Hobart 120CU20, Operation And Maintenance Manual With Illustrated Parts List

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OM-2228 / Operation and Maintenance Manual
120CU20 / Series 500120 / 400 Hz. Generator Set
October 15, 2013 Chapter 2-4
Page 3
9) GPU Control Monitoring
The GPU control system performs complete diagnostic testing and continuous monitoring of all critical
circuits and operating electrical values. If the control system senses a problem with one of the circuits or
if any of the electrical values exceeds its safe operating limit, the control system will shut the GPU down,
or may allow the GPU to continue operation depending on the severity of the condition.
a) Commands
The ongoing operations conducted by the GPU are driven by the list of commands in Table 1. The
control PC board communicates these commands to all of the PC boards in the GPU. The first half of
the fault code identifies the command that was present when the fault occurred.
Commands
01.
\
39.
Self-Test Mode
40. Engine Start Mode
50. Engine Idle Mode
70. Engine Run Mode
80. Engine Shutdown Mode
90. Engine Stop Mode
99. System Off Mode
Table 1 Operating Commands
(1) Self-Test Mode
When power is first applied to the control circuit, the GPU performs complete self-diagnostics of
the internal circuitry. During this self-test, the GPU will perform the commands listed in the
enclosed charts. When a fault is detected during the self-test, the current
“COMMAND” and
detected “FAULT” are displayed on the fault code display.
(2) Engine Start Mode
When the “ENGINE START” push-button is activated, the engine’s starter and the engine’s ECM
will be energized.