30/7/2016 Page 1TiSoft ElectricalDesign LineDetailedCalculationIEC60364

Line analytical calculations according to IEC 60364Switchboard - Working voltage DB2 , Switchboard , 3~400V 50Hz

Line No 7 , LOAD 7

Load electrical characteristicsNumber of phases / Rated voltage U 3~400 V

Installed power Pinst 50,00 kW

Simultaneity η 1,00

Absorbed power P 50,00 kW

Power factor cosφ 0,85

Load type Sockets

Design current Ib=P/(1.732·U·cosφ) 84,9 A

Circuit protection deviceProtection device nominal current In 100 A

Basic condition holds Ib < In < Iz 84,9 < 100 < 105,6

Installation Method, Correction factorsNumber : 72 (Table A.52.3)Sheathed single-core or multi-core cables direct in the ground– without added mechanical protectionReference Method : D2

Ground Temperature, Table B.52.15 = 25°C

Soil-thermal Resistivity = 3,0 K*m/W

Number of circuits = 6

Cables are touching

Ambient temperature correction factor , Table B.52.15 k1 0,95

Grouping correction factor , Table B.52.18 k2 0,50

Cable cross-section sizingCable NYY-O 3X150+70 sm + NYY 1X70 rm

Maximum permissible conductor temperature θcond,max 70,0 °C

Table with current rating of cables under reference conditions Table B.52.4 col. 8

Current rating of cable from the above table Ir 247,0 A

Current rating of cable under operation conditions Iz = Ir·k1·k2 105,6 A

Cable losses Ploss 2,7 W/m

Cable conductor temperature θcu 54,1 °C

Cable cross-section D 43,0 mm

Cable weight G 5.750,0 kg/km

Cable check to voltage dropDirect current resistance at 20°C (IEC 60502-1) R20 0,124 Ω/km

Corrected direct current resistance at 70°C R 0,148 Ω/km

Cable inductive reactance (IEC 60502-1) X 0,100 Ω/km

Cable length L 15,0 m

Cable impedance Z = L·(R·cosφ + X·sinφ) 0,003 Ω

Cable voltage drop ΔU = 1.732·Ib·Z 0,39 V

Cable voltage drop % ΔU% = (ΔU·100)/U 0,10 %

Cable permissible voltage drop ΔUmax% 2,00 %

Voltage drop % from the beginning of the installation ΔUtotal 0,51 %

Short-circuit enduranceProspective short circuit current on switchboard busbars Ik 10,04 kA

Conductor cross-section q 150,0 mm²

Material coefficient for copper conductors k 115 A/mm²

Short-circuit permissible cut time t 5 s

Minimum conductor cross-section qmin mm²

Tripping checkProtection device characteristic curve MCB B

Instantaneous element operation current I5 500 A

Source impedance r = U/Ik 0,02291 Ohms

Short-circuit current at the end of the line Io = U/(r+Z) 8.990 A

Line analytical calculations according to IEC 60364

Page 2 30/7/2016LineDetailedCalculationIEC60364 TiSoft ElectricalDesign

Basic condition holds I5 < Io 500 < 8.990

Line analytical calculations according to IEC 60364