In this very first blog i'm going to tell you about Lightening Arrester. LA is a Device Used on Power Systems above 1000V or 1KV to Protect other Equipment from Lightning and Switching Surges.
For example, on a pole a line is carrying 11Kv current, and to that line a an Impulse sensitive transformer is connected, which transfers current to residents of generally 230v. Lightening strikes contains 25-35 lakh KV of energy according to my research, so when it strikes on line of high voltage line the input to the transformer will be above its maximum rating, which in turn gets damaged and light goes out.
The solution to this problem is LAs. If LA is connected in parallel to the transformer and the grounded wire, the excessive amount of energy flows through LA, which also save the equipment form getting damaged.
From above example we can say the lightening arrester:
1)Does not Absorb the Lightning
1)Does not Absorb the Lightning
2)Does not Stop the Lightning
3)Does Divert the Lightning to Ground
4)Does Clamp (limit) the Voltage produced by the Lightning
5) Only protects equipment electrically in parallel with it
Lightening Arrester is made up of Metal Oxide Varister(MOV) disk. The MOV Disk is a Semiconductor that is sensitive to Voltage but, at normal Voltages the MOV disk is an insulator and will not conduct current. But at higher voltages caused by lightning it becomes a conductor.The MOV Disk is a very fast acting electronic switchIt is an open switch to standard system AC voltages and a closed switch to lightning voltages.
The action of the lightning arrester or surge diverter is as under:
(i) Under normal operation, the lightning arrester is off the line i.e. it conducts no current to earth or the gap is non-conducting
(ii) On the occurrence of over voltage, the air insulation across the gap breaks down and an arc is formed providing a low resistance path for the surge to the ground. In this way, the excess charge on the line due to the surge is harmlessly conducted through the arrester to the ground instead of being sent back over the line.
(iii) It is worthwhile to mention the function of non-linear resistor in the operation of arrester. As the gap sparks over due to over voltage, the arc would be a short-circuit on the power system and may cause power-follow current in the arrester. Since the characteristic of the resistor is to offer low resistance to high voltage (or current), it gives the effect of short-circuit. After the surge is over, the resistor offers high resistance to make the gap non-conducting.
The function of the lightning rods consists of emitting an ascending electrical unloading to influence the effect of the descendent tracer. When one propagates towards the cloud, this ascending unloading generates an electric field sufficient to modify the trajectory of the descendent tracer, allowing the unloading of the ray to earth. This process can be realized naturally but the action of lightning rods Ioniflash allows a fast activation but, providing an effective protection but.
This it is the concept of the fattened advance of.
1.Level of protection classified of very high
2.It does not need external power supply.
3. It does not need special maintenance.
So at last what flows through the Lightening Arrester? Voltage or Current?
The answer to this question is Current. Because voltage is just the potential difference between the tow conductors, its the current that is flowing.
The answer to this question is Current. Because voltage is just the potential difference between the tow conductors, its the current that is flowing.
