Hobart 60CU20 Operation And Maintenance Manual With Illustrated Parts List page 91

OM-2226 / Operation and Maintenance Manual
60CU20 / Series 500062 / 400 Hz. Generator Set
d If the under voltage circuit performs satisfactorily, return unit to normal operation by adjusting
output voltage coarse adjustment potentiometer for normal output voltage, pressing the
"TEST/REST" push button switch to clear the fault code.
(7) Check under-frequency circuit and fault code display.
At some frequency value 380 Hz or less, after 7 seconds, the frequency condition should signal
the under-frequency circuit protective monitor to OPEN the load contactor and display "70.23" 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 Reduce frequency in steps of 1 Hz, with a time delay of 7 seconds between steps.
c If the protective circuit opens the load contactor and displays fault "70.23" on the fault code
display after 7 seconds, at 380 Hz or less, all components of the system are functioning
properly.
d If the load contactor is not opened at 380 Hz or less after 7 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.
May 2, 2013
Figure 5: Engine Specific PC Board
Chapter 2-3
Page 9