor controller, Relais replaced?

pictures would be helpful so we can see if what you are looking at

 

[Guyfang]

Have you load checked the batteries? Not just charged. Load checked. Batteries can have a surface charge that looks good to a MM. But they break down ASAP. AND, does your set have the 50 AMP CB upgrade to the charging circuit?.

 

[B8136sx2196]

Have you load checked the batteries? Not just charged. Load checked. Batteries can have a surface charge that looks good to a MM. But they break down ASAP. AND, does your set have the 50 AMP CB upgrade to the charging circuit?.

Batteries are good. I don’t know what the 50 amp upgrade is.

 

[peapvp]

Batteries are good. I don’t know what the 50 amp upgrade is.

Ok, Guy can explain the 50A upgrade better then I can.

Now, looking at all the dust you got inside your cubicle, I can see oxidation on all your front panel switches etc.

The failure you are experience is most likely a failing Master Switch.
You need to clean your cubicle and then start deoxidizing all your connections and check all switches.

Did this cubicle had water / rain enter it at any time?

The dust inside looks like in the picture that there was at one point a higher amount of water / moisture in this cubicle

 

[B8136sx2196]

Ok, Guy can explain the 50A upgrade better then I can.

Now, looking at all the dust you got inside your cubicle, I can see oxidation on all your front panel switches etc.

The failure you are experience is most likely a failing Master Switch.
You need to clean your cubicle and then start deoxidizing all your connections and check all switches.

Did this cubicle had water / rain enter it at any time?

The dust inside looks like in the picture that there was at one point a higher amount of water / moisture in this cubicle

It is unknown about the water/rain entering the unit. When I got it all the covers were in place. I did vacuum some of the dust out. When I went back to my office to take the pictures it ran just like it should.
I do notice when I go to the start position on the switch from run/prime the the CIM goes blank and then comes back up after a few seconds. I do t know if that’s normal or not

 

[peapvp]

It is unknown about the water/rain entering the unit. When I got it all the covers were in place. I did vacuum some of the dust out. When I went back to my office to take the pictures it ran just like it should.
I do notice when I go to the start position on the switch from run/prime the the CIM goes blank and then comes back up after a few seconds. I do t know if that’s normal or not

No, that’s NOT normal. The CIM stays on without a flicker once the Master Control is ON until you turn Master Control Off
That points then to the ECS Engine Control Switch
Corrosion, Oxidation, dirt etc etc

 

[peapvp]

Or your batteries are not as good as you think they are and your 24V battery collapses when the starter is first energized

 

[peapvp]

That could be a bad starter then as well

 

[B8136sx2196]

That could be a bad starter then as well

Batteries have been replaced and so has the starter within the past two weeks

 

[peapvp]

Batteries have been replaced and so has the starter within the past two weeks

Ok, is this the time when the problem basically started? Or did you have this issue before replacing starter / batteries?
And the other question I have:
When does your Bravo excite?

A) during start (Version 1)

B) by manually exciting moving ECS from RUN/PRIME back to START for 2 to 4 seconds after engine started successfully (Version 2)