STARTING APU
1.
Turn FUEL SHUTOFF switch (Figure 3, Item 1) to ON position. LOW OIL PRESS light (Figure 3, Item 3) will
come on and stay on until engine runs.
2.
PREHEAT switch (Figure 3, Item 2) is kept on until engine starts.
NOTE
Starting APU in cold weather is the same as starting under normal conditions, except
PREHEAT switch is held in ON position for 2 minutes before attempting to start.
3.
Press and hold PREHEAT switch (Figure 3, Item 2) in ON position for 20 seconds for temperatures above
55°F (13°C), or for 2 minutes for temperatures below 55°F (13°C). While holding PREHEAT switch, move
START switch (Figure 3, Item 4) to ON, and hold until engine starts. If engine doesn't start in 1 minute,
release START switch and keep PREHEAT switch in ON position for another 20 seconds, or 1 minute in
temperatures below 55°F (13°C). Try starting APU again. If it still doesn’t start, troubleshoot (WP 0081).
4.
When engine starts, release two switches (Figure 3, Items 2 and 4).
Figure 3.
APU Control Box.
CAUTION
If LOW OIL PRESSURE light stays on after engine starts or comes on while engine is
running, turn FUEL SHUTOFF switch to OFF position. Failure to comply may result in
damage to equipment.
5.
Let APU warm up for 3 minutes before turning on APU GEN switch or operating the auxiliary
hydraulic system.
TM 9-2350-256-10
0042
0042-4