Table 5‐2 Troubleshooting Guide (Digital Controller Only)

Problem

Possible Cause

Remedy

Controller does not power up even with

Wiring Mistake

Check that there are no wiring errors/short circuits connected to the

correct DC power applied

 

controller.

 

Overload Condition

The MEC 20 contains an electronic fuse that trips when an overload

 

 

condition exists and does not reset until the supply voltage is

 

 

removed and reapplied after the overload condition is corrected.

LCD Display cannot be viewed

Microprocessor failure

Check that the controller's microprocessor is running by observing a

 

 

red flashing “watchdog” LED on the rear of the PCB. Replace

 

 

controller if failed.

 

Improper Supply Voltage

Check DC supply voltage at terminals B+ & B- (10-30VDC).

 

Improper contrast adjustment

Adjust LCD contrast potentiometer (R115) on rear of PCB for best

 

 

display.

Controller cannot be “Reset”

Engine not stopped

Verify the engine is at a complete stop before trying to reset.

 

Controller not in OFF mode

Set the controller to the OFF mode before trying to reset.

 

 

 

No “RUN” output signal

“Shutdown Faults” not reset

All shutdown faults must be reset (red shutdown LED must be off).

 

Engine speed not detected at cranking

Engine speed signal must be detected (speed signal green LED on)

 

 

during cranking if the “run-output fail safe” feature is enabled. Verify

 

 

correct magnetic pickup signal at cranking (2.0VAC min. during

 

 

cranking).

Run Contact not closing (terminals #18 & #19)

Check that the RUN output LED (on the rear of the PCB) is on. If yes, verify relay contact operation on terminals #18 & #19. Replace controller if failed.

Overspeed shutdown occurs at normal speed

Controller programmed values are wrong or controller has failed.

Verify the controller programmed values are correct for the number of flywheel teeth, nominal RPM, and overspeed setpoint percentage. Replace controller if failed.

Voltage or current metering is incorrect

Controller programmed values are wrong

Verify the controller programmed values are correct for the voltage

 

 

sensing PT ratio and/or current sensing CT ratio.

 

Ground is missing

Verify that the battery supply DC negative conductor is properly

 

 

grounded to the engine block (i.e. to a common ground point).

 

Analog input needs to be calibrated

Verify that the controller's analog input is properly calibrated.

 

Voltage sensing wiring mistake

Verify the voltage sensing wiring connection to the MEC 20 matches

 

 

power distribution type.

 

 

Note: standard direct voltage connection requires that the

 

 

generators neutral is solidly grounded.

 

 

 

Engine temperature or oil pressure

Analog input needs to be calibrated

Verify that the controller's analog input is properly calibrated.

display is incorrect

Failed engine sensor

Verify engine sensors.

 

 

Note: engine sensors must be factory supplied units only.

 

Ground is missing

Verify that the battery supply DC negative conductor is properly

 

 

grounded to the engine block (i.e. to a common ground point).

 

 

 

Engine temperature or oil pressure

Sending unit is disconnected (open

Verify the sending units wiring to controller terminals #37 & #38 (i.e.

displays 9999

circuit)

wiring is not open or shorted).

OR

Defective sending unit

Verify the engine mounted senders have correct resistance values

Engine alarms are ON for high engine

 

for corresponding input temperature or pressure.

temperature or low oil pressure when

Wrong Temp or pressure calibration

Verify calibration.

engine is operating properly

 

 

Keypad Buttons (switches) do not

Keypad not connected to controller

Verify the interconnecting ribbon cable between the lexan faceplate

operate.

 

and main printed circuit board is correctly connected.

 

 

Replace controller if failed.

MN2408

Troubleshooting and Maintenance 5‐3

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Baldor GLC60, GLC105, GLC45, GLC20, GLC65, GLC30, GLC100, GLC15, GLC25, GLC40 ‐2 Troubleshooting Guide Digital Controller Only