25-08-2017, 09:32 PM
LIGHTNING PROTECTION USING LFAs
LIGHTNING PROTECTION .pptx (Size: 474.74 KB / Downloads: 66)
INTRODUCTION
The outages of power lines due to the direct lightning strokes are one of the main causes of shortages of electric supplies and economic losses of power utilities.
To overcome this streamer developed Long Flashover Arresters which are new simple, effective and inexpensive for lightning protection of overhead distribution line .
Why Lightning Occurs?
The separation is caused by cosmic particles crashing into the atmosphere which leads to the electrons from these particles and so there become positive and negative ions which then separate to the top and bottom of the cloud.
And it is also the separation of charges that collide between the ice particles and rain droplets.
Lightning Arresters
These are protective devices for limiting surge voltages due to
lightning strikes or equipment faults
or other events, to prevent damage to
equipment and disruption of service.
These are also called surge arresters.
Lightning arresters are installed on many different pieces of equipment such as power poles and towers, power transformers, circuit breakers, bus structures, and steel super structures in substations.
What is LFA?
Long flashover arrestors are those devices which capture the high voltage sparks resulting out of lightning.
A flashover is the near simultaneous ignition of all combustible material in an enclosed area. It is the most dangerous time of a fire. When the room bursts into flame, flashover has occurred.
Types of LFA :
Loop type long flashover arrester
Modular type long flashover arrester
Compact Modular type long flashover arrester
Multi-Chamber arrester for OHL 20kv
Double long flashover arresters
Modular Long Flash-over Arrester
Modular Long Flash-over arrester (LFA-M) is designed to protect 6, 10 kV three-phase AC open and shielded wires OHL and substation approach zones from direct lightning strikes and induced lightning overvoltages.