Absolute Legend! Completed the Electrical Generation on Construction Sites during lockdown and it was full of so much information. Thanks for everything !
This is great if the customer owns all the equipment or is the utility company. If the transformers are utility company owned and the equipment is customer owned, we have to decide how to size the bus bar in the gear based on electrical loads attached. Utility companies can change their transformers as they see fit.
Hi Kevin, Agreed, if you are trying to conserve money we can base the bus bar on the connected loads, but make sure you future proof the design by adding lots of spare busbar capacity as upgrading the busbar size later when new feeders are added can be very painful in terms of outages and cost.... steve
stephen brooks Over the years doing electrical designs for all kinds of businesses, I have checked back with my customers and gotten a printout of their utility bills for a year minimum. The bus was sized using NEC calculations. Every time the results were very similar. A 3000 ampere rated service equipment would have maximum recorded 900 to 1100 amperes. Utility companies typically took our load information and multiplied it by .5. Respectfully, Kevin
please can you explain the choosing the CT, PT, Breaker size for outgoing and Incoming line for newly construction line from the existing feeder , thanks sir such a good explanation it has uses a lot for all
Generally, bus coupler breaker will be normally open. One transformer A will feed to bus A and trf B will feed to bus B. However, there will be some case that if one of transformer not available another will take all the load of bus A and B in this case bus coupler breaker will be closed it means that both trafo A & B shall be sized based on load on bus A plus load on bus B it means that bus coupler breaker just size as per transformer rating it is not required to unnecessary size double time of trafo rating this is the same thing of bus bar rating also Please check your presentation sir
Hi PP, This is a very simple example and most transmission level substations will have multiple incomers, transformers and busbars. The decision on the bus section breaker rating will be decided by the designers to provide the best operational flexibility & cost effectiveness for the system. Regards Steve
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
I dont think we need to size the busbar and Buscoupler to match with the sum of Secondary current from both the transformers (In the case of two transformers)as only one transformer will be working at a time when the buscoupler is closed..Please let me know your thoughts on this
Hi there sir. I would like to ask if I can use the same computation? Say, I need to determine the HV panel outgoing protection to a load 630Kva, 33/0.4Kv Transformer. Hope you could help me. Thanks.
Hi, The system voltage is kept constant regardless of the power output of the transformers or the size of the loads. If the voltage is constant then the only thing that can change as the power magnitude changes is the current and it does, when the power drawn by the load increases the current increases. Regards Steve
Thanks for that Stephen - in the first example with 1 incomer, the full load current of the secondary side of the transformer is 1050A, could I design the switchgear with a busbar rating of 1000A and an incomer breaker rating of 1000A (maximum peak load including future spare is 900A) . I have done similar on a project which I consider to be a sound design. I think it is fit for purpose but does it break any IEC codes do you know?
Hi Chi, In the UK we would always choose the rating above the transformer rated output , so 1250A in your case. The loads change over time so it’s not the best way to size the busbar. Regards steve
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WETT1001 to get them for $9.99 Regards Stephen Brooks
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
I have a question. Some peoples in youtube says for copper 1 sq mm = 1.4 Amps and for Al 1 sq mm = 0.8 Amps . Is it correct or not ? and how to calculate the current density for busbar if i want carrying current of 200 Amp as an example.
Thanks. I have some questions, could you explain how to calculate or do the sizing for bus-bar at MV side of power transformer HV 220kV/20kV, 12%, 125MVA, YNd11, ONAN/ONAF? where at PCC of transmission, it is 40kA at 220kV (HV side) which is the short circuit current value considered as designing at this high level voltage (220kV) (according to transmission operation) and in addition, the company of transmission gives us a value of 15kA(maximum demand of load) the maximum three phase short circuit current at the same point PCC (High voltage side).. So the second question, according to IEC standard or experience for designing MV switchgear at 20KV, what short circuit current value will it have to be used 40kA or 15kA (PCC connexion, 220kV) for sizing my MV switchgear, Ik and Ip (withstand simetrical and peak short-circuit current?
Hi Ahmed, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
Hi sir .. you said incomer 1 (800A) Incomer 2(800A) future (800A) ..and you going to choose 2500A busbar .if I saw in my switchgear diagram all incomer and buscoupler are same rating .. for example 2500A busbar we choosing Incomer and buscoupler 2500A breaker .. but current rating just 680A for both Incomer why?????
Hi Ahilan, You didn’t mention the system voltage but the utility may be future proofing the substation by having the highest rated circuit breakers possible. You will also find that the cost difference between 800/1250/2500 circuit breakers can be small for large equipment orders so it makes sense to go for the highest circuit breaker rating , this also reduces the need for different circuit breaker spares and allows the circuit breakers to be interchanged easily when one goes faulty. Steve
if you had say a 500 amp max load could you use a much higher rated busbar of say 2000 amp, i don't see why you need to have the busbar rating stay near the load value, seems to me you should or could just a much bigger bubar and you wont ever have a problem.
Hi, that’s correct. You don’t size the busbar based on the load, as loads can change over time. You size it based on the maximum amount of power available to flow into the substation steve
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
Hi Daniel Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code IGST1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks
Absolute Legend! Completed the Electrical Generation on Construction Sites during lockdown and it was full of so much information. Thanks for everything !
You're welcome!
Wow!! You are indeed a legend in the power sector and a great teacher too.
Thanks for the kind words Kenneth, glad you found the course useful!! Steve
A sound lecture with simplified examples. Great work
Many thanks!
Very good video Steve
Thanks alot for explaining i think we should raise the rating of bus bar over the selection value to carry the mechanical stress of cables
The cable rating will depend on the load being carried under all conditions and the two are not normally linked.
This is great if the customer owns all the equipment or is the utility company. If the transformers are utility company owned and the equipment is customer owned, we have to decide how to size the bus bar in the gear based on electrical loads attached. Utility companies can change their transformers as they see fit.
Hi Kevin,
Agreed, if you are trying to conserve money we can base the bus bar on the connected loads, but make sure you future proof the design by adding lots of spare busbar capacity as upgrading the busbar size later when new feeders are added can be very painful in terms of outages and cost....
steve
stephen brooks Over the years doing electrical designs for all kinds of businesses, I have checked back with my customers and gotten a printout of their utility bills for a year minimum. The bus was sized using NEC calculations. Every time the results were very similar. A 3000 ampere rated service equipment would have maximum recorded 900 to 1100 amperes. Utility companies typically took our load information and multiplied it by .5. Respectfully, Kevin
please can you explain the choosing the CT, PT, Breaker size for outgoing and Incoming line
for newly construction line from the existing feeder , thanks sir such a good explanation it has uses a lot for all
Noted
Generally, bus coupler breaker will be normally open. One transformer A will feed to bus A and trf B will feed to bus B. However, there will be some case that if one of transformer not available another will take all the load of bus A and B in this case bus coupler breaker will be closed it means that both trafo A & B shall be sized based on load on bus A plus load on bus B it means that bus coupler breaker just size as per transformer rating it is not required to unnecessary size double time of trafo rating this is the same thing of bus bar rating also
Please check your presentation sir
Hi PP,
This is a very simple example and most transmission level substations will have multiple incomers, transformers and busbars.
The decision on the bus section breaker rating will be decided by the designers to provide the best operational flexibility & cost effectiveness for the system.
Regards
Steve
Thanks, Greate lecture with simplified examples
You are welcome!
Thanks for your teaching.
You are very welcome
hey is there any scientific paper support your information like IEEE standard
I agree, it is better that the topic is supported by a standard
Does the course cover DC busbar sizing?
Hi Please can you send a for ELECTRICAL CONTROL AND PROTECTION PART 3
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
I dont think we need to size the busbar and Buscoupler to match with the sum of Secondary current from both the transformers (In the case of two transformers)as only one transformer will be working at a time when the buscoupler is closed..Please let me know your thoughts on this
both transformers can feed the busbars when they are operated in parallel
A very good and detailed video. Thank you sir
thanks
Very well explained. Thank you Sir.
You are welcome
Thank you very much. I have learnt something very useful.
You are welcome!
I am buying your course, please if you can put up a course on transmission line protection, and relay settings for that, thanks a lot
Hi Sharad, working on the transmission line protection course now...steve
wow!! very very nice not teacher but you are doctor congratulation.
Thank you! 😃
keep uploading the good concepts for selection of CT , PT , Breaker, cable sizing for Newly construction substation
thanks!
Hi there sir. I would like to ask if I can use the same computation? Say, I need to determine the HV panel outgoing protection to a load 630Kva, 33/0.4Kv Transformer. Hope you could help me. Thanks.
Hi Efren, the calculation is valid for all voltages. steve
Thanks for Helpful calculation -
Sir
Most welcome
Nice explanation sir.
Thanks and welcome
Nice explanation
Thanks and welcome
sir, do you know how to size cable for transformer neutral earthing? my transformer is delta y. 3MVA 33KV / 415 V.. I hope you can help me sir
Hi Sir. Just a quick question. The busbar rating for the current is multiplied by 3. But why is the voltage not mulplied by 3 also?
Hi,
The system voltage is kept constant regardless of the power output of the transformers or the size of the loads.
If the voltage is constant then the only thing that can change as the power magnitude changes is the current and it does, when the power drawn by the load increases the current increases.
Regards
Steve
nice explanation ... i gate good thing from ur tutor .thanks and keep going with other related components
Thank you, I will
Thanks for that Stephen - in the first example with 1 incomer, the full load current of the secondary side of the transformer is 1050A, could I design the switchgear with a busbar rating of 1000A and an incomer breaker rating of 1000A (maximum peak load including future spare is 900A) . I have done similar on a project which I consider to be a sound design. I think it is fit for purpose but does it break any IEC codes do you know?
Hi Chi,
In the UK we would always choose the rating above the transformer rated output , so 1250A in your case. The loads change over time so it’s not the best way to size the busbar.
Regards
steve
@@Electricalsteve Thanks very much Steve
Hi sir
It was very useful.we want more video for sizing each Electrical switch gears pls.thanks
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WETT1001 to get them for $9.99
Regards
Stephen Brooks
@@Electricalsteve what topic in the udemy website sir which includes equipmemt sizing? Thanks im interested.
very good information
Thanks
Great topic
The busbar sizing is as per IEC standard, because IEEE have only 1200, 2000, 3000A.
Hi Shelfrob, any mention of standards has deliberately been omitted, the focus is on the methodology..steve
a valuable information
thank you
You are welcome
Many thanks for you. Very good video
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
Very helpful ....Thank you Sir.
Please keep uploading more videos related to Electrical engineering.....can you help with transformer sizing as well.
Yes I will
Thanks alot , It was very useful 👌😍👍
Great info, thanks for posting
No problem!
thanks lot , nice video.
Glad you liked it!
Wow 😳.. thank you so much
Welcome!
I have a question. Some peoples in youtube says for copper 1 sq mm = 1.4 Amps and for Al 1 sq mm = 0.8 Amps . Is it correct or not ? and how to calculate the current density for busbar if i want carrying current of 200 Amp as an example.
Hi Wadi, this video covers busbars, not conductors. steve
why is conected shunt reactor on bus bar 400kv thank you
Superb trick
thanks!!
Thanks. I have some questions, could you explain how to calculate or do the sizing for bus-bar at MV side of power transformer HV 220kV/20kV, 12%, 125MVA, YNd11, ONAN/ONAF? where at PCC of transmission, it is 40kA at 220kV (HV side) which is the short circuit current value considered as designing at this high level voltage (220kV) (according to transmission operation) and in addition, the company of transmission gives us a value of 15kA(maximum demand of load) the maximum three phase short circuit current at the same point PCC (High voltage side).. So the second question, according to IEC standard or experience for designing MV switchgear at 20KV, what short circuit current value will it have to be used 40kA or 15kA (PCC connexion, 220kV) for sizing my MV switchgear, Ik and Ip (withstand simetrical and peak short-circuit current?
Hi Ki,
This video is a sample only, please take the course for full guidance on this and many other substation design issues.
Regards
steve
@@Electricalsteve okay, thank you.
@stephen brooks
Dear Stephen
I want to get a discount voucher for all your protection courses, please
Hi Ahmed,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
Thank you sir..This video is very helpful
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
Hi sir .. you said incomer 1 (800A) Incomer 2(800A) future (800A) ..and you going to choose 2500A busbar .if I saw in my switchgear diagram all incomer and buscoupler are same rating .. for example 2500A busbar we choosing Incomer and buscoupler 2500A breaker .. but current rating just 680A for both Incomer why?????
Hi Ahilan,
You didn’t mention the system voltage but the utility may be future proofing the substation by having the highest rated circuit breakers possible.
You will also find that the cost difference between 800/1250/2500 circuit breakers can be small for large equipment orders so it makes sense to go for the highest circuit breaker rating , this also reduces the need for different circuit breaker spares and allows the circuit breakers to be interchanged easily when one goes faulty.
Steve
@@Electricalsteve 415v
if you had say a 500 amp max load could you use a much higher rated busbar of say 2000 amp, i don't see why you need to have the busbar rating stay near the load value, seems to me you should or could just a much bigger bubar and you wont ever have a problem.
Hi, that’s correct. You don’t size the busbar based on the load, as loads can change over time. You size it based on the maximum amount of power available to flow into the substation steve
Sir how to drow single line diagram like this video
Hi Dill,
PowerPoint / Autocad are both ideal.
steve
Very informative video. Thank you
You're welcome
many many thanks .....
Welcome!
Sir good knowledge
Why in the equation of the power the power factor cos phi did not appear?
Hi Souad, because we are using the VA equation which does not contact power factor steve
@@Electricalsteve Thank you sir
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
How it possible request ur advice
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
Hi sir, what topic in udemy the sizing of equipment? I would like to buy thanks
Hi Mike,
This is a module on the air insulated design course hosted by udemy.
Steve
@@Electricalsteve hi sir, i have trouble in buying your videos. Paypal, cc or debit card cant be link to udemy :(
Thanks a lot
Most welcome
Is it possible to get 50kA for 630A busbars.
Hi Shihas,
At 400kV it’s a common busbar rating
Steve
Thanks Steve.
How about 132kV?
Hi Shihas,
40kA is common....
Steve
Nice
Thanks
Thanks sir
Welcome
like y suscrito...Thanks...
Good
Thanks
Hi Stephen can you please send me voucher discount
Hi,
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
Hi Stephen, could you please write me your email address? I need it in relation to the Udemy voucher. Thank you in advance.
Hi Daniel
Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code IGST1001 to get them for $9.99, vouchers expire in 5 days.
Regards
Stephen Brooks
@@Electricalsteve Thank you, purchased.
Useful information. Thanks a lot.
You are welcome