Calculation for Induced Voltage in Cable

Customer:‐ Consultant:‐ Document Name:‐ Calculation for Induced Voltage Cable Installation System:‐ Cross Bonding No. of Core and Cable Size :‐single core 630Sqmm Voltage Grade :‐ 38/66Kv Cable Laying Formation:‐ Flat formation

OPTION‐ D‐As per your Hand wirtten sketch Definitions/Input Parameters : D' = 59.1 mm S = 77.5 mm I = 450 A Ik3 = 31,500 A Ik2 = 31,500 A Ik1/E = 31,500 A F = 50 s‐1 w = 314 s‐1 L = 700 m

Geometric mean sheath diameter Axial spacing of phases Continuous / Operating current Short circuit current (rms) 3‐pole Short circuit current (rms) 2‐pole Short circuit current (rms) single‐pole; Phase‐to‐earth fault current System frequency Angular frequency of the system Length of earthing section

Normal Operation I = 450 A E' = 40.74 V/km E = 28.51 V /mtr

Sheath Voltage(Outer Sheath)

3 phase symmetrical fault (external) Ik3 = 31,500 A E' = 2,851 V/km E = 1,996 V /mtr Sheath voltage(Outer Sheath) Phase to Phase fault (External) I12 = Ik2 Ik2 = 31,500 A E1 = E2 = E E' = 2,851 V/km E = 1,996 V /mtr E'3 =

Fault current between phases 1 and 2 phases affected by fault current Sheath voltage

332 V/km

Single phase to earth fault (external) Ik1/E = 31,500 A Data of earth continuity conductor: Ac = 240 sqmm (Al) Rc = 0.0754 Ω/km Resistance of earth continuity conductor 28 mm Overall diameter of (stranded) earth continuity conductor gc = 11 mm Geometric mean radius of earth continuity conductor (ecc) Sic = 150 mm Geometric mean spacing(s) between ecc and cable phases (i) E' 4,493 V/km E' 3,145V Sheath voltage Internal cable faults (most unfavourable case) Ik1/E = 31,500 A Data of cable sheath: Asc = 206 sqmm Cross‐section of cable screen Rsc = 0.083 Ω/km Resistance of cable screen Ash = 0 sqmm Cross‐section of cable sheath Rsh = 0.000 Ω/km Resistance of cable sheath Rs = 0.083 Ω/km Resistance of combined sheath E im 8,479 V/km E re 5,005 V/km E' = 9,846 V/km E = 6,892 V Sheath voltage