DOCUMENT 1136
REV. G
Instruction Manual
Pro APF Series LED
ICAO TCL, IHP, & STP
8
CAUTION:
CAUTION
Power supply is hot when light unit is energized and remains hot for a short
time after the light unit is turned off
Remove and secure power to the light unit.
Separate the optical assembly from the light base by
removing the two bolts. There are two pry slots in the optical housing to help separate the optical assembly from
the base. Disconnect the light unit lead(s) from the isolation transformer(s). Turn the optical assembly upside
down and remove the four screws holding the inner cover to the light housing. Disconnect the power supply
lead(s) from the LED assemblies. Remove the two cap screws holding the LED module(s) to the optical housing.
Clean the inside surfaces of the lens(es) with denatured alcohol. Install the new module using thermal grease
between the LED module bracket and the optical housing. Tighten the screws to 2.49-2.71 N-m (22-24 in-lb).
Connect the power supply leads to the new LED assemblies. Inspect the feed-through terminals for signs of
corrosion. Replace feed-through assemblies per paragraph 9.5. Inspect/replace the optical housing’s o-ring per
paragraph 9.3. Assemble the inner cover onto the light housing. Tighten the mounting screws to 2.82-3.4
N-m (25-30 in-lb). Perform a pressure test as described in paragraph 9.6. Connect the light unit lead(s) from
the isolation transformer(s). Clean the mounting flange area of the light base. Place the light unit into the
light base. Torque bolts per section 8.4.
9.3 O-Ring Replacement
Every time the light unit is opened, the o-ring must be closely examined and replaced, if necessary. Refer to
section 10 to determine the appropriate replacement kit for your light unit. Any o-ring that is stretched,
torn, has permanent set, or some other defect which would prevent it from forming a watertight seal must
be replaced with a new o-ring.
Remove the old o-ring from the groove in the optical housing using a plastic, or comparably soft, tool.
Carefully clean the o-ring groove and flange mating surface on the inner cover. Take care not to damage
the mating surface or the o-ring. Coat the o-ring
with a thin layer of Dow Corning FS 1292 lubricating
grease. Position the new o-ring in the center of the groove and press it into place. Torque the inner cover
screws to 2.82-3.4 N-m (25-30 in-lb). Perform a pressure test as described in paragraph 9.6. Connect the
light unit lead(s) from the isolation transformer(s). Clean the mounting flange area of the light base. Place the
light unit into the light base. Torque bolts per section 8.4.
NOTICE:
NOTICE:
NOTICE
A bad o-ring seal is the most common cause of inset light unit leaks. It is
strongly recommended that a new gasket be installed every time the light unit is
opened
