(4) Visually check the lightning-protection system. Check all connections for
missing mounting brackets. Repair as required.
(5) Check the power company meter. The meter should be checked for creeping
under no-load conditions. If it is creeping with the light off, carefully check for grounds. If none
are found, notify the power company to correct the problem. Check the leads for tightness and
keep the meter surface clean.
(6) When the obstruction lights are mounted on disconnect hangers and are
equipped with lowering devices, wire guides, and pulleys, all fittings, supports, and cables
should be cleaned and lubricated. The contact surfaces of the electrical disconnect should be
(7) The duplex obstruction lights should be serviced as described above. In
addition, if a changeover relay is used, it should be cleaned and the relay housing gasket should
be kept in good condition. All missing cover screws should be replaced to prevent water,
moisture, and dust from entering the relay enclosure. Only one light in the double obstruction
light is energized when a transfer relay is used. Upon failure of the first lamp, the relay should
transfer power to the second or standby lamp. The relay is mounted in the fixture base. A pilot
lamp is normally provided across the standby lamp to provide a remote indication that one lamp
has burned out. Check the operation of this remote lamp.
(8) The beacon should be cleaned and reconditioned yearly or when a lamp is
replaced. Follow the procedures below:
(a) Clean and polish the globes and lenses using a glass cleaner or ammonia
and water. Wipe the globes dry before reassembling. Remove dust and dirt from grooves. A
stenciling brush or a small paint brush is especially useful for this purpose. Remove all paint
spots and streaks from along the edge of glass.
(b) Using a brush or cloth, clean the dirt and dust from fixture and open all
drain holes. Check the condition of sockets. Look for burned or galled screw bases, loose
connections, and frayed or broken insulation.
(c) Check the load contactor for pitted, burned, or misaligned contacts. Ensure
that the armature moves freely and that the spring tension is sufficient to pull the armature away
from the coil when de-energized.
e) Unscheduled Maintenance. Change the lamp when the burning time has attained
80 percent and not more than 95 percent of its rated life. Make certain that the correct lamp is
installed. Allow the new lamp to burn for a few minutes to make certain that the lamp is not