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8/20/2019 DET4TC Presentation.pdf
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New Earth Testers from Megger
Paul Swinerd
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Megger - Earth Testing Pioneer
Dr George Tagg pioneered earth testing at Megger
Designing, manufacturing and selling for well over50 years
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Days gone by
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Existing products
Direct 2 terminal & 3 terminal earth electrode testing
• DET3TA
• DET3TD
• DET3TC
• DET3/2
2 & 3 terminal and 4 terminal soil resistivity testing
• DET5/4D
• DET5/4R
• DET2/2
Stakeless testers
• DET10C-EU and DET20C-EU
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Products being replaced
DET5/4D
DET5/4R
• Last orders plan to be maximum 6 months from release ofnew products, so June 2007
• This is for sales of products – not support and repair of
the products which we plan to continue for a further five
years
Why?
• DET5/4 has been around for many years, now dated
• Although sound design, has basic user interface andfeature set
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The new family
New family to replace DET5/4D and DET5/4R
• DET4TC
– 2, 3 and 4 pole ground tester digital display
–Selective (ART) and Stakeless test capability
• DET4TCR
– As DET4TC but rechargeable
• DET4TC + KIT
–Fully kitted with ICLAMP and VCLAMP
• DET4TCR + KIT –Fully kitted with ICLAMP and VCLAMP
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DET4TC/R
Excellent user interface
Full diagnostics
New case design
(as DET3TD/TC)
Backlit display
ART
Stakeless testing
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DET4TC/R + KIT
Fully Kitted option
ICLAMP
VCLAMP
Stakeless test calibration
loop
Instrument calibration check
box Right angle adaptor kit
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Earth Testing theory
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Two Basic Test Types
Soil resistivity
• Choose location and design for earth system
Earth system resistance• Check resistance low enough
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Soil Resistivity
Theory
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Soil Resistivity
Purpose of this test:
• Find lowest possible resistance in an area
• Obtain the values needed to design the earth system Factors affecting soil resistivity
• Soil composition
• Moisture in the ground
• Temperature
Consider
• Resistivity will vary through the year
• Moisture more constant at water table
• Stable temperature below the frost line
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Soil Resistivity test methods
Purpose: Survey a site for the lowest resistance
connections for Earth.
Methods: 4-pole (Wenner method).
A A A
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Soil Resistivity test terms
Average soil resistivity, ρ = 2π AR ( cm)
Variables
• ρ is average soil resistivity to depth A in ohm-cm
• A is the distance between the spikes
• R is the resistance read from the earth tester
For example
• Planning to install 3m long electrodes?
• Then measure soil resistivity with spacing, A, betweenspikes at 3m
• The depth of test probes should be less than 3/20 =
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Soil Resistivity test terms
Soil resistivity is of interest because by rearranging the
formula and knowing its value from tables we can
calculate the resistance of the earth electrode required.
ρ = 2π AR ( cm) therefore electrode resistance R = ρ / 2π A
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Earth System Resistance
Theory
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But First
Earth system definitions
Why test?
Component parts of earth electrode resistance
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Earth system definit ions
Simple
• Generally consists of a single ground electrode driven into
the ground
Complex
• Multiple ground rods connected, mesh or grid networks
– More common in sub stations, cell sites etc
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Why test earth system?
Why a low earth resistance is required:
• Enable protective devices to operate in good time
• Reduce ground potential rises (GPR)
• Danger of shock from GPR (during fault)
– Step potential
– Touch potential
– Adjacent conductors
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Step and touch voltages
V VStep Touch
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Resistance and GPR from earth electrode
0.0
0.4
0.8
1.2
1.6
2.0
R e s i s t a n c e
( O
h m
s )
0
200
400
600
800
1000
V o
l t a g e
( V )
Resistance GPR
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Component parts of earth electrode resistance
1 – Resistance of the electrode and the
connections to it
2 – Contact resistance of the surroundingsoil to the electrode
3 – Resistance of the surrounding body
of earth around the electrode – these canbe thought of as “shells” and create a
sphere of influencesphere of influence
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Earthing System Resistance - theory
Purpose: Measure resistance of earthing system to
Earth - ascertain that prospective fault current can
be conducted safely to Earth and thus limit “touch
voltage”.
Methods:
• 2-pole: Direct measurement.
• 3-pole: Fall of Potential – Full method
• 3-pole: Fall of Potential – short method
• 3-pole: Slope Method.
• Selective measurements: ART
• Stakeless measurements: Earth Clamp.
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2-pole: Direct measurement
Measure “coupling” between two earth points; measure
resistance of earth electrode to Earth.
C1 (E)
C2 (H)P1 (ES)
P2 (S)Imeas
Emeas
Earth electrode
under test
Second earth electrode or other
low resistance, conductiveconnection to Earth.
Measures resistance ofthe two Earth electrodes
in series.
R = Emeas/Imeas
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2-pole: Direct measurement disadvantages
A series measurement of a resistance loop.
Accuracy depends on assumption that all other
elements in loop are of low resistance. Must disconnect individual ground electrodes to
measure them.
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3-pole: Fall of Potential (full method)
Classic method for measuring resistance of a single
earthing electrode, or of a system of electrodes to
Earth.
A
B
C2 (H)P2 (S)
C1 (E)
P1 (ES)
Imeas
Emeas
Earthelectrode
under test
Auxiliary testelectrodes
R = Emeas/Imeas
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Fall of Potential - Full Method
Vary location of P2 (Potential) spike by regular
steps along a straight line between the electrode
under test and the C2 (Current) electrode.
Plot graph of resistance measurements to distance
of P
Resistance of system taken where slope is flat. Note: The C spike must be outside the sphere of
influence to achieve a viable reading
f C S f
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Fall of potential - Current Probe Sphere of
Influence
Auxiliary
CurrentProbe (C)
Auxiliary
PotentialProbe (P)
GroundElectrode
UnderTest (X)
P probe must be outside of both
spheres of influence for correct
measurement
F ll f t ti l t t d lt
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)
Positions
GroundElectrode
UnderTest (X)
F ll f t ti l t t d lt
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential test and res lt
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential test and result
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential test and result
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential test and result
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential test and result
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential – test and result
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential – test and result
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Fall of potential – test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential – test and result
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Fall of potential test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential – test and result
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Fall of potential test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential – test and result
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Fall of potential test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
PotentialProbe (P)Positions
GroundElectrode
UnderTest (X)
Fall of potential – test and result
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Fall of potential test and result
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
Potential
Probe (P)Position
GroundElectrode
UnderTest (X)
True systemresistance
measured
here
Fall of potential – test and result
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p
CurrentProbe
Position
Distance of Potential Probe from X (dp)Ground
ElectrodePosition
X C R e s i s t a n c e i n O
h m s
CurrentProbe (C)
Potential
Probe (P)Position
GroundElectrode
UnderTest (X)
True systemresistance
measured
here
Usually approx 62%
of X to C distance
T i l P b S i
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Typical Probe Spacing
Single electrode
• C probe 15m away
• P probe 9.5m away
Large system, several electrodes or plates
• C probe 60m away
• P probe 38m away
Above only rough guide – look up tables available
Fall of Potential Method Disadvantages
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Fall of Potential Method – Disadvantages
Extremely time consuming and labour intensive.- Temporary probes must be placed.
- Cables must be run to make connections.
Space constraints can make it hard to place remoteprobes. (probes usually many meters away)
Must disconnect individual ground electrodes to
measure them.
3 pole: Fall of Potential (short method)
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3-pole: Fall of Potential (short method)
Reduced method based on fewer measurements, saving time
Earth
electrode
under test
B
C2 (H)
P2 (S)
Emeas
C1 (E)
P1 (ES)
Imeas
0.62B
Auxiliary testelectrodes
R = Emeas/Imeas
3 pole: Fall of Potential (short method)
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3-pole: Fall of Potential (short method)
Site P2 (Potential) spike at 62% of B and take
resistance measurement.
Locate P2 ± 0.1B around the 62% point and take
additional resistance readings, Rb and Rc.
If the three readings are within an agreed accuracy
limit, the system resistance is the average
Fall of Potential Method (short method)
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Fall of Potential Method (short method)–
Disadvantages
Not as accurate as less measurements are made
Space constraints can make it hard to place remoteprobes.
Must disconnect individual ground electrodes to
measure them
3-pole: Slope Method
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Alternative method applicable for physically
constrained sites.
B
C1 (E) C2 (H)
P1 (ES)
P2 (S)
Imeas
Emeas
Earth
electrode
under test
0.4B
0.6B
0.2B
Auxiliary test
electrodes
R = Emeas/Imeas
Distance to C probe (B)
Now 2 to 3 times the
maximum dimension ofearth system.
3-Pole: slope method
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3 Pole: slope method
Distance of Potential Probe from X (dp)
R e s i s t a n c e i n O h m s
CurrentProbe (C)
PotentialProbe (P)
GroundElectrode
UnderTest (X)
No flat area
3-pole: Slope Method
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3-pole: Slope Method
Vary location of P2 (Potential) spike by regular
steps along a straight line between the electrode
under test and the C2 (Current) electrode
Measure resistance at each step and plot a graph
of R versus distance.
Measure resistance at 0.2B, 0.4B and 0.6B: R1,
R2 and R3.
Slope coefficient, m=(R3-R2)/(R2-R1) relates
distance B and ideal distance of the voltage spike
(P2) for measuring the resistance.
3-pole: Slope Method
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Measure R1 at 20% distance to C2
C2 (H)
Earth
electrodeunder test
B
C1 (E)
P1 (ES)
Imeas
Emeas
0.2B
R1
C2 (H)
μ=(R3-R2)/(R2-R1)
R1= 9.3 ohm
R = Emeas/Imeasμ = (R3-R2) / (R2 – 9.3)
3-pole: Slope Method
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Measure R2 at 40% distance to C2
C2 (H)
Earth
electrodeunder test
B
C1 (E)
P1 (ES)
Imeas
Emeas
0.4B
R2
C2 (H)
μ=(R3-R2)/(R2-R1)
R1= 9.3 ohm
R2= 16 ohm
R = Emeas/Imeasμ = (R3 – 16) / (16 – 9.3)
3-pole: Slope Method
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Measure R3 at 60% distance to C2
C2 (H)
Earth
electrodeunder test
B
C1 (E)
P1 (ES)
Imeas
Emeas
R30.6B
C2 (H)
μ=(R3-R2)/(R2-R1)
μ = (19.2 – 16) / (16 – 9.3)
R1= 9.3 ohm
R2= 16 ohmR3= 19.2 ohm
R = Emeas/Imeas
3-pole: Slope Method
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Calculate value of μ
C2 (H)
Earth
electrodeunder test
B
P2 (S)C1 (E)
P1 (ES)
Imeas
Emeas
0.4B
0.6B
0.2B
Auxiliary test
electrodesR3R2R1
C2 (H)C2 (H)
μ=(R3-R2)/(R2-R1)
R = Emeas/Imeasμ = (19.2 – 16) / (16 – 9.3)
=0.478
3-pole: Slope Method
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p p
Tables of values for the co-efficient of slope
against actual P spike distance is published in the
instrument user guide.
Take calculated value of m and look up ideal
distance of the voltage spike (P2) for measuring the
electrode resistance
3-pole: Slope Method
=0 478
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=0.478
3-pole: Slope Method
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Measure electrode resistance at 0.632B
Earth
electrode
under test
C2 (H)
B
C1 (E)
P1 (ES)
P2 (S)
Imeas
Emeas
0.632B
Auxiliary test
electrodes
C2 (H)C2 (H)
R = Emeas/Imeas
3-pole: Slope Method - Disadvantages
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p p g
Less accurate than the full fall of potential
Requires maths
Must disconnect individual ground electrodes tomeasure them
Selective Measurements ‘ART’
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Attached Rod Technique
No need for the earth electrode to be disconnected
Uses current clamp ‘ICLAMP’ to measure currentflowing in electrode under test.
Application of ART
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Potential Probe (P) CurrentProbe (C)
Ground
Electrodes
Building earthconnection/s
I Total
I System
Ie
1Ie 2Ie 3
Ie test Test
Ie Test > I Total
20
X
Connection
ART with 4 pole measurement
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Potential Probe (P) CurrentProbe (C)
Ground
ElectrodesUnder
Test (X)
Building earth
connection/s
I Total
I System
Ie 1 Ie 2Ie 3Ie Test
C1 and P1 connections
Effects of Earth Coupling
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X Test
point
C P P
X Test
point
C
Result – Clamp low symbol or unexpected high reading
Answer use 3 pole method – disconnect electrode
Misuses – Telecom Guy Lines
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Current CPotential P
X
Connection
We MUST fully understand the test current path
The Best Application of ART
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Field of earth / Earth Farms
Pole mounted transformers
Domestic TT (earth electrode) systems Single guy lines on towers (isolated)
Lightning protection electrodes
Measuring Earth Leakage Current
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Building earth
connection/s
System leakage current
Ie 1 Ie 2Ie 3Ie 4 leakage (mA)
DET4TC set to A range
Using ICLAMP to measure electrode leakage current
“ Stakeless” Measurements
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No need for the earth electrode to be disconnected No need for test spikes to be used
Clamp-On / Stakeless Methodology
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Inject a voltage and measure the resultant current
produced in a ground loop.
Requires a complete electrical circuit to measure.
Measures the complete resistance of the path
(loop) the signal is taking.
In a multiple ground system the circuit can be
considered a loop comprising:
- The individual ground electrode.
- A return path via all other electrodes.
- The mass of earth.
Clamp-On / Stakeless Methodology
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In a multiple ground system the circuit can be
considered a loop comprising:
- The individual ground electrode.
- A return path via all other electrodes.- The mass of earth.
The single electrode will have a higher resistance
than the remainder of grounds connected inparallel.
Inject a voltage and measure the resultant current
produced in a “single turn” ground loop.
Clamp-On / Stakeless Methodology
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GroundElectrode
Under
Test
Building earth
connection/s
ICLAMP
VCLAMP
Clamp-On / Stakeless Methodology
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ICLAMP
VCLAMP
R testR1R2R3R4
25 Ohms 22 Ohms 19 Ohms 25 Ohms 45 Ohms
R Meas.= 50.6 Ohms
R Meas. = R test + 1 / (1/R1 + 1/R2 + 1/R3 + 1/R4)
Clamp-On/Stakeless Methodology
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For 6 similar electrodes each with a resistance of
10Ω
• Rloop = 10Ω + 2Ω = 12Ω reading on DET4TC/R
For 60 similar electrodes with a resistance of 10Ω
• Rloop = 10Ω + 0.17Ω = 10.17Ω reading on DET4TC/R
The more electrodes the more accurate the reading
Clamp-On /Stakeless Method - Advantages
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Test is quick and easy• No disconnecting the ground rod from the system.
• No probes need to be driven/cables connected.
Includes the bonding and overall connection resistance• Not available with Fall of Potential
Can measure the leakage current flowing through the
system..
Clamp-On /Stakeless Method - Disadvantages
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Effective only in situations with multiple grounds in parallel (polegrounds).
Cannot be used on isolated grounds (no return path)• Not applicable for installation checks/commissioning new sites
Cannot be used if an alternate lower resistance return exists notinvolving the soil
• Cellular towers
• Substations
Subject to influence if another part of the ground system is in“resistance area”
• Result will be lower than true resistance.
Test is carried out at a high frequency (enables the transformers
to be small)• Less representative of a fault at power frequency but easier to filter out noise
Requires a good return path
Clamp-On /Stakeless Method - Disadvantages
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Requires a good return path• Poor return path may give high readings.
Connection must be on the correct part of the loop for
the electrode under test
• Requires thorough understanding of the system
• Wrong connection can give a faulty result.
Susceptible to noise from nearby substations and
transformers (no reading). No basis for the test in standards – no objective
reference for the test results
Less effective for very “low” grounds• Extraneous elements in reading become comparatively large.
Applications – Service Entrance/Meter
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Ground
Rods
ServiceBox
Pole-Mounted
Transformer
Service
Meter
Applications – Lightning Protection
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Removable links
(Jug handles)
Link removed for
2 pole measurement
Lightning protection tape
Normal 2 Pole method
Applications – Lightning Protection
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Removable links
(Jug handles)
ICLAMP and VCLAMP
Lightning protection tape
Using ‘Stakeless’ method no need to remove link
Grounded
Misuses – Substations
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Substation PerimeterFence
E
Clamp-On
Ground
Tester
Substation
Ground
System
Test
Current
Misuses – Lightning ProtectionTest current flowing around loop
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Of lighting protection tape.
Lightning protection
tape
The Best Application of “ Stakeless”
Testing
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g
Field of earth / earth farms
Pole Mounted transformer electrodes
Pole mounted transformer guy line when connectedto earth system
Earthing in Sub-station cable cellars
• It is often impossible to drive in test spikes so this is an
ideal application for stakeless measurements
Single guy lines on towers
Lightning protection electrodes
DET4TC/R
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New product common philosophy
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Intuitive to use
One button operation
Automatic checking to avoid mistakes and poor
connections, indicated on display
Complete and ready to start testing kit, including
calibration certificate
Competitively priced to sell, including distribution
Combination of features, benefits and price makes
these ground testers the most attractive on the
market
New product common features
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Like DET3TD, based on building wiring housing
Delivered in plastic carry case
Includes stake and wire kit with each model
High quality large and easy to read backlit LCD
Includes batteries
Has quick start guide on the lid
Easy to use wearing gloves
Comes with calibration certificate as standard
Three year warranty
Avoids language variants for easy stock holding
Basic specification – DET4TC/R
2 terminal test, no links required
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3 terminal earth electrode test, no link required
4 terminal Resistivity test to 20k Ohms
ART (Attached Rod Technique)
‘Stakeless’ measurements Earth voltage measurement
Earth leakage current measurement (with ICLAMP)
Automatic checking of
• Current spike resistance
• Voltage spike resistance
• Earth noise voltage
• Blown fuse
• Battery status
Rechargeable batteries on DET4TCR
DET4TC/R specifications - electrical
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Resistance range (2,3 & 4 pole): 0.01 to 20kΩ Maximum P & C spike resistance: 100kΩ (50V output)
ART range: 0.01 to 20kΩ
Stakeless range: 0.01 to 200Ω
Earth voltage range: 0 – 100V
Earth current range (DET4TC/R + ICLAMP): 0.5mA to 19.9A
Test frequency: 128 Hz
Test voltage: 25V or 50V selectable (Factory set 50V) Earth noise rejection: 40V peak to peak
Battery type: 8 off AA cells or rechargeable
Approximate battery life: 700 consecutive tests
Safety: EN61010-1 CATIV 100V
EMC: EN61326-1:1998 heavy industrial
Common specifications - Mechanical
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IP54
Terminals: 4mm plug type
Dimensions: 203 x 148 x 78mm
Weight: 1kg
Operating temperature range: -15 to 55°C
Storage temperature range: -40 to 70°C
Humidity: 95% RH non-condensing at 40°C
DET4TC/R Accessories
St d d
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Standard• Hard carry case
• Stake and wire kit (15m, 10m, 10m, and 3m)
• External AC/DC adaptor – interchangeable plugs
Optional
• ICLAMP
• VCLAMP (includes calibration check pcb)• Calibration check box – 6220-824
• Right angled terminal adaptor set – 6220-803
• Black crocodile clip - 6220-850• Vehicle 12V charger lead – 6280-375
DET4TC/R + KIT Accessories
St d d
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Standard• Hard carry case
• Stake and wire kit (15m, 10m, 10m, and 3m)
• External AC/DC adaptor – interchangeable plugs• ICLAMP
• VCLAMP (includes calibration check pcb)
• Calibration check box – 6220-824• Right angled terminal adaptor set – 6220-803
Optional
• Black crocodile clip - 6220-850• Vehicle 12V charger lead –
Accessories – terminal adaptor set
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DET4TC/R Competitors
4620/30 / CA 6460/2
• Disadvantages DET4TC/R
AEMC / Chauvin Arnoux
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• Disadvantages
– 42V output only
– P and C high ind. combined
– No cal. Cert. – IP50
– No leads or case etc. std.
– Only 2kΩ range
– Links required• Advantages
– However many lead kit
options
• Advantages
– Superior noise rejection
– CATIV 100V
– Much lighter – ART and Selective
capability
– Earth leakage current
range – Earth voltage range
– Superior diagnostics
AEMC / Chauvin Arnoux
6470
• Advantages
DET4TC/R
• Advantages
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• Advantages
– 2 & 4 pole DC bond check
– 0 – 100kΩ range
– 16 or 32V output
– Auto frequency control – 50Hz earth resistance test
– Wenner method rho calc.
– Schlumburger method rhocalc.
– Memory for 512 tests – Software supplied
• Disadvantages
– IP54 but only with lid closed
– Rechargeable only
• Advantages
– ART & Stakeless
capability
– 25 or 50V output
– 128Hz only
– Much lighter
– Easy to use
– Hard carry case
Fluke
1623 (Saturn Geo Plus)
• advantages
DET4TC/R
Ad t
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• advantages
– Battery life 3000 tests
– 125 or 128Hz
– 2 years warranty
– ART noise current
rejection better at 3A
– Stakeless noise current
rejection better at 10A
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1625 (Saturn Geo X)• Advantages
– ART noise currentrejection better at 3A
– Stakeless noise currentrejection better at 10A
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• Advantages
– 2 pole DC bond check
– Wenner method rho
calc. – 125 or 128Hz
– Result memory
– Output to PC
• Disadvantages – Large 30cm required
between clamps
– Many accuracies not
specified
• Advantages
– Better quality
– Accuracy
– 25 and 50V output – Back lit display
– Superior noise rejection
– Superior temp specs.
– Ground voltage range
Features and Benefits
Tough rubber armoured IP54 rated instrument case
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Tough rubber armoured IP54 rated instrument case• Instrument will last a long time, and will be ready to test
when required
Supplied in tough blow moulded carry case• Helps prevent loss of accessories, also makes ideal ‘tray’
to put the instrument on when testing. Saves having to lay
the instrument directly onto muddy ground.
Supplied with calibration certificate, test leads and
spike kit
• Saves time having to source separate leads and spikes.
No waiting for calibration to be carried out. No hiddencosts. Convenient.
Features and Benefits
‘Attached Rod Technique’ capability ART
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Attached Rod Technique capability, ART• Saves both time and aggravation having to undo rusted
connections. No need to shut down supply to ensuresafety
‘Stakeless’ testing capability• Allows testing in areas when driving test spike is
impossible. E.g. Sub station cable cellars, or when testinglightning protection in concreted locations
One button operation with automatic noise checkand automatic P and C spike resistance check
• Little time required learning operation, and time saved not
having to spend considerable time troubleshooting poorconnections etc.
Features and Benefits
User selectable output voltage – 25V or 50V
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User selectable output voltage 25V or 50V• The ability to test in agricultural locations as per
IEC61557-5. 25V will not harm livestock
40V Pk to Pk Noise rejection• Can be used in most locations with ground noise such as
sub-stations, near transformers etc.
Back light
• Easier to operate when not having to use a torch to be
able to read the display
Potential Customers
Existing DET5/4 customers
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Existing DET5/4 customers
Petro-chemical companies
Utilities, Maintenance
Railways
Repair Organisations (Industrials),
Telecoms and Datacoms installers Specialist grounding/earthing companies and
consultants
Service providers
Insurance companies
Available?
New family in stock Dover from January Launch
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New family in stock Dover from January Launch
DET5/4
• Declare intention to be made obsolete June 2007
• Last orders accepted June 2007
• Repaired and calibrated for a further 5 years.
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