4.0 Troubleshooting
WARNING
ELECTRIC SHOCK HAZARD
• Do not operate a system that contains malfunctioning components. If a component malfunctions,
turn the system OFF immediately.
• Disconnect and lock out electrical power.
• Allow only qualified personnel to make repairs. Repair or replace the malfunctioning component
according to instructions provided in its manual.
• High voltage is present in an airfield series circuit which may result in personal injury, death, or
damage to the equipment.
• A failed Field Lightning Arrestor case may be live. DO NOT troubleshoot the Field Lightning Arrestor
on a live field circuit. Failure to disconnect the power supply may result in personal injury, death, or
damage to the equipment.
Failure to follow these warnings will result in death or equipment damage.
The Field Lightning Arrestor (FLA) is connected between the series circuit and earth ground. If damage to any FLA is
suspected, remove the series circuit wires from the output of the CCR and meg the entire series circuit. Compare this meg-
ohm reading with previously recorded readings. If there has been a sudden, significant drop in the meg-ohm reading, a
damaged FLA may be present. See FAA AC 150/5340-26, Chapter 5 for guidance on expected meg readings on new circuits
and normal degradation of existing circuits. Isolate the suspected failed FLA using normal series circuit troubleshooting
techniques. Note that the source of lowered insulation resistance may be due to existing series circuit wiring or isolation
transformers. See FAA Advisory Circular 150/5340-26 (current edition) for series circuit troubleshooting guidance.
Note
Series circuit insulation resistance is normally tested using either 500Vdc or 1000Vdc. The insulation resistance of
series circuits with Field Lightning Arrestors can be tested with voltages up to 5000Vac or 7070Vdc.
The following physical evidence may be present as a result of lightning strike(s):
•
A section of the airfield circuit may be dim or not lit.
•
Visual evidence of physical damage to either cordset or the FLA enclosure.
•
Ground wire is missing (vaporized).
•
Burnt smell is present.
The following troubleshooting may be performed on the FLA to further determine if the device has failed:
•
Remove the FLA from the series circuit.
•
Connect an ohmmeter from the male connector pin to the female connector pin. The measured resistance should be less
than 2 ohms. If the resistance is significantly higher, the lead connectors have been damaged. If the resistance is infinity,
there is an open in the cordset wiring. In either case, the FLA must be replaced.
•
. Connect the FLA to some mating cordsets and drop the FLA in a bucket of water. Connect the positive (red)
terminal of a meg-ohm meter to the cordset leads. Put the negative (black) terminal of the meg-ohm meter in contact
with the water or the ground wire. This is typically done by attaching a wire to a metal plate and dropping the metal plate
in the water. Bring the attached wire out of the water and connect it to the negative terminal of the meg-ohm meter. Meg
96A0489, Rev. B, 2018/03/06
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Summary of Contents for FLA
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