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Пікірлер: 40
@Deb002914 күн бұрын
Very helpful ❤
@pietervdberg7055 Жыл бұрын
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.
@surendrakverma555 Жыл бұрын
Excellent lecture Sir. Thanks 🙏🙏🙏🙏🙏🙏🙏🙏🙏
@relayprotectionelectrical Жыл бұрын
Most welcome
@rakeshparmar85702 жыл бұрын
Good explanation
@taimur6492 жыл бұрын
Very informative
@Abi-og5jr8 ай бұрын
How did you got the value t = 0.6 for lv and t=0.8 for hv
@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.
@santhoshr532 жыл бұрын
Plz make video on Calculation for instantaneous over current
@salamkadhim6949 Жыл бұрын
شكرا جزيلا
@samadhanmore3760 Жыл бұрын
Determine the time of operation of the two relays
@MansourAlramlawi2 жыл бұрын
Many thanks for your explination, could u share with us a reference for these calculations?
@syed_taha_ahmed Жыл бұрын
What does numeric relay indications I> I>> and I>>> means?
@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.
@AjeetKumar-iq7fp2 жыл бұрын
Thanks sir
@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 .
@sudampatra5608 Жыл бұрын
Can we use relay rest ratio here
@dawodtawer19532 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 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
@badshahibrahim84752 жыл бұрын
Sir please make for Motor feeder 🙏🏻🙏🏻🙏🏻🙏🏻
@relayprotectionelectrical2 жыл бұрын
Ok I will
@badshahibrahim84752 жыл бұрын
@@relayprotectionelectrical yes sir I hope 👍🏻
@Deepak_Kumar1993_ Жыл бұрын
@@relayprotectionelectricalw8ing for long time
@ganeshachally48812 жыл бұрын
Sir why you didn't take the power factor in calculating the full load current
@relayprotectionelectrical2 жыл бұрын
Maximum fault current is considered in this case and i.e. why unity pf is considered for this purpose.
@badshahibrahim84752 жыл бұрын
Thank for it 👍🏻👍🏻
@lokeshjuneja203911 ай бұрын
volume is very low in video.
@AjeetKumar-iq7fp2 жыл бұрын
Part 2
@great_India33442 жыл бұрын
TMS formula is written wrongly
@relayprotectionelectrical2 жыл бұрын
Yes it is. But TMS calculated is right. Thank you for watching video carefully...