Calculate Numer of Plate / Calculate No of Plate Earthing As per IS 3043-1987 Short circuit Current(Isc) Duration of Fault in sec (t)
Enter Soil Resisitivity (ρ) If You Know Measurement of Soil Resistivity by Using Megger Distance Betweem successive Electrodes (D) Earth Megger Reading (R.)
Soil Resisitivity (ρ)
65000 1 100 100
Am p Se c
Ω-Mt. Mt.
0 757 1
Permissible Current Density at Earth Electrode (Id) Permissible Earth Resistance of System Detail of Plate Earthing: Plate W idth Plate Height Surface Area of both sides of plate(S) Max.Current Dessipated by One Electrode Resistance of Plate
600 600 0.72 545.04 290.14
No of Co Copp pper er Pl Plate ates s Ear Earth thin ing g Re Requ quir ired ed
119
Ω Ω-Mt. Amp/Sq.Mt
Ω mm mm Sq.Mt Am p
Ω Nos No s
Overlall Resistance of Earthing with 119 Nos of Electrodes
2.4381
Ω
Earth Resistance of Buried Strip / Wire: Strip W idth(t) Strip Length(L) Depth of Burial of Strip Electrode(w) Surface Area of both sides of Strip(S) Max.Current Dessipated by One Electrode Resistance of Strip Total Earth Resistance of Plate Earthing & Strip
12 2200 200 5.28 3996.96 0.0526
mm Mt mm Sq.Mt Am p
0.05152
Ω
Ω
Earthing Strip Size A=(IscX√t)/K Current Density permissible at an Earth Electrode Id=(7.57*1000)/√(ρxt) Amps/Sqmeter Amps/Sqmeter No of Plates required N=Isc/Id/S
Plate R=(ρ/S)*(√Π/S) Ohm Pipe or Rod R= (100ρ/2ΠL)*log℮(4L/d)ohms (100ρ/2ΠL)*log℮(4L/d)ohms Stip or Conductor R=(100ρ/2ΠL)*log℮(2L²/wt) R=(100ρ/2ΠL)*log℮(2L²/wt) ohms
ipe Earthing
Jignesh.Parmar, www.electricalnotes.wordpress.com, jiguparmar @yahoo.com
Calculate No of Pipe Earthing As per IS 3043-1987 Short circuit Current(Isc) Duration of Fault in sec (t)
Enter Soil Resisitivity (ρ) If You Know Measurement of Soil Resistivity by Using Megger Distance Betweem successive Electrodes (D) Earth Megger Reading (R.)
Soil Resisitivity (ρ) Permissible Current Density at Earth Electrode (Id) Permissible Earth Resistance of System Detail of Pipe Earthing: Diameter of Pipe(d) Radius of GI Pipe(R.) length of Pipe(L) Surface Area(S) Max.Current Dessipated by One Electrode Cast Iron Pipe Resistance
No of Pipe Earthing Required
50000 1 72.44 72.44
Amp Sec
Ω-Mt. Mt.
0 889.42 1 100 0.05 3 0.943 838.37 0.799
60
Ω Ω-Mt. Amp/Sq.Mt
Ω mm Mt. Mt. Sq.Mt Amp
Ω Nos
Overlall Resistance of Earthing with 60 Nos of Electrodes
0.0133
Ω
Earth Resistance of Buried Strip / Wire: Strip Width(t) Strip Length(L) Depth of Burial of Strip Electrode(w) Surface Area of both sides of Strip(S) Max.Current Dessipated by One Electrode Resistance of Strip
12 2200 200 5.28 4696.14 0.0050
mm Mt mm Sq.Mt Amp
Total Earth Resistance of Pipe Earthing & Earth Strip
0.0037
Ω
Ω
Normal Short Circuit Value 440KV 40 KA for 1 to 3 Sec 220KV 40 KA for 1 to 3 Sec 132KV 35 KA for 1 to 3 Sec 66KV 25 KA for 1 to 3 Sec 11KV(Urban) 35 KA for 1 to 3 Sec 11KV(Rural) 25 KA for 1 to 3 Sec 415V 10 KA for 1 to 3 Sec 220V 6 KA for 1 to 3 Sec
Yes No
Calculate Size of of Earth Strip As per IS 3043-1987 Short circuit Current(Isc) Duration of Fault in sec (t)
33880 1
Volumetric haet capacity of conductor material (Qc) Reciprocal of Tmp.coeff of Resistivity at 0 deg.Centrigade (B)
Electrical resisitivity of conductorat 20 deg.Centrigade(∂20) Final Temprature of conductor(øt) Initial Temprature of conductor(øi) Value of k Constant for 1sec Allowance for Corrosion in Earth Strip
www.ele jig Amp Sec
Copper Aluminium 0.0345 0.025 234.5 228 0.0001724 0.0002826 395 325 40 40 205.60 126.05 0%
Per Year
Number of Year before replacement say
0
Year
Safety Factor
1
Lead 0.00145 230 0.000214 325 40 34.94
Calculated Earth Strip Size
Earthing Strip Size (Copper): Earthing Strip Size (Aluminium): Earthing Strip Size (Lead): Earthing Strip Size (GI):
164.79 268.77 969.76 419.90
Sq.mm Sq.mm Sq.mm Sq.mm
Calculate Size of Earthing Conductor Short circuit Current(Isc) Duration of Fault in sec (t)
Earthing Conductor Size for XLPE Conductor (Al.) Earthing Conductor Size for XLPE Conductor (Cu.) Earthing Conductor Size for PVC Conductor (Al.) Earthing Conductor Size for PVC Conductor (Cu.)
33880 1
360.43 235.28 451.73 294.61
No 1 1 2 1
Value Amp Sec
Sq.mm Sq.mm Sq.mm Sq.mm
Cable XLPE PVC
Jignesh.N.Parmar tricalnotes.wordpress.com,
[email protected]
Normal Short Circuit Value 440KV 40 KA for 1 to 3 Sec 220KV 40 KA for 1 to 3 Sec 132KV 35 KA for 1 to 3 Sec 66KV 25 KA for 1 to 3 Sec 11KV(Urban) 35 KA for 1 to 3 Sec 11KV(Rural) 25 KA for 1 to 3 Sec 415V 10 KA for 1 to 3 Sec 220V 6 KA for 1 to 3 Sec
GI J/ Cent-mm3 0.0038 Cent 202 0.000138 Ω-mm 500 Cent Cent 40 80.69 °
°
°
°
Actual Earth Strip Size Width(mm) Thickness(mm) 10 20
Status O.K
164.79
0.00
200
10
30
O.K
268.77
0.00
300
60
10
O.K
969.76
0.00
1200
10
20
Increase No or Size of Strip
419.90
0.00
200
of k Constant for 1 Sec. Al. 94 75
Cu. 144 115
