Excellent presentation and clearly explained the all details of Protection coordination and relay selection. This is one of the excellent video i seen in my lifetime. Could you please provide similar for Underground cable protection and how to select the settings and discrimination ?
Sir,the video was really good but i have one doubt as below: Why did we select the time as 0.25sec. After selecting 1sec. In the previous bus? Shouldn't we select 1.25 sec and then in increasing order?
Wonderful explanation. Also make a video on what should be the pick up value of current for both Relays i.e (51,50) and (51N,50N) feeder wise. Also explain upto how many upstream relays should be taken as backup protection for the downstream relays.
Suppose you set the pick up current for 51 at 120% of of the full load current, then you may set 50 pick up at 600%. It depends upon the withstand characteristics of the equipment to be protected. There is no such had and first rule
Thank you sir. In the explained case, I should set the Incomer of PCC at 120% of transformer LT side FLA as pickup value for 51. But what should be the pick up value for 50? On which basis I should set it's pick up value? Means 600% of what? For motor and transformer feeder, I understood. But it's confusing when it comes for any Incomer of PCC or MCC for 50.
For incomer of pcc from trafo does not have 50. They only have 51. Remember 50 shall be given for the last feeder at certain voltage level. Like motor. Or transformer. Say you have a 11/0.433 kV trafo. So at 11 kV level you will give 50. Because at 11 kV the trafo is the end feeder. That means fault current is fixed. When you will go to the 415 V side there you will get a different fault current. At 11 kV there shall be anotger 51, which shall be the back up of the 415v (pcc incomer) 51 relay. Here the 50 will have a pick up sightly higher than the transformer inrush current.suppose the trafo takes 11 times of hv side full load current as inrush. SO 50 puck up will be higher than that
Sir, When the last feeder say a motor or an SFU is considered and inst time is considered as 25 MS . Then the buscoupler operating time is 25 MS + 250 MS= 275 MS , Isnt it ? 250 MS being the discriminating time .
Hi Sir. Thanks for this video and the good explanation. What about the coordination between the motor feeder and bus coupler at PCC/PMCC? The motor feeder is 0.05 sec and the bus coupler is 0.75 sec?
Sir... in addition if u select .05 sec at hv side of transformer for 50....then how 51 will coordinate with transformer lv side 51 which selected with 1 sec.
Hey, how do we determine the time of the relay for transformer protection which has both 50 and 51? Should we consider the time delay of 51 as we do for 50 i.e. 0.05 sec. in the same relay?
Sir nowdays numerical relay come with both 50/51 protection in a single module... So if I use this module at MCC incomer level... How can we choose our desired protection, can we set these relay protection mode (50 OR 51) accordingly??
I have watched your overcurrent settings practice. The last feeder to motor has instantaneous element which is fine. Now the bus tie has no instantaneous element and the incomer to bus tie board has not instantaneous as well. Why? Why a main should not have instantaneous element ?
Sir... U select the protection, 50 and 50N as an only in end of feeder or starting of new leval voltage like Motor and transformer HV side.. Time discrimination will give to 50 protection.. Example motor is 0.7 pickup Time dial is 0.05 The up stream is 0.220 ms... Here if we are not using 50 protections... How to give time discrimination.. (U said taht 51 to 51...time discrimination..)
I've a doubt. if there is a fault and 415V incomer relay fails to operate then in that case, transformer incomer 66kv should operate. But here TMS for incomer 66KV is greater compared to outgoing 66 KV from 132/66KV. Then instead of 66/.433KV the relay at 132/66KV shall operate. Please explain.
Hi sir, Can you kindly tell, why did you select 0.25 s delay for each relay? And is 60ms is tripping time of Air circuit breaker ? Because we assign a min time delay to tail end relay and then calculate tripping time of each upstream relay ? Why did you not used calculation method? Thanks!
Thank you so much sir... Most practical content is ever seen !! Sir as you said in video at end feeder (motor) we used instantaneous relay and at upstream time delay relay are preferred but generally we don't provide numerical relay to low rated motor feeder. So can we provide instantaneous relay at MCC incomer level (considering it as a end point in system) ??
For low end motor mccb is considered, which acts as instantaneous relay during high fault current. Mcc incomer is not an end point system because there is motor downstream. So you need to co ordinate with the motor feeder and also with the bus coupler....
Dt is definite time relay. That means you have a pickup current set point and a definite operating time. So if the fault current crosses the set pick up the relay will trip as per the time setting. Suppose you have set a relay to pick up at 10A, with a delay of 0.05 sec. So if fault current goes beyond 10 A, may be 12, may be 15 or 50 the relay will operate at 0.05 sec. Where as idmt relay will take less time to operate if fault current is higher. Please see my different idmt characteristics video. Where better explanation has been given
If we use instantaneous relay for motor protection, during startup the motor starting current will be 7 times of full load current. By the time 50,50N will always trip due to over current.... Hence I thought 51 to be considered for load end feeders (motor feeders). Please explain
i have a video on motor characteristics and Protection, watch that. 50N won't pick up as its input CT s are connected residually. So if there is balanced current the ct will give zero current. for that i have another video ct connection for earth fault detection. watch that too... you confusions will be cleared
sir thanks for good information i think you know about siprotech relay can you make video on that how we set the setting of overcurrent, earth fault,over voltage, under voltage settings.
There is nothing called relay pick up time. The term is pick up current. If current through relay crosses the set value then the relay picks up. And as per its setting it trips after the calculated time
Thanks for great description and clarifying time gradation for different voltage level and time zone from fault accruing point of view. Good job
i really 💕 your videos salute you am in kenya sir Keep up
very nicely explained
Good explanation.
hi sir you are genius ,kindly keep more videos on protection and coordination
superb sir, These things are not taught in engineering . It is learnt during job work only
Sadly ... engineering schools don’t teach these stuff .. thanks to UA-cam
Excellent presentation and clearly explained the all details of Protection coordination and relay selection. This is one of the excellent video i seen in my lifetime. Could you please provide similar for Underground cable protection and how to select the settings and discrimination ?
Very informative video thanks sir
Sir very nicely explained, very critical concept.
Very good lecture Sir. Thanks
Very well explained. Keep it up.
very very great bro , i learned a lot today
you people are great
Well explained!
Thank you.
Thank you for sharing your knowledge..
Nice video sir...please make videos on DC system
Sir,the video was really good but i have one doubt as below:
Why did we select the time as 0.25sec. After selecting 1sec. In the previous bus?
Shouldn't we select 1.25 sec and then in increasing order?
Nice Lecture. I'm very impressed.
Good information
Wonderful explanation. Also make a video on what should be the pick up value of current for both Relays i.e (51,50) and (51N,50N) feeder wise. Also explain upto how many upstream relays should be taken as backup protection for the downstream relays.
Suppose you set the pick up current for 51 at 120% of of the full load current, then you may set 50 pick up at 600%. It depends upon the withstand characteristics of the equipment to be protected. There is no such had and first rule
Thank you sir. In the explained case, I should set the Incomer of PCC at 120% of transformer LT side FLA as pickup value for 51. But what should be the pick up value for 50? On which basis I should set it's pick up value? Means 600% of what? For motor and transformer feeder, I understood. But it's confusing when it comes for any Incomer of PCC or MCC for 50.
For incomer of pcc from trafo does not have 50. They only have 51. Remember 50 shall be given for the last feeder at certain voltage level. Like motor. Or transformer. Say you have a 11/0.433 kV trafo. So at 11 kV level you will give 50. Because at 11 kV the trafo is the end feeder. That means fault current is fixed. When you will go to the 415 V side there you will get a different fault current. At 11 kV there shall be anotger 51, which shall be the back up of the 415v (pcc incomer) 51 relay. Here the 50 will have a pick up sightly higher than the transformer inrush current.suppose the trafo takes 11 times of hv side full load current as inrush. SO 50 puck up will be higher than that
Sir,
When the last feeder say a motor or an SFU is considered and inst time is considered as 25 MS . Then the buscoupler operating time is 25 MS + 250 MS= 275 MS , Isnt it ? 250 MS being the discriminating time .
Yes. Correct
Hi Sir. Thanks for this video and the good explanation. What about the coordination between the motor feeder and bus coupler at PCC/PMCC? The motor feeder is 0.05 sec and the bus coupler is 0.75 sec?
kindly sir make a full video on a cement plant strarting from a substation 132kv to 6.6kv to panels and pmcc 415v and mcc 415
Sir... in addition if u select .05 sec at hv side of transformer for 50....then how 51 will coordinate with transformer lv side 51 which selected with 1 sec.
Brilliant
Hey, how do we determine the time of the relay for transformer protection which has both 50 and 51? Should we consider the time delay of 51 as we do for 50 i.e. 0.05 sec. in the same relay?
Sir nowdays numerical relay come with both 50/51 protection in a single module...
So if I use this module at MCC incomer level... How can we choose our desired protection, can we set these relay protection mode (50 OR 51) accordingly??
nice video
I have watched your overcurrent settings practice. The last feeder to motor has instantaneous element which is fine. Now the bus tie has no instantaneous element and the incomer to bus tie board has not instantaneous as well. Why? Why a main should not have instantaneous element ?
very helpful!
Sir... U select the protection, 50 and 50N as an only in end of feeder or starting of new leval voltage like
Motor and transformer HV side..
Time discrimination will give to 50 protection..
Example motor is 0.7 pickup Time dial is 0.05
The up stream is 0.220 ms...
Here if we are not using 50 protections... How to give time discrimination..
(U said taht 51 to 51...time discrimination..)
Sir.....u have not mentioned the earth fault coordinations and what about 51NS...
I've a doubt. if there is a fault and 415V incomer relay fails to operate then in that case, transformer incomer 66kv should operate. But here TMS for incomer 66KV is greater compared to outgoing 66 KV from 132/66KV. Then instead of 66/.433KV the relay at 132/66KV shall operate. Please explain.
Hi sir,
Can you kindly tell, why did you select 0.25 s delay for each relay? And is 60ms is tripping time of Air circuit breaker ?
Because we assign a min time delay to tail end relay and then calculate tripping time of each upstream relay ?
Why did you not used calculation method?
Thanks!
discrimination time of 25 msec is a standard practice. and 60 msec is the time for breaker contact separation.
Incredible explanation. Please make the next video about differential protection setting
Yes i will make. Please give me some time
Nice Explanation.
I have another video of relay co ordination. You can check that also
@@electricaltechnologyandind5335 I already found that.
Thank you
Thank you so much sir... Most practical content is ever seen !!
Sir as you said in video at end feeder (motor) we used instantaneous relay and at upstream time delay relay are preferred but generally we don't provide numerical relay to low rated motor feeder.
So can we provide instantaneous relay at MCC incomer level (considering it as a end point in system) ??
For low end motor mccb is considered, which acts as instantaneous relay during high fault current. Mcc incomer is not an end point system because there is motor downstream. So you need to co ordinate with the motor feeder and also with the bus coupler....
Sir pls make video on short circuit calculation
Sir can make videos for difference between DMT &IDMT
Dt is definite time relay. That means you have a pickup current set point and a definite operating time. So if the fault current crosses the set pick up the relay will trip as per the time setting. Suppose you have set a relay to pick up at 10A, with a delay of 0.05 sec. So if fault current goes beyond 10 A, may be 12, may be 15 or 50 the relay will operate at 0.05 sec. Where as idmt relay will take less time to operate if fault current is higher. Please see my different idmt characteristics video. Where better explanation has been given
If we use instantaneous relay for motor protection, during startup the motor starting current will be 7 times of full load current. By the time 50,50N will always trip due to over current.... Hence I thought 51 to be considered for load end feeders (motor feeders). Please explain
i have a video on motor characteristics and Protection, watch that. 50N won't pick up as its input CT s are connected residually. So if there is balanced current the ct will give zero current. for that i have another video ct connection for earth fault detection. watch that too... you confusions will be cleared
sir thanks for good information i think you know about siprotech relay can you make video on that how we set the setting of overcurrent, earth fault,over voltage, under voltage settings.
There are so many things. Okay, I shall keep in mind
Why 51 is not used for 132Kv side for co-ordination??
Thanks for nice vedio .Sir would u please upload the SLD of substations132kv/33kv and explain it.?
Sld varies as per requirement. There is nothing fixed rule
Awesome sir,
Request to make video on REF. Relay.
Already there... Please check my all videos. Especially the protection playlist. Thank you..
Thanks
Thanks bro
Sir, please post a video on relay settings
there are so many... watch my Protection series
Sir what is relay pickup time
There is nothing called relay pick up time. The term is pick up current. If current through relay crosses the set value then the relay picks up. And as per its setting it trips after the calculated time
Yes Sir thank you
Sir please make a video on relay pick up current in stage wise
Why calculate fault current
please explain it with an example & coordination graph.
I have recently uploaded a video.. watch that fully. You will get your answer😊
Sir explain about PSM and tsm
Please see idmt relay settings video...
Sir hindi me video bnao plz
Please speak in Hindi with loudly
i really 💕 your videos salute you am in kenya sir Keep up
very well explained
kindly sir make a full video on a cement plant strarting from a substation 132kv to 6.6kv to panels and pmcc 415v and mcc 415