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AIR DISCHARGE OR BREAK
DOWN MECHANISM
Lightning is a fast and instantaneous exchange of electric charges
between Earth and cloud. The negative clouds are mainly stormy and are
the base of lightning strikes.
The lower part of the storm cloud is negatively charged when the cloud
moves, it generates on the Earth a charge of equal value and opposite
sign.
When the accumulation of charge exceeds a critical potential (when the
voltage gradient reaches a value of about 10 KV/cm) a channel of
electrodes leaves the base of the cloud in the form of a faintly
luminescent traject and progresses rapidly toward the earth.
The intensity of discharge current is often more than 30,000 A, and
sometimes reaches 200,000 amperes.
MATERIAL SPECIFICATION
All products in lightning protection are Produced in accordance
with BS 6651 that ensure a satisfactory life span of at least 30 years.
To ensure an effective system and a satisfactory long term performance
all fittings need to be mechanically robust and provide good corrosion
resistance qualities in widely differing environments.
Aluminum and copper, the two metals most commonly used in lightning
protection system particularly where they come into contact with each
other.
If aluminum is selected as the material for air termination networks and
down conductors, it has to be connected to copper at or around the test
clamp. This connection should be positioned at the beginning of the
earth termination network.
This is because both BS 6651 and the Earthing code BS 7430 do not
permit aluminum to be buried underground.
The contact surfaces of dissimilar metals should be kept completely dry
and protected against the ingress of moisture, otherwise corrosion will
occur. A particularly effective means of excluding moisture is to
inhibitor pastes, bitumastic
paint or approved protective wrapping.
AIR RODS & SADDLES
These rods are manufactured from solid copper C101 or C102 with
nickel-chrome coating.
The stainless steel rods are also available.
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AIR ROD
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MULTIPLE AIR ROD
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FLAT SADDLE
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BRIDGE SADDLE
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STRIP AIR ROD BASE
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CONDUCTOR AIR ROD
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ROD BRACKETS (AIR ROD SUPPORTS)
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ROD TO TAPE COUPLING
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FIXINGS & CLAMPS
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CROSS
TAPE CLAMP
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CABLE
TO TAPE JUNCTION CLAMP
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METALLIC TAPE CLIP
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CABLE
CLIP
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CROSS
TAPE TEST CLAMP
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TAPE
CLAMP
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ONE
HOLE CABLE CLIP
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TOWER
EARTH CLAMP
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(B")
Bond
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CABLE
TO CABLE TEST CLAMP
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TAPE
TO TAPE TEST CLAMP
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SQUARE CONDUCTOR CLAMP
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