OPERATING THE APU (continued)
If APU engine does not start within one minute, release START switch, but continue to
hold PREHEAT switch to ON for another 20 seconds (in temperatures above 55°F
[12.8°C]) or one minute (in temperatures below 55°F [12.8°C]). After allotted time, hold
START switch to MOMentary ON again. If engine still does not start, troubleshoot APU
While holding PREHEAT switch (2) to MOMentary ON, move START switch (5) to MOMentary ON. Hold both
switches (2 and 5) ON for about 2 to 5 seconds, then release. APU engine should start.
To avoid damaging the APU engine, if LOW OIL PRESSure lamp
remains lit after engine starts, or if it lights during APU
operation, turn FUEL SHUT OFF switch to OFF to stop APU.
Notify Unit maintenance if this problem occurs.