EARTHING CALCULATION FOR TOUCH AND STEP VOLTAGEFull description
MS excel Spreadsheet to help you find earthing values for substationFull description
Earthing TrafoFull description
ieeeFull description
Descripción: ieee
Full description
Calculation for Short Circuit Current Calculation using IEC / IEEE Standard. This report contains the description for calculating the short circuit current using IEEE 909 and circuit breaker…Full description
Sag
Descripción: Sag Tension Calculation
Earthing JMC
ITEM
DESCRIPTION
SYMBOL
VA V ALUE
STEP 1
FIELD DATA 1
Dimension of the grid in E alignment direction (m):
LE
123
2 3 4
Dimension of the grid in N alignment direction (m): Soil Soil resi resist stiv ivit ity y (Ohm (Ohm*m *m): ): Total enclosed area by ground grid (m2):
LN ρ
81 210 9963
A
STEP 2
5 6 7
CONDUCTOR SIZE Symmetrical grid current (A): Duration of fault current (s): Material thermal capacity per unit volume in Joules/cm3/ºC:
8
Ground conductor thermal coefficient of resistivity at 0 ºC:
9 10 11 12 13 14 15
Ig tc TCAP α0
1000.00 0.3 3.42
Ground conductor thermal coefficient of resistivity at reference temperature of 20 ºC:
αt
0
Ground conductor resistivity at reference temperature of 20 ºC: Ko = 1 / α0
ρt
1.72
Ko Tm Ta Sm Sr
234 250 40 3.23 240
hs ρs
0.04
Maximum allowable temperature (ºC): Ambient temperature (ºC): Required conductor cross-section (mm2): Actual conductor cross-section (mm2):
0
STEP 3
16
TOUCH & STEP CRITERIA Su Surface layer thickness (m):
Tolera Tolerable ble touch touch voltag voltage e (V): (V):
Etouch50
546.10
Tolera Tolerable ble step step volt voltage age (V): (V):
Estep50
1549.03
STEP 4
21 22 23 24 25 26 27 28
INITIAL DESIGN No. of parallel conductors in E alignment direction (m) No. of parallel conductors in N alignment direction (m) Spacing between parallel conductors in E alignment direction (m) Spacing between parallel conductors in N alignment direction (m) Number of ground rods: Le L ength of each ground rod (m): Grid burial depth (m): Total length of grid conductor (m):
29
Total effective length of grounding system conductor (m):
5 4 30.75 27.00 17.00 3.05 0.75 939
Nr Lr h Lc LT
990.85
Rg
1.1375
STEP 5
30
GRID RESISTANCE Resistance of grounding system (Ω): STEP 6 AND 7
31
IgxRg
Page 1
NO
80811017.xls
STEP 8
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
MESH & STEP VOLTAGES Corrective weighting factor: Corrective weighting factor: Peripheral length of the grid (m): Geometric factor: Geometric factor: Geometric factor: Geometric factor: Geometric factor: Diameter of the conductor (m): Spacing factor for mesh voltage: Correction factor for grid geometry: Effective length for mesh voltage: Actual mesh voltage (V): Spacing factor for step voltage: Effective length for step voltage: Actual step voltage (V):