2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
DEVELOPMENT CONSULTANTS PRIVATE LIMITED Reviewed for general conformance with Contract drawings and specifications. ACTION :
1
1 Approved 2
Approved except as noted. Forward final drawing.
4
Disapproved.
5
For information/reference only.
Approved except as
3 noted. Resubmission
Blank
required. Approval of Contract documents by the Consultant shall not relieve the Seller of his responsibility for any errors and fulfilment of Contract requirements.
Design Memorandum For Grounding System Doc. No. PE-DC-391-509-E002 Revision 20
Digitally signed by Shouvik Patari DN: cn=Shouvik Patari, o=DCPL, ou=DCPL,
[email protected] m, c=IN Date: 2014.01.30 16:08:27 +05'30'
BHARAT HEAVY ELECTRICALS LIMITED POWER SECTOR PROJECT ENGINEERING MANAGEMENT NOIDA-201301 INDIA
Doc. No. PE-DC-391-509-E002
Design Memorandum For Grounding System Rev No: 0 2 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Date: 19.02.13 02.01.14
INDEX S. No.
DESCRIPTION
SHEET NO.
1.
SCOPE
2.
DESIGN PHILOSOPHY – BELOW GRADE GROUNDING
3-4
3.
DESIGN PHILOSOPHY – ABOVE GRADE GROUNDING
4-5
4.
REFERENCES
5.
ANNEXURE-A1: CALCULATIONS OF GROUNDING CONDUCTOR SIZE
6-7
ANNEXURE–A2: ETAP REPORT –GROUND GRID INPUT DATA & RESULTS
14 8-10
6.
3
5
ANNEXURE-B: MATERIAL AND SIZE DETAILS OF BELOW GRADE AND ABOVE GRADE GROUNDING SYSTEM (i) SAMPLE CALCULATION
15-18 11-14
8.
ANNEXURE-C: SOIL RESISTIVITY DATA ANALYSIS
20-21 15-16
9.
ANNEXURE-D: SOIL RESISTIVITY TEST RESULTS
22-26 17-21
~ 2 ~
19
Doc. No. PE-DC-391-509-E002
Design Memorandum For Grounding System Rev No: 2 0 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
1.0 1.1
Date: 02.01.14 19.02.13
SCOPE This document covers the design of below and above grade grounding system for the main plant area of 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI.
1.2
The (a) (b) (c) (d)
following aspects of below grade grounding system design are covered: Determination of size of ground conductor. Establishing the ground grid configuration. Determination of ground grid resistance. Check on Step and Touch potential.
1.3
The methodology and material details of above grade grounding system are also covered in this document.
1.4
The following calculations/ details are not covered in this document: (a) Grounding for switchyard areas (OPGCL Scope). (b) Grounding for Coal Handling area / Ash Handling area (CHP & AHP vendor Scope). (c) Grounding for plants & facilities not part of Main Plant Package. Further, interconnection of aux. Plants/ other areas grounding grid with main plant grounding grid shall be in Customer’s scope inline with Cl. 2.1.2 below.
2.0
DESIGN PHILOSOPHY OF BELOW GRADE GROUNDING SYSTEM
2.1
Type of grounding
2.1.1
Ground grid of mild steel rod material designed to limit step and touch potentials within tolerable limits is provided for the Main Power House Area covering Transformer Yard, TG Building, Boiler area, ESP and ESP Control Room area covered within this envelope. Detailed calculations for the above are covered in Annexure-A1 & A2.
2.1.2
Ground grid shall be connected to the 400 kV switchyard ground grid and auxiliary plant grounding systems through at least two interconnections with test facility. The interconnecting conductors will be run parallel to and as close as possible to the interconnecting cable path on pipe cum cable trestle/ duct bank/ trench as applicable.
2.1.3 Risers with an effective cross sectional area equivalent to below ground earth conductor are provided from the below ground grounding system for connection of above ground (equipment) earth leads. 2.1.5
For electronic grounding, one number electronic grounding pit is provided for each unit and one number electronic grounding pit each for the auxiliary area in BHEL Scope (where MAX DNA /PLC control panels are located). Only electronic ground connections are brought to this pit. No other ground connections (i.e. system/ equipment ground connections) are permitted for connection in this pit. For ~ 3 ~
Doc. No. PE-DC-391-509-E002
Design Memorandum For Grounding System Rev No: 02 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Date: 19.02.13 02.01.14
details of electronic grounding, system supplier, BHEL/EDN documentation shall be referred. 2.1.6
All system neutrals (including neutrals of power transformers), grounding terminals of EHV surge arrestors and EHV voltage transformers are connected to two nos. treated test pits, which in turn are connected to the ground grid.
2.1.7
All lightning protection down conductors are connected to dedicated ground electrodes through isolating links and then to the grounding system.
2.1.8
The sizes of conductors for below grade grounding are tabulated in Annexure-C, Table-1.
2.2
Design Criteria
2.2.1
Average soil resistivity has been computed based on Soil Resistivity Measurements (Test results are attached at Annexure-D) furnished by OPGCL as part of Contract Specification “ Vol-A: Geo technical Investigation Report”.
2.2.2
The size of grounding conductor is based on the maximum ground fault current value of 50 kA for 1 second, with all below grade joints being welded type. The minimum rate of corrosion of steel for selection of grounding conductor is considered as 0.12 mm per year. The grounding grid has been sized for a power plant life of 40 years.
2.2.3
For a fault located within power station premises, the ground grid design is based on the maximum fault current that is expected to occur during the design life of the station. The total ground fault current is contributed by generating station and transmission/ distribution system. The ground grid layout is based on the larger of the two i.e. contribution of generating station and contribution of transmission/ distribution system.
3.0
DESIGN PHILOSOPHY OF ABOVE GRADE GROUNDING
3.1
Type of grounding
3.1.1
A continuous 50 X 6 mm Galvanised flat MS conductor (runway conductor) shall be installed along all cable trays/ racks, which shall serve as main grounding conductor for receiving individual ground connections. Taps from runway conductor are connected to each section of other trays at an interval of about 10 m. The runway conductor is connected to the below grade grounding system at every available building column within plant buildings, and through risers at approximately 10 m interval in outdoor trestles/ trenches.
3.1.2
Sub-mat of galvanized conductor of 75 X 10 mm is provided in the floor finish for connecting the earth leads from various equipment located in the area. This submat is connected to the below grade grounding system at minimum two points through galvanised flats. ~ 4 ~
Doc. No. PE-DC-391-509-E002
Design Memorandum For Grounding System Rev No: 20 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Date: 02.01.14 19.02.13
3.1.3
75x10 mm galvanised M.S. flats are run as main earth conductor along building columns / walls and securely fixed to the same by welding / clamping at intervals not exceeding 750 mm. Connections from runway conductor/submats are made to the main earth conductor.
3.1.4
Railway tracks are bonded across fish plates and earthed at regular intervals. At the point where rail track leaves plant area, the rail section is provided with insulated joint at both ends.
3.1.5
Metallic hand rails, fencing of transformer yard, etc. are connected to the below ground earthing system. Earthing conductor is buried at least 2000 mm outside the fence of electrical installations. Every alternate post of the fences and all gates are connected to earthing grid by one lead.
3.1.6
Each street lighting pole/flood light pole and lighting mast will be grounded by 35x6 mm GS flat, which will be connected to two no. 40 mm dia & 3m long earthing spike, directly driven into ground at a depth of 1 meter from ground level. The junction box at each lighting pole is grounded at two (2) points from two (2) nos. earthing terminals by 16 SWG GI wire. One 16 SWG GI wire shall be taken upto the junction box from lighting fixtures and connected to grounding point.
3.1.7
Cable screens and armour (wherever applicable) are earthed at both ends for multi core cables. For single core cables, the same is done at switchgear end only.
3.1.8
Above grade ground conductor connections are welded except at the equipment end, where the connections are bolted.
3.1.9
The sizes of conductors for above ground grounding are tabulated in Annexure-C, Table-2.
3.1.10 Electrodes for lightning protection shall be as per “Design memorandum for Lightning Protection system” PE-DC-391-509-E003. 4.0
REFERENCES
4.1
Codes and Standards: (1) IEEE Std. 80/2000: IEEE Guide for safety in AC substation Grounding. (2) IEEE Std. 665/1995: IEEE Guide for Generating Station Grounding. (3) IS 3043: Code of practice for grounding (4) Indian Electricity Rules 1956 (5) CBIP Manual TR-5
4.2
Project Documents: (1) Plot Plan, PEM Drg. No.PE-DG-391-100-M001. (2) Soil Resistivity test report (Annexure-E).
~ 5 ~
ANNEXURE- A1
CALCULATION OF GROUNDING CONDUCTOR SIZE
Doc. No. PE-DC-391-509-E002 Rev No. 2 00
Design Memorandum For Grounding System 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
02.01.14 19.02.13
CALCULATION OF GROUNDING CONDUCTOR SIZE
Annexure-A1
As per equation 40 of IEEE-80-2000 cross sectional area of earthing conductor shall be: A
4
I x sqrt [ {( tc x r x r x 10 )/ TCAP}/ ln { (K0 + Tm)/ (K0 + Ta)}]
(mm2)=
where, A= I= tc= r=
Conductor cross section in sq. mm. Ground fault current (rms) in kA Time of flow of current Thermal coefficient of resistivity (for mild steel as per CBIP manual TR-5)
= = =
r= Ground conductor resistivity (for mild steel as per CBIP manual TR-5)
=
50 kA 1 sec. 0.00423 deg. C at 20 deg. C 15 micro-ohm cm
TCAP = Thermal capacity factor in J/cu.cm./ deg.C = 4.184 x SH X SW [As per Eq. 39 of IEEE-80-2000] SH = SW = Hence, TCAP =
Specific heat in Cal/gm/deg. C (for mild steel as per CBIP manual TR-5) Specific weight in gm/cc (for mild steel as per CBIP manual TR-5)
4.184 x 0.114 x 7.86
=
=
0.114
=
7.86
3.749
Tm = Max. allowable temp. = 620 deg. C (for mild steel as per CBIP manual TR-5) Ta = Ambient temperature =
50 deg. C
Tr = Reference temperature =
20 deg. C
T
K0 1
r
r
= (1/0.00423) - 20 = 216.41
Substituting these values, the conductor cross section Since
=
608.13 sq.mm.
AD
Corresponding Diameter of Conductor
D
=
27.83 mm
Minimum rate of corrosion of steel considered
=
0.12 mm. / yr.
Life for which the Earth Mat is designed
=
Total corrosion allowance for the expected life of the plant
=
Thus the Diameter of Conductor with corrosion allowance The conductor dia selected
= = =
40 yrs. 0 0.12 x 2 x 40 mm 9.60 mm. 27.83 + 9.6 mm 37.43 mm 40.00 mm.
Dia of the conductor in metres.
=
0.04 m.
ANNEXURE- A2
ETAP REPORT –GROUND GRID INPUT DATA & RESULTS
Project:
2X660 MW BANHARPALI TPS
Location:
BANHARPALI
Contract:
391
Engineer:
VKS
ETAP 5.5.6C
Study Case:
GRD1
Electrical Transient Analyzer Program
Ground Grid Systems IEEE Std 80-2000
Number of Ground Conductors:
31
Number of Ground Rods:
60
Total Length of Ground Conductors:
9614.00 m
Total Length of Ground Rods:
180.00 m
Frequency: 50.0 Unit System:
Metric
Project Filename: OPGCL
Page:
1
Date:
02-01-2014
SN:
BHARATBHEL
Filename: OPGCL
Project:
2X660 MW BANHARPALI TPS
Location:
BANHARPALI
Contract:
391
Engineer:
VKS
ETAP 5.5.6C
Study Case:
GRD1
Page:
2
Date:
02-01-2014
SN:
BHARATBHEL
Filename: OPGCL
Ground Grid Input Data System Data: Short-Circuit Current
Freq. Hz
Ambient Weight Temp. °C kg
50.0
50
Total Fault Current kA
50.00
38.880
Fault Duration (Seconds)
X/R
Sf Division Factor %
Cp Projection Factor %
14.00
73.4
100.0
Tf for Total Fault Duration
Tc for Sizing Ground Conductors
1.00
Ts for Available Body Current
1.00
1.00
Soil Data: Surface Material
Upper Layer Soil
Material Type
Resistivity m
Clean limestone
3000.0
Depth m
Resistivity m
Material Type
0.15
Lower Layer Soil
Moist soil
50.0
Material Constants:
Conductor/Rod
Type
Conductor & Rod
Mild Steel, MS
Conductivity
r Factor @ 20 °C
K0 @
%
1/°C
0 °C
10.8
0.00423
216.4
Depth m
MaterialType
1.00
Moist soil
Resistivity of Fusing Ground Conductor Temperature @ 20°C °C 620.0
.cm 15.00
Rod Data: Diameter cm
Length m
4.000
3.0
No. of Rods 60
Cost $/Rod
Arrangement Rods along Grid Perimeter
0.0
Grid Configuration:
Conductor Size mm²
Depth m
1257
1.0
Grid Length m
Number of Conductors
Lx
Ly
in X Direction
in Y Direction
in X Direction
Separation m in Y Direction
374.00
264.00
13
18
22.0
22.0
Cost: Conductor Total No. 31
Total Length m 9614.0
Rod Cost $96
Total No. 60
Total Length m 180.0
Cost $1
Total Cost $97
Cost $/m 0.01
Shape: Rectangular
Resistivity m 50.0
Thermal Capacity Per Unit Volume J/(cm³.°C) 3.75
Project:
2X660 MW BANHARPALI TPS
Location:
BANHARPALI
Contract:
391
Engineer:
VKS
ETAP 5.5.6C
Study Case:
GRD1
Page:
3
Date:
02-01-2014
SN:
BHARATBHEL
Filename: OPGCL
Ground Grid Summary Report Rg Ground Resistance Ohm
GPR Ground Potential Rise Volts
0.076
2209.9
Touch Potential Tolerable Volts
Calculated Volts
519.5
Step Potential Calculated %
338.7
Tolerable Volts
65.2
1730.2
Calculated Volts
Calculated %
107.3
6.2
Total Fault Current:
38.880 kA
Reflection Factor (K):
-0.967
Maximum Grid Current:
29.167 kA
Surface Layer Derating Factor (Cs):
0.773
Decrement Factor (Df):
1.022
Grid area is smaller than 6.25 m² or greater than 10,000 m²
Report of Intermediate Constants for IEEE 80 Methods - Correction factor for grid geometry regarding touch voltage (Kim):
- Correction factor for grid geometry regarding step voltage (Kis): - Spacing factor for touch voltage (Km): - Spacing factor for step voltage (Ks):
2.891 2.891
0.795 0.187
- Corrective weighting factor that adjusts for the effects of inner conductors on the corner mesh (Kii): - Constants 1 related to the geometry of system (K1):
1.358
- Constants 2 related to the geometry of system (K2):
5.629
1.000
One-Line Diagram - OLV1 (Short-Circuit Analysis)
page 1
U1 30346 MVAsc
Grid1 Bus3 400 kV
43.8 3.1
HVCB-1
HVCB-2
T1 810 MVA
8.89
Bus1 21 kV
7 kV
T2 810 MVA
Bus2 21 kV
62.07
Gen Unit#1 660 MW
Jan 02, 2014
Project File: OPGCL
7 kV 8.89
62.07
GCB-1
14:21:09
50.0
3.1
GCB-2
Gen Unit#2 660 MW
kA
One-Line Diagram - OLV1 (Short-Circuit Analysis)
page 1
U1 30346 MVAsc
Grid1 Bus3 400 kV
244.
25.89 9.4
HVCB-2
T1 810 MVA
8.88
Bus1 21 kV
T2 810 MVA
kV
0
Bus2 21 kV
0
Gen Unit#1 660 MW
Jan 02, 2014
Project File: OPGCL
kV 8.88
0 0
GCB-1
14:21:44
44.6 6
9.4
HVCB-1
GCB-2
Gen Unit#2 660 MW
V 39 k
kA
One-Line Diagram - OLV1 (Short-Circuit Analysis)
page 1
U1 30346 MVAsc
Grid1 Bus3 400 kV
252.
28.54 10.36
NO HVCB-1
Bus1 21 kV
T2 810 MVA
Bus2 21 kV
kV 9.05
0 0
GCB-1
Gen Unit#1 660 MW
14:22:54
Jan 02, 2014
38.8 8
HVCB-2
T1 810 MVA
Project File: OPGCL
GCB-2
Gen Unit#2 660 MW
6 kV
kA
ANNEXURE- B
MATERIAL AND SIZE DETAILS OF BELOW GRADE AND ABOVE GRADE GROUNDING SYSTEM
Doc. No. PE-DC-381-509-E002 Design Memorandum For Grounding System 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Rev No. 2 0
02.01.14 19.02.13 Annexure-B: Material and Size Details Of Below Grade & Above Grade Grounding System TABLE-1: BELOW GRADE GROUNDING SYSTEM - CONDUCTOR SIZES
SL. NO.
TITLE
MATERIAL
SIZE
MS ROD
40 MM. DIA
GALVANISED MS FLAT
75X10
1
MAIN STATION GROUNDING GRID
2
EARTH CONDUCTOR IN CONCRETE FLOOR
3
ELECTRODES IN TEST PITS
MS ROD
40 MM. DIA
4
ELECTRODES FOR LIGHTNING PROTECTION DOWN CONDUCTORS
MS ROD
40 MM. DIA
5
OTHER ELECTRODES
MS ROD
40 MM. DIA
Doc. No. PE-DC-381-509-E002 Design Memorandum For Grounding System 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Rev No. 2 0
02.01.14 19.02.13 Annexure-B: Material and Size Details Of Below Grade & Above Grade Grounding System TABLE-2: ABOVE GROUND EARTHING SYSTEM - CONDUCTOR SIZES
SL.NO.
TYPE OF EQUIPMENT
SIZE (MM)
MATERIAL
NO. OF LEADS
1
RISERS
75 X 10
GALVANISED STEEL FLAT
N.A.
2
SUB-MAT BURIED IN FLOOR FINISH
75 X 10
GALVANISED STEEL FLAT
N.A.
3
50 x 6
GALVANISED STEEL FLAT GALVANISED STEEL FLAT GALVANISED STEEL FLAT
N.A.
5
RUNWAY CONDUCTOR/ MAIN EARTH LEAD ALONG COLUMNS 11 kV/3.3 kV/ 415 V SWITCHGEAR / MCC SYSTEM NEUTRALS
6
415 V DISTRIBUTION BOARDS
50 x6
GALVANISED STEEL FLAT
TWO
7
FUSE DISTRIBUTION BOARDS
50 X 6
GALVANISED STEEL FLAT
TWO
8
11 kV & 3.3 kV MOTORS
50 X 6
GALVANISED STEEL FLAT
TWO
9
415 V MOTORS : ABOVE 90 KW
50 X 6
GALVANISED STEEL FLAT
TWO
10
415 V MOTORS : ABOVE 30 KW &
35 X 6
GALVANISED STEEL FLAT
TWO
11
415 V MOTORS : ABOVE 5 KW & UPTO 30 KW 415 V MOTORS : UPTO 5.5 KW
25 X 3
GALVANISED STEEL FLAT GI WIRE
TWO
35 X 6
GALVANISED STEEL FLAT
TWO
8 SWG
GI WIRE
TWO
50 X 6
GALVANISED STEEL FLAT
TWO
4
13
75 X 10 75 X 10
8 SWG
TWO TWO
TWO
14
CONTROL PANEL & CONTROL DESK
15
PUSH BUTTON STATION & JUNCTION BOX
16
CABLE TRAYS
17
BUS DUCT ENCLOSURES
a)
ISOLATED PHASE BUS DUCT
75 X 10
GALVANISED STEEL FLAT
TWO
b)
SEGREGATED PHASE/ NON SEGREGATED PHASE BUS DUCT
75 X 10
GALVANISED STEEL FLAT
TWO
Doc. No. PE-DC-381-509-E002 Design Memorandum For Grounding System 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Rev No. 2 0
02.01.14 19.02.13 Annexure-B: 18
RAILS & METAL PARTS, FENCE
35 X 6
GALVANISED STEEL FLAT
ONE
19
TRANSFORMER TANKS/ RADIATORS
75 X 10
GALVANISED STEEL FLAT
TWO
20
GENERATOR ENCLOSURE
75 X 10
GALVANISED STEEL FLAT
TWO
21
WELDING OUTLETS 3-PHASE RECEPTACLES
35 X 6
GALVANISED STEEL FLAT
TWO
22
LOCAL PANELS, LIGHTING POLES
35 X 6
GALVANISED STEEL FLAT
TWO
23
LIGHTING FIXTURES,SINGLE PHASE RECEPTACLES
16 SWG
GI WIRE
ONE
24
LIGHTING DISTRIBUTION BOARDS
50 X 6
GALVANISED STEEL FLAT
TWO
SAMPLE CALCULATION 1.0
TYPICAL SIZING CALCULATION FOR EARTHING CONDUCTORS OF PLANT AUXILIARIES
1.01 NEUTRAL & ENCLOSURE EARTHING OF GENERATOR TRANSFORMER, STATION
TRANSFORMER, LT AUXILIARY TRANSFORMER, LT BUSDUCT, LT PCC/PMCC A= I= tc = A=
0.01216 I
tc
( As per equation 33 of IEEE-80-2000 )
40000.00 Amperes 1.00 Sec 486.40 Square mm
Hence the Size chosen 65 x 10 mm is adequate 1.02 11 kV EQUIPMENT
A= I= tc = A=
0.01216 I
tc
( As per equation 33 of IEEE-80-2000 )
40000.00 Amperes 1.00 Sec 486.40 Square mm
Hence the Size chosen 65 x 10 mm is adequate 1.03 11 KV/ 3.3 KV/ 415 V SWITCHGEAR , MCCS
A= I= tc = A=
0.01216 I
tc
( As per equation 33 of IEEE-80-2000 )
50000.00 Amperes 1.00 Sec 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate 1.04 RISER, SUB-MAT
A= I= tc = A=
0.01216 I
tc
( As per equation 33 of IEEE-80-2000 )
50000.00 Amperes 1.00 Sec 608.00 Square mm
Hence the Size chosen 65 x 10 mm is adequate
1.05 SYSTEM NEUTRAL
The maximum system neutral fault current is 50 kA of the 415 system, so that will be considered for calculations. A= 0.01216 I t c ( As per equation 33 of IEEE-80-2000 ) I= 50000.00 Amperes tc = 1.00 Sec A= 608.00 Square mm Hence the Size chosen 65 x 10 mm is adequate
ANNEXURE- C
SOIL RESISTIVITY DATA ANALYSIS
Doc. No. PE-DC-391-509-E002 GROUNDING SYSTEM DESIGN MEMORANDUM 2x660 MW IB TPS (UNIT-3 & 4), BANHARPALLI
Annexure-C: Soil Resistivity Data Analysis
ERT NO.
AVERAGE SOIL RESISTIVITY (IN OHM METER) AT 2 METER DEPTH
1
ERT 1
21.100
2
ERT 2
21.850
3
ERT 3
23.110
4
ERT 4
21.350
5
ERT 5
20.220
6
ERT 6
21.850
7
ERT 7
26.870
8
ERT 8
26.250
9
ERT 9
24.860
10
ERT 10
25.240
Net Average Resistivity (Ohm-m) at 2 M depth
23.270
Sl. No.
Since the below grade earthing system is to be laid at a depth of 1M. Soil resitivity value considered after taking suitable margin of over 100% = 50 (Ohm-m)
12 of 17
Rev No. 02 01 Date:19.02.13 02.01.14
ANNEXURE- D
SOIL RESISTIVITY TEST RESULTS
- ,.,.n crn.
51. No.
ERT No.
Location
Spacing in M'tr.
1
2
3
4
5
6
2.00
1.98
2486.88
3.00
1.32
2486.88
0.93
2336. 16
6.00
0.48
1808. 64
8,00
0.21
1055.04
-2.00
2.0i
2524 .56
3.00
1. 8 2
3428. 88
4 .00
1.4 5
3642.40
6.0 0
0. 95
3579.60
8 .0 0
0. 3 5
1758.40
Resistance fn
-
I
9
9.00
Cooli ng Tower ,Area
4.00 -
10
10.00
Panel Bui ldin g Area
'.(1
Mtr.
'Resistivity In
'~ ~
~
"
"., ~.
114
OPGC
SWAYIN & ASSOCJ.ATES
,, '-~7Sjlir
'
SI. No.
ERT No.
Location
Spacing In Mtr.
1
2
3
4
\
n
Reslstarice In ' 5
Mtr.
Resistivity in
•.
n cm.
6
-
I I
I
2.1 4
2. 00
2687.84
I
I
7
7.0.0
SWitch ya rd Area
.-..
i .-·~
. S '
.....
.....
8.00
Sw itchyard Area •
I
3.00
1.12
21 10 .08
4.00
. 0.76
1909 .12
6 .00
0. 32
1205.76
8 ..00
0.0 7
351.68
2.00
2.09
2625.04
3.00
1.03
1940.52
4.00
0.68
1708.16
6.00
0.28
1055.04
8.00
0.06
cr.I
--
-
301.44 -
113
OPG.C
SWAYIN &. ASSOCIATES
.. ',,-, , . . _ '
I151. No. . 1
4
5
ERT No.
Location
Spacing. hi Mtl'.
2
3
4
4; 00
5.00
TG Suilding Area
Boller Area
t{esisthiity In n ·em.
Resistance Ii, n Nt-r; . 5
I ~
(;
2 ..00
1.70
2135.20
3.00
0.85
· 1601 .40
4.00 .
0.30
753.60
6.00
0.07
263.76
. 8.00
0.00
0.00
2 .00·
1.61
2022. 16
3;0'0
0.79
1488.36
4.00
0. 29
728.48
6. 00 .
0.04
8. 00 .
0.00
0.00
.-; . .,
2.00
1. 74
21 85 .44
3. 00
0. 98
1846 .32
.. ; ..,', 'I: '"
4.. 00
0.47
11 80.64
6. 00
0.19
715.92
8.00
0.02
100.48
. - '
J
a·
150.72 .r' ' '' ~,,,,
6
6.0 0 ·
Bo ner Area
~
- ----
112 OF'GC ..... - -~-.-"'----~.-.-. --.-. . . --- .- -... --.---- -:-.,.-~ ..,.__if.,
'
IA~ULAIIQ~ QF 5QIL. Br;~15TIVITY 51. No.
ERT No.
Location
Spacing in Mtr.
1
2
3
4
Resistance in I
2.00
\
3.00 1
1..00
........
2.00
Resistivity in
n em.
5
6
1.68
2110.08
-
I
1582.56
0.84 0.26
6 53.12
0.06
22 6.08
8.00
0.00
0.00
2.00
1.74
21 85.44
3.00
0.92
1733.28
4.00
0.41
1029. 92
6.00
-0.12
4 5.2 .16
8.00
0. 00
0 .00
2. 00
'1.84
231 1.04
3 .00
1. 1 3
2 128.9 2
4.00
0 .77
1934 .24
6 .00
0 .4 1
1544. 88
0 .09
452.16
4.00 6.00
2
n Mtr.
I
-
Transformer Area
Transformer Area
~
.-
-
I
i
I
A
3
3.0·0
TG Building
Area
8 .00 --
OPGC
111
SWAYIN & ASSOCIATES
