Restricted Earth Fault Protection working | REF relay working principle | REF relay working Part-1
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- เผยแพร่เมื่อ 29 ส.ค. 2024
- Restricted Earth Fault Protection working
the working of REF high impedance protection
Definition for REF
Restricted earth fault protection is a sensitive way to protect a zone between two measuring points against earth faults.
zone present in REF protection
i) inzone
ii)outzone
#REF #REFworking
Much needed sir... Great explanation.. thank you sir
Always welcome
Nice video sir.very informative and clear video.
Thanks and welcome
Very well explanation thanks Anna.
ABB relays:
REM= Relay for Electrical Machine (Motor or Generator)
RET= Relay for Electrical Transformer
REF=Relay for Electrical Feeder
RED=Relay for Electrical Differential
REL=Relay for Line (Distance Protection)
Rex= basic protection NOC/NEF
REM is mainly used for motor and REG is mainly used for generator
Well explained !
Good
Very good. Thanks 🙏🙏🙏🙏🙏
you are welcome
ஹாய் ப்ரோ சூப்பர்
most welcome
Please make video on SKE11 synch check relay, slip frequency test.
Keep it up...
Thank for it 👍🏻👍🏻👍🏻👍🏻
You're welcome 😊
Thank you sir
Thanks sir such a good vedio
Many thanks.
You are welcome!
I am waiting your next videos'
soon i am going to upload
Super job ana
I am shorting r phase with respective to earth for ref stability in primary method and how much current will flow in primary and secondary of transformer is there any calculation for that
please follow transformer stability primary injection
Case 2 : As per your video ,Neutral Ct secondary current will choose low resistance path & it will make the relay trip .
Same scenerio if we consider for case 1 How the neutral secondary current will flow in core balanced side since its a high impedence path .
Please clarify sir..
if flow of the current in same direction then it will have low resistance path.
Case1 current flow of neutral current is showing incorrect in flowing red dot animation.
according to P1 and P2 the current flow on CT secondary. Thank you.
Sir is that REF protection and sensitive earth fault one and the same or what please
both are different
Can you do a case study: when one phase is fully loaded, other two half loaded, EF in one winding & same current passes through N CT as in fully loaded phase but half of this passes through other two phases??
Thanks in advance
yes i will make later for you
Pls understand for PT selection for double bus bar single breaker
Earth fault will not created
Sir please prepare a video regarding differential protection
Also about the motor protection testing on Micom P242
th-cam.com/video/xy-EvpOtyjo/w-d-xo.html
@@baranitech1026 thank you sir
Please do a video on NGR
Surely I make video on NGR
Please do a video on NGR@Barani Tech
yes
6:24 what is reason for B phase Ct providing high impedence to flow of nutrel ct fault current?already B phase load current 1A flowing through B phase.then at the time of fault current cant to flow through B phase ct?kindly explain sir
it is the node of all three phase R, Y and B . not only for B phase CT
no current out form Core balance CT so neutral CT current not able to enter
What is core balance ct
sum of all phase
In first case the fault current is able to travel the high impedance path whereas in second case it chooses low impedance path? Can you please explain the difference... Meaning the first case has 1 amp total fault current which chooses high impedance path whereas 0.5 amps chooses low impedance path... Pleassexplain
if the flow in same direction it can able to flow easily
Good info : question - what will happen to REF if CT of faulty phase becomes saturated during through fault condition ?
before it get saturation relay has to give trip .
In saturated condition neutral secondary current shall flow through phase CT due to minimum impedence ...
in second case R phase current will be zero?
IF ITS FULLY SHORT THEN IT WILL BE ZERO, IF ITS HAVE RESITIVE LEAKAGE CURRENT THEN IT WILL TAKE LOAD CURRENT ALSO.
hi , how to calculate in current for ex: I1+I2+I3=0 (1.5+1+1= 0.5) explain plz
i1
Convert from polar to rectangular form, that way it'll be easier to understand.
@@baranitech1026 brother please explain below thing
If we take angle for (1.5+1+1=0
.5)
1.5 sin 0° + 1 sin 240° + 1 sin 120°= 0
.5 sin 0°
= 1.5 (0) + 1 sin (-3/2) + 1 sin (3/2) = 0.5(0)
Then value wil come
0 - 0.866 + 0.866 = 0
Total value is 0
Please clarify my doubts sir
What happens if no fault happened and load is unbalanced , will the relay trip
no it will not trip unbalance current and NCT current get balanced
But unbalance current will not pass through transformer neutral CT right?
Only fault current can pass through the neutral point CT
@@akhilsm6840 without help of neutral line the star connection cann't able to take unbalance current
U meant to say then total 5 CT will be required for 3 phase 4 wire system am I right sir
hello please what software tool do you use for drawing these schemes
only ppt
Pop up notes on display is obstructed the image of diagram. Due to which , I am not able to understand properly. So I request you sir to please avoid displaying the notes on display .
okay i will avoid
Don't hide all by subtitles
i try to reduce subtitle sizes small
Hindi