Dimensioning of electrical installations
Contents
1. Free distance from wall at least one cable diameter Suomen S hk urakoitsijaliitto ry 1995 p 315 Figure 4 Method of installation E or F Handbook EN pdf 2007 p 27 30 APPENDIX 2 13 Current carrying capacities and correction factors Table 1 Conductor current carrying capacity table Different installation ways according to SFS Conductor nominal 6000 cross section mm A C D E Cu 1 5 14 18 5 26 19 2 5 19 25 35 26 4 24 34 46 36 6 31 43 57 45 10 41 60 77 63 16 55 80 100 85 25 72 102 130 107 35 88 126 160 134 50 105 153 190 162 70 133 195 240 208 95 159 236 285 252 120 182 274 325 292 150 208 317 370 338 185 236 361 420 386 240 278 427 480 456 300 316 492 550 527 Al 16 43 62 78 65 25 56 77 100 83 35 69 95 125 102 50 83 117 150 124 70 104 148 185 159 95 125 180 220 194 120 143 209 255 224 150 164 240 280 260 185 187 274 330 297 240 219 323 375 350 300 257 372 430 404 APPENDIX 2 2 3 Table 2 Correction factors of overhead cables if the temperature differs from 25 C Environment Correction factor temperature C PV C insulation PEX amp EPR insulation 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 1 15 1 10 1 05 1 00 0 94 0 88 0 82 0 75 0 67 0 58 0 47 1 11 1 07 1 04 1 00 0 96 0 92 0 88 0 84 0 79 0 73 0 68 0 62 0 56 0 48 0 39 Table 3 Correction factor depending on surrou2. Microsoft Excel is a good software for most calculations This is why it is listed as an alternative for the dimensioning of electrical installations To make a complete calculation tool in Excel would probably take a very long time but a simple version can be made in just a few hours if you are a skilled Excel user There are simpler approximations to the formulas presented in the theory chapter chapter 2 which are significantly easier to work with in Excel than the ones mentioned above The question is whether the customer approves such approximations At least in MV calculations they won t measure up for the regulations Calculations in Microsoft Excel can be used especially for simple calculations in small plants Most computer users have Microsoft Excel installed on their computers and have some kind of knowledge of the program The biggest drawback with calculations in Excel is how to gather and present data about devices To make a database similar to the one in e g Febdok would take ages In practice it means that after calculations are done the user would have to go through numerous device datasheets to study device properties which is very time consuming To my employer this alternative might not be very attractive A more standardised way of documentation is preferred In extensive plants it would definitely not be user friendly 39 7 Benefits and drawbacks The main goal set by the employer was to find a calcula
3. installations 2 1 Types of distribution systems The dimensioning of distribution systems may at some points differ depending on the type of system in question The type of system depends on how live conductors and earthings are realized In AC systems there are one two or three phase conductors and usually one neutral conductor and a protective conductor The neutral conductor is also considered a live conductor Suomen S hk urakoitsijaliitto ry 1995 p 52 56 2 1 1 IT systems In an IT system no live parts are earthed directly Exposed conductive parts are connected directly to earth IT systems are commonly used as LV subsystems to increase reliability Suomen S hk urakoitsijaliitto ry 1995 p 56 L L Figure la IT AC system Figure 1b IT DC system 2 1 2 TN systems In a TN system one point is earthed directly and the exposed conductive parts are connected to this point with a protective earthing conductor or PEN conductor TN systems are the most common systems used in power distribution The TN system is divided into three different systems depending on neutral and protective earthing conductor mutual arrangements TN S has separate neutral and protective earthing conductors in the entire system In TN C S neutral and earthing conductors are combined in parts of the system In TN C neutral and earthing conductors are combined in the entire system Tiainen 2008a p 30 31 TN C i TN S TN C TN S F
4. Elektroteknik Vasa Inriktningsalternativ Elkraftsteknik Handledare Matts Nickull Titel Dimensionering av elanl ggningar Datum 7 feb 2011 Sidantal 45 Bilagor 3 Abstrakt Detta examensarbete r en unders kning av hber kningsprogram f r dimensionering av elanl ggningar Examensarbetet r gjort i samarbete med Vaasa Engineering Oy M let r att hj lpa uppdragsgivaren med att hitta ett ber kningsprogram som r l mpligt f r deras behov F rst behandlas den grundl ggande teorin g llande mnet En kort f rklaring av hur dessa program kan utnyttjas inom projektplanering l nkar teorin till praktisk anv ndning av ber kningsprogram Dessa program presenteras ur synvinkeln tillvagagangssatt f r ber kning av elanl ggningar Efter presentationen sammanfattas ber kningsprogrammen i en utv rdering av f r och nackdelar Resultatet r en rekommendation av vilket ber kningsprogram uppdragsgivaren borde anv nda f r dimensionering av elanl ggningar Examensarbetet avslutas med en kort sammanfattning samt diskussion Spr k engelska Nyckelord ber kningsprogram elanl ggning Vaasa Engineering Oy OPINN YTETY Tekij Mats Lindstedt Koulutusohjelma ja paikkakunta S hk tekniikka Vaasa Suuntautumisvaihtoehto S hk voimatekniikka Ohjaaja Matts Nickull Nimike S hk laitteistojen mitoitus P iv m r 7 helm 2011 Sivum r 45 Liitteet 3 Tiivistelm T m opinn ytety k sitt las
5. calculation result reports most softwares automatically compile tables of cables and device lists as well Once more the benefit of professional documentation of calculation results to provide the customers with is highly valued Two calculation softwares are chosen to be examined particularly thoroughly These are chosen since they meet the requirements at most points Two other alternatives for dimensioning electrical installations are also briefly discussed and presented however these are not examined any further nor are they considered in the final evaluation The presentation of the softwares is meant to give an idea of how they can be utilized in the dimensioning of electrical installations which is a significant part of project planning 18 4 ABB Doc 1 0 0 0009 Doc is a calculation software by ABB based on drawing single line diagrams Doc automatically dimensions cable cross section area protection devices and switching devices in low and medium voltage power plants The user can choose between light and professional profiles The profile is selected on program start up The main functionalities of ABB Doc are e Drawing single line diagrams and auxiliary circuits e Calculation of currents voltage drops and short circuits e Dimensioning cables and verifying cable protection e Dimensioning of switching and protection devices e Setting and coordination of protection devices e Calculation of over temperatures in switchboards e P
6. gt 0F1 4 HD4 UniMix R 24 0 E wel C M14 1s H OA sp 072 5203087 wi Ean HD4 UnMixR 24 0 on E wc33 gt FUZ3 DFAA 0096 104 162 IIN gt 0F41 5203C10 DDA203 gt 0F42 5204C10 C wW42 1E 3s i New De 1E 4kA 1E 3KA TELA 0 1kA IKA 10KA 100KA EKA 1ESKA G Relations 1 7 Protecti Protect Verification Status ES TE 0F24 WC24 OL Ib 13 114 lt ith 131A lt TAATA Jasaan mAN Ok C 0F24 Wc24 SC Fin m re edin OIN IL AOAN PE AI Ok D 0F24 WC24 NDT at Max tripping time 0 288IkA lt Ikmin L PE 1 415 kA Dk 7 0F25 WC25 OL Ib 1 64 lt Ith 2 04 lt EAN end 3 8 lt gt 145 268 Ok C 0F25 WC25 SC Protection guaranteed up to Ik LLL 4 1 kAJL IK L PE 4 1 kA Ok E 0F25 WC25 NDT at Max tipping time 0 035IkA lt Ikmin L PE daa Ok Y I 0F32 5 WC32 SC Protection guaranteed up to Ik LLL 2 0 kAl Ik LN 2 0IKA Ik L PE 2 0IkA Ok O 0F32 5 WC32 NDT at Max tipping time 0 630 KA lt Ikmin L PE 1 092IKkAJ Ok O 033 WC33 OL Ib 8 0jAD lt Ith 10 0J4 lt Iz 15 01AD and IF 16 014 lt 1 4512 21 84 Ok D FU33 WC33 SC Protection guaranteed up to Ik LLL 2 0 kAl Ik LN 2 0 kAD Ik L PE 2 0IkAJ Ok gt FU33 WC33 NDT I at Max tripping time 0 054 kA lt Ikmin L PE 0 137 k Ok D 0F41 5 WC42 NDT ld 0 030 4 lt Ikmin L PE 0 115IkA and Td 0 04fs lt Max fing tne 0401 Ok gt 0F42 5 WC42 OL Ib
7. on a perforated horisontal or vertical cable shelf 1 00 0 88 0 82 0 77 0 75 0 73 0 73 0 72 0 72 In one layer on a ladder on a support or on fasteners 1 00 0 87 0 82 0 80 0 80 0 79 0 79 0 78 0 78 APPENDIX 3 Generator technical specification PERFORMANCE DATA Main standard Rated power factor Insulation class Temperature rise Ambient temperature Altitude over sea level Cooling Protection Mounting arrangement Weight Inertia Direction of rotation Facing drive end Maximum overspeed Winding pitch Stator winding resistance Rotor winging resistance Ex Stator winding resistance Ex Rotor winding resistance IEC 34 40 C lt 1000 m ICOA1 IP23 IM 2105 IMB34 one bearing SAE flange coupling disc normal feet 125 kg with SAE 5 7 5 0 13 kgm C Two thirds 2 3 0 577 Q per phase at 20 C series star connection 0 796 Q at 20 C 11 30 Q at 20 C 0 172 Q at 20 C Total Harmonic Distortion THD lt 3 5 at no load operation or rated Linear balanced load Voltage regulation 1 Cooling Air 0 06 m3 sec Telephone Interference TIF lt 50 1800 rpm Frequenc Voltage series star 3ph 480 277 Voltage parallel star 3ph 240 138 220 230 240 254 240 254 266 277 A A Voltage parallel delta 3ph Rated continuous output Voltage series delta 3ph 138 Xd u 1998 1903 1768 149 2233 2088 2 000 1
8. protection devices can be viewed figure 14 In the box on the left the user can verify characteristics of the single objects Several circuit breakers can be chosen into the same time current graph so that selectivity can be verified In the relations box on the bottom of the window there is a list of the protection verified by doc The available curves are time current tripping characteristics specific let through energy and current limitation curves When protection relations are satisfied the state is OK and the color of the text is black If the protection relation is failed the text is red and the state is FAILED If adjustable protection devices are used e g device with microprocessor unit and some thermo magnetic type devices the user can adjust the settings of the device until the protection relation is satisfied The curves can be printed or attached to the single line diagram if desired 28 lt unnamed gt Curves a aloja ajalla 401215 pov Ms 77 C Objects a ILL reo ILN ME UPE LPELLL LetLL Heti Ite Peak gt QF1 2 CEF 24kV BA 44 A 7 9F1 3 HD4 UniMix R 24 0 E wc13 C TM13 3 122 200 va 423 A30 20 01 290V 508 SEN E 023 M5450320 24 2164000 ZAIDI E ae PLA MENIT 1005 fE 8 5 293001 230V 5050 QF25 Ms116 2 50 1081
9. should at least be able to calculate short circuit currents voltage drops and touch voltages and also to verify selectivity It is also important that the documentation of calculations is distinct and professional The pros and cons of some calculation softwares will be evaluated to help the employer decide which tool is most suitable for their needs This requires some thorough knowledge about the tools in question 3 My expectations of this assignment are primarily to learn how calculation tools can be utilized in the best possible way in project planning I also expect to learn more about how each component in electrical installations affects the characteristics of electricity 2 Theory The dimensioning of cables and over current protection devices is one of the most important things when planning electrical installations Load ability short circuit current and voltage drop are all affected by the conductor dimensions Conductor cross section areas and the over current protection devices must be chosen so that fault protection reguirements are met in any situation Other factors that should be considered are future extensions of the plant and economical aspects The economical aspects can be purchase and installation costs or loss and maintenance costs This chapter contains the fundamental theory of dimensioning electrical installations It includes explanations of the most vital properties and calculation procedures of electrical
10. that are protected with lt 31 A overload protection In circuits with gt 32 A the disconnection time is allowed to be lt 5 0 s Between switchboards the maximum disconnection time is also lt 5 0 s Tiainen 2008a p 164 2 3 3 Protection of cables A cable is protected against short circuit if the specific let through energy of the preceding protection device is lt the withstood energy of the cable equation 3 I lt k S 3 Pt is the specific let through energy of the protection device S is the cable cross section area k is a factor that depends on the cable insulating and conducting material Handbook EN pdf 2007 p 70 9 Short circuits must be cut at latest when the conductor reaches its highest allowed temperature In short circuits that last lt 5 s the time t can be calculated equation 4 in which the temperature of the conductor rises to its allowed maximum residue limit The conductor is assumed to be in its normal highest allowed temperature before the short circuit 1 k Sy 4 I t Duration in seconds A Cross section area I RMS short circuit current k In PVC insulated Cu conductors k 115 PVC insulated Al conductors k 74 Suomen S hk urakoitsijaliitto ry 1995 p 339 340 2 4 Calculation of impedances The impedance of transformers generators motors cables and the upstream network affect the short circuit current The impedance is divided into positive negative and zero seguence im
11. 10 000 components from different manufacturers in relation to ABB Doc which is limited to ABB products It also has a database over outdated components which can be useful when working on existing old circuits The device database provides a great advantage over the other programs I have looked into Febdok is however not able to calculate MV devices which is a definitive drawback It also feels a bit old although Febdok has been used in Norway for more than 15 years Several updates have naturally been made but still it doesn t feel particularly up to date 41 Bugs or errors were not found in Febdok which might be a result of many years of development However one thing that was noted was when a new connection node departure was used with 16 A fuses and from that connection node four other connection nodes were created to form a chain of e g socket outlets The load current of each socket outlet was set to 16 A the total current of the departure seen at the distribution board was 5x16 A or 80 A altogether In practice this is not possible since the departure fuse has a rated current of only 16 A This can be corrected easily by using the diversity factor i e if you have 5 socket outlets the diversity factor should be 0 2 Thus when using Febdok most components must be chosen manually and the electric loads in each switchboard should be observed so that the drawn plant corresponds to reality even if a calculation software is u
12. 6 23 MI CULL CUNT TIES e te T 2 3 1 Characteristics of short circuit CUITONtS ooooconnncccnoncccnoncccnnncnonnnnnononcnnnnnannnnnnno 7 2 3 2 Protection against contact voltage sseesserressrrssrrrsrrrsrrrerrrerrrrrrrrrrrrrrnrr rr rr rna 8 2 3 3 Protection OF cables smava s et diia atados 8 24 gt Calculator of impedances Se Sa 9 2 5 Calculation of short circuit currents sssusa Samaa a Tamm ss veneen 11 2 6 The short circuit power method ia dd dias 12 Zed Voltage drop A E a a Eea earen 14 2 07 SEIGCIVILY seiis hn a nahan E NRA R saa E sas ease 15 Calculation softwares utilized to 16 ABB DDG TO 00009 PS KSS SN acer e a A A eee N Tua 18 AAP lt ABB DIES UN as 18 Alo General POPE dis 19 A AN vsk sakan un ao daan e avenida aa kona miko dias Kukaan 21 41 35 ABB D c TOOIDAKS ost seg tu ding 21 42 Drawing in ABB DOC isamaa tsastva vasa rasa AAA na Masa aan 23 421 A A E ge leat 23 JII gt AUIITATISS aa mat Sune seas ss O ds SEA Ord NO TSn saada Te EDNA M sOas I ssa la saN 24 425 NM eta sak RR ee ee 25 43 Calculation module ato 25 AA Curves Module sorcer ort n a dali 27 AS Doc mentation Modulens iine SS 28 Febdok A O 30 Sar A A A A eT ee 30 22 A O E 32 5 2 1 Febdoktoolbariiiiia a Tdi 32 2 22 Transformer and UPS usina ira in 33 5 2 3 The sinele Ime diagtaM ss srusen e e eE EEE E 34 oe R D EVEIA TO N KERE DI EEEE eS 34 221 A a A N A a E m 35 2 2 2 Comments on Cana tada 36 53 4 Febdok Goc
13. 8 0 8 lt lth 10 014 lt I2 18 51AD and IF 14 514 lt 1 4512 26 8 AJ Ok LA TT 0F42 5 WC42 SC Protection guaranteed up to Ik LLL OAKA Ik LN 0 2IKA Ik LPE kal Dk v emoa Figure 14 ABB Doc curves module 4 5 Documentation module In the documentation module the user can choose what is to be included in the project documentation The single line diagrams are the only compulsory pages in the documentation Other pages that are desired by the user can be chosen by ticking its box On the right of the window figure 15 are the commands of the documentation manager With the compile layout command the heading and the layout of each page can be compiled The name of the project the customer the designer the descriptions and the dates etc are chosen with the compile layout command There is also a command to export reports into xls files if this format is preferred Project documentation manager I Project documentation 7 Calculation and dimensioning criteria 7 Short circuit calculation hypothesis JE Single line diagram E M Reports 7 Table of LV cables 7 List of MV devices JU List of LV devices 7 Report of MV circuit breakers Trip units 7 Report of LV circuit breakers 7 Short circuit calculation MV Report of protections Figure 15 ABB Doc documentation module 30 5 Febdok 5 0 42 Febdok is a software tool made for the dimensioning and docum
14. 92 Xd s 1729 1628 1494 1225 1957 1817 1728 1 642 Xq u 1 033 0 984 0 914 0 77 1155 1079 1 034 0 993 po Xy 0391 0373 0 346 0 292 0437 0409 0 392 0 376 po X s 0355 0339 0315 0265 o397 0372 0 356 0 342 0 265 0 241 23 kVA Rated efficienc 83 89 po Xu 0265 0 252 0 233 0194 0298 0 278 0 254 po Xs 0241 0229 0 212 0176 o271 0 253 0 241 0 231 po Xy 0192 0183 0 17 0143 0212 0198 0 189 0 182 po Xs S 0175 0166 0155 0 13 0192 018 0172 0 165 po Xiu 0109 0103 0 096 0081 0121 0113 0109 0 104 po As 0163 0156 0144 0122 0181 0169 0162 0155 A Xow 0027 0 026 0 024 0 02 0 03 0 028 0 027 0 026 Po pis 0 127 0121 0113 0 095 0 142 0133 0128 0122 SCR short circuit ratio ro Xd u 058 061 067 082 051 oss oss 0 61 s saturated value u unsaturated value values are p u at rated voltage and power Tdo Td 0 049 s 0 00049 s 0 0058 s CE Markin Generator fulfills the requirements of Low Voltage Directive 2006 95 EC X Generator supplied to EEA area will be CE marked n n Document identification Lang Rev ind Sheet ABD ABB Generators Ltd SAMG 5855421 en B TEMPLATE TECHNICALSPECIFICATION DOT FILENAME AMG 0180BB04 TECHNICAL SPEC DOC PRINTDATE 9 9 2010 9 59 00 AM SAVEDATE 9 9 2010 9 52 00 AM Figur 1 Generator technica
15. UNIVERSITY OF APPLIED SCIENCES Dimensioning of electrical installations Calculation softwares examined Mats Lindstedt Bachelor s thesis Electrical Engineering Vaasa 2011 BACHELOR S THESIS Author Mats Lindstedt Degree programme Electrical Engineering Specialization Electrical Power Engineering Supervisor Matts Nickull Title Dimensioning of electrical installations Date 7 Feb 2011 Number of pages 45 Appendices 3 Abstract This thesis is an examination of calculation softwares for the dimensioning of electrical installations The thesis is done in cooperation with Vaasa Engineering Oy The goal is to help the employer find a calculation software that is suitable for their needs First the fundamental theory concerning the subject is dealt with A short description of how the softwares are utilized in project planning links the theory to a practical usage of calculation softwares These are presented from the angle of plant calculation procedures After the presentation the calculation softwares are summarized in an evaluation of benefits and drawbacks The result is a recommendation of which calculation software the employer should use for dimensioning electrical installations The thesis is concluded with a short conclusion and discussion Language English Key words calculation software electrical installation Vaasa Engineering Oy EXAMENSARBETE Forfattare Mats Lindstedt Utbildningsprogram och ort
16. ages incorrect situation must be corrected before proceeding with calculation e Warning messages warn the user of possible errors but do not block the calculation Doc calculation and dimensioning results o Ikmax at all points of the diagram and Ikmin at the end of each line e Phase and neutral currents at all points of the diagram e Cosp on each busbar and line and active and reactive power required at the supply e Minimum cross sections of cables that satisfy thermal and voltage drop criteria e The most economical ABB protection and switching apparatus e Moving a single or two phase load from one phase to another to achieve a balanced load e Dimensioning of transformers and generators The user can modify the device selections made by Doc This is done by choosing the objects manually and locking them with the padlock symbol Choosing objects manually can be useful e g when one type of cable is already used at a point of the single line diagram and the user wishes to use the same type at another At the footer of the single line diagram figures 11 and 12 there is a table where the calculation and dimensioning results are shown figure 13 This way of presenting the results is very distinct and the user gets a very good overview of the calculation results for each single departure N N T Figure 13 ABB Doc calculation results 4 4 Curves module In the curves module the characteristics of
17. ance Z R jX 8 Zero sequence impedance Z R 3 R j X 3 X 9 x Stator resistance Risa 2 T f A T 10 T is the stator time constant Asynchronous three phase motors contribute to the short circuit current for 5 6 periods i e 100 120 ms in 50 Hz frequency The positive and negative sequence impedances of a motor can be considered equal The zero sequence Zom impedance should be given by the manufacturer If the motor is not earthed Zom is infinite Positive and negative sequence impedances are calculated as in equation 11 Zi Z Zu Ry JX y 11 2 Ly a 12 Lir S I I r is the current while the rotor is blocked Cable impedances limit the short circuit current Positive and negative seguence impedances can be set egual eguation 13 11 Z Z Z R jX 13 The zero sequence impedance varies depending on the return path of the fault current L to N Z Ze j3 Zye Rc 3 Ryc Xe 3 X ne 14 L to PE TN S Z 2 LR RICA ag OS L to ground TT Z Zo J Re 3 RENA ASA 16 The upstream network is the distribution net e g MV The zero sequence impedance is not considered since the primary winding is generally delta connected U Network impedance Z Z Zy 17 V3 1 Handbook_EN pdf 2007 p 228 230 2 5 Calculation of short circuit currents When calculating maximum short circuit currents Ikmax all elements contributing to the SC current mus
18. ation softwares e g ABB Doc Many of these resemble each other significantly and therefore they are not all presented The other alternatives are not included in the evaluation of the benefits and drawbacks chapter 7 6 1 My Ecodial L My Ecodial L is a calculation software by Schneider electric It is quite similar to both ABB Doc and Febdok Even though it hasn t been examined any further a quick tour has been studied and the impression indicates that My Ecodial L is very user friendly The software is free and can be obtained from Schneider on reguest The diagrams are drawn with ready macros by drag and drop The macros resemble the ones in ABB Doc Although it doesn t have as much functionalities as Doc it seems a bit easier to use My Ecodial L is not able to calculate MV protection devices nor UPS systems Electrical installation amp energy efficiency 2010 online 38 Since My Ecodial L hasn t been looked into thoroughly any detailed evaluation cannot be made But it is considered to be one good alternative among numerous others The reason why 1t has not been studied any further is because it is a component manufacturer calculation tool such as ABB Doc Doc is more complete and therefore it is a better alternative for the employer My Ecodial L should however be kept in mind maybe not as the only calculation tool but perhaps as an alternative for those who are interested 6 2 Calculations in Microsoft Excel
19. bars In the LV macro toolbars the most common symbols for rapid and easy drawing are found At professional profile the free drawing toolbar is available for customized drawing All LV 22 macro toolbars and MV macro toolbars are also available The user can choose what toolbars should be visible by clicking Toolbars in the View menu In the following screenshot all available toolbars are visible DOC lt unnamed gt ajaja File Edit Objects MVObjects Tools View Help BSas HMABBNI PP 9593 88 ABH edamaqeaea an B0 880 1140 CSF Hee TY 1 14008 MHT fo np wr 1 5 Command lt _zoomwhee1 gt aaa E a SIN EIT IT TRI all EEEa rs m f a UR 4 4 sila UA E IIA HRES ME RTI M L las ME lol e Ready 145 73 161 18 SNAP GRID 14 48 Figure 10 ABB Doc LV columns layout On the right in figure 10 there are some symbols where the user can switch between the following modules Drawing the MV network Drawing the LV network Curve verification and drawing 88 Calculating and dimensioning Drawing of auxiliaries K ig Documentation 23 4 2 Drawing in ABB Doc Drawing in ABB Doc is rapid and simple especially by using the macros The macros consist of e g a protection device or disconnector cable and load There are different macros to choose between depending on the protection device and load in question At light profile using the macros is the on
20. can select which installation material should be available e g certain manufacturers In the utility menu the user can set the information about the network company System Setup E Cable types Protective devices Earthing system Calculating From IT TN C 5 Origin of installation f z 400 Utility G Distribution board System voltage v N CTT C TNS Point of delivery Freguency Hz 150 CDC C Transformer Voltage drop Warninglevel for total 4 Warninglevel For distr boards 2 3 7 Use sum of load currents Figure 16 Febdok system setup Installation menu When setting the installation data the user is supposed to set the data to correspond to the most common plants that are going to be dimensioned further on This data can however be set just as easily when a new installation is created Use sum of load currents should only be chosen if the user has full control of the simultaneously used loads on the departures from one switchboard Otherwise Febdok calculates voltage drops on the basis of the main cable load In the application menu the user is recommended to tick the box default prefix for circuit Id s if certain circuit Id systems are followed This makes it faster to name the Id s of each departure 32 5 2 Drawing in Febdok When a new installation is created the installation information window appears Febdok will suggest the standard settings for the installation Th
21. choose some devices manually Too high a voltage drop is indicated by a warning message There seems to be some bugs in ABB Doc though since it crashed a few times during the work Especially when trying to make changes upstream in the diagram problems may occur Some problems that occurred were solved by redrawing in a different way But for some problems it was very difficult to figure out the reasons If the user can manage by only using the macros problems will seldom occur In general ABB Doc is a very useful tool It has a lot of functionalities and setup possibilities It is very rapid to use once it has been learned A problem with Doc is that its device database 40 covers only ABB devices This might seem quite obvious but it is a problem for the employer who is using components from several different manufacturers ABB Doc benefits e Rapidtouse e Complete and professional looking single line diagram e Thecurves module is good e MV calculations and devices ABB Doc drawbacks e NoDC calculations e Some bugs e Limited to ABB components 7 2 Febdok benefits and drawbacks Febdok is a calculation software which is easy to use and very fast to learn It is a versatile and distinct tool when it comes to dimensioning electric circuits The ability to calculate DC circuits is useful for the employer since many circuit breakers and disconnectors are controlled by DC motors Febdok has a huge database with more than
22. computer softwares potrero power absorbed by the loads and relevant position definition of the Laa of the aot distribution centers switchboards definition of the paths and calculation of the length of the connection definition of the total power absorbed taking into account the utilization factors and demand factors pens of transformers and generators with margin connected to future predictable power supply requirements by approximation from 15 30 Dimensioning of conductors evaluation of the current Ip in the single connection elements definition of the e conductor type Conductors an insulation materials configuration definition s the cross section and of the current carrying capacity calculation of the voltage drop at current under ic reference conditions motor starting Verification of the voltage drop limits at the final loads negative outcome Short circuit current calculation maximum values at the busbars beginning of line and minimum values at the end of line Selection of protective circuit breakers with ark kina all lye et i rated current I not lower than the load curren ca oros wats Via brow ot footer ft kt jota cacas Je the protection of conductors cn of he pain api oct le dat haa Give of the circuit breaker shall be higher than the load current but lower than the iron shs OE T E the specific let through energy negative by the circuit breaker under short cir
23. cuit conditions shall be lower than the specific some EE NRE ARS AEN ae IIN OON verification of the protection against indirect contacts depending on the distribution system Verification of the coordination with other equipments discrimination and negative back up verification of the coordination with switch disconnectors outcome Definition of the components auxiliary circuits terminals and switchboard Figure 6 Dimensioning procedure Handbook_EN pdf 2007 p 24 17 Figure gives a very good overview of how electrical dimensioning is systematically carried out The calculations softwares that are examined are based on drawing a single line diagram Therefore calculations can be done as the single line diagram takes form nevertheless the approach is generally very much the same The primary reason for why calculation softwares should be utilized in dimensioning electrical installations is to save time Moreover calculations are tiresome to repeat every time a new plant is to be dimensioned The risk of incorrect dimensioning is also reduced since the user only has to set the data of the plant electrical loads together with general installation information Calculations are entirely done by the computer software based on these settings Calculation softwares also contain ready made databases over components which is useful since summarizing the detailed data necessary would be hard work In addition to
24. d v aa 4 Calculations according to standard method tec 60909 1 v LV section parameters 400 v M LLLN gt tt v 50 Hz Cable dimensioning according to standard ces 64 8 v Plant loads Temperature P kW A Ambient for overtemperature in enclosures 30 fc Q kvar cosip Used for derating of electrical devices 40 Fe eE Protection of people In LLLN circuits choose circuit breakers with 4P v Max contact voltage 509 M In LN circuits choose circuit breakers with 1P4N v Max tripping time jo4 Is MCB s for Industrial use IEC 60947 2 Rt fi 62 A Choose automatically Miniature CB for Ib up to 63 A IV Neutral section 50 of Phase when allowed by standards Moulded case CB for lb up to 200 18 Close options lt lt lt Choose layout Figure 8 ABB Doc plant general properties In the LV supply the only parameter reguired is the three phase short circuit current at the supply point This short circuit current should be informed by the distribution company or plant holder If either the three phase fault impedance or short circuit apparent power is known the short circuit current can be calculated by clicking the calculator button The MV LV trafo is used for representing the LV side in medium or large plants The parameters needed in this supply are the rated apparent power short circuit voltage and the numb
25. entation of electrical installations Febdok is developed by Norwegian Nelfo and has been used in Norway for more than 15 years The functionalities of Febdok are e Calculation of short circuit and fault currents e Calculations of touch voltages and voltage drops e Dimensioning of cables busbars and protection devices e Verification of selectivity and protection device check up e Documentation of electrical installations Nelfo Foreningen for EL og IT Bedriftene Febdok is available in Norwegian Swedish Danish Finnish and UK versions The difference between the versions is e g the program language cable markings and possible calculation differences In this chapter a demo of the Finnish version is looked into The demo is downloaded from S hk info fi and works on one computer for 45 days All properties except documentation are available in the demo version 5 1 Febdok setup When Febdok is started and the user has logged in a window that contains information about licence and software version is shown Further licence information is found in the licence menu In the System setup menu figure 16 the user can set the standard settings for installations Febdok will now use these settings every time the user creates a new installation The system setup window includes installation application cable types protection devices utility and users access rights menus 31 In the cable types and protection devices menus the user
26. er description The diagram 1s drawn by clicking the symbols in the toolbar When a new device is added to the diagram a setup window for the departure appears 5 Installation Network Documentsfreports Register Setup Windows Help oro AOR D AO D Ess N Aa m Figure 17 Febdok toolbar 33 The departures to choose between when drawing the diagram are listed below When new departures are created the parameters for devices included in the active departure must be set Departure settings are e g load cable and protection device properties method of installation additional protection or other additional devices New distribution board 11 New grouping ja New branching node f New connection node O New motor ja New variable load O New fixed load Y New distributed load street light circuit N New control circuit 7 New spare circuit 5 2 2 Transformer and UPS When a new departure is created the user can choose to add a transformer or UPS to the departure Transformers can be used in the departures to change the voltage level eliminate upstream disturbances or for electric insulation The UPS uninterruptable power supply is used in places where the electricity must be maintained even when the network voltage is interrupted Figure 18 Transformer and UPS symbols 34 5 2 3 The single line diagram The diagram is drawn by selecting a switchboard or grouping and adding the departures from the toolbar The single
27. er of transformers The MV supply is used to represent also the MV side of a transformer when you want Doc to select MV devices The parameters needed are the rated voltage short circuit current the state 21 of neutral and the ground fault current at the point of delivery Short circuit currents are calculated in the same way as in the LV supply The ground fault current can be calculated if the capacity to ground or the Petersen coil parameters are known Other parameters that can be selected are e g the type of AC system frequency 50 Hz or 60 Hz parameters that affect protection of people calculation standard method etc 4 1 2 Selecting layout When the general plant properties are defined the next window that appears is the layout selection This doesn t affect the calculation results in any way In light profile the only alternative is LV columns The layout can be changed during an ongoing Doc project In professional profile the user can choose between e MV columns recommended for drawing MV compartment diagrams e LV columns recommended for drawing LV plants e Free recommended for customized and or special diagrams on A2 Al AO formats Layout selection E Layout selection Layout selection Choose layout MV columns Choose layout LV columns Figure 9 Available layouts in ABB Doc 4 1 3 ABB Doc Toolbars At light profile the available toolbars are LV macro toolbars and auxiliary tool
28. ese settings are the ones that have been set in the system setup window figure 16 The parameters must be set to correspond to the electrical installation as it will be realized Febdok can dimension the installation based on any point where the short circuit currents are known If there is one point with known SC currents calculate from origin of installation distribution board supply point should be chosen However if the installation is to be calculated from a transformer calculate from transformer is chosen The SC currents at the transformer will now be calculated based on the transformer data Multiple transformers can also be chosen The first distribution board is adjacent to the point calculate from In this menu the type of distribution system phases mutual arrangement etc are set It should be noted that this is the data at the first distribution board Selections made at this point may limit the alternatives in possible sub switchboards further on in the installation There is also a load data box in this menu but the load data doesn t have to be set at this point It is more practical to return to this menu when each single load has been determined When one or a few departures are being added to an existing plant the first distribution board load can be set based on e g the main fuses rated currents 5 2 1 Febdok toolbar The toolbar figure 17 is very distinct and does not need any furth
29. f 2007 p 232 2 6 The short circuit power method The short circuit current can also be calculated by using the short circuit power method This method gives an approximate short circuit current in a simple way The result is generally within acceptable accuracy First the short circuit power Sy for all the elements included in the installation must be determined Network short circuit power Sknet or short circuit current Ircnet is generally given by the distribution company at the supply point e g at a transformer If not reference values Table 2 can be used Table 2 Reference values for Network short circuit power Handbook EN pdf 2007 p 212 Net voltage Short circuit power Un kV Sknet MVA lt 20 500 lt 32 750 lt 63 1000 13 Generator short circuit power Sig contributes to Ik Sig can be calculated if the generator reactance Xq is known appendix 3 Xa is generally given in percent of generator impedance Za and can either be subtransient transient or synchronous reactance depending on in which instant Sx is to be calculated Subtransient reactance is usually used in calculations being the worst case scenario The short circuit power of a transformer limits Ix Cables also limit the short circuit current Cable short circuit power can be calculated according to a good approximation ee S 6 100 Generator short circuit power Sic e 22 X d Motor short circuit power S
30. g The result of the thesis work is my opinion about which calculation software can be utilized best in project planning for my employer The goal has been reached based on my results my employer will be able to choose a good software for their needs 9 2 Discussion An examination like this can be done in many ways I chose to deepen myself into the softwares that seemed most interesting Another way would have been to look into a greater number but that would have been done more superficially My opinion is that the result is more credible with more thorough studies If I should do a similar examination again I would spend much more time planning the approach I think I would have saved a lot of time by making up a schedule at the beginning and trying to stick to it Another thing that I would do is spend more time on the theory before even beginning to examine calculation softwares However the result was achieved and I believe I have got a good view of how calculation softwares should be utilized in the best possible way I could still test the softwares in more extensive plants and compare results and the time consumed to get an even better foundation to base the results on I would also consider including several softwares in the final evaluation 45 List of sources DOC_EN pdf ABB Doc Help User manual release 1 0 0 007 Electrical installation amp energy efficiency Electrical engineering community 2010 Best e
31. he conclusion of this is that seen from the device diversity point of view Febdok is more versatile This is the biggest advantage over ABB Doc which is limited to only ABB devices 43 The verification of selectivity is done in similar ways in both programs but it is more distinct in Febdok whereas the curves module used for the verification of selectivity in ABB Doc is more versatile The content of the documentation is very similar in the two softwares The single line diagram looks more professional in ABB Doc When the properties of both programs were summed up I reached the conclusion that the calculation software I am going to recommend to my employer is Febdok The reason why 1 chose this software is that it is very user friendly and still versatile It is very easy to learn and I believe that the project engineers will find it useful in the dimensioning of electrical installations The great device database is also one of the main arguments that I have based my decision on Additionally Febdok is the only calculation software I have looked into that meets all the basic reguirements which after all does have great importance for the final result of my thesis work The current version of Febdok is 5 0 42 and possible software and device updates are included in the user license 9 Conclusion and discussion 9 1 Conclusion When I was first given the assignment I had a good idea about how the assignment should be carried out I bega
32. ical appliances are used When it is not likely that several appliances are used simultaneously the load can be based on the highest probable load Tiainen 2008a p 141 2 3 Short circuit currents A short circuit is a fault of negligible impedance between conductors having a difference in potential Handbook_EN pdf 2007 p 209 In electrical installations the prospective short circuit current must either be measured or calculated to guarantee disconnection in case of short circuit In short circuit situations the current must be cut very fast to prevent overheating and to secure safety for humans and animals Components must also be able to withstand and disconnect very high SC currents High SC currents appear especially in circuits with generators and motors SC currents are naturally also very high close to distribution transformers Short circuit protection is often combined with overload protection Suomen S hk urakoitsijaliitto ry 1995 p 338 339 2 3 1 Characteristics of short circuit currents The characteristics of short circuit currents can be divided into far from generator and close to generator short circuit Far from generator the initial symmetrical SC current 7 has a constant amplitude and is therefore equal to the steady state SC current Close to generator I is decaying Far from generators the three phase SC current is the highest of the short circuit currents In close to generator short circuits
33. igure 2a TN AC system Figure 2b TN DC system 2 1 3 TT systems In a TT system one point is earthed directly Exposed conductive parts are connected to separate electrically independent earth electrodes The TT system is generally not used in distribution TT systems are used in special cases such as secondary windings of voltage transformers Suomen S hk urakoitsijaliitto ry 1995 p 56 Figure 3a TT AC system Figure 3b TT DC system 22 Conductor current carrying capacity Electric currents heat the conductor it flows through because of power losses due to electric resistivity in the conductor The heat is transferred from the conductor to the surroundings through its insulation and protective layers Since the cable has a certain heat resistivity the temperature of the conductor rises until it reaches the point where the transferred heat corresponds to the heat losses in the cable Larger cross section area of the conductor reduces electric resistivity and thus the power loss is reduced Suomen S hk urakoitsijaliitto ry 1995 p 293 That is cross section area and cable construction have great impact on the current carrying capacity Other factors that affect the current carrying capacity are the method of installation ambient temperature other nearby cables air circulation and heat resistivity of the surrounding soil in earth cables Reference methods of installation are found in appendix 1 Conductor current carrying capaci
34. im 3 U Ag 123 er 100 Transformer short circuit power Si Sur 24 U U 2 Cable short circuit power approximation S a 25 C Short circuit power at the fault point can now be calculated by using equation 26 or 27 Elements in series S 26 Elements in parallel S Sic Sim Siz Sic 27 The short circuit current is calculated as in formula 28 or 29 3 phase short circuit current 28 J3 U 2 phase short circuit current sh 29 n Handbook EN pdf 2007 p 211 220 14 2 7 Voltage drop By voltage drop is meant how much the voltage at the consumption point differs from the rated voltage at the supply point In LV installations the voltage drop is recommended to be no more than 4 of the rated voltage at the supply point if no other requirements are set SES 6000 5 52 525 Higher voltage drops are allowed in circuits that contain electric motors or other devices with high inrush currents The voltage drop can be calculated by using equations 30 32 In DC circuits AU 12 r 1 30 In 1 phase AC circuits AU 1 2 1 r cosptx sin 9 31 In 3 phase AC circuits AU I l J3 r cosgtx sing 32 When the load is inductive the is when capacitive it is Voltage drop in Au i 100 33 n AU isthe voltage drop in volts I is the load current in amperes l is the length of the cable r is the self resistance in ohms meter x is the self reactance i
35. ject components design and engineering procurement and supply project management installation start up commissioning and user training to customers worldwide VEO also offer plant modernizations maintenance system updates and switchgears They develop and manufacture all of their core products in house As well as their own products VEO also deliver components from leading manufacturers throughout the entire energy field This helps them to remain at the leading edge of development and to offer optimum preferred solutions to their customers www veo f1 1 2 Goal and expectations Dimensioning electrical installations can sometimes be tough and time consuming especially in extensive installations that may include several motors transformers or generators Those who plan electrical installations must also be able to provide their customers with professional documentation My employer operates in the power generation distribution and industrial fields The electric installations in these kinds of plants are usually very extensive This makes calculations very challenging Particular effort is put on reliability since operation interruptions may become very expensive This is why the employer has given me the assignment to look into some software tools that will help the project engineers with the calculation of electrical installations The goal is to find a software tool that is user friendly rapid to use and versatile The program
36. kentaohjelmistoja s hk laitteistojen mitoitusta varten Opinn ytety on tehty ytheisty ss Vaasa Engineering Oy n kanssa Tavoitteena on auttaa teht v n toimeksiantajaa heille sopivan laskentaohjelmiston l yt misess Ensiksi on k sitelty aiheeseen liittyv perusteoria Lyhyt selitys siit miten ohjelmistoja voi k ytt projektisuunnittelussa sitoo teorian k yt nn lliseen laskentaohjelmistojen k ytt n N m ovat esitetty laitteistojen laskentamenettelytavan n k kulmasta Ohjelmistojen esittelyn j lkeen niist on yhteenveto etujen ja haittapuolien arvioinnin yhteydess Tulos on suositus siit mit laskentaohjelmistoa toimeksiantajan tulisi k ytt s hk laitteistojen mitoitukseen Opinn ytety n p tt lyhyt yhteenveto ja keskustelu Kieli englanti Avainsanat laskentaohjelmisto s hk laitteisto Vaasa Engineering Oy Table of contents 1 Intro dC ido 1 2 10 Vaasa Engineering OY Lataa tiiit a Taa t ostava Taskut sas ae guts haan alae imua 2 22 GOal ANd expectations iisen een satasta vana aa Lene KNN n naa aavan oe pa aukeaa Senan 2 MIPS OT ys sri seas stage Sansa s ty NA SS SR dere NR AAA SARS NG 3 2 1 Types of distribution EMS tl idas 3 al MESS E 4 2 12 TN SSS Samaa alan ahon nee n ld as 4 24 3 TT SYstems o 5 2 2 Conductor current carrying Capacity ceeseccesscecsencecseeeecesececseececeeececseeeeeneeeeesaes 5 221 a E 6 222 Overload PEO ass A ea eae de wise a ee
37. king the padlock symbol Now Doc won t choose the devices automatically but the calculations show if they meet the reguirements 4 2 2 Auxiliaries Auxiliary circuits can also be drawn with Doc Drawing the auxiliaries is only possible as free drawing figure 9 1 e there are no available macros in the drawing of auxiliaries mode The auxiliary circuits are only drawn to get a more complete diagram for documentation and do not affect the calculation results 25 4 2 3 MV diagram The screenshot figure 12 is an example of a MV switchgear with a measurement unit two transformers and two departures The LV departure from the transformer is cross referenced to another page The green color of the lines indicates that the diagram is calculated and dimensioned correctly Figure 12 ABB Doc MV diagram 4 3 Calculation module Calculation is done when the single line diagram is drawn and the data of the objects have been defined The user can modify the calculation procedure if desired However the Doc preset calculation procedure covers most common plants By using the options command in the tools menu the user can select Show calculation settings before dimensioning to view or modify the calculation parameters DOC EN pdf p 48 26 During the calculation process a window that shows the progress of the calculation is visible There are two types of error messages that may appear during the calculation e Blocking mess
38. l specification http www05 abb com global scot scot234 nsf veritydisplay 591668c948a8fca2482576f5002cf66e file amg 2 00180bb04 20technical 20spec pdf
39. lectrical calculation software review Online Read 25 01 2011 http engineering electrical equipment org electrical software best electrical calculation software review html Finlands standardiseringsf rbund 2008 02 SFS Handbok 600 sv L gsp nningselinstallationer och s kerheten vid elarbeten Handbook EN pdf ABB Doc Help Electrical installation handbook Volume 2 Electrical devices 5 edition March 2007 Bergamo ABB SACE International electrotechnical commission 2001 IEC 60909 Short circuit currents in three phase AC systems Part 0 Calculation of currents Nelfo Foreningen for EL og IT Bedriftene Febdok Hovedside Online Read 30 11 2010 http nelfo no viewPage aspx mid 93 Suomen s hk urakoitsijaliitto ry 1995 S hk asennukset 1 Espoo Suomen s hk urakoitsijaliitto ry Tiainen E 2008a S hk asennukset 1 Espoo S hk info Oy Tiainen E 2008b Febdok helpottaa s hk verkon mitoitusta S hk info 2 2008 Online Read 04 02 2011 http www sahkoinfo fi Download aspx id 2150 amp type 1 Vaasa Engineering Oy Company presentation Online Read 29 01 2011 http www veo fi In English Company presentation APPENDIX 1 12 Reference methods of installation Reference method of installation A Isolated conductors in an installation pipe mounted in insulated wall Multi core cable mounted in insulated wall Isolated conductors in an installation pi
40. line diagram is desired every device might be wanted in the diagram This is a problem with Febdok The drawing process becomes very clumsy and the documentation does not look good However if the maximum load decreases along the circuit or the user wishes to decrease the conductor cross section area the new connection node departure can be utilized This makes it possible to choose a new cable after each termination point e g junction boxes or socket outlets With this type of departure a diversity factor should be used 37 5 4 Febdok documentation Since only the demo version of Febdok has been accessible the documentation procedure couldn t be looked into any further However a ready project documentation done in Febdok has been studied What should be mentioned about the result of the calculations is that the documentation is very distinct and everything is presented in a logical way The only thing that wasn t impressive at all was the looks of the single line diagram The documentation includes a cover address information supply point data a single line diagram a list of devices a table of cables reports of fault currents and fault messages calculation results and a discrimination analysis 6 Other alternatives In this chapter alternatives for dimensioning electric circuits are briefly presented Beyond the ones mentioned here there are numerous other alternatives Some component manufacturers have their own calcul
41. line diagram takes form as new departures are added The drawing cannot be manually customized in any way The layout is shown in the screenshot below figure 19 Some notes have been made in it to describe the symbols Distribution boards are shown in the main window Departures from the active switchboard are shown in the window on the right FEBDOK Installation Febdok1 SystemTN C S SFS 600 2007 EE 43 Installation Network Documentsfreports Register Setup Windows Help ax ORD ADR Oo oR amp of L tr de 6 5 bares Q Q sr Hm a Active distr board DB_1 bd EH lt V Live conductor Temperature in ro distribution board C EN 001 50 m MCMK S256 1 KW Inst met 04 BAL wma tt K JENE mst mein Ae zom mussa jan mia Ex 2 ee han EES BES amp O Upstream network and first distribution board Variable load departure e Om MK90 3x1 5 5 inst meth E 2 Distribution board Variable load departure QD cig 3 Distribution board 63A fuse grouping G RCD grouping 6 Grouping departure 25A MCB 30mA RCD Fixed load departure lighting Motor departure 86060609 Control circuit departure ES v Press F1 for help Figure 19 Febdok layout 5 3 Calculation results Information about cable current carrying capacity voltage drops and power losses is shown in the cable menu Current carrying capacitie
42. ly way to draw the single line diagram At professional profile the user can either use the macros or choose loads and protection devices more freely Loads can also be more customized at professional profile 4 2 1 LV diagram The screenshot displays a LV single line diagram drawn at light profile The yellow color of the lines and symbols indicates that the diagram has not yet been calculated On the left is the supply point chosen by the user in this case LV supply Fal MCB WITH SC PROTECTION OL PROTECTION AND RCD DISCONNECTOR gt INCOMING MCB WITH SC PROTECTION AND OL PROTECTION SUB SWITCHBOARD Figure 11 ABB Doc LV diagram 24 The incoming disconnector Figure 11 feeds a switchboard The switchboard feeds a sub switchboard a motor and a board sublevel The sub switchboard feeder is cross referenced and the sub switchboard can be drawn on a new page The board sublevel is used when it is desirable to protect several departures by e g one RCD By double clicking the load symbol the user can configure the parameters of the load The cable dimensions and the characteristics of the protection device should now be chosen automatically by Doc However if some devices or cables are preferred to be chosen manually it can be done by double clicking the symbol and the parameters of the device can be chosen If the user wants to choose devices manually the parameters can be locked by clic
43. maximum SC currents at the beginning and end of the line and the minimum SC current at the last point of the circuit The screenshot figure 21 displays a single phase load In three phase load departures maximum and minimum three and two phase SC currents are also displayed in this window 36 Aside from the short circuit currents Febdok calculates for how long cables can withstand the short circuit currents and verifies however the protection device disconnection times are fast enough The Let through energy and breaking capacity of each PD are verified by Febdok as well PD data 4 fr Fault current seen by PD k r Disconnecting times s gt PD ka52 12 Ref designation Breaker class Manufacturer Breaker Unit Nominal current 4 Tripping class Iscip max TrippingUnit Isc1p max end Isc1p min Breaking capacity ka EM pics Max length for electromagnetic release m Cable current carrying capacity BERS a a N Click in the Fields above to see the Fault locations Figure 21 Febdok I t menu 5 3 2 Comments on the calculations When drawing e g socket outlet departures it is no use drawing any other than the one at the end of the circuit since the maximum short circuit current always appears in the beginning of the conductor This is where the voltage drop and minimum short circuit currents are least favourable On the other hand if a complete single
44. n by searching the internet for different alternatives in order to get a view over the product range on the market When I had made up my mind about what softwares 1 wanted to study further I sent guestions and reguests to the suppliers in order to acguire further information At this point I still hadn t made up my mind about how to present the softwares in my thesis One thing that was very clear to me from the beginning was how to present the theory behind calculation procedures The basics were found without problem in electrical installation handbooks and the SFS 600 handbook Calculation procedures of short circuit currents took me many hours I studied extensive IEC regulations in order to sort out the calculations that are relevant for my assignment The calculation of impedances was the most time consuming 44 operation However once this was sorted out it was easy to see the big picture and then the calculation procedure became very clear to me The presentation of calculation softwares was finally written parallel to the testing I chose to present the softwares by systematically going through how calculation results are approached I found this a good way of giving the reader an idea of how the calculation softwares are used During this stage I also formed my opinion about the benefits and drawbacks I had to try to keep the presentations short and focus on the essentials otherwise the thesis could easily have become too lon
45. n ohms meter Un is the rated voltage 0 is the phase angle between the voltage and the current in degrees Au is the proportional voltage drop in Tiainen 2008a p 167 168 15 2 8 Selectivity Selectivity means that protection devices only work in that part of the circuit where they are supposed to work in case of overload or short circuit This is generally the last protection device preceding the point where a fault occurs Selectivity can be verified by studying the characteristics of protection devices Selectivity may in some cases lead to unreasonable over dimensioning and is therefore not always necessary Tiainen 2008a p 166 N N 4 N N CTT VR t N B HS MAIN Figure 5 Low voltage selectivity with ABB circuit breakers QT1_EN pdf 2008 p 5 Figure 5 presents the characteristics of two protection devices The red curve represents the characteristics of the protection device closest to the fault point circuit breaker B In this example selectivity is accomplished 16 3 Calculation softwares utilized The theory dealt with in chapter 2 is the foundation for electrical dimensioning This chapter briefly describes the dimensioning procedure and why calculation softwares should be utilized in the process The flow chart figure 6 is a suggestion of how the dimensioning of electrical installations should be approached with or without help from
46. nding ground temperature Ground Correction factor temperature C PVC insulation PEX amp EPR insulation 0 1 13 1 10 5 1 09 1 06 10 1 05 1 03 15 1 00 1 00 20 0 95 0 96 25 0 90 0 93 30 0 85 0 89 Table 4 Correction factors concerning ground heat resistivity Heat resistivity K m W 0 7 1 0 1 2 1 5 2 0 2 5 3 0 Correction factor 1 10 1 00 0 92 0 85 0 75 0 69 0 63 Table 5 Ground heat resistivity values Ground type Heat resistivity K m W Dry sand 0 humidity Dry gravel or mud Semi dry gravel svamp mud an humidity Semi dry mud and humid gravel d sand 10 Humid mud and sand 25 humidity 3 0 1 5 1 2 1 0 0 7 APPENDIX 2 3 3 Table 6 Correction factors concerning other nearby cables or current circuits Placement cables are touching Number of current circuits or multi conductor cables 2 3 4 5 6 7 8 9 12 16 20 Bundle in air on a surface immersed or inside a case 1 00 0 80 0 70 0 65 0 60 0 57 0 54 0 52 0 50 0 45 0 41 0 38 In one layer on the wall on the floor or on a non perforated cable shelf 1 00 0 85 0 79 0 75 0 73 0 72 0 72 0 71 0 71 In one layer attached directly under a wooden ceiling 0 95 0 85 0 72 0 68 0 66 0 64 0 63 0 62 0 61 In one layer
47. pe mounted in installation strip Suomen S hk urakoitsijaliitto ry 1995 p 314 A ON la Vd AN Figure 1 Method of installation A Handbook EN pdf 2007 p 27 30 Reference method of installation C Multi core cable fixed to the wall Single core cables fixed to the wall Multi core cable in stone constructions Single or multi core cables mounted in an open or ventilated channel Multi core cables in channels or installation pipes in an open space or in contact with a brick wall the values should be multiplied by 0 8 Suomen S hk urakoitsijaliitto ry 1995 p 315 Figure 2 Method of installation C Handbook EN pdf 2007 p 27 30 APPENDIX 1 2 2 Reference method of installation D Multi core cables in channels placed in the ground Single core cables in channels placed in the ground Single or multi core cables mounted directly in the ground The current carrying capacity table table 1 is based on a ground heat resistivity value of 1 0 k m W and an installation depth of 0 7 m Suomen S hk urakoitsijaliitto ry 1995 p 315 Figure 3 Method of installation D Handbook EN pdf 2007 p 27 30 Reference method of installation E Multi core cables in overhead installation Free distance from wall at least 0 3 times the diameter of the cable Suomen S hk urakoitsijaliitto ry 1995 p 315 Reference method of installation F Single core cable in overhead installation
48. pedance These impedances must be determined in order to be able to calculate the short circuit current The transformer impedance can generally be considered to consist of positive and negative seguence impedance In some cases it may include zero seguence impedance but can generally be neglected Transformer winding impedance limits the short circuit current 2 Transformer impedance Ly al lc 5 100 S Synchronous generators contribute to the short circuit current To calculate generator impedances some approximations must be made The positive sequence reactance Xa can be assumed to consist only of the sub transient reactance Xg Negative sequence reactance X varies between X and X In case that X and X differ much the average value between these two reactances can be used If not the negative seguence can be approximated to take 10 the same value as X The zero sequence reactance X varies between a value of 0 1 0 7 times the positive or negative seguence reactance e 2 Zero sequence reactance X o Yn 6 100 S Xo is a parameter of the generator appendix 3 Other parameters to include in calculations are grounding resistance and reactances Rg and Xe If the generator star point is not connected to the ground the grounding impedance is considered infinite Generator impedances can be calculated as follows Positive sequence impedance ZA 7 Negative sequence imped
49. rinting the project documentation DOC EN pdf 4 1 ABB Doc setup On start up the user can choose between light or professional profile figure 7 Light profile is recommended for calculating simple low voltage circuits In the professional profile all Doc functionalities are available Professional profile is recommended for calculating more complex circuits with MV supplies or generator supplies 19 H DOC User profile selection DOC features Single line diagram drawing Short circuit calculation Voltage Drop Calculation Low Yoltage Power supplies Medium Yoltage Power supplies Medium voltage devices selection Discrimination studies Free drawing Do not ask again on start up profile choice is available under Tools Options mn Figure 7 ABB Doc user profile selection 4 1 1 General properties The general properties window opens when a new project is created figure 8 The window can be opened later on and some properties can be adjusted if they are not dependent on the single line diagram connected to the supply There are four different power supplies to choose between At light profile the alternatives are LV supply and MV LV trafo At professional profile the MV supply and Generator are also available The generator supply should be used in island operation Plant general properties MV LV Trefo An Vec Y OH S Paes v 1000 gt M eli aa 3lo 50 A Neutral balance
50. s are based on conductor cross section area conductor material cable type method of installation ambient temperature closeness to other circuits and heat resistivity of the surrounding soil in earth cables Current carrying capacity calculations should always be done to the least favourable conditions The minimum cross 35 section area concerning the current carrying capacity is chosen by Febdok by eliminating too weak cables from the cable selection field Whether the voltage drop is within limits is calculated when the cable for each departure is chosen A warning message will pop up if the voltage drop exceeds the warning levels set The cross section area will not be changed automatically but the user can choose to increase the cross section area in order to decrease the voltage drop Max cable busbar length refers to the allowed max length of the conductor in question considering the voltage drop Current carrying capacity 4 Load current Ib 4 16 Voltage drop To load To last distribution board EAG Along cable busbar Max cable busbar length a Voltage at load terminals v EX Un for the load v EN 92 Losses in cable busbar w Figure 20 Febdok cable menu 5 3 1 1 t menu In the I t current time menu data about the protection device of each departure can be viewed Short circuit currents seen by the protection device are displayed in this window The SC currents displayed are the
51. sed to dimension electrical installations professional common sense should always be used On the other hand it won t be a problem once the program is learned properly and these minor faults are known None of the programs that were looked into in this thesis worked entirely automatically meaning that only the load would have to be set and the program would choose the rest of the devices automatically My conclusion is that Febdok is a great program for dimensioning electrical installations Documentation is very complete and distinct On the other hand the single line diagram is not complete enough for my employer s needs but Febdok is a good complement to e g Autocad for project documentation According to an article in S hk info 2 2008 a property for moving information directly from a CAD program to Febdok is under development Tiainen 2008b online If this property becomes available in the future Febdok will be even more attractive for those who plan electrical installations Febdok benefits e The extensive device database e Ease of use and fast to learn e Distinct documentation e Calculation of DC circuits possible e Verification of selectivity is simple 42 Febdok drawbacks e Feels a bit old and the single line diagram does not look very good e No MV calculations but this wasn t required either e You have to choose most components manually 8 Result The goal with my thesis work was to find a calculation soft
52. t be chosen to give the highest possible contribution All equivalent short circuit impedances must be introduced at the smallest possible value Cable and overhead line resistances are introduced at a temperature of 20 C Motors that contribute to Ikmax shall be included in calculations Voltage factor Cmax Table 1 must also be included Table 1 Voltage factor c IEC 60909 0 table 1 Voltage factor c Voltage factor c for calculation of Nominal voltage Un Maximum SC Minimum SC currents Cmax currents Cmin Low voltage 100 V 1 05 0 95 to 1000 V 1 10 Medium voltage 1 kV kV 1 10 1 00 High voltage gt 35 kV For low voltage systems with a tolerance of 6 for example systems renamed from 380 V to 400 V For low voltage systems with a tolerance of 10 12 When determing Ikmin the contributing elements are chosen to have the least possible contribution to Ik Motors should be excluded from calculations Resistance of cables and overhead lines are introduced at the conductor temperature at the end of the short circuit The voltage factor Table 1 is chosen to be Cmin IEC 60909 0 ch 2 4 2 5 U 3 phase short circuit l BZ 7 Z 18 Aner tlr 4 U 2 phase short circuit l i 19 Aner 47 4 ae c U Phase to neutral short circuit lay EN 20 13 G Zne Z Z Z RE c U Phase to PE short circuit Line E 21 2 NB AZ mer Zr Z Z pe Handbook EN pd
53. the single phase short circuit current can be higher than the three phase Figure 4a Far from generator short circuit current Figure 4b Close to generator short circuit current http images books24x7 com bookimages id_15535 fig4 2 jpg 8 The minimum short circuit current Ikmin appears at the very end of the line and is determined to ensure fast disconnection in case of short circuit The minimum SC current is the single phase short circuit Maximum SC current Ikmax is calculated directly behind devices Ikmax 18 determined to ensure that the components can withstand and disconnect the high current during short circuit IEC 60909 0 2 4 2 5 2 3 2 Protection against contact voltage Contact voltage is the voltage that appears between two parts and both live parts can be touched simultaneously by humans or animals SFS 6000 1 826 11 05 Protection against contact voltage is primarily accomplished through automatic disconnection in case of insulation faults To avoid physiological defects due to electric currents flowing through the human body in a fault situation maximum disconnection times have been given Residual current devices RCD and low voltage systems can be used as additional protection where needed Suomen S hk urakoitsijaliitto ry 1995 p 74 The disconnection times are strictly dependent on the minimum short circuit current The disconnection time must be lt 0 4 s in circuits
54. tion tool that is easy to use so that all project engineers would be encouraged to use it In this way the project planning time can be shrunk and the engineers have a distinct documentation to provide their customers with The choices are made after considering what programs would suit the employer s needs the most Every calculation tool has its pros and cons This means that finding the best one is more about finding the best compromise for the employer s needs In this chapter the benefits and drawbacks for the software s are listed 71 Benefits and drawbacks of ABB Doc ABB Doc is very rapid to use but it takes some time to learn all the functionalities It feels very up to date and the single line diagram looks very professional and distinct Doc is able to calculate MV components and it seems more focused on industrial use The MV calculations might be useful for my employer although that wasn t reguired in the beginning However Doc is not able to calculate DC circuits which is also very important for the employer On the other hand DC calculations are guite easy to do by hand or in Microsoft Excel When drawing in DOC it is enough to select what types of protection devices and cables shall be used When the loads have been determined the user can simply click the calculate button and the cables and protection devices are dimensioned automatically However when it comes to voltage drop and selectivity the user might have to
55. ty values depending on the method of installation are found in appendix 2 table 1 Correction factors concerning temperatures ground heat resistivity and other nearby cables are found in appendix 2 tables 2 6 Suomen S hk urakoitsijaliitto ry 1995 p 293 2 2 1 Conductor overload An over current is any current that is higher than the installation design current An overload current is a current that is higher than the allowed current while there is no fault in the circuit Overload causes overheating of electrical components Tiainen 2008a p 140 2 2 2 Overload protection Overload protection devices must be dimensioned so that the over current is disconnected before the conductor insulation connections or the cable surroundings are overheated Overload protection must meet the requirements presented in equations 1 and 2 In practice the protection device is chosen to the next standardized size bigger than I L appears in the product standard or is given by the manufacturer Tiainen 2008a p 140 I SI SI 1 I lt 1 45 I 2 IL The current that the circuit is planned for I Conductor constant current carrying capacity I Protection device nominal current I The current that ensures the protection device to work as supposed to SFS 6000 4 43 433 1 The electric load I can either be estimated or calculated if the load is known and consistent Estimation of the circuit load is based on how electr
56. umiemtatiOnn a wccisscccssecceaswacanvs lessuncasustaisvensvaasaaussaasscansceeadedeastaasdaceeaaennens 37 607 Other aleman li 37 6 3 1 Myecodial Lis aiii 37 0 3 2 Calculations in MICTosokt excelkuuussa usa nos cas 38 J Benefits and dra back idol 39 7 1 ABB Doc benefits and drawbacks O a id 39 72 Febdok benefits and drawbacks isis aer ind 40 8 Resultan erena vana A RE A A LIN aka EEEE eE AEE aa 42 O Conclusi n and discussis ssiri isiin esii NT a o aaas 43 A E 43 OD A A A SG 44 Eist Of SOIKOON eae ASS ds 45 Appendices 1 Reference methods of installation 2 Current carrying capacities and correction factors 3 Generator technical specification 1 Introduction When planning electrical installations safety is always the highest priority The protection requirements as regards humans and animals must be fulfilled in any situation Electrical faults may also cause fire This is why electrical installations must be planned and dimensioned correctly to ensure a safe installation for users The installation should also be reliable and qualitative to guarantee device operations and to prevent failures in sensitive devices Quality means that disturbances harmonics and voltage levels should be kept within margins The protection of humans is primarily done by preventing them from contact with live parts through isolation enclosure or barriers However if these are defective the protection should be fulfilled in other
57. ware that is simple rapid and versatile without compromising on accuracy To choose one software is very difficult since they all have different qualities The goal was to decide on only one calculation software so that it can be used as a standard calculation procedure In the evaluation I didn t only look at the requirements set in the beginning of this project since I also found other useful functionalities during my work Considering user friendliness Febdok has an advantage over ABB Doc It is a bit easier to use but most of all faster to learn ABB Doc has more functionalities and settings which makes it more versatile but it doesn t have the functionality to calculate DC circuits like Febdok has ABB Doc is the only one of the two that can calculate MV plants This is the biggest difference between these two softwares as regards functionalities They seem aimed at different areas considering this fact DC calculations were listed as one of the important functionalities and MV calculations were not When taking the importance of DC circuits in outdoor switchgear into account Febdok is more suitable for the employer ABB Doc was considered a bit faster to use than Febdok The devices are chosen more automatically than in Febdok where basically every single device has to be chosen manually This might be a result of the huge device database of Febdok and of the fact that there are several different manufacturers to choose between T
58. ways Exposed conductive parts may in some cases also become live due to isolation faults In fault situations the current must be cut very fast to prevent injuries or fire Satisfaction of the reguired demands must be proven through calculation or measurements with an approved instrument Since measurement cannot be done in advance calculations should always be done By making correct calculations expensive misdimensioning will also be avoided This thesis deals with calculation softwares for the dimensioning of electrical installations First some potential programs are looked into on the basis of wishes and advice from the employer and a guick overview of the properties of different programs In the theory chapter the regulations concerning dimensioning of electrical installations have been studied The theory is primarily based on the Finnish standardization association s regulations for low voltage systems SFS 6000 Most of the information is taken from student literature found in the library parallel to the SFS 6000 Some comprehensive information is taken from IEC 60909 short circuit currents in three phase AC systems Software handbooks also contain very good information on the field 1 1 Vaasa Engineering Oy Vaasa Engineering Oy often referred to as VEO provide automation and electrification solutions for the energy sector covering energy production transmission distribution and use They deliver turnkey projects pro
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