Dear sir,I have one question.What will be the current in HV & LV of Dyn11 transformer,if any one phase of trafo secondary(star) gets earthed.Please explain easy calculation method of fault current Thanks
We have a factory that requires 6 MVA electric power , Can we use one large transformer and limit the fault current with NGR? our transformer is 11/0.4 KV
Request you to upload a video on symmetrical & unsymmetrical fault analysis calculations on the basis of pu calculation of + sequence, - sequence & zero sequences of the system.
thank you so much sir for the option 1 is when the LCT and NCT =4000/1A .. knowing that FLC=3333.33 A AND the EARTH FAUlt is restricted TO 100 A , I JUST Wanna know if we use NCT RATIO 4000/1A , the reflectecd EARTH fault current will be so low in NCT 4000/1A (100/4000) . the sensitivity of th relay is it supported in this case ?.. thank's sir
it may support.. you have to check the minimum relay pick up current. but problem lies elsewhere. suppose if the fault is at 100% of voltage you will get calculated fault current. but if the fault is inside i.e. not at 100% then fault Current will be low.
It should be closer to the earth point. Intention is to cover maximum area under protection. If you connect CT before NGR or NGT, then the area coming under NGR or NGT will NOT be protected.
You are indicating fault at nutral wire as i understand. But if the neutral is isolated and faulted then there will be no current, there is other method to detect that type of faults. The NCT is often installed at trafo neutral bushing
Its conductor cross section shall be higher. Suppose your full load current is 500 A, but you are using a 100/1A CT, so your ct secondary will see a current of 5A. In that case secondary conductor cross section shall be suitable for 5A. Also primary conductor cross section shall be suitable for 500A . Nothing but higher cross section conductor shall be required
AMPERE HOUR. THAT MEANS THE BATTERY COULD DELIVER 200 A CURRENT FOR 1 HOUR AT 12 VOLTS. YOUR MOBILE BATTERY HAS ALSO THAT RATING. SAY 5000 mAH. THAT MEANS IF YOU USE YOUR MOBILE TO RUN PROCESS OF 5 A, YOUR BATTERY WILL LASTS ONLY FOR AND HOUR....
Sir Generally 11/.440 kv Transformer is the distribution xmer and most of time it is 200 KVA RATTING SO distribution xmer no any REF protection Is provided, & sir the Zone of protection of REF is HVCT TO NCT so there is any concept of LVCT In 2 winding/ with tertiary. But in case of Auto transformer LVCT come in to pictures for REF protection. So my question is, you so the REF protection between LVCT TO NCT HOW is possible???
first of all you may have seen the 11/0.433 kv trafo for distribution agencies. thats why you may not have seen rating above 200 kva. and i haven't understood rest of your queries...
please see SLD in thislink. (red highlighted) drive.google.com/file/d/13UzHKotDOdwJThTNIU_9x2whoG0pxan4/view?usp=sharing here both CTs for neutral differential (PX class) are rated to 4000A where as NER rated to 400A. Can you please advice why it so, instead of 400A both neutral CT & LIne CT (law imp scheme) or 400A for neutral CT & 4000A for LIne CT (high imp scheme) ? Also note for 51G, its 400A. why its is 400A when others rated to 4000A
The REF used there is a high impedance REF system. So here line ct and neutral must be same ratio. Other wise if earth fault occurs outside of the protection zone then also the relay will operate, because the line ct and neutral ct will generate different secondary current
But I am not receiving such feedback from anyone else. I hope it is just a network related issue, and would be resolved shortly.☺ Please let me know if the issue has been resolved
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Thank you sir,so much helpful🙏🙏,Plz Upload new video☑️
Very good 🙏🙏🙏🙏🙏🙏
good....please brief technically more inside all video
Excellent
Sir can you please make a video of how to select NGR. And where we use solid grounding and where we use NGR...
Sir I request you to please make a video one transformer % Impendance voltage.. please
Make a video on low impedence REF
Calculation for stablizing resistor
Super 👍👏
Dear sir,I have one question.What will be the current in HV & LV of Dyn11 transformer,if any one phase of trafo secondary(star) gets earthed.Please explain easy calculation method of fault current
Thanks
We have a factory that requires 6 MVA electric power , Can we use one large transformer and limit the fault current with NGR?
our transformer is
11/0.4 KV
sir please make a video about the unbalance current in 3 phse induction motor and how to measure it and compensate it... thanks in advance
Request you to upload a video on symmetrical & unsymmetrical fault analysis calculations on the basis of pu calculation of + sequence, - sequence & zero sequences of the system.
Okay, i shall try
How git the neutral current value in second diagram..
Line to neutral = 230 V, Resistance = 2.5. Therefore, current = 92 Amps.
Probably. But not sure. Open to corrections.
Hindi me Explain karne me Tx Dena padta kya aap ko....
Kindly upload 2nd part of this video as soon as possible..
I hope you have enjoyed the first part. I am planning to upload the second part friday. Please stay tuned.
i have to question sir
the option 1 is not recommanded . is it ?
how can we calculate the neutral resistance? thank you
i cant remember what the option 1 was.
for neutral resistance calculation watch my ngr sizing calculation video
thank you so much sir for the option 1 is when the LCT and NCT =4000/1A .. knowing that FLC=3333.33 A AND the EARTH FAUlt is restricted TO 100 A , I JUST Wanna know if we use NCT RATIO 4000/1A , the reflectecd EARTH fault current will be so low in NCT 4000/1A (100/4000) . the sensitivity of th relay is it supported in this case ?.. thank's sir
it may support.. you have to check the minimum relay pick up current. but problem lies elsewhere. suppose if the fault is at 100% of voltage you will get calculated fault current. but if the fault is inside i.e. not at 100% then fault Current will be low.
let me want to know the CT coneection with NGR / The NCT should be connected either before or after NGR ?
It should be closer to the earth point. Intention is to cover maximum area under protection. If you connect CT before NGR or NGT, then the area coming under NGR or NGT will NOT be protected.
You are indicating fault at nutral wire as i understand. But if the neutral is isolated and faulted then there will be no current, there is other method to detect that type of faults. The NCT is often installed at trafo neutral bushing
Sir then when we use option 3?
Need differential relay settings
Sir in option 3 if the LCT rating is 100/1A how the LCT will carry the full load current. Kindly explain.
Its conductor cross section shall be higher. Suppose your full load current is 500 A, but you are using a 100/1A CT, so your ct secondary will see a current of 5A. In that case secondary conductor cross section shall be suitable for 5A. Also primary conductor cross section shall be suitable for 500A . Nothing but higher cross section conductor shall be required
Any book reference?
Please give me answer
A battery rating 12 volt and 200 AH
In above data what is AH?
AMPERE HOUR. THAT MEANS THE BATTERY COULD DELIVER 200 A CURRENT FOR 1 HOUR AT 12 VOLTS. YOUR MOBILE BATTERY HAS ALSO THAT RATING. SAY 5000 mAH. THAT MEANS IF YOU USE YOUR MOBILE TO RUN PROCESS OF 5 A, YOUR BATTERY WILL LASTS ONLY FOR AND HOUR....
@@electricaltechnologyandind5335 Sir, please send your mobile number
Sir Generally 11/.440 kv Transformer is the distribution xmer and most of time it is 200 KVA RATTING
SO distribution xmer no any REF protection Is provided, & sir the Zone of protection of REF is HVCT TO NCT so there is any concept of LVCT In 2 winding/ with tertiary. But in case of Auto transformer LVCT come in to pictures for REF protection.
So my question is, you so the REF protection between LVCT TO NCT
HOW is possible???
first of all you may have seen the 11/0.433 kv trafo for distribution agencies. thats why you may not have seen rating above 200 kva.
and
i haven't understood rest of your queries...
How to calculate the current?? 3333.33A
Rated current=2.5 MVA/ 1.732*433
Sir, how can we calculate short circuit current if upstream side transformers connected primary side parallel or secondary side paralally connected
Same explain in Hindi
please see SLD in thislink.
(red highlighted)
drive.google.com/file/d/13UzHKotDOdwJThTNIU_9x2whoG0pxan4/view?usp=sharing
here both CTs for neutral differential (PX class) are rated to 4000A where as NER rated to 400A. Can you please advice why it so, instead of 400A both neutral CT & LIne CT (law imp scheme) or 400A for neutral CT & 4000A for LIne CT (high imp scheme) ?
Also note for 51G, its 400A. why its is 400A when others rated to 4000A
The REF used there is a high impedance REF system. So here line ct and neutral must be same ratio. Other wise if earth fault occurs outside of the protection zone then also the relay will operate, because the line ct and neutral ct will generate different secondary current
For 51N 400/1A ct has been used to increase sensitivity of the relay. Often 200/1 A ct is also used.
@@electricaltechnologyandind5335 when selection same rated CTs, doesn't it require to match rating of NER?
Error when vdo playing
Try after sometime. Or check your internet connectivity. I am also checking...
@@electricaltechnologyandind5335 not only this vdo all videos are same problem on your chanel.
Is it showing error??? Or getting stopped after some time?
But I am not receiving such feedback from anyone else. I hope it is just a network related issue, and would be resolved shortly.☺
Please let me know if the issue has been resolved
Kuch smj me nhi aaya
Totally doubt...
Why??