DOCUMENT 2529
REV. E
Instruction Manual
Model 4 – Style III
Taxiway Omni-directional Light L-852T
3
The preferred method of maintaining these lights is to periodically and systematically replace the units and
return it to the maintenance shop for renovation. As an alternative, the units can be serviced in the field.
However, it is recommended that field servicing be limited to cleaning the lens only as described in section
8.1.
8.1
Cleaning Lenses
With a compressed air blast or suitable brushes, remove all accumulated debris from the unit. Clean the
outer lens surface with a detergent solution. If the lens is coated with a substance impervious to the
detergent, a suitable solvent should be sparingly applied with a wad of cotton or a patch of cloth on the end
of a wood splint. After the solvent has acted the remaining solvent and softened coating should be removed
with a clean piece of cotton or cloth. Care
should be taken to avoid excessive contact between the solvent
and the lens seal. Remove all remaining solvent from lens and seal. A gentle air blast may be used.
8.2
Relamping
LED Module Replacement Kit P/N 21334 contains all necessary parts to change the LED module.
Remove and secure power to the fixture.
Turn the fixture upside down and remove the four screws
holding the inner cover to the light housing. Disconnect the LED module leads from the power supply. Remove
the lens retaining bracket screws from the light housing. Remove the lens-retaining bracket and remove the LED
module and thermal tape by unscrewing the screw
s.
Install the new LED module and thermal tape by
reversing the procedure above and making sure that the screws are tightened to 25 - 30 in-lbs; tightening
the lens retaining bracket screws may cause damage. For the heater option fixture, make sure that the
heater wires are aligned with the slot on the lens retaining bracket so that they are not pinched.
Inspect/replace the optical housing’s o-ring per paragraph 8.4. Assemble the inner cover onto the light
housing. Assemble the inner cover onto the light housing. The screw-hole patterns in the inner cover and
light housing are offset to insure proper alignment. Torque the mounting screws to 25 - 30 in-lbs. Perform
a pressure test per paragraph 8.7. Clean the mounting flange area of the base. Place the fixture into the base.
Apply Loctite 242 (P/N 10048-30), per manufacturer’s instructions, to all mounting bolts and immediately
torque them to 225 - 235 in-lbs.
8.3
Power Supply Replacement
Remove and secure power to the fixture.
Turn the fixture upside down and remove the four screws
holding the inner cover to the light housing. Disconnect the LED module leads from the power supply.
Disconnect the power supply leads from the feed-thru on a standard fixture or both the feed-thru and thermostat
on a heater option fixture. Remove the power supply bracket screws and remove the bracket, power supply, and
rubber isolator. Install a new power supply with the rubber isolator and bracket. Torque the power supply
bracket screws to 25 - 30 in-lbs. Inspect/replace the optical housing’s o-ring per paragraph 8.4. Assemble
the inner cover onto the light housing. The screw-hole patterns in the inner cover and light housing are
offset to insure proper alignment. Torque the mounting screws to 25 - 30 in-lbs. Perform a pressure test per
paragraph 8.7. Clean the mounting flange area of the base. Place the fixture into the base. Apply Loctite
242 (P/N 10048-30), per manufacturer’s instructions, to all mounting bolts and immediately torque them to
225 - 235 in-lbs.
8.4
O-Ring Replacement
