What is rated voltage of surge arrester?
It is necessary to use an 18 kV arrester with an MCOV of 15.3 kV. Finally, for a resistance-grounded 13.8 kV system, the choice will be between arresters rated 12 kV, 15 kV and 18 kV, depending on the time needed to relay ground faults off the system.
How do you calculate lightning arrester rating?
Selection of LA
- For 220KV side: Voltage rating = 1.1 × 220 × 0.8 = 193.6KV. Power frequency spark over voltage = 1.5 ×193.6 = 290.4KV.
- For 110KV side: Voltage rating = 1.1 × 110×0.8 = 96.8KV.
- For 66kV Side. Voltage rating = 1.1 × 66×0.8 = 58.08kV.
- For 11 KV side: Voltage rating = 1.1× 11×0.8 = 9.68KV.
What is discharge class of surge arrester?
discharge class. IEC classifies arresters by their nominal discharge current. For 10 and 20 kA arres- ters, they are also classified by energy capa- bility expressed as line discharge class (2 to 5) verified in a long duration current test and a switching surge operating duty test.
What is difference between surge absorber and surge arrester?
– Lightning arresters are devices that help prevent damage to apparatus due to high voltages. – A lightning arrester may be compared to a relief valve on a boiler or hot water heater. It will release high pressure until a normal operating condition is reached. – When a high voltage (greater than the normal line voltage) exists on the line, the arres
What does surge arrester stand for?
What is Surge Arrester? Definition: A protective device that is used to protect the electrical power system from surges caused by lightning is known as surge arrester. It includes two terminals like high voltage and ground. Once an electric surge travels through the surge arrester from the power system, then a huge voltage current can travel to the insulation directly otherwise to the ground
How to size surge arrestors?
Introduction.
What is surge current and surge current rating?
The surge current rating is inversely related to the duration of the surge. The surge duration is usually measured in terms of number of cycles of normal power frequency. One cycle surge current rating is the maximum value of allowable non-recurrent half-sine wave duration.