MEP 806B Low Frequency

[eng251ine]

New to me 806B. 199hrs on clock. Added fluids, starts and runs well. Configured board and switch for 120/208v operation and frequency selector switch is in the 60hz/400hz position.
CIM displays 54hz upon startup, frequency adjust toggle has no impact on output - up or down. Verified CIM display accurate with known good DMM. No other errors displayed.

Things I've done:

• Worked through the Speed Control Unit Adjustment Procedure as posted in another 806B forum. Speed Trim, Gain, Stability adjustment have no impact on frequency or detectable change in engine speed.
• Removed Mag Pickup to verify it was clean, found a small nick in the pick up. Replaced with new pickup and adjusted to 1.25v output as directed in TM
• Removed Electro Mechanical Control to check operation of linkage reinstalled correctly with positive linkage engagement - no change to operation
• Verified Electro Mechanical Control working (i.e. moving), not sure if working properly
• Checked throttle linkage inside injector pump for movement and binding, appears normal
• Tried adjusting low speed throttle adjustment on injector pump, no detectable change in operation
• Removed backplane and cleaned contacts

This unit otherwise appears to run well, but I have not run it under a load yet.

Any ideas would be greatly appreciated.

 

[Guyfang]

The 806B. Oh Boy; the I/O does not know what to tell the ESD, and the result is being displayed, and DMM confirmed. Sounds like it was set up at one time for something other than 60 HZ operation at 120/208VAC. You changed the reconnect board around a bit trying to get it to be set to what he needs. This gonna be weird, but lets start with basics:

Open left side engine door( left side if you are at the control panel). Ensure the injection pump mounting ear with the ½ inch mounting nut looking at you with the hard to see horizontal mark (the other 2 have none) is about even with the horizontal mark on the timing cover(also hard to see because of paint) . check the attachment ADC100 attached. This ensures the actuator and injection pump is set up correctly.

Data Plate: MEP-806B I hope.
Check the data plate on the main Gen and ensure it is a 60 HZ Main gen. Don’t ask it has happened to me a lot.

Now: again: recheck everything connected to the reconnect board including the wiring and caps on the back. Ensure the base and all the wiring is tight; now after remounting, put the outer board on there and ensure it is also tight. The small wires there are connected to the I/O telling it a lot on AC OUT PUT. This is a real pain and you turn into a pretzel doing it right. Take your time.

If everything is good so far, now open the control box top cover. Starting from the LEFT; Modules are secure and they do not have to be baby Huey’d tight, LSS-100; EDS-5551, AVR100, and the I/O says TCM-100. Make sure the ribbon cables from the circuit board are secure to the TCM-100.

Initial setup: (With control box cover off) Please be careful as there are hot things in there that will jump and get you. AUX control panel on the box floor, ensure Voltage selector is on 208, down. Make sure the wiring is correct on that one too. Now ensure the frequency select is correct set to 60 HZ up. And now go to the I/O. Black cover removed using a small screw driver located upper right side, just above the J20 and J21. All DIP switches, rockered OFF (bottom of the switch flush with the switch housing, and then switch from the left the second switch. Sets the gen for 60KW) ensure all the wiring is secure with that small flat tip. (pain in the Ass) Now go to the ESD 5551. Remove the three black covers. One covers S1 and ensure both DIP Switched are OFF.

Now boot up the thing and now use the control PAD to ensure the operating parameters are set to what you want for your power being applied. Hit that RESET switch for 3 seconds and now start the thing and use attached file(info pulled from various places in the manual). If it don’t work out there are other issues and you needs to be specific.

 

[Guyfang]

Should have added, if it were me, would check to see if the main gen is a 60 hertz model first thing. As is written, seen that, more then once. 400 hertz main gen in a 60 hertz machine will give you those same symptoms.

By and large, the 805a/b gen set books can be used for the 806B gen sets. But pay attention. Have to look, in one or the other -24P, the NSN's were mixed up, and the CECOM never issued a change.

Two NSN's for the main gen.
6115-01-397-2106
Part numbers:
88-2109
MJB2502L-511E5

6115-01-578-3459 This is the Prime NSN.
Part number:
MJB2502L617E4

If my flea bitten old brain remembers right, it should also say what hertz the main gen puts out.

 

[eng251ine]

Thanks for the great info. This is exactly the response I was looking for. It has been busy here, so here is what I have been able to check so far.

• Data Plate indicates 806B 60hz
• Injection pump in the proper orientation
• All modules are secure
• Dip Switches on I/O and SW1 are in proper configuration for 60kw and 50/60hz
• Voltage switch on Aux Panel is set to 208, Frequency switch is set to 60hz

I have not yet pulled the reconnect board and checked connections, although everything in there seems factory, untouched. But it never hurts to check
I haven't verified the wiring is correct to the voltage and frequency selector switches
I haven't run through the ADC100 setup yet

I am going to verify the NSN's on the gen head today and will report additional information as soon as I can.

Thanks for all the help and wealth of knowledge!