What is difference between earth leakage relay and
restricted earth fault relay ?
- 22 Answers
- 43690 Views
- I also Faced
- E-Mail Answers
Answer Posted / vijay
For protection of Transformers or generators normally
Differential protection is used. If the faults in the
winding are nearer to neutral (say 5% of turns from neutral
earth fault occurred), due to less fault voltage, fault
current will be less which cannot be sensed by differential
protection. Hence a separate protection called Restricted
Earth fault protection is used for detecting the earth
faults near to neutral.
For the Earth faults and faults like above Earth leakage
relay also senses the fault.
There is a difference in construction of Earth leakage relay
and REF.
In REF separate CTs are used for each phase and neutral. all
the four CTs are summed up and if there is difference it
indicates earth fault.
In Earth leakage CT core is common for all the phases i.e
in a circular core all the three wires are passed and acts
as primary. as the core is common all the currents are
summed up(vector addition)and if there is difference it
indicates earth fault.
as the core is common it used only for Low voltage applications.
| Is This Answer Correct ? | 7 Yes | 1 No |
Post New Answer View All Answers
how to remover corona effect and hysteresis losses from contactor
Mention how NPN and PNP transistor works?
detailed procedure how we calculate cost for pcc m10 and rcc m20 including centering and labour excluding steel/ iron
What is transient response?
Write down the design procedure of commutaj.
what can be the causes of capacitor start motor having a higher current that its actual
list of tests to be carried out at manufacturers end while purchasing a step up transformer of 11kv to 66kv ,2MVa Capacity.
How to work definite,over pluxing,revers power,OSR relay
What are the different sign conventions used in electric circuits?
pre arcing time of ehv breaker
what is the differencce inn series and cascade connection??
in science exhibition how lamp can blink when you clap near the lamp ? thank you
why the difference arise between HT reading & LT reading (submeters fixed in complexes, apartments etc)if the power factos exceed from 0.9 to 1 can the ht meter reads fast?
Should power factor be low or high?
I have iti elec, 1st aid, and 5 yrs experience in 7.5 mw power plant. Am i eligeble for 11kv license in telangana state..when, how to apply for that.?
