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MS Topic 2 Lightning Protection - Coggle Diagram
MS Topic 2 Lightning Protection
Introduction
Average 20,000A
Lightning protection is to protect persons, building and properties
Single stroke lightning - 250A to 200,000A
Lightning protection system provides lightning current a path to flow to earth safety without damaging buildings.
Current flows through path with lower resistance, therefore lightning protection system must have a lower resistance than material of construction of buildings.
Surge Protection
Install in main electrical switch board
To protect electrical/electronic equipment from transient overvoltage
Light protection system
Down conductor
Earth termination
Air termination network (Vertical and horizontal)
General rule governing
Air Termination
Tip of vertical conductor should be not less than 300mm in height above object to be protected
Roof conductor (horizontal) should be connected to form a closed loop, covering sides of the rectangular surface
Horizontal conductor protects up to 10m
Horizontal conduction are install flat on surface to protect roof surface
Vertical conductors are to protect objects that protrude out of roof surface
Lightning current is intercepted by the
Air Termination
and carry via the down conductor to earth termination
Down conductors
1 Down Conductor every 15m
Place round outside walls of building, install at exposed corner
Conductor which runs from the air termination to earth termination
Earth Termination
To discharge lightning current into earth
Each Down Conductor should be connected to an earth termination
Resistance should be less than 10Ω
Assignment
Earth electrode's measure should not exceed 10Ω
Test link is not supposed to be underground
Down Conductor in conduit should be minimum 1500mm down to ground level
Down Conductor should be minimum 500mm
belong ground level