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The Franklin Rod
Highly conductive metal rods of copper, stainless steel or
copper coated mild steel with spikes on top in different
shapes and configuration were the most conventional Lightning
Protection devices used world over and were commonly known as
Franklin Rods. The system offered a conical protection and the
cone angle reduced with increase of height for a class I
protection. At 20 meters height, the maximum available
protection cone is of 45° for a Class III protection.
Drawbacks
Its coverage zone is very limited, and conditioned just by the
height and required protection level.
Franklin Point functioning is not based on Discharge Formation
Fundamentals. For bigger dimension installations number of
rods with mesh network have to be worked out.
The devices being passive in nature and having a limited
protection zone, the research for more advanced terminal was
pursued. The Early Streamer Emission terminal using Radio
Active transmission came in use in year 1915. The same
subsequently changed over to Electro Magnetic transmission
after WHO stopped use of Radio Active element in environment.
ESE Terminals
Early Steamer Emission Terminals are available in the market
in different shapes and configurations. These devices offer
protection with relatively free of space charges, capable of
creating photo ionization, which concentrates
electric field to release free electrons on the approach of
Lightning leader. The lightning is encountered not only at much
higher heights than the highest point above the building
tower, where otherwise a passive rod normally waits for
lightning to strike, but also ahead in time. The basic gains
of this kind of active device are, much larger area
of protection, keeping the flash and fire away from
installation and no induced voltages affecting the electrical
and radio services.
Early Streamer Emission Terminal (ESE)
ESE TERMINAL is a dynamic external lightning protection
device, which is radio quiet and its operation only occurs
during the lightning event. The system comes in two pieces
which are screwed together and the total assembly is mounted
on a Mast with the help of an adaptor. The unit is mounted one
meter. above the highest point on the building or any
installation under protection. The installation
can be on a tower, rooftop or on the sidewall of the building.
The adaptor has the provision of fixing the Down Conductor.
The Down Conductor is taken through the Mast to the earth pit.
A Lightning Counter is mounted through which the Down
Conductor passes enroute to the pit. The Lightning Counter is
positioned at a height /place normally just above the guard
pipe, which can be easily monitored.
Working Principle
Lightning formation is preceded by an increase, higher than
(10KV/m) in the ambient electric field. The triggering device
of the ESE TERMINAL lightning conductor, which automatically
turns into pre-control situation, directly accumulates this
natural energy. Lightning conductor uses the atmospheric
electric field as its only power supply, is totally autonomous
and maintenance
free.
Lightning discharge approach provokes an intense and sudden
increase of the electric field, thus originating a lightning
strike risk area. If this risk area takes place in the zone
protected by the ESE TERMINAL, the sudden variation of the
electric field simultaneously activates the inbuilt control
system, which in synchronization with lightning approach
provides the safest controlled discharge path to the earth.
The ESE TERMINAL offers a drum shape umbrella top protection
to the site. Its operation and functioning can be tested at
any time through the ESE tester. All ESE Terminals are
certified for effective performance in all weather conditions
because of NOREN sealing tested in accordance to UNE 21308 and
IEC 61312. The system is tested to with stand multiple strikes
of more than 100 kA of 10/350µs wave shape.
Lightning formation is preceded by an increase, higher than
(10KV/m) in the ambient electric field. The triggering device
of the ESE TERMINAL lightning conductor, which automatically
turns into pre-control situation, directly accumulates this
natural energy. Lightning conductor uses the atmospheric
electric field as its only power supply, is totally autonomous
and maintenance
free.
The area of protection offered by any ESE Terminal depends
upon the height of installation and the model selected. |
