Thank you for a very clear easy to follow video on the topic. Made a lot of things clear for me. I posted a question under another comment about t=0.6s for LV and t=0.8s for HV. If you could answer we will highly appreciate it.
@relayprotectionelectrical
Жыл бұрын
Thank you for your valuable comment. Tms of LV and HV can be so chosen that both the HV and LV over current relat trip simultaneously. Now a days if LV OC trip then there will be an inter trip will be sent to HV master trip relay from LV OC relay. Now for the time 0.8 S. 0.8 S is the maximum time that can be given to the transformer to trip as it should not exceed far end line in zone-3 time which is normally set as 0.8-1 S . So if Zone3 encroach lower voltage level far end FDR should not trip prior to transformer trip and i.e. why 0.8 S is the time for transformer trip in back up OC.
@pietervdberg7055
Жыл бұрын
Thank very much for the explanation.
@pietervdberg7055
Жыл бұрын
@@relayprotectionelectrical Another question please that I forgot to ask. The I(set) value being 110% of full load current and then calculate I(set)(s) = I(set)/CT ratio, is it the same as relay pickup current that is used in some calculations. Some I have seen are 120% and others as 125% of full load current. Is the formula to calculate t.m.s. for normal inverse curve? Thank you.
@Deb0029
2 ай бұрын
Very helpful ❤
@surendrakverma555
Жыл бұрын
Excellent lecture Sir. Thanks 🙏🙏🙏🙏🙏🙏🙏🙏🙏
@relayprotectionelectrical
Жыл бұрын
Most welcome
@syed_taha_ahmed
Жыл бұрын
Do you have posted video on transmission line over current relay settings? How receiving and sending end relays are set? Please make a video on current discrimination and overcurrent relay settings for transmission lines.
@MansourAlramlawi
2 жыл бұрын
Many thanks for your explination, could u share with us a reference for these calculations?
@santhoshr53
2 жыл бұрын
Plz make video on Calculation for instantaneous over current
@Abi-og5jr
10 ай бұрын
How did you got the value t = 0.6 for lv and t=0.8 for hv
@rakeshparmar8570
2 жыл бұрын
Good explanation
@taimur649
2 жыл бұрын
Very informative
@salamkadhim6949
Жыл бұрын
شكرا جزيلا
@samadhanmore3760
Жыл бұрын
Determine the time of operation of the two relays
@syed_taha_ahmed
Жыл бұрын
What does numeric relay indications I> I>> and I>>> means?
@AjeetKumar-iq7fp
2 жыл бұрын
Thanks sir
@KarrarH-el4th
Жыл бұрын
PLZ Why this values of t=0.6 & 0.8 from what get it plz
@pietervdberg7055
Жыл бұрын
Yes please can you clarify the times of t=0.6s for LV and t=0.8s for HV. Is it a general norm for different voltages. Is specified in IEC etc Hope to hear from you.
@relayprotectionelectrical
Жыл бұрын
@@pietervdberg7055 Thank you for your valuable comment. Tms of LV and HV can be so chosen that both the HV and LV over current relat trip simultaneously. Now a days if LV OC trip then there will be an inter trip will be sent to HV master trip relay from LV OC relay. Now for the time 0.8 S. 0.8 S is the maximum time that can be given to the transformer to trip as it should not exceed far end line in zone-3 time which is normally set as 0.8-1 S . So if Zone3 encroach lower voltage level far end FDR should not trip prior to transformer trip and i.e. why 0.8 S is the time for transformer trip in back up OC.
@sudampatra5608
2 жыл бұрын
Can we use relay rest ratio here
@mustafakhalidjasim3160
Жыл бұрын
Why you have used z%equal to 12%,where you get it?, thanks
@relayprotectionelectrical
Жыл бұрын
You can get %Z of Transformer in nameplate .
@badshahibrahim8475
2 жыл бұрын
Sir please make for Motor feeder 🙏🏻🙏🏻🙏🏻🙏🏻
@relayprotectionelectrical
2 жыл бұрын
Ok I will
@badshahibrahim8475
2 жыл бұрын
@@relayprotectionelectrical yes sir I hope 👍🏻
@Deepak_Kumar1993_
Жыл бұрын
@@relayprotectionelectricalw8ing for long time
@badshahibrahim8475
2 жыл бұрын
Thank for it 👍🏻👍🏻
@ganeshachally4881
2 жыл бұрын
Sir why you didn't take the power factor in calculating the full load current
@relayprotectionelectrical
2 жыл бұрын
Maximum fault current is considered in this case and i.e. why unity pf is considered for this purpose.
@dawodtawer1953
2 жыл бұрын
Hello everyone I hope someone answer my question I have six generators (1 MVA each)feeding 11 kv switchgear through transformer 0.4/11 kv i need to add two more generators (1 MVA each) with parallel transformer 0.4/11 kv to same switchgear. My question is do i need to change the protection settings?
@mageshgopi5644
2 жыл бұрын
System prospective current value increased and system impedance has reduced . So a comprehensive short circuit calculation and protection setting study is required
@pietervdberg7055
Жыл бұрын
@@mageshgopi5644Yes agree with this reply. When operating transformers in parallel the total impedance of the transformer combination will reduce, depending on the number of transformers and their impedances. Similar to connecting resistors in parallel. This will cause the total system impedance to decrease resulting in an increase in the prospective short circuit current. So yes in depth calculations and analysis of the network is required. Consider introducing a busbar system with busbar incomers from generators and transformer feeders as well as bus couplers for different sections to avoid paralleling transformers but to provide flexibility of the network. Not sure what the network looks like. Also bear in mind that when the network is changed such that the system impedance is decreased and fault currents increase substantially you might reach a point where the fault current could exceed the max fault current rating of switchgear, cables, etc
@lokeshjuneja2039
Жыл бұрын
volume is very low in video.
@AjeetKumar-iq7fp
2 жыл бұрын
Part 2
@great_India3344
2 жыл бұрын
TMS formula is written wrongly
@relayprotectionelectrical
2 жыл бұрын
Yes it is. But TMS calculated is right. Thank you for watching video carefully...
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