APU STARTUP AND SHUTDOWN (CONT)
The hydraulic tank oil valve must be open prior to starting the APU or serious
damage to the hydraulic pump will result.
(4) Open hydraulic tank oil valve (7), handle in line with valve body.
(5) Check that fuel petcock (8) is in open position, handle in line with filter body.
(6) Unhook strap and lower step section (5) to normal position. Secure in place by hooking step retainer (4) to
catch on fixed bottom step section.
Hearing protection is required within 10 feet (3m) of the APU when the APU is
running or injury to personnel may result.
(7) Open cover (9) to APU control box (10). Press knob and pull out throttle control (11) fully.
Oil pressure light must go out within 15 seconds. If oil pressure light stays lit, shut
down APU immediately or damage to equipment may result.
On APU with AP engine serial number 504697 and subsequent, the glow plug
indicator is changed from a glow-type indicator to a lamp driven by a timer.
(8) Turn START switch (12) counterclockwise to GLOW position and hold. Observe (a) or (b) as follows:
(a) In about 15 to 20 seconds, depending upon outside ambient temperature, the glow plug indicator (glow
type) (13) will glow brightly.
(b) The glow plug indicator (lamp) (13) will light immediately. In five seconds the light will extinguish,
indicating that the glow plug is warm enough to assist in starting.
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