Hobart 60CU20 Operation And Maintenance Manual With Illustrated Parts List page 92

OM-2226 / Operation and Maintenance Manual
60CU20 / Series 500062 / 400 Hz. Generator Set
(8) Check over-frequency circuit and fault code display.
At some frequency value 420 Hz to 440 Hz, after 5 seconds, the over frequency sensing circuit
should signal the over-frequency circuit protective monitor to OPEN the load contactor and
display "70.22" on fault code display.
At any frequency value exceeding 440 Hz, the over-frequency circuit should immediately signal
the protective monitor to OPEN the load contactor and display "70.22" on fault code display...
To check the under frequency protective components, proceed as follows:
a While the unit is operating normally under load, set the frequency adjust switch to "TEST".
Rotate the frequency adjust potentiometer to adjust frequency to 400 HZ.
b Increase frequency in steps of 1 Hz, with a time delay of 5-7 seconds between steps.
c If the protective circuit opens the load contactor and displays fault "70.22" on the fault code
after 5 seconds at 426 Hz, all components of the system are functioning properly.
d If the load contactor is not opened at 426 Hz after 5 seconds, refer to Troubleshooting Chart
in Chapter 2, Section 4.
e Return unit to normal operating condition by setting the frequency adjust switch to
"NORMAL" and pressing "TEST/RESET" button switch to clear fault code.
NOTE: If the generator is operating under load at this point, open the contactors. There will be no
further need for the load bank in the following checks.
f) Testing for engine ECM faults
(1) Set the starter enable/disable switch to "DISABLE". "DISABLE" will prevent the engine from
starting, but will still supplying 12 VDC to the control system, while checking the ECM faults.
(2) Press the green "ENGINE START" push button switch. Although the engine is not running, the
green light in the "ENGINE START" switch will flash to indicate that power is available to the
engine ECM.
(3) If no active codes are recorded, both the "Engine Stop" and "Check Engine" lamps will come on
and stay on.
If active codes are recorded, both lamps will come on momentarily and then begin to flash one
code of the recorded faults.
May 2, 2013 Chapter 2-3
Page 10