Panel Design & Calculate Size of Bus bar

Example: Calculate Size of Bus bar having Following Details

  • Bus bar Current Details:
  • Rated Voltage = 415V,50Hz ,
  • Desire Maximum Current Rating of Bus bar =630Amp.
  • Fault Current (Isc)= 50KA ,Fault Duration (t) =1sec.
  • Bus bar Temperature details:
  • Operating Temperature of Bus bar (θ)=85°C.
  • Final Temperature of Bus bar during Fault(θ1)=185°C.
  • Temperature rise of Bus Bar Bar during Fault (θt=θ1-θ)=100°C.
  • Ambient Temperature (θn) =50°C.
  • Maximum Bus Bar Temperature Rise=55°C.
  • Enclosure Details:
  • Installation of Panel= Indoors (well Ventilated)
  • Altitude of Panel Installation on Site= 2000 Meter
  • Panel Length= 1200 mm ,Panel width= 600 mm, Panel Height= 2400 mm
  • Bus bar Details:
  • Bus bar Material= Copper
  • Bus bar Strip Arrangements= Vertical
  • Current Density of Bus Bar Material=1.6
  • Temperature Co efficient of Material Resistance at 20°c(α20)= 0.00403
  • Material Constant(K)= 1.166
  • Bus bar Material Permissible Strength=1200 kg/cm2
  • Bus bar Insulating Material= Bare
  • Bus bar Position= Edge-mounted bars
  • Bus bar Installation Media= Non-ventilated ducting
  • Bus bar Artificial Ventilation Scheme= without artificial ventilation
  • Bus bar Size Details:
  • Bus bar Width(e)= 75 mm
  • Bus bar Thickness(s)= 10 mm
  • Number of Bus Bar per Phase(n)= 2 No
  • Bus bar Length per Phase(a)= 500 mm
  • Distance between Two Bus Strip per Phase(e)= 75 mm
  • Bus bar Phase Spacing (p)= 400 mm
  • Total No of Circuit= 3 No.
  • Bus bar Support Insulator Detail:
  • Distance between insulators on Same Phase(l)= 500 mm
  • Insulator Height (H)= 100 mm
  • Distance from the head of the insulator to the bus bar center of gravity (h)= 5 mm
  • Permissible Strength of Insulator (F’)=1000 Kg/cm2

 Untitled

Calculation:

(1) De rating Factors for Bus bar:

  • (1) Per Phase Bus Strip De rating Factor (K1):
  • Bus bar Width(e) is 75mm and Bus bar Length per Phase(a) is 500mm so e/a is 75/500=0.15
  • No of Bus bar per phase is 2 No’s.
  • From following table value of de rating factor is 1.83

Number of Bus Bar Strip per Phase (K1)

e/a No of Bus Bar per Phase
1 2 3
0.05 1 1.63 2.4
0.06 1 1.73 2.45
0.08 1 1.76 2.5
0.1 1 1.8 2.55
0.12 1 1.83 2.6
0.14 1 1.85 2.63
0.16 1 1.87 2.65
0.18 1 1.89 2.68

0.2

1 1.91 2.7

 

  • (2) Bus bar Insulating Material De rating Factor (K2)
  • Bus bar having No insulating material. It is Bare so following Table
  • De rating Factor is 1.
Bus Bar Insulating Material (K2): De rating Factor
Bare 1
PVC Sleeving 1.2
Painted 1.5

 

  • (3) Bus bar Position De rating Factor (K3)
  • Bus bar Position is Edge-mounted bars so following Table
  • De rating Factor is 1
Bus Bar Position(K3): De rating Factor
Edge-mounted bars 1
1 bar base-mounted 0.95
several base-mounted bars 0.75

 

  • (4) Bus bar Installation Media De rating Factor (K4)
  • Bus bar Installation Media is Non-ventilated ducting so following Table
  • De rating Factor is 0.8
Bus Bar Installation Media(K4): De rating Factor
Calm indoor atmosphere 1
Calm outdoor atmosphere 1.2
Non-ventilated ducting 0.8

 

  • (5) Bus bar Artificial Ventilation De rating Factor (K5)
  • Bus bar Installation Media is Non-ventilated ducting so following Table
  • De rating Factor is 0.9
Bus Bar Artificial Ventilation Scheme (K5): De rating Factor
without artificial ventilation 0.9
with artificial ventilation 1

 

  • (6) Enclosure & Ventilation De rating Factor (K6)
  • Bus bar Area per Phase = Bus width X Bus Thickness X Length of Bus X No of Bus bar per Phase
  • Bus bar Area per Phase = 75x10xX500X2= 750000mm
  • Total Bus bar Area for Enclosure= No of Circuit X( No of Phase + Neutral )X Bus bar Area per Phase
  • Here we used Size of Neutral Bus is equal to Size of Phase Bus
  • Total Bus bar Area for Enclosure=3X(3+1)X750000mm
  • Total Bus bar Area for Enclosure=9000000 Sq.mm
  • Total Enclosure Area= width X Height X Length
  • Total Enclosure Area=1200x600x2400=1728000000 Sq.mm
  • Total Bus bar Area for Enclosure / Total Enclosure Area =9000000/1728000000
  • Total Bus bar Area for Enclosure / Total Enclosure Area=0.53%
  • Bus bar Artificial Ventilation Scheme is without artificial ventilation so following Table
  • De rating Factor is 0.95
Volume of Enclosure & Ventilation De rating Factor (K6)
cross Section area of Bus bar/Total Bus Bar Area Indoors ( Panel is well Ventilated) Indoors ( Panel is Poorly Ventilated) Outdoor
0% 0.95 0.85 0.65
1% 0.95 0.85 0.65
5% 0.9 0.7 0.6
10% 0.85 0.65 0.5

 

  • (7) Proxy Effect De rating Factor (K7)
  • Bus bar Phase Spacing (p) is 400mm.
  • Bus bar Width (e) is 75mm and Space between each bus of Phase is 75mm so
  • Total Bus length of Phase with spacing (w) =75+75+75+75+75=225mm
  • Bus bar Phase Spacing (p) / Total Bus length of Phase with spacing (w) = 400 / 225 =2
  • From following Table De rating factor is 0.82
Proxy Effect (K7): De rating Factor
1 0.82
2 0.82
3 0.82
4 0.89
5 0.95
6 0.99
7 1

 

  • (8) Altitude of Bus Bar installation De rating Factor (K8)
  • Altitude of Panel Installation on Site is 2000 meter so following Table
  • De rating Factor is 0.88
Altitude of installation site (Meter) (K8) De rating Factor
2200 0.88
2400 0.87
2500 0.86
2700 0.85
2900 0.84
3000 0.83
3300 0.82
3500 0.81
4000 0.78
4500 0.76
5000 0.74
  • Total De rating Factor= K1XK2XK3Xk4Xk5Xk6Xk7Xk8
  • Total De rating Factor =1.83x1x1x0.8×0.9×0.95×0.82×0.88
  • Total De rating Factor =0.90

(2) Bus bar Size Calculation:

  • Desire Current Rating of Bus bar (I2) =630 Amp
  • Current Rating of Bus bar after De rating Factor (I1)= I2 X De rating Factor or I2 / De rating Factor
  • Current Rating of Bus bar after De rating Factor (I1)=630×0.9
  • Current Rating of Bus bar after De rating Factor (I1)=697Amp
  • Bus bar Cross Section Area as per Current= Current Rating of Bus bar / Current Density of Material
  • Bus bar Cross Section Area as per Current= 697 / 1.6
  • Bus bar Cross Section Area as per Current= 436 Sq.mm
  • Bus bar Cross Section Area as per Short Circuit= Isc X√ ((K/( θtx100)x(1+ α20xθ) xt
  • Bus bar Cross Section Area as per Short Circuit= 50000X√ ((1.166/( 100×100)x(1+ 0.00403×85) x1
  • Bus bar Cross Section Area as per Short Circuit=626 Sq.mm
  • Select Higher Size for Bus bar Cross section area between 436 Sq.mm and 626 Sq.mm
  • Final Calculated Bus Bar Cross Section Area =626 Sq.mm
  • Actual Selected Bus bar size is 75×10=750 Sq.mm
  • We have select 2 No’s of Bus bar per Phase hence.
  • Actual Bus bar cross section Area per Phase =750×2= 1500 Sq.mm
  • Actual Cross Section Area of Bus bar =1500 Sq.mm
  • Actual Bus bar Size is Less than calculated Bus bar size.

(3) Forces generated on Bus Bar due to Short Circuit Current

  • Peak electro-magnetic forces between phase conductors (F1) = 2X(l/d)X(2.5xIsc)2/100000000
  • Total width of Bus bar per Phase(w)=75+75+75=225mm =2.25cm
  • Bus bar Phase to Phase Distance (d)=400+225=625mm=6.25cm
  • Peak electro-magnetic forces between phase conductors (F1) =2x(50/63)x(2.5×50000)2/100000000
  • Peak electro-magnetic forces between phase conductors (F1)=250 Kg /cm2
  • Peak electro-magnetic forces between phase conductors (F1)=2.5 Kg /mm2
  • Actual Forces at the head of the Supports or Bus Bar (F)=F1X(H+h/H)
  • Actual Forces at the head of the Supports or Bus Bar (F)=2.5x(100+5/100)
  • Actual Forces at the head of the Supports or Bus Bar (F)= 3 Kg /mm2
  • Permissible Strength of Insulator (F’) is 10 Kg/mm2
  • Actual Forces at the head of the Supports or Bus Bar is less than Permissible Strength
  • Forces on Insulation is in within Limits

(4) Mechanical strength of the bus bars

  • Mechanical strength of the bus bars=(F1X i /12)x(1/ Modulus of inertia of a bus bar )
Value of Modulus of inertia of a bus bar or of a set of bus bars (i/v)
No of Bus Strip per Phase Vertical Bus Bar (cm3) Horizontal Bus Bar (cm3)
1 1.66 16.66
2 14.45 33.33
3 33 50

 

  • From above table Value of Modulus of inertia of a bus bar=14.45
  • Mechanical strength of the bus bars=(250×50/12)X(1/14.45)
  • Mechanical strength of the bus bars= 72 Kg/cm2
  • Mechanical strength of the bus bars= 0.72 Kg/mm2
  • Permissible Bus bar Strength is 12 Kg/mm2
  • Actual Mechanical Strength is less than Permissible Strength
  • Mechanical strength of Bus bar is in within Limit

(5) Temperature Rise Calculation

  • Specified Maximum Temperature Rise (T1) is 35°c
  • Calculated Maximum Temperature Rise (T2)=T/(log(I1/I2)1.64)
  • Calculated Maximum Temperature Rise (T2)=35/(Log(697/630)1.64)
  • Calculated Maximum Temperature Rise (T2)= 30°c
  • Calculated Bus bar Temperature rise is less than Specified Max Temperature rise
  • Temperature Rise is in within Limit

Results:

  • Size of Bus bar = 2No’s 75x10mm per Phase.
  • Total No of Feeder =3 No’s
  • Total No’s of Bus bar = 6 No’s 75x10mm for Phase and 1No’s 75x10mm for Neutral.
  • Forces at the head of the Supports or Bus Bar (F)= 3kg/mm2
  • Mechanical strength of the bus bars= 0.7 Kg/mm2
  • Maximum Temperature Rise=30°c

125 Responses to Panel Design & Calculate Size of Bus bar

  1. THIS IS GOOD REFERENCE FOR LV AND MV SWGR. DESIGNERS.

  2. atmakur murali Krishna's avatar atmakur murali Krishna says:

    Extremely useful information

  3. RAMACHANDRAN S's avatar RAMACHANDRAN S says:

    Thank u for this useful information.Great

  4. ganapathy sadayan's avatar ganapathy sadayan says:

    Hi, Mr. Jignesh Parmar,

    The above information is really useful for us who ever doing the design and selection of busbar for panel engineering.

    Thanks for this information, kindly share electrical technical information to us.

    Ganapathy.

  5. Ibrahim's avatar Ibrahim says:

    thank alot for this valuable information however, I notice that you are considering derating factor for busbar calcualtion is 0.9 then after derating current rating shall be reduced but in your calculation it is increasing. can you please explain why it is so or it is only a typing mistake.

  6. karan's avatar karan says:

    thank u sir, for this information

  7. P.Ramesh kanna's avatar P.Ramesh kanna says:

    useful information

  8. Hitesh parikh's avatar Hitesh parikh says:

    Dear sir,

    This information very much use to new design Engineer.

    Hitesh parikh
    Design Engineer in MV SWGR company

  9. Biswanath Hazra's avatar Biswanath Hazra says:

    Truly useful. Thanks for sharing.

  10. indrajit's avatar indrajit says:

    Dear Sir,

    thanks for your above article, I also want the same type of calculation for Earthing bus bar(Conductor) for electrical panel.

  11. Datta's avatar Datta says:

    Thanks Sir,
    I need more elaboration on the temperature rise calculation. I am not able to get the answer 30 in the given example. Deg cel with the given formula. My T1= 40 Deg cel, I1= 4055 Amp, I2= 4000 Amp , T2= ?
    : Calculated Maximum Temperature Rise (T2)=35/(Log(697/630)1.64)

    Pl help,

    Thx,
    Datta

  12. Faizal Ruzley's avatar Faizal Ruzley says:

    Good Info,

    Thanks for detail and calculation,good for RMU and CSU design.

  13. phaneendra kumar's avatar phaneendra kumar says:

    Thank you for your information.I am doing Air core reactor designs myself.I know the temperature rise of the conductor.It is R&D ..I am not getting Economical Designs…They are going very large size for smaller current and impedance… Will you pleas help to do learn reactor design….I am doing this research my self from last one year..

  14. Vinodkumar's avatar Vinodkumar says:

    Dear Sir,

    Very use ful information you have given to us. Thank you . I have one doubt . Can you please tell me why we choose 2nos of 75X10 bus bar for each phase when one is enough for the Isc rating. Is there anything else we have to know.

  15. Nani's avatar Nani says:

    sir,
    i want to learn more from u……

  16. Paulraj's avatar Paulraj says:

    Ji,
    Let me know the factors reference for PVC sleeve & matt black painted busbar.

  17. hi,
    nice info indeed.
    i’d also like to know how you chose the above bus bar size and please post the board with the bus bar dimensions.

    thanks

  18. rajeev's avatar rajeev says:

    thank
    you sir

  19. mourad's avatar mourad says:

    Thanks a lot brother

  20. vipin khandelwal's avatar vipin khandelwal says:

    Hello Sir,

    Thanks for the information but I have one doubt . Can you please tell me why we choose 2 nos of 75X10 bus bar for each phase when one is enough for the Isc rating. Is there anything else we have to know.
    Which standard reference you have considered ?

    Thanks,
    Vipin

  21. eqsgroups's avatar eqsgroups says:

    Dear Sir,
    Please provide following information given below-
    1- How to select Al Bus bar (Info of Al Bus bar Material )
    2-How to compare Al and Cu Bus bar to select for same rating.
    3-Any thumb rule is there to select bus bar size quickly.
    4-Please provide bus bar selection chart for AL and Cu Both.
    5-How to select no, of Bus bar per phase.

  22. Subhadeep Banerjee's avatar Subhadeep Banerjee says:

    Thank u sir, this will help me a lot in my field of job…

  23. Girisha CD's avatar Girisha CD says:

    Very Usefull document….

  24. ron's avatar ron says:

    Power distribution load centers generally have 2 methods of current supply. Source current is either introduced at one end of the bus (top fed) with branch circuit loads distributed through taps and over-current devices along the bus. Many smaller capacity load centers (100-225 amperes) have current supplied through a main breaker connected to the mid-section of a bus. How is bus design affected with a center fed approach as opposed to a top fed approach? Did your calculation assume the top fed design approach? Thank you

  25. K. Sivakumar's avatar K. Sivakumar says:

    Can you refer to relevant IS/IEEE/IEC Standard that you followed for these calculations? You may mail me at: “sreeraasi94@gmail.com”

  26. sandeep tawade's avatar sandeep tawade says:

    can provide bus bar size calculation for 3sec

  27. dinesh's avatar dinesh says:

    hello sir i have 63 A mcb 24 nos out going. so what would be a main incommer.

  28. rahul's avatar rahul says:

    Very thankful to you
    Dear Sir,
    Please provide following information given below-
    1- How to select Al Bus bar (Info of Al Bus bar Material )
    2-How to compare Al and Cu Bus bar to select for same rating.
    3-Any thumb rule is there to select bus bar size quickly.
    4-Please provide bus bar selection chart for AL and Cu Both.
    5-How to select no, of Bus bar per phase.

  29. Zee's avatar Zee says:

    Jignesh .Parmar,

    Its a blessing that you are maintaining this site……

  30. TranMinh's avatar TranMinh says:

    Someone explains to me: Number of Bus Bar Strip per Phase (K1)..What is bus bar strip

  31. Mahesh's avatar Mahesh says:

    Please tell me what is the formula for determine MCCB maximum working temperature..?

  32. Mushtaq Ahmad's avatar Mushtaq Ahmad says:

    Thanks a lot for sharing such a useful article

  33. Nandarathana's avatar Nandarathana says:

    Dear Sir,

    Please explain why did u take 50 deg. C as ambient temperature? Is it actual ambient temperature of settled value after temperature has risen due to heat emitted?

    Thanks

    • BAMBANG Yuwono's avatar BAMBANG Yuwono says:

      Thankyou for all your usefull refference. And 1 question Ihave small power plant with 1 set 500 kva cat,365 kva cat, n 100 kva cummin eng I want to built synchronize both of thre genset for safe operation and load sharing….best regard Bambaang Yuwono.

  34. Ramesh's avatar Ramesh says:

    Dear Sir,
    I want to design a Bus bar of rating 700V, 130A DC supply , then what is thinkness of bus bar size when it is a copper material

  35. BAMBANG yu's avatar BAMBANG yu says:

    Thankyou for all your usefull refference. And 1 question Ihave small power plant with 1 set 500 kva cat,365 kva cat, n 100 kva cummin eng I want to built synchronize both of thre genset for safe operation and load sharing….best regard Bambaang Yuwono.

  36. Ravindra's avatar Ravindra says:

    how to select busbar as per rating changes of panel… for eg.. 1000A ACB, 2500A ACB … WHICH SIZE OF BUSBAR
    WE HAVE SELECT

  37. Nur.Md.Badsha's avatar Nur.Md.Badsha says:

    Please let me know about I/d(50/63) for F1

    N.M.badsha
    Electrical & Electronic Engineer,KUET
    Experience on power Distribution,pharmaceutical,Food & Beverage Production Machineries.

  38. Rajan's avatar Rajan says:

    Hi – is there any reference document to substantiate the consideration of current density 1.6A/mm2

  39. abhinav shukla's avatar abhinav shukla says:

    thank you sir for sharing your valuable knowledge

  40. S.Selvam's avatar S.Selvam says:

    Sir,
    Pl.provide us design calculation for AMF Panel bus bar size – Both three phases & one neutral ,we have three DG Set which are 500KVA each and controlled by 800A / 1600A ACB with protection

  41. gulshad khan's avatar gulshad khan says:

    MD GULSHAD KHAN

    IT IS A VERY USEFUL CALCULATION FOR SELECTING THE BUSBAR

  42. NAGA CHAITANYA VEMURI's avatar NAGA CHAITANYA VEMURI says:

    can you please clarify me, for HIGH RISE Buildings , Bus bars are used instead of only using armored cables . Is this because of economical factor or any technical advantage is there.?

  43. Amita's avatar Amita says:

    Tanks, it is very useful
    If it is possible for you, please tell us about your standard or document reference.
    Best regards.

  44. zillur rahman's avatar zillur rahman says:

    can i use half grade copper bus bar for 1000amps cos formula

  45. Greetings to you Mr.Jignesh Parmar.
    You are doing a great service yo practicing engineers.After all, teaching is a noble way of serving the people.

  46. zillur rahman's avatar zillur rahman says:

    can iuse half grade copper bas bar 500&1000amps change over switch formula?

  47. SUNNY KUMAR's avatar SUNNY KUMAR says:

    thanks for this useful information. which standards are applicable to this calculation.

  48. amitkumar's avatar amitkumar says:

    Thanks for bus bar information

  49. Papoo Sankaran's avatar Papoo Sankaran says:

    Item(6) De-rating Factor K6:

    Area of Busbar is mentioned as Width x Thickness x Length.x No.of busbars. How can the product of these three dimensions be “area”, it can be only “volume”; Please clarify.

  50. lohit's avatar lohit says:

    thanks for the information

  51. Vasu's avatar Vasu says:

    you want panel board design for LT switchgear & current rating busbar calculation (copper & Aluminium)

  52. Sonia's avatar Sonia says:

    According to which IEC standard is performed this calculation?

  53. Rohith's avatar Rohith says:

    any one knows how to find bus bar size with a only amps rating. because i dont know about the bus bar size mean, how could i find the bus bar rating with a only amps. any one know the formulas ?????

  54. Palwe Babasaheb's avatar Palwe Babasaheb says:

    it will be gr8 if you provide backup sheet (All table source))for above calculations.

  55. D.VAMSI KRISHNA's avatar D.VAMSI KRISHNA says:

    thnks for the information sir,, can you post a quick thumb rule to check the size of busbar with respect to CB used (ex.800A MCCB/ACB etc)

  56. Shyam Pathak's avatar Shyam Pathak says:

    I request you to please mention reference IS / IEC standard for better understanding

    As per temperature rise calculation : Source Reference : IEC 62271 – 1

  57. mohit jain's avatar mohit jain says:

    great job sir……………..thanks for the info

  58. NARSIMULU's avatar NARSIMULU says:

    the above mentioned explanation is based on which Forum or what?

  59. bhas karan's avatar bhas karan says:

    Current Rating of Bus bar after De rating Factor (I1)= 0.9*630 = 567 or 697 ???

  60. AHMED SAAD's avatar AHMED SAAD says:

    KINDLY PROVIDE US WITH THE RELATION BETWEEN BUS BAR SIZING AND INTERNAL SEPARATION

  61. Venkatesan's avatar Venkatesan says:

    For outdoor installation, factor k6 has to be 0.95,0.9 & 0.85. For Indoor installation with poor ventilation, k6 to be 0.65,0.6 & 0.5.

  62. K THIRUMAL RAO's avatar K THIRUMAL RAO says:

    Thanks Mr. Parmar, I was looking for data related to the torque limits for the bus bar joints and its impact on temperature rise of bus bars during normal usage. Are there any methods to deduce temperature during full load conditions based on temperatures available during part load condition of the system ( like we have seen temperature rise near MCCB 630 A terminals of 55deg above ambient of 35 deg at a constant load of 300A, what would be temp at say 600A, is 55+35 = 90Deg acceptable at 50% load )

  63. Rajesh's avatar Rajesh says:

    Sir,in bus bar size calculation from where we get the values of alpha, Dita,and Dita t

  64. Arunkumar's avatar Arunkumar says:

    Please advise from which standard the derating factors are taken

  65. Vijay Kumar's avatar Vijay Kumar says:

    can i share this on my personal blog ???
    really useful info !!!

  66. Karthik's avatar Karthik says:

    dear sir ,
    Confirm temperature inside outdoor Metering panel when carrying full load current at an ambient of 40 Deg.C.

  67. ARIJIT ROY's avatar ARIJIT ROY says:

    It is a very usefull calculation, which could serve my present requirement. In future pls forward the useful eletrical calculation to my mail id. Thank you.

  68. ARIJIT ROY's avatar ARIJIT ROY says:

    Could you help me to forward the cu bus bar-bar dimensions(wdth x thknss ) for 1000Amp, 500Amp, 300Amp, & 200Amp Bar .

  69. omer asif's avatar omer asif says:

    how to calculate Resistivity of copper bus bar

  70. pavitra's avatar pavitra says:

    hi jignesh

    can you mail me copy of Indal text book and Thomas & rata text book if you have.

    regards

    pavitraagal@gmail.com
    +91-9826719220

    • SIVAKUMAR K's avatar SIVAKUMAR K says:

      Dear Ms. Pavitra, Just now I have sent the book by mail to your above mail ID. Please acknowledge receipt.

  71. sai krishna betha's avatar sai krishna betha says:

    This gives the volume of the right, how you considered it as area?

  72. manoj's avatar manoj says:

    sir kindly show me the calculator of selection switch gear and cable size

  73. rasoul Zare's avatar rasoul Zare says:

    Dear Jignesh
    This is very useful technical information which you share
    Thanks

  74. punitha's avatar punitha says:

    Sir,

    How to calculate bus duct earthing size

  75. RAJESH's avatar RAJESH says:

    Hi Jignesh,

    I need to know the temperature of a copper busbar and steel pad at 12.5KA ISC fault level for 2 sec. if we know the size of bus bar or spade?

    Rajesh

  76. Kamal Trivedi's avatar Kamal Trivedi says:

    Dear Jignesh,
    Will You please give me t Busbar calculation for 1250 Amps, Alluminium, PMCC Panel, Permissible Temp 45 Deg C, InsulatedHeat Shrink Sleeves, Volatge 415 V , 50 Hz, Humid Atmosphere Assam-Noonmati.. Regards, Kamal Trivedi (kamaltrivedi@ymail.com

  77. ranjith's avatar ranjith says:

    Dear Sir,

    On which standard basis, your made panel sizing and calculation. which is not specified. Kindly clarify.

    Thanks & Regards,
    K. Ranjith

  78. Akhil S M's avatar Akhil S M says:

    Dear sir

    Could u please share the derivation for that formula to calculate area of busbar as per the short circuit capacity please.

  79. Joy Mukherjee's avatar Joy Mukherjee says:

    What will be the magnitude of current of one 1600 KVA 3 phase Transformer at its LV winding side.
    The manufacturer has consider the Busbar size is 100×12 mm=1200 sq.mm.copper Bus single. what is the Current density of the Copper and is the Busbar size sufficient for that Transformer?

  80. DK's avatar DK says:

    Hi
    Could you please explain about Various Testing in ACB & Protection Relay.

  81. Dinesh Kumar Sarda's avatar Dinesh Kumar Sarda says:

    Kindly confirm the name of the standard followed by you to arrive at the formulae defined above and how shall be the approach to calculate for DC currents.

  82. Vinodhkumar.R's avatar Vinodhkumar.R says:

    Can this calculation applies for Busbar design in relays and contactors

  83. AWNISH KUMAR's avatar AWNISH KUMAR says:

    Can you please let me know below mentioned parameter in case of Aluminium bus bar

    1) Temperature Co efficient of Material Resistance at 20°c(α20)=
    2) Material Constant(K)=
    3) Bus bar Material Permissible Strength=

  84. T Vel Murugan's avatar T Vel Murugan says:

    Sir i want BUS Bar Capacity and Size for250 Amps incomer MCCB and 100 Amps MCCB-07 Nos out going

  85. Anuj's avatar Anuj says:

    how to choose material constant value?

  86. Vijay Patel's avatar Vijay Patel says:

    As per which IS/IEC standard is this calculation performed??

  87. Munavar ali's avatar Munavar ali says:

    Hi Sir,
    Any standard of MDB & SMDB incoming and out goings standard Fault rating (kA) . ex SMDB incoming 35kA , SMDB Out goings for DB-25kA , MCC – 35kA.
    Please clarify
    Thanks,
    Munavar

  88. VINOD KUMAR's avatar VINOD KUMAR says:

    All calculation above mentioned are nice i got result same as you, but in “TEMPERATURE RISE CALCULATION” how would you get 30 deg.C as maximum temperature rise.

    please explain.

  89. Vishal Patel's avatar Vishal Patel says:

    Dear Sir,

    Please help me for find 1250A copper bus bar size as per temperature rise with Calculation and formula

  90. aziz's avatar aziz says:

    Hello dear

    in electrical panels, the main bus bar and sub bus bar size is different ? or the same ?

  91. RTN's avatar RTN says:

    hello, what if I need to compute for the total ampacity for more than 3 busbars per phase? what data do I follow for K1?

  92. Gautam Shukla's avatar Gautam Shukla says:

    Dear Jignesh,
    Can you please let me know source reference for insulation material on busbars PVC Sleeve / Painted???

  93. shivakumar.N's avatar shivakumar.N says:

    Sir, what is the material constant for aluminium busbar K=?

  94. Swanand Shivalkar's avatar Swanand Shivalkar says:

    Hello sir,
    MULTIPLICATION ERROR.

    Current Rating of Bus bar after De rating Factor (I1)=630×0.9
    Current Rating of Bus bar after De rating Factor (I1)=697Amp

  95. Rahul Dhamne's avatar Rahul Dhamne says:

    Hello Sir,

    I have some doubts in your bus bar sizing calculation sheet

    1. Is operating and Final Temperature of Bus bar during Fault are same for Aluminium and Copper
    2. I am not getting how is Bus bar Position: i.e. Edge mounted, 1 bar base mounted, several base mounted
    3. What is the Bus bar Material Permissible Strength: for aluminium.

    Please reply to queries

  96. vijay's avatar vijay says:

    Based on the busbar sizing calculation, understood that 1 run of 75X10 mm for phase busbar is sufficient . whereas in actual bus bar size 2 runs of 75 X 10 mm. is it required to go with 2 runs of busbar. ??? Is this is oversizing of busbar ..? Please explain

  97. Vikas dubey's avatar Vikas dubey says:

    Sir , long distance low voltage cable selecting sizes example 650 amp load and distance 500 mtr and voltage 400 so what’s size of cable will be use …

  98. Sai krishna Betha's avatar Sai krishna Betha says:

    What is the technical reference or Indian standard reference for this design?

  99. Rupashree Ramu's avatar Rupashree Ramu says:

    Thus u have calculated for aluminium or copper.

  100. Magee Siva's avatar Magee Siva says:

    sir in 11kv system 3200a what size aluminium bu bar to consider

  101. Junaid Zaman Khan's avatar Junaid Zaman Khan says:

    what would be the cross sectional area of busbar for 250A on 50KA 1sec

  102. bhavesh shah's avatar bhavesh shah says:

    VERY GOOD INFORMATION CAN YOU CALULATE FOR 1250A BUSBAR copper.

  103. Pardeep Kumar Saini's avatar Pardeep Kumar Saini says:

    Sir, can I have reference about the Derating factor K2 (insulating media) I. E. what is the source of it.

  104. ashiq's avatar ashiq says:

    Thanks sir,
    For good inormation

  105. kaushalya's avatar kaushalya says:

    Please confirm the Copper busbar for 4000A Breaker -2 no 75KA Rating Panel width 3.5 Meter Height -2.3m

  106. Md.Sohraf's avatar Md.Sohraf says:

    please,
    explain me , 3 phase ,400volt, 7000amp rating copper bus bar. please give me calculation busbar to busbar how much gap.

  107. Md.Sohraf's avatar Md.Sohraf says:

    i want to how much gap busbar to busbar.

  108. Mahesh Kubade's avatar Mahesh Kubade says:

    spacing between bus …..elaborate .?

  109. CHANH YANGKONGJEE's avatar CHANH YANGKONGJEE says:

    In K2 below, why when use PVC sleeving & painted, the current capacity rating of busbar is increase ?

    2) Bus bar Insulating Material De rating Factor (K2)
    Bus bar having No insulating material. It is Bare so following Table
    De rating Factor is 1.
    Bus Bar Insulating Material (K2): De rating Factor
    Bare 1
    PVC Sleeving 1.2
    Painted 1.5

  110. abdul rasheed's avatar abdul rasheed says:

    what is the distance (in mm ) between the busbar in secondery selective arrangment

  111. Umar Farooq's avatar Umar Farooq says:

    Hello Sir,
    Can you help me for the calculation of Busbar size in sandwich busduct design

  112. Hi,
    Please define well ventilated and poorly ventilated Indoor room

  113. H.S.Kumar's avatar H.S.Kumar says:

    VINOD KUMAR says:
    September 25, 2019 at 10:37 am
    All calculation above mentioned are nice i got result same as you, but in “TEMPERATURE RISE CALCULATION” how would you get 30 deg.C as maximum temperature rise.

    please explain…….. Mr. Parmar, is this question kept open without answering since 2019?

    I am also not getting 30degrees centigrade….There must be something wrong in the formula or value indicated ….Pl explain

  114. ANUBHAV CHAUHAN's avatar ANUBHAV CHAUHAN says:

    please provide the Aluminum constant (k) value ?
    what is the material of constant pls explain?

  115. yogesh panchal's avatar yogesh panchal says:

    what will be the output busbar ampere ratings in panel for 1250A ACB incommer.

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