To enlighten a small bulb; We just need to switch ON the button. While for turning the bulb off; A button must be shifted to OFF position. It is that much simple. But Electrical system is complex & complicated which is equipped with multiple components & accessories which are performing multiple functions more than just switching.
Electrical power; A sign of growth if used in a safe manner otherwise dangerous outcomes will get happen. Safety of humans & machine; is mandatory. It is the safety & security which makes the Electrical system complex & bulky.
For protection from overload & short circuit situations; circuit breakers & overload relays are connected. But apart from that; there are many more things like Surges & transients in a power system. Which should be controlled & safely handle otherwise these components can damage the entire system.
This post is entirely dedicated to Surges occurring in power system. In this post, Along with surges, surge arresters, principle of surge arresters & working methods of surge arresters are been discussed.
SURGE
“ Due to switching, lightning, Charging & discharging of loads; Voltage spikes get generated in power line. That high magnitude voltage spikes Which are appearing for a small interval of time for micro seconds; are known as Surge. “
This surge can go beyond multiple times to the working voltage level. In worst cases, These surges can damage the whole system. That’s why protection from surges is very important.
SURGE/LIGHTNING ARRESTER
From surge protection; Arresters are been employed which are also known as surge suppressors or surge protection devices(SPD). Surge arrester is a type of element which diverts the path of high voltage spikes, Either through blocking or Either through shorting it.
A GIF below shows the impact of surge on running power system. In along with it, A time varying waveform is shown parallelly. In normal condition, Waveform is stable. While When surge appear across the system, Waveform get disturbed !
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WORKING PRINCIPLE OF SURGE/LIGHTNING ARRESTER
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WORKING METHODS OF SURGE/LIGHTNING ARRESTING
There are different types of elements which are used in manufacturing of different types of surge arresters. All the elements have different working phenomenon but motto is the Same, “Either diverts the surge or Block the surge ! ”
MOV
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TVS DIODES
Transient voltage suppressor diodes are specially designed for high voltage transients. At normal working voltage level; very minor milli amps flows through it. While at high transient voltage; It starts conducting & diverts the high voltage transient towards the earthing.
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GAS FILLED SPARK GAP (GSG)
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SPARK GAPS
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SUMMARY
- Due to switching, lightning, Charging & discharging of loads; Voltage spikes get generated. That high magnitude voltage spikes appears for a small interval of time for micro seconds; are known as Surge .
- From surge protection; Arresters are been employed which are also known as surge suppressors or surge protection devices(SPD).
- Surge arrester is a type of element which diverts the path of high voltage spikes, Either through blocking or Either through shorting it.
- Surge Arresters are specially designed for particular high voltage range; much beyond the normal voltage range. At normal voltage level arrester work as an open circuit & offer infinite resistance. While in surge conditions; its resistance get lowered & offer a closed circuit path Which results current get diverted towards earthing.
- MEHTODS OF SURGE ARRESTING ARE : MOV, TVS Diode, Gas filled Spark Gap, Spark gaps.