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PRECIOHM ET – EARTH TESTER
Taurus Powertronics – Training
Taurus Earth Tester
1/3/2011Taurus Confidential Document
Earth Tester
04/10/2023Taurus Confidential Document
Current Terminal
Potential Terminal-P1
Potential Terminal-P2
Earth Terminal
Range Selector
RS 232 Port
Mains Switch
Power ON
Memory
Battery Indication
Reset Set Print
Salient Features
Fall-Potential method of Earth Resistance Wenner method for Soil Resistivity measurementHigh dynamic measurement range of 0.01Ω to
20kΩDigital display in Ω with accuracy of ±2%Complete suppression of induction and leakage
power frequencies & its harmonics.Modular with in-built rechargeable batteryAvailable in models of 0–2kΩ & 0-20kΩCompact, portable, AC mains & battery operatedHoused in IP67 pelican casing
1/3/2011Taurus Confidential Document
SOIL RESISTIVITY
1/3/2011Taurus Confidential Document
Factors to be considered
Temperature
Humidity
Type of Soil
Strata of the Soil
Depth of Peg insertion
1/3/2011Taurus Confidential Document
Principle of Operation– Soil Resistivity
1/3/2011Taurus Confidential Document
Wenner 4 Pole Method
a a ab
V
I
ρ = 2πa
ΔvI
ρ = 2πaR
ρ = Resistivity (Ω-m) a = Probe Spacing (m)Δv = Voltage Measured
(volts) I = Injected current (Amps) R = Measured resistance
(Ω)
a = 10*b
Principle of Operation
Soil Resistivity Measurement: Four pole - Wenner Method A constant current with low frequency (128Hz) is
passed to current terminal The voltage across potential terminals P1& P2 is
measured Soil Resistivity is calculated using formula ρ = 2пaR
1/3/2011Taurus Confidential Document
Schematic Diagram
1/3/2011Taurus Confidential Document
Wenner 4 Pole Method for Soil Resistivity Measurement
a a ab
a = 10*b
P2P1E C
Operating Procedure
Soil Resistivity Measurement Install four terminals in the ground equally spaced
in a straight line Using the connecting cables, connect the E, P1,
P2 and C terminals to the corresponding electrodes.
Press the SET button and read the digital display. Record the reading at the appropriate location Using the obtained R-value, calculate the value of
resistivity (ρ), which is represented by the units of Ω-m (Ohm-Meter)
1/3/2011Taurus Confidential Document
Soil Resistivity Measurement Testing Layout
1/3/2011Taurus Confidential Document
a a ab
P2P1E
EP
1P
2
C
C
a
a
a
b
P2
P1
E
C
Building A Soil Resistivity Profile
A minimum of 3 direction of testing
Property line
ρx
ρy ρz
ρx + ρy + ρz 3
ρ =
SUB STATION EARTH MEASUREMENT
1/3/2011Taurus Confidential Document
Principle of Operation—Earth Resistance
1/3/2011Taurus Confidential Document
Distance of potential probe in meters
Ground Electrode Potential
probe (P) Current probe (C)
Current probe resistance
Ground probe resistance 61.8%
CXRes
ista
nce
in
ohm
s
Three pole -Fall Potential Method
Principle of Operation
Earth Resistance Measurement: Three pole -Fall Potential Method A constant current with low frequency (128Hz) is
passed to current terminal The voltage across potential terminal P1& earth
terminal measured The resistance is calculated using formula R =
1/3/2011Taurus Confidential Document
VI
Schematic Diagram
1/3/2011Taurus Confidential Document
d
3 Pole Method for Earth Resistance Measurement
d
h < 5% * d
h
Substation Earth Pit P2 C
Operating Procedure
Earth Resistance Measurement Connect equipment earth terminal to the station
earth pit Potential terminal to centre peg at distance 30m
from the earth pit Current terminal to current peg at distance 60m
from the earth pit The depth of penetration is less than 5% of the
distance between the pegs All the pegs are connected in straight line
1/3/2011Taurus Confidential Document
Case Study
1/3/2011Taurus Confidential Document
Case Study – PGCIL-NR ІІ
Place: Sonepat (PGCIL -NR ІІ)Date: 11/12/2010Substation: 400/220 kV S/s Powergrid,
MohanaContact Person: Mr. Shrivastava, Manager
Mr. Anil Kumar, DT Customer Requirements
Repeatability of the values & Heavy duty battery
Readings
1/3/2011Taurus Confidential Document
Earth Pit Resistance R 0.90 Ohms
Soil Resistivity 5.1 Ohm-meter
Case Study – PGCIL-NR ІІ
Place: Nalagarh (PGCIL -NR ІІ)Date: 13/12/2010Substation: 400/220 kV S/s Power Grid,
ReruContact Person: Mr. Manish Gandotara,
Manager Mr. Vikram Sarochaya,
Engineer Readings
1/3/2011Taurus Confidential Document
Earth Pit Resistance R=(Pit connected to grid)
0.60 Ohms
R= ( Individual earth Pit) 36.5 Ohms
Soil Resistivity 16.48 Ohm-meter
Case Study – PGCIL-NR ІІ
Place: Banala (PGCIL -NR ІІ)Date: 14/12/2010Substation: 400/220 kV S/s PowerGrid,
JhiriContact Person: Mr. Amit Kumar,
Sr.Engineer Mr. Pravesh Kaundal,
EngineerReadings
1/3/2011Taurus Confidential Document
Distance ‘A’meters
Resistance ‘R’ Ohms
ResistivityOhm-meters
Location A 5 6.55 205.67
Location B 4 25.5 640.56
Location C 4 24.5 615.44
Case Study – PGCIL-NR ІІ
Place: Chamba (PGCIL -NR ІІ)Date: 16/12/2010Substation: 400/220 kV S/s Power Grid,
Sultanpur
Contact Person: Mr. Manish Sharma, Chief Manager
Mr. Mahendra Kaloria, Engineer
Readings
1/3/2011Taurus Confidential Document
Earth Pit Resistance R=
2.5 Ohms
Soil Resistivity 138 Ohm-meter
Q & A
1/3/2011Taurus Confidential Document