Electrical Notes

Electrical Calculation and Electrical Notes on Electrical Engineering:

All Notes ,Calculations & Abstracts are Based on Some Electrical References. All References are mention at end of each Notes.

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Electrical Notes:                                                .

(1) Motor & Starter:                                                                                                     .

  1. Star-Delta Starter
  2. Direct On Line Starter
  3. Motor Name Plate Terminology
  4. Overload Relay Size & Contactor for Starter
  5. Abstract of NEC:430 for Size of Cable for Single or Group of Motors
  6. Standard Electrical Motor Connections
  7. Electrical Motor Quick Reference

(2) Transformer:                                                                                                        .

  1. Parallel Operation of Transformer
  2. Vector Group of Transformer
  3. Auto Transformer Connection
  4. Scott-T Connection of Transformer
  5. Zig-zag Connection of Transformer
  6. Star-Delta Connection of Transformer
  7. Delta-Star Connection of Transformer
  8. Delta-Delta Connection of Transformer
  9. Star-Star Connection of Transformer
  10. Various Routine Test of Power Transformer-(Part-4)
  11. Various Routine Test of Power Transformer-(Part-3)
  12. Various Routine Test of Power Transformer-(Part-2)
  13. Various Routine Test of Power Transformer-(Part-1)
  14. Abstract of over current Protection of Transformer (NEC 450.3)
  15. Electrical Safety Clearance for Transformer
  16. Abstract of National Electrical Code for Transformer’s Protection
  17. Difference between Power Transformer and Distribution Transformer
  18. Type & Selection of Current Transformer
  19. Transformer Accessories.
  20. Minimum Acceptable specification for Metering C.T
  21. Transformer Quick Reference

(3) Lighting Luminars:                                                                                       .

  1. Electrical Illumination Values -(Part-1).
  2. Electrical Illumination Values-(Part-2).
  3. Electrical Illumination Values-(Part-3).
  4. Electrical Illumination Values-(Part-4).
  5. Electrical Illumination Values-(Part-5).
  6. Quick Reference Lighting Power Densities
  7. Difference Between High Bay-Low Bay and Flood Light Fixture
  8. What should you know before buying LED Bulbs (Part:3)
  9. What should you know before buying LED Bulbs (Part:2)
  10. What should You know before buying LED Bulb (Part:1).
  11. Selection of Street Light Luminar-(Part-6)
  12. Selection for Street Light Luminar-(PART-5)
  13. Selection for Street Light Luminar-(PART-4)
  14. Selection for Street Light Luminar-(PART-3)
  15. Selection for Street Light Luminar-(PART-2)
  16. Selection for Street Light Luminar-(PART-1)
  17. Different Types of  Lamps
  18. What is Fixture’s Beam Angle & Beam Diameter (Part-2)
  19. What is Fixture’s Beam Angle & Beam Diameter (Part-1)
  20. Type of Light Bulb base & Socket (Part-1)
  21. Type of Light Bulb base & Socket (Part-2)
  22. Type of Lighting Bulbs (Shapes and Sizes) Part-1
  23. Type of Lighting Bulbs (Shapes and Sizes) Part-2
  24. Type of Lighting Bulbs (Shapes and Sizes) Part-3
  25. Type of Lighting Bulbs (Shapes and Sizes) Part-4
  26. Type of Lighting Bulbs (Shapes and Sizes) Part-5
  27. Various Factors for Illumination Calculations
  28. How to Design Efficient Street Lighting-Part-4
  29. How to Design Efficient Street Lighting-Part-3
  30. How to Design Efficient Street Lighting-Part-2
  31. How to Design Efficient Street Lighting-Part-1

(4) MCB / MCCB / Fuse / Relay:                                                                                     .

  1. MCB / MCCB / ELCB Quick Reference (Part-1)
  2. MCB /MCCB / ELCB Quick Reference (Part-2)
  3. What is Correct Method of MCB Connections
  4. Setting of overload, Short circuit & Ground Fault Protection of MCCB (PART-1)
  5. Setting of overload, Short circuit & Ground Fault Protection of MCCB (PART-2):
  6. Type of Tripping Mechanism of MCB / MCCB-(Part-1)
  7. Type of Tripping Mechanism of MCB / MCCB-(Part-2)
  8. How to select MCB / MCCB (Part-1)
  9. How to select MCB / MCCB (Part-2)
  10. How to select MCB / MCCB (Part-3)
  11. Selection of 3P-TPN-4P MCB & Distribution Board
  12. Difference Between  MCB/MCCB/ELCB/RCCB
  13. Type & Selection of Fuse
  14. Specification for Re wirable Cut Out Fuse Unit
  15. Over Current Relay(Type-Application-Connection)
  16. Types and Revolution of Electrical Relays
  17. Working Principle of ELCB and RCB

(5) Earthings:                                                                                                            .

  1. Earthing Strip / Wire / Pit Quick Reference (Part-1)
  2. Earthing Strip / Wire / Pit Quick Reference (As per CPWD) (Part-2)
  3. Difference between Bonding, Grounding and Earthing
  4. What is Earthing
  5. Single Earthed Neutral and Multi Earthed Neutral.
  6. Method for Installation of Earthing Strip
  7. Methods of Earth Resistance Testing (Part-1)
  8. Methods of Earth Resistance Testing (Part-2)
  9. Methods of Earth Resistance Testing (Part-3)
  10. Quick Reference -Earthing

(6) Cables:                                                                                                               .

  1. Cable Construction & Cable Selection-Part:4
  2. Cable Construction & Cable Selection-Part:3
  3. Cable Construction & Cable Selection-Part:2
  4. Cable Construction & Cable Selection-Part:1
  5. Cable Tray Size as per National Electrical Code-2002. Article 392
  6. Difference between Unearthed Cable & Earthed Cables
  7. Type of Gland
  8. Gland Size Selection
  9. EHV XLPE – Current Rating
  10. XLPE Cable-Current Rating
  11. PVC Cable-Current Rating
  12. EHV/HV Cable Sheath Earthing
  13. Low Voltage and High Voltage Cable Testing
  14. HIPOT Testing
  15. Type of Cable Tray.
  16. Method for Installation of Cable Tray-(PART 1)
  17. Method for Installation of Cable Tray-(PART 2)
  18. Method for Installation of Cable & Wire (Part-2) 
  19. Method for Installation of Cable & Wire (Part-1)

(7) Power Factor Correction / Harmonic:                                                          .

  1. what is Power Factor & Automatic Power Factor Correction
  2. Harmonics and It’s Effects

(8) Power Distributions & Transmissions:                                                        .

  1. Vibration Damper in Transmission Line
  2. Total Losses in Power Distribution and Transmission Lines-(Part 2)
  3. Total Losses in Power Distribution & Transmission Lines-(Part 1)
  4. Size and Location of Capacitor in Electrical System-(Part 2)
  5. Size and Location of Capacitor in Electrical System-(Part1)
  6. Impact of Floating Neutral in Power Distribution
  7. Effects of High Voltage Transmission Lines on Humans and Plants
  8. Analysis the Truth behind Household Power Savers
  9. Types of Neutral Earthing in Power Distribution Systems
  10. Type of Electrical Power Distribution systems
  11. 11KV/415V Overhead Line Specification as per REC
  12. Power Quality
  13. Ferranti Effect in Transmission Line
  14. What is Corona Effect in Transmission Line 
  15. How Reactive Power helpful to maintain a System Healthy
  16. Types of Overhead Conductors
  17. Guideline to Design Electrical Network for Building / Small Area.
  18. Effects of unbalanced Electrical Load (Part:2)
  19. Effects of unbalanced Electrical Load (Part:1)

(9) Demand Factor-Diversity Factor-Utilization Factor:                                 .

  1. What is Demand Factor-Diversity Factor-Utilization Factor-Load Factor
  2. Demand-Diversity Factor Value Quick Reference

(9) Sub Station / Electrical Equipment Safety Clearance:                          .

  1. Electrical Safety Clearance for Electrical Panel 
  2. Electrical Safety Clearance (Western Power Company ,Australia )(Part-6)
  3. Electrical Safety Clearance (New Zealand Electrical)(Part-5)
  4. Electrical Safety Clearance (ETSA Utilities,Australia) (Part-4)
  5. Electrical Safety Clearance (Northern Ireland Electricity )(Part-3)
  6. Electrical Safety Clearance (IE/CEA) (Part-2)
  7. Electrical Safety Clearance (Qatar General Electricity) (Part-1)
  8. Sub Station Abstracts-(Part-1)
  9. Sub Station Abstracts -(Part-2)
  10. Sub Station Abstract -( Part-3)
  11. Electrical Clearance in Substation.
  12. Typical Limiting Values of Substation Equipment.
  13. Standard Makes for Electrical Equipment
  14. Minimum Electrical Equipment Clearance (As per BS / IE Rules).
  15. Electrical Voltage Limit Quick Reference

(9) Diesel Generator Set:                                                                                   .

  1. Quick Reference of Diesel Generator Set-(Part-1).
  2. Quick Reference of Diesel Generator Set-(Part-2).

(9) Lighting Arrester / SPD:                                                                               .

  1. Lighting Arrester
  2. Selection of Surge Protective Device (SPD)- (Part 4)
  3. Selection of Surge Protective Device (SPD)- (Part 3)
  4. Selection of Surge Protective Device (SPD)- (Part 2)
  5. Selection of Surge Protective Device (SPD)- (Part 1) 

(10) Inverter / UPS:                                                                                                .

  1. What is Difference between UPS & Inverter
  2. Selection of Various Types of Inverter-(Part-1)
  3. Selection of Various Types of Inverter-(Part-2)
  4. Selection of Various Types of Inverter-(Part-3)
  5. Selection of Various Types of UPS (Part-1)
  6. Selection of Various Types of UPS (Part-2)

(10) Electrical Abstract- (NBC / NEC / IE Rule / CEA / CPWD / IS Code):            .

  1. Internal Electrical Work Abstract of CPWD
  2. Electrical Abstract-National Building Code (NBC)
  3. Electrical Abstract -National Electrical Code (NEC)
  4. Indian Electricity Rules-Abstract.
  5. Indian Standard Code-Abstract (IS:1554/IS:15652/IS:1678/IS:1255/IS:694
  6. Indian Standard Code-Abstract (IS:5613/IS:5039/IS:11892/IS:1455/IS:11171.

(11) Others (Electrical):

  1. Electrical Useful Equations.
  2. Electrical Costing (Per Sq.foot) Quick Reference
  3.  IP Rating for Electrical Enclosure
  4. Insulation Resistance (IR) Values of Electrical Equipment
  5. Electrical Energy Saving Tips

(12) HVAC:

  1. Quick Reference -HVAC (Part-1)
  2. Quick Reference -HVAC (Part-2)
  4. Method for Installation of HVAC System (Part-4) 
  5. Method for Installation of HVAC System (Part-3)
  6.  Method for Installation of HVAC System (Part-2)
  7. Method for Installation of HVAC System (Part-1)

(13) Fire Fighting:

  1. Quick Reference-Fire Fighting (Part-1)
  2. Quick Reference-Fire Fighting (Part-2)

281 Responses to Electrical Notes

  1. noel ramos says:

    subscribe me about your Electrical Notes posts

  2. Habeeb says:

    Thanks for you and your website. It is very useful for all electrical engineers.

  3. VIKRAM says:


  4. gobinath says:

    what is the reason for in earth fault relay does not operate while fault occurs near by the neutral point

  5. mozes says:


  6. ritu says:

    hey…ur website is really very very good…plzz keep up the great workk…god bless you…u are amzinngngngng!!!

  7. Varun says:

    God Bless U, Sir u are doing a great work.Thanking U.

  8. Nandip Agrawal says:

    Please let me know abour Surge Protector in details

    How Surge protector is installed in Main Distribution Panel ?

  9. BBQ Grill Covers says:

    This article was really nicely written, and it also contains several helpful details. I appreciated your expert manner of writing this submit. You’ve created it easy for me to realize.

  10. Dear sir,
    your web site very useful for all Electrical Engineer.
    I want to know for Earthing Truck 11kv ,sub station automation.

  11. dipalee says:

    this website is really great…..!! thank you sir…

  12. Anand says:

    Dear sir

    Will u explain the duty cycle of the breakers i.e O-0.3Sec-CO-3Mins-CO

  13. sheeba says:

    if possible ,include somthing about electrical system design & estimation……….

    It is very helpful for us.

  14. Mboga Ratego says:

    I have a 500kVA generator supplying 33kV line with a distance of 55km, The line has 7 transformers at the receiving i.e 55 km from the generator station, the problem is that this system has refused to work, it trips after every 3 hours, What could be the problem with this arrangement,The voltage is too high at the receiving going upto 255V for single phase, attempts to transpose the line has also failed to work

  15. can u give me UPS sizig and BBank sizing calculation

  16. subhash says:

    this site is wonderful i will inform my friends also about this site u r doing gate job

  17. Masood says:

    please tell me how i can see current transformer pdf view because when i open pdf file of current transformer it show wordpress registration i completed registration but no view of pdf. please reply thx

  18. narendra charola says:

    it’s real good collection keep it up.

  19. aditya says:

    Can u explain about grouser an Earth fault detector

  20. bharat says:

    What would be minimum clearence betn HV bushing top lead abd upper gandry?

  21. mansoor says:

    Hello Sir

    Thank u very much for uploading these information, can u upload UPS Selection and cable selection for UPS and Cable/ Copper strip size for UPS Neutral earthing? and some important information about electrical design for distribution side of IT, Residential & Commercial buildings.

  22. jagadish says:

    hello sir,

    firstly i want to thank you… secondly can i known about power quality in elobrated way plssss

  23. sateesh says:

    useful site for all electrical engineers.

  24. sir please i really need the current transformer notes but i can,t acess on that notes so can you help me about that.
    waiting your reply

  25. sathish kumar says:

    hello sir,
    relly great work.sharing of knowledge makes it you different from others

  26. Mitul says:

    Hi Jignesh..Good work…keep it up..
    I want to know about Partical Discharge Test.

  27. ranjeet p.desai says:

    thanks for sharing

  28. bani says:

    hi jignesh its really good work….i want to know switch gear,,,more….but no notes regarding that
    pls can u update….this site s very helpful for us…..good

  29. Mohd Daud Othman says:

    good reference for me…tq

  30. Ugo Ezeani says:

    I can only say you are doing a great job. You are a gift to the electrical community
    Please can i get your e mail address.

  31. Dashmesh Singh says:

    best site for practical engineers


    Dear jignesh
    i must applaud you for such beautiful,simplified and greatly livid articles. you are infact generating tremendous interest level among the common engineers , your article seems to be a engrossing novel for the all the level of technocrats . My hats off to you for a yeoman service .

    Arvind Singh Rathore

  33. joseph says:

    can u blog something about 1 phase and 3 phase motors

  34. Min Htet says:

    can you send your all post as PDF files to my email because your all posts are very great and useful to me? I afraid, I can not visit your website one day.

    • Dear Min,
      Just Copy of the text from Blog-open MS word just past it then convert it to PDF if you need in PDF.
      It is not possible to convey PDF copy of all Notes personally to every one.

      • Sivakumar says:

        Respected Sir,
        Iam A.Sivakumar working as a Technician.I face problems in interview regarding to Deisel Generators….I Request you sir Please send the notes about generators & normal and critical problems which are commonly occures…Iam the regular viewer of you Web-site.I learnt a lot by your website…Thanking you sir..

    • m shabeer says:

      How we get this notices in Pakistan
      Am SHABEER

  35. prasad says:

    Dear Parmar sir,

    You hav given such a wonderfull information, as there are so many sites but this is one and only site which fullfill any electrical engineer or contracter information needs. And ur excel programs are also wonderfull. Now i m became fan of u. I future days i will defenatiely donate as well i will buy excel program also.

    Thank you very much. God bless u.

  36. DIPA, Ahmedabad says:

    Kindly post some User Manual, WS Tutorials/Guides and other installable (crack) files for ETAP 11. I think ETAP 11 is HOT topik for Electrical Engg.
    This is my Humble request to you to send me some informations at my e-mail Id.

  37. Ravi says:

    Sir it is very helpful & Thank you for giving good amount of knowledge, i request you to kindly send me the all the notes to my mail id, as it is very helpful & i cant access net when i require some time so i will have to carry hard copy
    request you to kindly send all notes in PDF mode to my mail id


    • Just Copy The text of Article from Blog and paste it to MS word.
      It is not possible to send mail personally.
      I hope You will understand my Problem.

      • selvam k says:

        i need to know about the generator please update details

      • akshat saxena says:

        Dear Mr Parmar ,please let me know the procedure the book… Will i be getting a soft copy or hard copy couriered ?… Also if i m getting a soft copy on purchase, will i be able to take a print out of the same?

  38. shiraz ul Islam says:

    keep it up

  39. Saikat das says:

    Thanks for efforts for us,your notes really help us a lot,i an glad to see few more topics on machine design and fundamentals.again thanks a lot.

  40. Chinmoy Sen says:

    I am in mech. engg. I have many query in basic electrical. Your articles helped to understand basic funda. Thank you very much.

  41. Kiran Kumar --- SYSTEM DESIGN ENGINEER says:

    Thanks a Lot for your data it has really helped me in my professional life, for every enthusiastic learner this data is very useful………! According to me think you are doing your level best……..!

  42. Inverters in chennai says:

    Awesome blog! keep it up.

  43. argha says:

    i am a electrical engg……this blog helps me a lot .plz upload more question answer article ,it is very helpful for interview.

  44. priyanka says:

    how voltage change from 11v to max .voltage in power transmission system??

  45. janahiram says:

    thanks.very useful

  46. kurniawanpramana says:

    THIS IS TREASURE :D, thank you 😀

  47. pssrpskumar says:

    Thanks a Lot for your data it has really helped me in my professional life, for every enthusiastic learner this data is very useful………! According to me think you are doing your level best……..!.
    actually i need AC & DC UPS sizing calculations spread sheet in Excel format.please send as early as possible .this is my email :psrpskumar@gmail.com

  48. Kaveri Sudhagar>G says:

    Dear Sir,

    Your artical is very good & usefull. Pls add about DG Sets. Types of DG Sets & Different. Pls do needfull

  49. shahid says:

    one of the best website
    thank u sir

  50. Rojen says:

    Hats off to you Sir… Effort behind this is great…

    Thank you so much…. Very informative…..

  51. sami says:

    thanks a lot for all, please can i ask you for : line protection setting calculation 🙂

  52. sundar says:

    Dear friend

    Nice details,, I need NGR details. can you post that

  53. Khin Shwe says:

    Thank you very for your Electrical notes.

  54. Unknown says:

    I am really thanks and salute 2 u………

    Good job

  55. aniket says:

    sir i want to know the distance b/w two pole ht an lt both

  56. Oswaldo says:

    thank you dude. for the information… greetings from El Salvador C.A.

  57. Arul says:

    Please provide me Electrical Panel Inspection check list that will be grateful to you


  58. Amal Kumar Maiti says:

    Mr. Jignesh Parmar, You are the great. One of the most powerful Technical Site I have ever seen.
    Every person will be benefited from you.

  59. Palanisrinivasan says:

    Could you please send as commend, how to select the suitable under/over voltage protection relay from different manufacturers for primary star and secondary 2VT open delta connection PT.

  60. I really seem to agree with everything that
    was in fact written within “Electrical Notes Electrical Notes & Articles”.
    I am grateful for all the information.I appreciate it-Lanora

  61. Nimesh says:

    thank you jignesh parmar. this basic information relating ele. engg.is very useful for every electrical engineer. and also thank you my ketul sir who suggest me to use this site……

  62. kalesh says:

    This is very useful information. Thank you sir.

  63. GAYA3 says:

    Sir can you help me to design a Current Transformer with basic requirements and the necessary calculation for designing it, with a best example…. i’m inreal need for the info. please help me….

    with regards,


  64. pravin mali says:

    thank you sir.u r proud of gujrat.

  65. pravin mali says:

    please inform me via mail about uptate and changes

  66. Pravin mali says:

    jignesh sir, i want know about 67-restricted relay for transformer protection.pls, give me reply.i am waiting.
    From:Pravin Mali

  67. Very nice post. I definitely love this website. Stick with it!

  68. mwadym says:

    Dear Expert,
    what is the effect of power cable laid in looping?

  69. vishal mullewar says:

    sir can you please provide some information about Transformer differential protection , stability , sensitivity of transformer differential relay, HV REF /LV REF stability & sensitivity.

  70. rahul says:

    Sir would you please give notes about Load choking..?

  71. m.uthandaraman says:

    there are very usful to many peoples who interested in electrical.. i have many douts.., in that one dout is.

    why we considered per unit impedance during the calculation of transformers operated in parallel? and its uses? give some exambles how the load divide depends upon their p.u impedance value of the transformers?

  72. Kiran kumarGudla says:

    Really superb sir,for your wholehearted support to all Elegant eectrical engineers..Hats off u sir………..

  73. Salinee says:

    this web page is really very interesting. Sir, can you please provide notes on generators..thanks.

  74. EDWIN RAYER G says:

    how can i find out the loss of transformer in kw

  75. Deepak Agrawal says:

    dear Jigneshji,
    can u provide me with some reactor sizing, for capacitors for hormonics prone area

    i mean, whats 7%, 14% reators, when what specs are to be used and all

  76. Aung Zaw Htun says:

    I want to know how to choose of neutral cable rating

  77. Pankaj says:

    Hello sir,
    it is helpful notes for electrical engineer…pls provided Electrical Testing notes on practical basis..like transformer testing, breaker testing, oLR testing, relay testing, micom relay testing, cable testing, etc. positive response awaited from u..
    thanking you,

  78. eass says:



    I need your reference:
    All manufacturer’s are followed IEC & IEEE standard for design MV switchgear at rated 40 deg. C ambient temperature. However, if ambient temperature increase to 50 deg. C, then How manufacturer should satisfy their clients (Client has been some current rating limitation bus bar as well as CB) technically. Please provide me details

  80. PK Goyal says:

    Dear Mr Parmar,
    You are one of the greatest, broad hearted and kind human being who believe in sharing the knowledge they possess as you will agree that the knowledge you have will be lost for ever when you leave this world. It will enrich the knowledge of others interested in the subject and immensely benefit the mankind in its pursuit to excellence.

    I have come across with your articles while looking to solve one of my problems and I seek your wise advise in the matter. We have one tea manufacturing industry near Siliguri in the district of Darjeeling (West Bengal). We have taken up the task of efficient utilisation of electricity by looking into each and every factor affecting the electricity charges viz., contract demand, actual requirement, power factor, load factor, installation of required equipments, earthing, overall electrical wiring etc.etc., We have no idea about these and other factors affecting electric consumption. For this we need your guidance and like to know as to how you can help us or guide us in the matter. This is a business requirement and therefore, it will definitely be on cost basis.
    Waiting to hear from you,
    With regards,
    PK Goyal

  81. swaroop says:

    A dought on carbon brushes, can we use commutator carbon brushes to slip ring induction motor.


    Dear Jignesh parmar,

    I am working in 2MW Photovoltanic Solar power plant as Electrical Engineer (O&M), these plant generate power at day time & take power (Import) at night. At night Import power is used for plant lighting only as generation stopped after sunset, At the time of Import power, we have a light load (near about 10KW), due to which our power factor is Low. & Electricity board charge panalty for low power factor. How can i improve power factor to 90-95%.

    Thanks & Regards,
    Leeladhar kashyap

  83. Ramu says:

    what happened for my query dated on 22-10-13

  84. KESAVAN says:


  85. Sukanta Bhowmik says:

    I want to know about tranformer

  86. Rajaram Mahadeo Mane says:

    I want to know about Lighting arresters.

  87. soe tun says:

    I have a problem while downing electrical tools,what should I do then?I want to get all of excels,plz advise me

  88. gaurav says:

    Thank you very much………….
    Information is very helpful for us

  89. Renganathan says:

    Sir I need to know different types of relay operation for protection of transformer

  90. Swapan says:

    Dear Sir,
    I saw almost all of your posts those are very helpful now I request you to post the different cable sizing processes for domestic, commercial & Industrial Electrical works for practical purposes……

    Swapan Kr. Bera, kolkata, West Bengal, India

  91. m says:

    what is need for generating the power are 3.3kv, 6.6kv,11kv,66kv ?

    in terms of form factor why?

    any special in form factor ?

  92. geetha sundar says:

    need for form factor?
    why generating voltage are 6.6,33kv,11kv?

  93. geetha sundar says:

    why our country frequency say as 50hz? any reason
    in others are 60hz … i am totally confused for silly questions

  94. dear sir,
    i want to know abt the windings of cieling fan and complete information about the structure and working of cieling fan

  95. please tell me difference between mcb/mccb/elcb/rccb

  96. P.Koteswar Rao says:

    df/dt settings required please

  97. amirnangial says:

    there is 11kv/230 single phase transformer ,one of secondary conductor is grounded why?

  98. amirnangial says:

    in overhead system, most of fault are single line to ground why?

  99. saisiva says:

    guruji u r great

  100. saisiva says:

    i think in case of over head transmission line probability of failing a line is high compared to probability to fail all line so single line to grnd faults are more

  101. saisiva says:

    sir why should capacitors be placed at 2/3 of feeder length from sending end

  102. faisal says:

    What is power factor sir

  103. Bhaskar Joshi says:

    Dear Jignesh,
    My capacitor bank always showing overload, i have checked all the contactor, fuse, and replace the controller but still the same probelm
    can you please help me what i should do

    thank you for your help


  104. Prasanta Das says:

    Dear Mr. Jignesh,

    I want to know the details about DG Synchronization? can u help me?

  105. Nand Kishor says:

    excellent work sir

  106. animal jam codes for membership says:

    What’s up, I check your new stuff on a regular basis.

    Your story-telling style is awesome, keep up the good

  107. ashish dandale says:

    awesome sirrrrrrrrrrrrrrrrrrrr

  108. CHHABILA KU SAHOO says:


  109. jayesh.s. chauhan says:

    sir i want to know why always ‘ earth foult realy connected on ‘y’ phase”

  110. Ajay says:

    How to connect cable sheath earthing in case of core balance current transformer? Whether we have to pass it from CBCT or not?

  111. raza says:

    dear what is the LTMR relay ? were using this relay?

  112. manivannan says:

    Kindly forward the difference between thermal magnetic release MCCB and microprocessor based release MCCB

  113. Arabinda Seth says:

    Dear sir I m working for state transmission utility One of our 220/132/33kv grid ss is having lot of system disturbances .there are 11nos 220kv feeders an.d it is connected to hydropower station of 600 mw.it is a one and half breaker system can you suggest any remedies to avoid system disturbances

  114. dass says:


    dear sir how to calculate 3.5 ar alu cable current carrying capacity

  115. sir i need electrical notes daily updates

  116. Gerald says:

    Why ELCB is not advisable for a Motor Control Panel? What is the difference between teh ELR & ELCB?

  117. MPCB is the best one for local control panel

  118. amir says:

    why the relation of voltage and current is inversely proportional in case of transformer?

  119. Arif says:

    I would also like to join.

  120. Md jawed says:

    Sir ,i have need electrical notes in pdf ,by post

  121. Md jawed says:

    Sir ,i have need electrical notes in soft copy ,by post all volume

  122. smutuki says:

    This is good helpful and essential material

  123. nazer says:

    dear sir i hope every thing going well
    i want to know how to connect the 1600 kva transformer to panel?
    if you give me the answer i will great full.

  124. Please also post regarding re-generative Braking system & power return arrangement for Induction Motor which to be used for Dyno.

  125. sreerag ks says:

    good morning sir,
    i just want to know how 4 number of 3.7kw subimersible motor is connected in a generator given supply and how to calculate the kva rating for these motors…that is for 3.7kw motor starting current will be 35A..after that it will require 10A ..so how can we select the suitable generator for this…

  126. SABARIKUMAR R says:

    sir, Does electrical questions also included in the electrical document pdf?

  127. Syenzo says:

    Hello, I love your page. All information very useful. Thank you so much 🙂

  128. vinoth says:

    hi sir what are the precautions needed while testing the earth leakage relay?????

  129. guna says:

    dear sir, A engineering industry have a total connected load is 1400KW , avilable HT supply is 22KV, how to calculate 22KV/415V transformer KVA rating and how to estimate the KVA demand for Electricity board.

  130. pankaj patel says:

    Your personal contect number please send sir?

  131. jayaprakash.A says:

    you the jack of all electrical information, hats off

  132. masry gomaa says:

    thank you for this site

  133. Thrinley Zangpo says:

    Hi Jignesh Sir, I am one of the regular readers and followers of your website. I find this (your) site very knowledge enriching and insightful. On behalf of all the followers/viewers, I would like thank you for opening sharing your experience and expertise. Thank you once again.

    Well, I would like to seek your advice/assistance on ‘How to calculate the electrical clearances of overhead electrical conductors of all voltage levels (415 volt, 6.6 kV, 11 kV, 33 kV, 66 kV, 132 kV, 220 kV, 400 kV, etc.)”. If there are any specific formulae, kindly share me. I would be very grateful.

    +975-1760 9279

  134. prasad says:

    We have a 5 nos of 1600kv transformer one of conected to emergency panel with generator facility. if there is any issue in emergency panel than triping many area elcb link to emergecy panel please advice.

  135. fawad says:

    nice work, very informative for each person

  136. Veeregowda AH says:

    sir i want electrical all notes with free cost

  137. jayaraj.k says:

    this site is very very useful for every electrical engineers thanks a lot for your post and notes.

  138. Arun KUmar says:

    Dear Sir,
    I am the one of the great fan of yours. I am working as maintenance engineer from past 7 years. I would like request you, to provide more details on electrical maintenance safety and necessary of maintenance for Breakers,MCCB,DG sets Compressor etc… It would be useful for the maintenance persons.

    Thanks & Regards,

    M.Arun Kumar

  139. harendra kumar sharma says:

    Hi sir,
    Please tell me , ” how a reactor will design for 230kvar star grounded capacitor,50Hz,input voltage 11Kv, and the source transformer is 9Mva”
    What will be value ( or configuration) of detuned reactor. Also Please tell me which formula will be used.
    I am waiting your response .


  140. tanzeel says:

    Thanks a lot sir for such a useful information

  141. HARSHIL PATEL says:

    Best site of electrical engineering..

  142. ari says:

    it is very usefull sir .
    but i dont know onething . wt is the formula for making / breaking capacity of contactor .how to find it

  143. rajesh harode says:

    Dear sir
    I like your blogs it is very useful for me
    But my English is not good so help me .
    If you are send me your PDF file in Hindi then I will purchase your file surely.
    So sir pls provede me in Hindi format or if already you wrote in Hindi then send me purchase link because I can’t find .

    Thank you. Rajesh harode

  144. Ajay says:


  145. kalyan says:

    dear sir,

    I like this page. And it is very useful to improve my knowledge.

    Thank you

    M.Kalyan kumar

  146. Ravi kant says:

    . Electrical Energy Saving Tips

  147. Tarun Srivastava says:

    Sir Please help us to understand REF And SEF scheme

  148. fawad says:

    Respected sir, please tell me what is the difference between the above electrical notes serial no 1 to serial no 128 up to transformer & when i shall purchase ($9) from you?

    • fawad says:

      difference between the posted electrical notes serial no.1 – serial no.128 and buy electrical notes.
      sir i am waiting your answer
      with best regards

  149. roopan says:

    i need the use of metering panel and bus sectional panel in 11 kv and above…kindly give me explanation…

  150. chandandhir says:

    iam very greatfull to be this page iam glad if will touch this web site foe electrical parmanent ,this site give us many kind of knowldge related eletrical.thanks again’

  151. what is the unit of resistivity

  152. anjan says:

    Very nice description

  153. patrick says:

    need this notes

  154. jitender says:


  155. jitender says:

    Please tell me, how to read schematic diagram. ………

  156. pandidurai says:

    I want important notes in electrical

  157. md.tausif says:

    Give me Design of sub station in detail and all the equipments use and its function …..sir please

  158. FRANK says:


  159. Than Htun says:

    Dear sir,

    I would like to know IEC over current relay setting range.Please help me. Thank you

  160. Asarudeen Fahad says:


  161. Prashant Kumar Sharma says:


  162. Siva says:

    Sir please send the Electrical rules..1956

  163. anand says:

    dear sir please tell me the correct formula for getting multiplying factor of 3 phase 4 wire trivector electronic meter.

  164. Great post. I was checking continuously this blog and I am impressed!

    Extremely useful info particularly the last part :
    ) I care for such info a lot. I was looking for this certain info for a long time.
    Thank you and good luck.

  165. sanjay prajapati says:

    Hard copy available of material

  166. soumya says:

    hii i like… electric note book

  167. Rakesh Sharma says:

    Dear sir,
    please tell me about the burden of ps class in ct and pt.

  168. Sandip Mehta says:

    Dear Sir,

    Can a generator at a power plant be connected to the grid through a power cable?
    Further, what is the upper limit to the length of a cable used in power distribution?

  169. pinal vaghasiya says:

    Hello sir…
    i am pinal vaghasiya.
    working in electrical consultancy & contractor company.
    & my role as design engineer.
    i need some help..
    i need protection for 1-phase & 3-phase connected load when neutral is cut.
    at that time i am using ELCB & MCB for Protection.
    i need relay or any mechanism that give protection to equipment, when neutral is cut, my MCCB also trip at main power control panel side.

  170. KARTHIKEYAN MC says:

    Dear team members,
    Thanks for the reply, I want these electrical notes as in the type of PDF format, can I get…?

  171. ram says:

    Dear sir,
    please tell me 24DC control bus bar sleeve color code. ?

  172. Kapil Jaysawal says:

    Dear Sir,

    Your site is very benificial for freshers & Trainee….thanks alot…

  173. Dr C Kumar says:

    Dear sir, Let me know about ; Over current protection, Transformer differential
    Protection &Distant protection of transmission line
    numerical relays Relays using static comparators

  174. Kasturi Gurunath Chavan says:

    Dear Sir,
    I am kasturi Chavan from Mumbai I am studing your notes for design. I am enjoining your notes very much.
    Please I want the HVAC design notes for study. Please reply me how i can access form Internet. Please tell me the site of the same.

  175. Raj singh says:

    nice work
    really great job

  176. Danush says:

    Hello Sir
    I m Danish . Could you please tell me about life safety calculation in DiaLux . As I m familiar about DiaLux for normal & emergency calculation , but no idea about life safety . Could u please help me out for the same .


  177. santosh says:

    plz share some idea of TOD meter also and its calculation

  178. Usman Malgadeen says:

    Dear sir,
    Your website very useful to me as a trainee..

  179. Use of CCTv’s has grown to be an integral part with
    the security system. Having all such problems wireless
    CCTV can be a popular one inside minds of all. Best cctv dvr system CCTV is considered to be
    the most effective technique of reducing crime.

    A CCTV dome camera is repeatedly outfitted which has a dark colored glass
    dome. There are theories behind the role that CCTV surveillance devices play in lessening crimes.

  180. imran ali says:

    Dear Sir,
    Please add electrical protection and testing notes.
    What are the full contents if I buy this notes.

  181. dharmaraja says:

    sir, your articles are very nice… i am searching about home electric appliance maintenance details… but i did not get correct circuit diagram…wherever i search. such that washing machine, electric oven, electric cooker, ceiling fan, table fan, food mixer,,grinder, fridge,iron box.i need used motor type and clear circuit diagram with working procedure for motor type appliances. only circuit diagram need for other appliances….


    subscribe me about your Electrical Notes posts

  183. Ramasubramanian says:


  184. dhinesh kandasamy says:

    what is the conductivity of copper

  185. Ashok says:

    hello sir,

    Please clear my confusion. I want to use a LBS for transformer protection [500 kva]. Fuses are used for over current protection. But what about the under voltage and e/f protection??? How to incorporate these devices in LBS?..

  186. Rahul Hussain says:

    Dear Sir.

    Please explain me what is star delta connection

  187. Jayesh Patel says:


  188. VIJAY SHUKLA says:

    I want to know the effects of ice loadings on cables and conductors and effects. also solutions to save the cables from heavy loadings.

  189. nagendra says:

    if motor have 15HP 21amps but it takes only 14 amps how much rating relay is given to trip the motor

  190. danidhariya milan says:

    how to know current transformer test in LCM

  191. Vamsi Krishna Amara says:

    Dear Sir,

    I have a question that, In EHV Network if the star point of source transformer is operating with solid/ resistance/ impedance grounding then is it necessary that any of the other receiving end transformers also required star point grounding in case of that receiving end transformer’s primary is star connected winding (The winding which is connected in the network).

    In our case we are at receiving end with Star, Star & Tertiary winding transformer, we are experiencing disturbance tripping of HV Side stand-by earth fault during any upstream side faults.

    Hence, we hope to leave the HV Star Point un-grounded to avoid disturbance tripping.

    Please suggest me in this regard.

    Thank you very much in advance.

  192. Ramesh Pindariya says:

    Dear Sir,

    We had discussion about 33kv Telescopic Earth discharge rod, there were question from team that discharge rod cable size must be same current capacity of 33kv line, even there was audit observations for same and they need IS reference for same.

    need guidance for same.

  193. vishal patidar says:

    wow sir u r great.

  194. Dhanasekar says:

    Dear sir

    if there is a armored rusted HT 11000 volts cable, can we use that?

  195. Naidu says:

    How to download electrical notes…..

  196. Mani Charan says:

    Dear Sir,

    I am a big fan of your blog.

    please clarify me the difference between testing and commissioning in electrical engineering.

  197. kiran maharana says:

    Hello sir ..,
    I need some data about PLC ….
    Please help me.

  198. Kamal Kumar says:

    Dear Jignesh sir

    what will be happen if i change NGR of 45 MVA,DYN11 transformer for reducing fault current.
    Now it is 2.5 ohms 2500 amp. But i want to install 63.3 ohms 100 amp for avoid 10 mw TG tripping in inst. over current fault.

  199. Rajapandi selvaraj says:

    Dear sir i need transformer protection system details, please just share your notes in your website

  200. shamim parwe says:

    Dear sir,

    I humbly request to you that please you drop the notes of Low current systems like
    1.) Fire alarm
    2.) CCTV
    3.) MATV
    4.) PAVA ( public address audio visual) system
    5.) Data system
    6.) Intercom system
    7.) Telephone
    8.) Door access control system
    Please description of which type of CABLE used in this system and details.

  201. Vedendra singh says:

    Please tell me Sir
    Exactly answers,
    Transformer’s rating in KVA, Why?

  202. SOURISH BHOWMIK says:

    Please provide some articles about fractional KW motors,special type of motors,single phase motors their applications,operating principles and applications.

  203. Omer Mirza says:

    Please write an article about bundled conductors & separators used for it

  204. Omer Mirza says:

    Dear Mr. Jignesh,

    Please write an article about batteries.

  205. Mohamed Naqhiuddin says:

    Share a notes on low voltage services

  206. m shabeer says:

    Am Electrical engineer from pakistan how i buy u r notice plz tel me

  207. Naman Shah says:

    Hi Jignesh Sir,

    Can you please help me in calculating impedance matrix of the two limb core construction each limb having Primary winding and 2 secondary winding And Primary of both the limb is connected in parallel.

    Thanking you in advance

  208. Hi sir,

    I have purchased this electrical tool. its really very useful for us.
    I want to highlight that there is an error in page287 about pole height calculating w.r.t road width.

  209. Dear jignesh,
    how can i buy electrical articals?and where i can receive the material after payment inform me once

  210. bk tiwari says:

    Good for candidate,,,,

  211. great blog post….complete guidance mentioned in it. thank you for sharing with us.

  212. Mary mbugua says:

    Kindly I need some notes

  213. Hemant singh says:

    Dear sir
    Your notes is very important for me
    Please write notes on electrical maintenance

  214. John says:

    Hello sir !,

    your blog is excellent, thank you so much for these information.

    please i need good references / blogs for Low voltage systems like security systems, access control systems, fire systems, GSM ,…

    also for Mechanical systems mainly cooling systems HVAC , etc ,…

  215. khoshhal says:

    this web is very useful thank you very mach from your service
    Dear Sire
    I hope you are doing well, i need ACSR cable calculation,if you have time please calculate it me.

    best reguard
    Khoshhal naizia
    Electrical engineer

  216. AJAY says:

    Jignesh.Parmar JI,

    Its really a wonderful Link you have provided. Its like a SEA of Electrical knowledge.

    Great Work Keep it up.

    Ajay Prasad.

  217. Hari kumar says:

    How to choose grounded system and ungrounded system….based on??

  218. Telco says:

    Do you have articles relating to dc power system design for telecommunications?

  219. khoshhal naizi says:

    this website is very very useful, thanks alot from your hard working.

    best reguard
    Khoshhal naizia
    Electrical Engineer

  220. Ranjana says:


  221. CHANDAN JANA says:

    Dear sir,
    Please explain me how to calculate transformer size?

  222. Yogi says:

    Dear Sir,

    There is FMR (fuse monitoring relay) installed across fuse unit to monitoring fuse healthiness of all 3 phases.
    Sir what is the working principle of FMR ????

    Please reply….

  223. Sajan paul says:

    Respected sir im a electrician and a small contractor .im so inspired by your teaching i wish if u started a app in ur name so a common electrician can use to calcute cable
    mcload mcb etc by just typing the desired figure and knowing the answer .thanks and Regards mob no 7400379661

  224. Somnath Gupta says:

    Dear Sir is any where it is accepted that Earting to body of equipments is done by just twisting the GI wire around the stud ? is it safe looking into the purpose of earthing for equipment & Body.

    • m shabeer says:

      Sir i whant to electrical notice MUHAMMAD SHABEER from pakistan 00923437697178 Who am buy the notice kindly update

      On Mon, 9 Dec 2019, 14:35 Electrical Notes & Articles, wrote:

      > Somnath Gupta commented: “Dear Sir is any where it is accepted that > Earting to body of equipments is done by just twisting the GI wire around > the stud ? is it safe looking into the purpose of earthing for equipment & > Body.” >

  225. Offsidetech says:

    good opportunity for students great work

  226. NUR says:

    I try to buy your electrical software, but its keep rejecting my payment…

  227. Mahesh Saptarshi says:

    Found 1.8V in between Neutral & earth while 25 HP submersible pump in working condition.

  228. U.ramesh says:

    In 1phase circuit., load is controlled br phase in a switch whwn neutral is connected with load like lamp, fan etc. Why????

  229. Gulam Ahmad Raza says:

    Dear Sir,
    I want any new posts to be updated in mail or whatsapp that we can benefit from the posts you send to people. Mail I’d ( gulam80068@gmail.com) WhatsApp number ( +97477212668 )
    Thanks you

  230. Wise Mateo says:

    Thank you sir, it really help me alot

  231. Satheesh says:

    Dear Sir
    am getting below AC voltages kindly give the solution

    L1 to E:149V
    L2 to E: 270V
    L3 to E:393V
    N to E:160V

  232. Sanjaya Kumar Patel says:

    Thanks for all your articles.kindly publish some articles related to Generator and protection relay(testing and relay coordination).So that it will be more beneficial to all.
    Thank you Sir.

  233. debu02 says:

    Hello Sir,
    I purchased your full notes. I want to know that if reversion happened in your notes, will I automatically get updated one or I have to pay again?

    How to know that notes are being updated, version is not mentioned in your website, only inside the note’s PDF it is mentioned.

  234. orlio net says:

    Please search-orlionet.blogspot.com

  235. Silas Auta says:

    I wanted to download the notes but I failed may you help me please
    Thanks Silas

  236. Raju says:

    Sir Iam from andhra pradesh, i need hard copy of your book where I get?

  237. xeniusm2m says:

    As you have mentioned Diesel generators too. We can optimize its limit by using IoT/M2M solutions.

  238. Thank you so much. Your blog helps me a lot

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