Thanks for making this video. It's the best I have found on this topic. Can you please provide info on how the reference materials used on this video? The derating factors and cable size tables will be especially helpful.
de rating factor reduces the current carrying ability of the cable , so 187A x 0.76 = 142A , as the FLA of transformer = 131A, selection of the cable size of 50sq.mm is good. correct me if iam wrong.
Softwares are usually rough estimates and calculations vary according to the Cable manufaturers specifications or tables. So you must understand the cable size Calculation for right selection of cables.
Brother you need to divide by 1000 if you are taking length in Meter. If your length is already in KM, then no need to divide by 1000. Means if you are taking 15km then no need to divide by 1000
When you divide with derating factor, you will get the value of current, including derating factor margin. When you multiple with derating factor, you will get a value of current after deration which means you need to add additional derating margin to find out the value of current to be selected from cable table.
Hi H N, As I have known for the motors, we should be aware of voltage drop in both steady state & starting of motor. Could you explain for these cases of Motors?
Power factor assume to be 0.8 in the selected case study, however the value may changes according to your requirements or conditions. The value of @ will be be calculated from cos@ which further derive the value of sin@.
Hi Artemois, It all depends on how much your concerned utility or electrical distribution company allowed on one feeder. I have shared the allowable load limit that is 5MW on one feeder referring to what allowed in Pakistan. It varies country to country.
Ayman, These calculations are for medium voltage cables and short circuit fault current calculated at specified duration of time. I think you are mentioning about fault current of system which are require to be calculated on base MVA of system.
@@transientmatter6088 It depends, you may be right. What would be your reference for short circuit current before selecting a MV cable. I would recommend to comply all the three criteria.
Thanks for making this video. It's the best I have found on this topic. Can you please provide info on how the reference materials used on this video? The derating factors and cable size tables will be especially helpful.
Thanks for sharing these valuable details.
Kindly send the link to get this chart.
It would be helpeful if you share the standards you're taking into account
de rating factor reduces the current carrying ability of the cable , so 187A x 0.76 = 142A , as the FLA of transformer = 131A, selection of the cable size of 50sq.mm is good. correct me if iam wrong.
That is what I thought myself. De-rating means reducing the rating of something and they should be multiplied.
You re wrong
آفرین جوان
Very thorough and clear - thx.
Thanks for share verry interesting content
Very Good. Keep it up. Make more videos.
Do you know about any software for a medium voltage cabling calculations?
Softwares are usually rough estimates and calculations vary according to the Cable manufaturers specifications or tables. So you must understand the cable size Calculation for right selection of cables.
what is the difference between HV and LV cable sizing?
Appreciate your effort.
Thanks Man... really appreciate
How to calculate if we want to use 2 or 3 nos of cables per phase?
how can u add Rcos@ and X sine@ .these are complex numbers. it should be
hi sir, i gave one doubt if the length is 15000 MTR as my able length is 15KM shall i need to divide it my 1000 or 10000..
Brother you need to divide by 1000 if you are taking length in Meter. If your length is already in KM, then no need to divide by 1000. Means if you are taking 15km then no need to divide by 1000
Current after derating factor why it is devided by 0.76..it should be 131*0.76 apprximately 100 Amp
When you divide with derating factor, you will get the value of current, including derating factor margin. When you multiple with derating factor, you will get a value of current after deration which means you need to add additional derating margin to find out the value of current to be selected from cable table.
Hi H N, As I have known for the motors, we should be aware of voltage drop in both steady state & starting of motor. Could you explain for these cases of Motors?
Please watch my separate video on cable size Calculation for motors and group of motors
many thanks
Hello Sir, what are you showing the tables to calculate HV/MV Cables from which IEC Code?
IEC 60502-2
@@electricalknowledge2654 Thank you very much sir
from where you get the cos@ & Sin@ value? respectively 0.8 &0.6 please clear.
Power factor assume to be 0.8 in the selected case study, however the value may changes according to your requirements or conditions. The value of @ will be be calculated from cos@ which further derive the value of sin@.
@@electricalknowledge2654 could you please clarify the 'The value of @ will be be calculated from cos@ which further derive the value of sin@'?
Could you please advise how we can find the Max. Load Allowed on 1 Feeder @ HT = 5MW or 6.25MVA or 328A?
Hi Artemois, It all depends on how much your concerned utility or electrical distribution company allowed on one feeder.
I have shared the allowable load limit that is 5MW on one feeder referring to what allowed in Pakistan. It varies country to country.
@@electricalknowledge2654 Thank you very much!
It depends upon the current carrying capacity of the conductor used.with ACSR dog conductor, you may transmit 5 MVA load at 11kv
120Kw motor need to cable size , with copper and aluminum, please brief example with formula
Can be use 95 sqmm
Hello! May I ask the references for the derating factors Tnx
thx
How many transformers can feed from m v switchgear in one loop
Ali, It depends upon what rating of transformer you are connecting to one feeder. However, 5MVA can be allocated on one feeder usually by WAPDA.
Hi , Can you please send us the table for single core cables please ?
I also need the table
Could possible to share supporting documents
can you please share the excel sheet for the easy calculation for pakistan.
I think 2nd slid calculation is wrong. it will be only 2500KVA or you need to divided 1000 also. thank you
Saddam, Answer is correct i.e 131A. However, you are right, the voltage is 11000V instead of 11kV thus to ensure the units are same.
current for low voltage side is incorrect because short circuit current must be calculate for medium voltage network 500 MVAS.C
Ayman, These calculations are for medium voltage cables and short circuit fault current calculated at specified duration of time.
I think you are mentioning about fault current of system which are require to be calculated on base MVA of system.
Sir, plz share this cable catalog
You can download catalogue from Pakistan Cables Limited website
👍😉
Ok
seen
when you size mv cable , only short circuit power is enough ,
You must comply three criteria i.e. Current Carrying Capacity, Voltage Drop and Short Circuit Current.
@@electricalknowledge2654
Experience of 30 years says
Short circuit power enough for mv cable..
@@transientmatter6088 It depends, you may be right. What would be your reference for short circuit current before selecting a MV cable.
I would recommend to comply all the three criteria.
Hi. Can you please share your email id for a project?