Alpha Technologies AlphaGen 5.0kW Auxiliary Power Unit - Manual (Page 22)

1. System Overview
22
031-132-B0-001 Rev. A TM ©2000
1.6 Operator’s Interface Overview
Refer to Figure 1-8 on the following page:
The three positions of the rocker switch are RUN - AUTO - STOP (RAS).
The RAS switch is normally left in the center, AUTO, position so that the ECM
has control of the generator set. A minor alarm is indicated when the RAS
switch is not in the AUTO position. The STOP ("down") position is used to stop
or prevent APU operation during maintenance. Placing the RAS switch to the
STOP position for three (3) seconds, then switching back to AUTO will
clear any latched alarms and start the generator if the cause of the
alarm has been corrected. Placing the RAS switch in the RUN ("up") position
will cause the engine to start and run until this switch is released to AUTO. The
engine may not shut down immediately when the switch is returned to AUTO
from RUN, because the ECM’s shutdown criteria must be met in order to
shutdown the engine. Also, each time the RAS switch is placed in the AUTO
position (from the STOP position), the ECM will start and run the APU for one
minute after a short delay.
The service reset push-button switch has two purposes. It resets the
engine service timer when depressed for 5 seconds and can be used to
determine which alarms are active (see "ECM Alarm Overview" section 1.7).
The service interval is a programmable counter within the ECM that defaults to
100 hours. When 100 hours of engine run time elapses, the Service Required
notification is set and the notification LED illuminates. After the engine has
been serviced, pressing and holding the service reset switch for 5 seconds will
reset the 100-hour service counter. All of the LEDs flash, while the switch is
depressed, until a five-second timer elapses at which time all of the LEDs
remain on solid until the switch is released. This provides feedback to the
technician, indicating the effective resetting of the engine service counter.