Preface
11
031-132-B0-001 Rev. A
TM
©2000
Auxiliary Power Unit (APU) Notes
NOTE:
When the engine is stopping, a small amount of unburned fuel
may be detected by the odor of gas fumes. Fans are used to
expel these fumes from the enclosure and may be detected
outside the enclosure for a short period of time after engine
shutdown. This is a normal condition and does not present a
hazard.
NOTE:
Most utilities add a chemical agent to the gas which produces
a strong odor so leaks can be detected before they reach a
dangerous or explosive level. It may be possible to detect this
gas additive odor even though the gas hazard sensor does not
issue an alarm. The gas sensor will issue an alarm when the
detected levels of gas reaches 10% - 20% of the Lower
Explosive Limit (LEL). The alarm must remain active for at
least three seconds before it will be recognized by the Engine
Control Module (ECM). See section 1.7 for additional
information.
The gas hazard sensor has a 10 minute delay for periods of
purging and power-up. During the purge phase, the Green
alarm light will flash. When the purge phase is completed, the
light will glow steadily. In the event the detector has been
disconnected from power for more than 24 hours, it may
require a period of more than 10 minutes to complete its
purge phase. In that event, push the reset button to disable
the alarm for repeated purge cycles. Also, the reset button
may be used to disable the alarm for 10 minutes at any time.
NOTE:
If gas fumes are detected before the engine is run, or in
excess of approximately 10 minutes after running the
engine, you must check the system for leaks as
described in the INSTALLATION manual and correct as
necessary.
