MEP803A Dead Panel

[stugpanzer]

I used my genny for an extensive outage back in August. I started the genney in September as I usually do monthly to give her a bit of exercise. Today I went out to start it and I have nothing from the panel. When I shut the unit down I always make sure the load is off and let it run for 5~10 minutes then shut it off either by dial switch or by the big red stop button. When I start this genny I pull th ered stop switch out and then I turn the start dial slowly (allowing the fuel pump to run) until I get to the start point and I have nothing. No fuel pumping and no starter. I checked both batteries and they are good. I did a quick test with the Dead Crank Switch by cranking the engine and it turns with no issues. I looked behind the panel and saw no loose or chewed wires so I am down to (presuming) checking fuses and breakers. Any suggestions for troubleshooting my issue?

Thanks in advance!

 

[Zed254]

From TM troubleshooting section.....
Engine fails to crank.
TEST OR INSPECTION
Step 1. Check that DEAD CRANK switch is in the NORMAL position.
CORRECTIVE ACTION
Place switch in NORMAL position.
TEST OR INSPECTION
Step 2. Check that DC CONTROL POWER circuit breaker is energized (in)......this is CB1 behind control panel.
CORRECTIVE ACTION
If DC CONTROL POWER circuit breaker is deenergized (out), go to Step 3.
TEST OR INSPECTION
Step 3. Check that Emergency Stop Switch is out.
CORRECTIVE ACTION
Pull Emergency Stop Switch out.
TM 9-6115-642-10 0009
TROUBLESHOOTING – CONTINUED
0009-2
TEST OR INSPECTION
Step 4. Defect is Engine Starting/Electrical System. Check battery connections.
CORRECTIVE ACTION
If loose or corroded, notify next higher maintenance level.

 

[DieselAddict]

Exercise the Estop button a few times.

 

[Ray70]

Can you clarify exactly what is happening?
It sounds like you have power at the panel since you say you turn the switch slow and allow the fuel pump to run for a while??
If that is true then you issue is at or down stream of the S1 start switch, not the e-stop, CB1 or anything prior to the S1 switch.
Do you have panel lights and the gages move down when you first turn to Aux or Prime/Run and are the fuel pumps running at first?

 

[stugpanzer]

Can you clarify exactly what is happening?
It sounds like you have power at the panel since you say you turn the switch slow and allow the fuel pump to run for a while??
If that is true then you issue is at or down stream of the S1 start switch, not the e-stop, CB1 or anything prior to the S1 switch.
Do you have panel lights and the gages move down when you first turn to Aux or Prime/Run and are the fuel pumps running at first?

I could see why my writeup would make you think I have power to the panel. I was just explaining my startup procedure. With that said, I have no power to the panel. Nothing is working, including the fuel pump.

 

[Guyfang]

Ok, start at the MT4. Everything starts from here. You have to have 24 volts here, at the MT4, to get the engine to turn over with S10. So make sure the S10 is in the NORMAL position. Mesure from ground to S10-3. You should have 24VDC. Then mesure from ground to S17. When S17 is pushed in, (off) you should have 24 VDC to one side, and nothing to the other. Pull S17 out. Now you should have 24 VDC on both sides of S17. If you still have voltage to both sides, go to CB1-2. with CB1 pulled out, you should measure 24 VDC to CB1-2, and nothing on CB1-1. Push in CB1. Then Mesure for 24 VDC at CB1-1. If there is still 24 VDC, go to S1-1. Do you still have 24 VDC?

 

[Light in the Dark]

I would check the E-stop switch, even by disconnecting it and jumping the leads together.

 

[stugpanzer]

Ok, start at the MT4. Everything starts from here. You have to have 24 volts here, at the MT4, to get the engine to turn over with S10. So make sure the S10 is in the NORMAL position. Mesure from ground to S10-3. You should have 24VDC. Then mesure from ground to S17. When S17 is pushed in, (off) you should have 24 VDC to one side, and nothing to the other. Pull S17 out. Now you should have 24 VDC on both sides of S17. If you still have voltage to both sides, go to CB1-2. with CB1 pulled out, you should measure 24 VDC to CB1-2, and nothing on CB1-1. Push in CB1. Then Mesure for 24 VDC at CB1-1. If there is still 24 VDC, go to S1-1. Do you still have 24 VDC?
View attachment 815441

Guyfang, I was waiting for your reply! I only just now started taking a look. I have always run the Cold Crank switch in the off position. I briefly switched up to crank which did turn over the engine. Then I put it to normal and when I turn the Master (start) switch to the Prime & Run aux fuel setting while the crank switch in the normal setting, I can hear the aux pump but when I switch to Prime & Run I hear nothing and then when I go to start I get nothing. I still need to check the voltages at the locations you state in your post.

 

[stugpanzer]

Thanks, everyone. I believe I might have a glitchy E-Stop Switch.

 

[Light in the Dark]

From your description, this is what I thought you were going to find. Here is the replacement: https://www.alliedelec.com/product/idec-corporation/ayw401-r/70172557/

 

[stugpanzer]

From your description, this is what I thought you were going to find. Here is the replacement: https://www.alliedelec.com/product/idec-corporation/ayw401-r/70172557/

Thank you!

 

[Light in the Dark]

I just had to replace one a few weeks ago, so I had the link handy. I've even seen these things fail under the vibration of running... the red stop slides itself closed under load. But sometimes its just an internal failure, either way... cheap and quick enough fix.