Megger DET2/3 Operating Manual
DET2/3
Advanced Earth (Ground) Tester
User Guide
Contents
Safety 1
Safety warnings ...............................................................................................................................................1
Live earth safety precautions
Voltage measurement categories
...........................................................................................................................................................2
CAT IV
............................................................................................................................................................2
CAT III
............................................................................................................................................................2
CAT II
Test leads and clamps
Safety and hazard icons
Warning Icons
Warnings, Cautions and Notes
Warnings
Cautions
.............................................................................................................................................................3
Notes
..................................................................................................................................................3
.......................................................................................................................................................3
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............................................................................................................................2
.....................................................................................................................2
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..................................................................................................................................3
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Introduction 4
Applications .....................................................................................................................................................4
Agricultural location.
Features
Accessories
...........................................................................................................................................................4
......................................................................................................................................................4
.....................................................................................................................................4
Overview 5
User interface ..................................................................................................................................................5
Display
Controls
Navigation control panel
Terminals
Soft keys
.............................................................................................................................................................6
...........................................................................................................................................................7
..................................................................................................................................8
.........................................................................................................................................................8
..........................................................................................................................................................9
Operation 10
Power on / off ................................................................................................................................................10
Auto off.......................................................................................................................................................10
Power options
Earth test options
Output voltage
Test frequency..............................................................................................................................................10
Noise filter
Test leads and terminal connections
Test modes
.............................................................................................................................................10
..........................................................................................................................................10
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Manual mode
Continuous graphical mode
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DET2/3
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Set-up 12
Modify parameters.........................................................................................................................................12
General set-up
Graph set-up
Language set-up
...............................................................................................................................................12
.................................................................................................................................................13
............................................................................................................................................13
Earth / ground resistance 14
Test procedure .............................................................................................................................................14
Earth / ground resistivity 17
Test procedure .............................................................................................................................................17
Continuity Test 20
Test procedure .............................................................................................................................................20
Null test leads
................................................................................................................................................21
Leakage Current Test 22
Test procedure .............................................................................................................................................22
See Data management (page 33).
................................................................................................................22
Test methods and set-up 23
Fall of potential (FoP) test ...............................................................................................................................23
Four terminal test lead set-up
Four terminal ART test lead set-up
......................................................................................................................23
...............................................................................................................24
Three terminal test lead set-up
Three terminal ART test lead set-up..............................................................................................................25
Slope method (FoP)
Description
Slope four terminal test lead set-up
Slope three terminal test lead set-up
61.8% Rule (FoP)
61.8% Four terminal test lead set-up
61.8% Three terminal test lead set-up
Two terminal earth resistance test
Two clamp (stakeless) test
........................................................................................................................................25
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Calibration check tools 31
Instrument calibration check ..........................................................................................................................31
Checking instrument accuracy
Clamp calibration check
.......................................................................................................................31
.................................................................................................................................32
Data management 33
Save test result ...............................................................................................................................................33
To edit a record file name as...
USB connection
Single test result: download or delete
Multiple test results: download or delete
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.............................................................................................................................................34
.......................................................................................................................33
............................................................................................................35
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Maintenance 36
General maintenance .....................................................................................................................................36
Cleaning
Battery
Battery status
Battery replacement.
Battery charge
12 V supply
........................................................................................................................................................36
...........................................................................................................................................................36
...............................................................................................................................................36
....................................................................................................................................37
.............................................................................................................................................38
...................................................................................................................................................38
Specifications 39
Measurement specifications ...........................................................................................................................39
Instrument specifications................................................................................................................................40
Instrument calibration check tool
Electrical specification
Mechanical specification
Clamp calibration check tool
Electrical specification
Mechanical specification
..................................................................................................................................40
..............................................................................................................................40
..................................................................................................................................41
..............................................................................................................................41
...................................................................................................................40
..........................................................................................................................41
Accessories 42
Repair and warranty 43
Calibration and repair 44
Return procedure ...........................................................................................................................................44
Approved service centres
...............................................................................................................................45
End of life 46
WEEE directive ..............................................................................................................................................46
Battery disposal
.............................................................................................................................................46
Declaration of conformity 47
Bibliography 48
Notes 49
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Safety
Safety
The safety warnings given in this document are indicative of safe practice and shall not be considered exhaustive.
Additionally, they are not intended to replace local safety procedures where the instrument is used.
Note: This User Guide uses the term ‘earth’ throughout some market areas may use the term ‘ground’.
Safety warnings
These safety warnings must be read and understood before the instrument is used. Retain for future reference.
Caution: The instrument must be operated only by suitably trained and competent persons.
If this instrument is used in a manner not specified by the manufacturer the protection of the instrument may
be impaired.
The instrument must NOT be used if any part of it is damaged.
Damaged test leads must NOT be used. Periodically inspect all test leads. Cables and connectors must be in
good order, clean and have no broken or cracked insulation. Users must exercise caution when connecting to
and disconnecting from the system under test. Do not touch any part that could be hazardous live.
Make sure that there are no hazardous voltages before connecting the instrument. Special precautions are
required when working with an untested and possibly 'live' earth. Isolation switches and fuses (not supplied)
must be used.
The instrument will indicate the presence of hazardous voltage between the P terminals. In the absence of
an indication do not assume that there are no hazardous voltages.
Do not touch the test leads or any conductive parts in the test circuit while a test is in progress.
Do not leave the instrument unattended when connected to the system under test and always disconnect the
instrument after tests have been completed.
The only clamps certified for use with the DET2/3 are the Megger MCC1010 and MVC1010, no other clamps
are to be used with this instrument. It is unsafe to use any other clamps.
This instrument contains a lithium-ion high energy battery pack.
Do not pierce, damage, disassemble or modify the battery. The battery contains safety and protection
devices, which if tampered with may cause the battery to generate heat, rupture or ignite.
If a battery is suspected to be faulty, replace it with a Megger approved battery pack. Refer to the User
Guide for instructions on how to change the battery.
If an instrument is suspected to contain a faulty battery, the battery must be removed before the
instrument is shipped.
Do not ship a faulty battery, either separately or inside an instrument.
The instrument must be set to OFF and the lid must be installed and securely closed before the instrument
is shipped.
Do not heat or dispose of the battery in a fire.
Do not subject the battery to strong impact, mechanical shock or excessive heat.
Do not short-circuit or reverse the polarity of the battery pack.
Users of this equipment and their employers are required by Health and Safety Legislation to carry out valid risk
assessments of all electrical work so as to identify potential sources of electrical danger and risk of electrical injury
such as inadvertent short circuits. Where the assessments show that the risk is significant then the use of fused
test leads may be appropriate.
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Safety
Live earth safety precautions
A 'Live' earth is one that carries current from the mains supply, or could do so under fault conditions. The
following warnings apply in addition to those listed previously:
All persons involved must be trained and competent in isolation and safety procedures for the system to be
worked on. They must be clearly instructed not to touch the earth electrode, test stakes, test leads, or their
terminations, if any 'live' earths may be encountered. It is recommended that they wear appropriate rubber
gloves, rubber soled shoes, and stand on a rubber mat
The earth electrode under test should be isolated from the circuit it protects before a test is started. If this is
not possible, ART may be used to measure electrode resistance
The instrument terminals should be connected to the system under test through isolation switches. The
isolation switches must be rated to handle the likely maximum fault voltages and currents that could be
encountered at the installation.
The isolation switch must be open when any physical contact is made with the remote test stakes, or the
connecting leads, for example, when changing their position
The instrument terminals should be connected to the system under test through fuses, that are rated to
handle the likely maximum fault voltages and currents that could be encountered at the installation
Voltage measurement categories
The rated measurement connection voltage is the maximum line to earth voltage at which it is safe to connect.
CAT IV
Measurement Category IV: Equipment connected between the origin of the low-voltage Mains supply and the
Distribution Panel.
CAT III
Measurement Category III: Equipment connected between the Distribution Panel and the electrical outlets.
CAT II
Measurement Category II: Equipment connected between the electrical outlets and the User’s equipment.
Measurement equipment may be safely connected to circuits at the marked rating or lower. The connection rating
is that of the lowest rated component in the measurement circuit.
Test leads and clamps
Megger supply test leads designed for the DET2/3 which are rated correctly for the test voltage generated by this
instrument, but not all are rated for mains connection. Users must select the correct leads for their project, this
will be either low voltage type rated 50 V, 1 A or leads designed for mains environment rated at 300 V.
Caution: Measurement leads connected to this instrument must be rated at least 50 V, 1 A.
The terminals for connecting current and voltage clamps are not isolated from the measurement terminals. If the
DET2/3 is used in a CAT IV 300 V environment, the clamps and their measurement leads must be rated the same
or higher. Only the Megger MCC1010 and Megger MVC1010 are sufficiently rated, no other clamps are to be
used.
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Safety and hazard icons
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This section details the various safety and hazard icons on the instruments outer case.
Icon Description
Warning: High Voltage, risk of electric shock
F
Caution: Refer to User Guide
G
Equipment complies with current EU directives
Equipment complies with current 'C tick' requirements
Do not dispose of in the normal waste stream
Warning Icons
This section details the warning icons that can show on the display.
Safety
Icon Warning Description
External Voltage Warning If an external voltage is applied between the terminals and the instrument
F
Internal Error Warning Internal Error Warning switch off and back on. Contact Megger if not
Read the User Guide Refer to the user guide if this message shows.
is set to On, the high voltage warning will flash to say that the item
under test is live and might be dangerous and the test is disabled.
The high voltage warning message will flash if more than 30 V potential
difference is applied between the voltage terminals and the current
terminals.
This warning will not show if all terminals are at the same high voltage.
Note: The warning will not operate if the instrument is set to Off.
cleared.
Warnings, Cautions and Notes
Warnings
Warnings alerts the reader to situations where a hazard to personnel can occur. They are placed before the event
to which they relate and are repeated at each applicable occasion.
Cautions
Cautions alerts the reader to situations where equipment damage may result if a process is not followed. They are
placed before the event to which they relate and are repeated at each applicable occasion.
Notes
Notes give additional information that aid the reader in the use or understanding of the equipment or subject,
they are not used when a Warning or Caution is applicable.
They are not safety related and may be placed either before or after the associated text as required.
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DET2/3
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Introduction
Introduction
This user guide details the operational and functional details of the DET2/3 advanced earth (ground) tester.
Please read this user guide fully before attempting to use the DET2/3.
The DET2/3 automatic earth test instrument is designed to measure earth Electrode Resistance and Soil Resistivity,
with highly accurate results. It is powered by an internal rechargeable battery which has a long usage period.
The battery is recharged with an external power supply unit.
Please refer to the image opposite on page 5 for detail of the DET2/3 layout.
For personal safety and to get the maximum benefit from this instrument, make sure that the safety warnings and
instructions (Safety (page 1)) are read and understood before the instrument is used.
The list of tests and connections detailed in this user guide are not exhaustive. Refer to the booklet Getting
Down To Earth for more information.
Applications
The DET2/3 can be used on large or more complex earth systems, which include communications earth systems
and difficult test environments. It can be used to test in accordance with BS 7430 (Earthing), BS-EN-62305
(Lightning Protection), BS-EN-50122-1 (Railway Applications) and IEEE Standard 81.
Soil resistivity measurements are used to establish the optimum electrode design and site, as well as performing
archaeological and geological investigations.
Where there is doubt about a particular application, reference should be made to the advice and guidance
contained in the publication Getting Down to Earth.
Agricultural location.
The DET2/3 can be used in agricultural locations (as per IEC 61557-5) where, to comply with the standard, the
output voltage must be set to 15 V.
It can also set to 15 V when risk assessment determines that a 50 V test voltage is too high.
Note: IEC 61557-5 recommends that the output is below 25 V in agricultural locations.
Features
The DET2/3 provides accurate 1 mΩ resolution measurements of earth Electrode Resistance.
With its microprocessor controlled system it provides a flexible user-friendly approach to earth tests by the
provision of excellent error detection capabilities and full test information shown on a large colour display.
Test frequency, test voltage and filtering can be quickly and easily adjusted so that adverse conditions, which can
influence the test, can be overcome.
Resistance measurements can also be made with a switched dc signal at a variable frequency of between 10 Hz
and 200 Hz.
A wide band of test current frequencies, with a resolution of 0.5 Hz, can be used to eliminate errors caused by
noise in the earth.
The DET2/3 also includes an automatic frequency selection feature that scans for frequencies with the lowest
noise level and then runs a test at that frequency.
Accessories
A large range of accessories are available, contact Megger for details (Refer to page 42).
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Overview
User interface
Overview
1
10
9
2
3
4
5
7
68
No. Description No. Description
1 External power / battery charge socket 6 Function switch (Controls (page 7))
2 Display 7 Navigation control panel (page 8)
3 USB: 1x Type A / 1x Type B 8 Mode switch (Controls (page 7))
4 Soft keys (page 9) 9 Save (Test Result Management (page 36))
5 Terminals (page 8) 10 External power LED (Power on / Charge (page 10))
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Overview
Display
2
1
3
4
4
5
No. Description No. Description
1 Status bar 4 Test mode: Secondary measurement result
Data management mode: Asset number
2 Main display / Primary measurement result 5 Test mode: Test parameters
Data management mode: Record name
3 Soft key functions
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Controls
Refer to user interface (page 5).
Mode switch Function switch
1
Overview
1
2
3
2
MAN
3
4
OFF
5
No. Description No. Description
1 Continuous graphical mode (page 11) 1 ρ (Resistivity)
2 Manual mode (page 11) 2 4 Pole (ART)
3 Power on / off (page 10) 3 4 Pole
4 Test result management (page 33) 4 3 Pole (ART)
5 Set-up (page 12) 5 3 Pole
6 2 Pole
7 Dual clamp
8 A (leakage current)
9 Ω (continuity)
See Test methods and set-up (page 23).
4P
4P
3P
Ω
3P
2P
A
Ω
8
9
4
5
6
7
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Overview
MVC1010
Navigation control panel
2
1
TEST
3
OK
6
5
No. Description No. Description
1 Home 4 Back
2 Navigation arrows 5 OK
3 Test 6 Menu
4
Terminals
See Test methods and set-up (page 23)
MCC1010
V
MVC1010
E
X
CAT IV 300V
Y
V
C1
P1
ES
P2
C2
H
I
I
E
S
1
2
3
4
5
No. Description
1 MCC1010 (used for ART, Noise current and stakeless tests)
2 MVC1010 / C1 E Voltage clamp, (current)
3 E/X / P1 ES (Potential)
4 Y / P2 S (Potential)
5 MVC1010 / C2 H Voltage clamp (current)
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Soft keys
ALL
b
2 aR
Soft Key Description Soft Key Description
Overview
15/50V
Hz
a(a+b)R
Select 15 / 50 V
ALL
Noise filter on / off
Delete all test records
Send all test records to USB
USB
Automatic frequency Scan Delete single test record
Earth / ground resistivity test
method
Send single test record to USB
USB
Metres or feet Average
Clear
Back Resistivity spacing adjustment
NULL
Null
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DET2/3
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Operation
Operation
Before each use of the instrument, visually inspect the instrument case, test leads, stakes and connectors to
confirm their condition is good, with no damaged or broken insulation.
Power on / off
Rotate the mode switch away from Off to a mode to power up and activate the instrument
Rotate the mode switch to Off to power down the instrument.
Auto off
The instrument switches Off after a period of inactivity (user adjustable) (see General set-up (page 12)).
To start the instrument again rotate the mode switch to Off and then select a mode.
Power options
Internal battery
Mains supply: The instrument charges using the dc adapter, which will work at voltages between 100 and
240 V ac. You may continue to use the instrument while the internal battery is charging.
(See Battery charge (page 38)).
Green LED: On charge
Amber LED: External power On
12 V dc supply: Operate the instrument while connected to a 12 V dc supply. See 12 V supply (page 38).
See also Specifications (page 39).
Earth test options
Output voltage
The maximum output voltage of the instrument is ±50 V. This can be reduced to ±15 V for operation in situations
which require it. The most appropriate output voltage should be selected by the user based on local safety
procedures.
To change the output voltage
15/50V
Press
Test frequency
The instrument can either scan the usable frequency range to identify the test frequency with the lowest noise,
or the frequency set be manually set, as required.
Auto: Press
after the measurement mode is selected. The display will show the selected output voltage.
Hz
. The instrument searches for the best frequency
Manual: Press to set a frequency between 10 Hz and 200 Hz
Noise filter
Press (noise filter) to give additional noise rejection on the input signal in order to produce more stable
results, this will also extend the test duration.
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Operation
Test leads and terminal connections
Test lead set-up and terminal connections are described as part of the test procedure.
Important: When the instrument is connected to electrodes, make sure that all leads and cables are fully
unwound and laid out without loops.
Important: When running test leads out to each remote spike, take care not to lay them close to each other.
This is to minimise the effect of mutual inductance. Test leads must be spread out at least one metre apart.
Test modes
The instrument can operate in two modes to do a test:
Manual mode
In manual mode the test result can be shown as a single digital read out result, or as a continuously updated
digital read out result.
Continuous graphical mode
In continuous mode a continuous updated graph is displayed.
Green line: Measurement line
Black Line: Recorded average
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