Alpha Technologies AlphaGen PN-6x-T 7.5kW 48VDC - Technical Manual - Manual (Page 12)

12 042-288-B0-001, Rev. A
Auxiliary Power Unit (APU) Notes
• While the engine is stopping, a small amount of unburned fuel may be present. Fans are used to expel
these fumes from the enclosure, but fumes 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.
• 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% to 20% of the Lower Explosive Limit (LEL). 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 fl ash. 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. The reset button may be used to disable the alarm for 10 minutes at any time.
• If gas fumes are detected before running the engine, or more than 10 minutes after running the engine,
check the system for leaks and correct as necessary.