After isolating a probable failed field lightning arrestor, make a visual inspection of the cord set and arrestor body for charring
or a bulged arrestor body (caused when surge currents in excess of the MOV rating passes through the field lightning
arrestor). If damage is suspected, replace the field lightning arrestor with a new one.
If it is suspected that the internal MOVs have degraded due to excessive surge current, causing a drop in insulation resistance
to earth ground, test as follows:
•
Place the field lightning arrestor in a bucket of water
•
Attach the red (+) lead of a megger to the male L-823 pin
•
Connect the black (-) lead of the megger to the arrestor earth ground lug
•
Meg the field lightning arrestor at 1000 VDC for one minute
•
Replace the field lightning arrestor if resistance is less than 2 GΩ
2.2 Introduction
The Field Lightning Arrestor incorporates distribution class Metal Oxide Varistors (MOVs). When a voltage transient occurs,
the impedance of the MOVs changes from a near open circuit to a highly conductive path to ground, clamping the voltage to
a safe level to protect the equipment. After passage of the surge, the MOVs return to their initial state, conducting minimal
leakage current.
The manual shows the information necessary to:
•
Install and maintain the Field Lightning Arrestor.
Dimensions
6.28
3.53
3.53
Field Lightning Arrestor
Rating: 5KV, 20 A
Part# AD071P01
Airfield Lighting Field Lightning Arrestor
Airfield Lighting Field Lightning Arrestor
6
Copyright
©
2017–2018 ADB Safegate, All Rights Reserved
Summary of Contents for FLA
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