Why we not use the impedance relay in protection of short transmission line ?
Answer Posted / nagesh.patwari
1. During Short circuit current Step and Touch potential increases.Step potential : It is the potential developed between the two feet on the ground of a man or animal when short circuit occurs. This results in flow of current in the body leads to electrical shockTouch potential: It is the potential that is developed between the ground and the body of the equipment when a person touches the body during fault condition. When operating personnel touch an electrical equipment during short circuit condition, fault current flows through the human body. This is defined as touch potential.Gravel/Stones in the substation is provided to reduce the step potential and touch potential when operators work on switch yard.2. Power Transformers installed in the substations will have oil as cooling and insulating medium. Oil leakage takes place during operation or when changing the oil in the transformer. This oil spillage which can catch fire is dangerous to the switchyard operation. So Stones/Gravel is provided to protect from fire when oil spillage takes place.3. Stones eliminate the growth of small weeds and plants inside the switch yard4. Improves yard working condition5. Provides protection from wild life and snakes.
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
what is die electric strnth of transformer ?
Which do you think is the most significant cause of energy loss in a factory?
What are reasond for high wattage in single phase induction motors
In AC if the direction of current keeps reversing every half cycle, how does it propogate through the transmission lines?
what types of cable used in underground coal mining?
if 12v battery get discharged for 2 months after if we put charge it will charge again?how much time it will take to charge?
why steady state stability limit is greater than transient stability limit ? How it can be explained ?
a battery is having capacity 100AH and 25% charging .if a load taking 10A & connected 6 hour .what is the final condition of the battery.
What is stacking factor? What is its approximate value?
What is the de rating factor of cable? What is the importance of the de rating factor in cable selection?
what is servo motor and how it works?
What is the simplest formula to calculate the rotor diameter of a synchronous generator?
What is an 86-P or an 86-A trip
what is the main parts of transformer? how it is functioning? pls giv the ans briefly.
what is the use of surge suppresser in 33 KV incoming panel. where it must be installed,inseries with incoming cable surge suppresser must be at incoming of the breaker are outgoing of the breaker