AEMC 6470-b User manual

DIGITAL GROUND RESISTANCE
AND SOIL RESISTIVITY TESTER
ENGLISH User Manual
6470-B
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Statement of Compliance
Chauvin Arnoux®, Inc. d.b.a. AEMC®Instruments
certifies that this instrument has been calibrated
using standards and instruments traceable to
international standards.
We guarantee that at the time of shipping your
instrument has met its published specifications.
An NIST traceable certificate may be
requested at the time of purchase, or obtained
by returning the instrument to our repair and
calibration facility, for a nominal charge.
The recommended calibration interval for this
instrument is 12 months and begins on the date of
receipt by the customer.
Serial #: ________________________________
Catalog #: ______________________________
Model #: 6470-B
Please fill in the appropriate date as indicated:
Date Received: _________________________________
Date Calibration Due: _______________________
Chauvin Arnoux®, Inc.
d.b.a AEMC®Instruments
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READ CAREFULLY BEFORE
USING FOR THE FIRST TIME
Your instrument is equipped with a NiMH battery. This technology offers several
advantages:
• Long battery charge life for a limited volume and weight.
• Possibility of quickly recharging your battery.
• Signicantlyreducedmemoryeffect:youcanrechargeyour
battery even if it is not fully discharged.
• Respectfortheenvironment:nopollutantmaterialssuchaslead
or cadmium, in compliance with the applicable regulations.
After prolonged storage, the battery may be completely discharged. If so, it must
be completely recharged.
Your instrument may not function during part of this recharging operation.
Full recharging of a completely discharged battery may take several hours.
NOTE: In this case, at least 5 charge/discharge cycles will be necessary for
your battery to recover 95% of its capacity.
To make the best possible use of your battery and extend its effective service life:
• Only use the charger supplied with your instrument. Use of
another charger may be dangerous.
• Only charge your instrument at temperatures between 0° and 40°C.
• Complywiththeconditionsofusedenedintheoperatingmanual.
• Complywiththestorageconditionsspeciedintheoperating
manual.
NiMH technology allows a limited number of charge/discharge cycles depending
signicantly on:
• The conditions of use.
• The charging conditions.
Please refer to § 9 for correct replacement of the battery.
Do not dispose of the battery pack with other solid waste. Used batteries
must be entrusted to a qualied recycling company or to a company
specialized in processing hazardous materials.
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Ground Resistance Tester Model 6470-B 3
Table of Contents
1. INTRODUCTION ................................................................................. 6
1.1 International Electrical Symbols...........................................................7
1.2 Denition of Measurement Categories.................................................7
1.3 Receiving Your Shipment.....................................................................7
1.4 Ordering Information ............................................................................7
1.4.1 Kits, Accessories and Replacement Parts ..............................8
2. PRODUCT FEATURES......................................................................... 9
2.1 Description ...........................................................................................9
2.2 Key Features......................................................................................10
2.3 Control Features ................................................................................11
2.4 Display ...............................................................................................12
2.5 Button Functions ................................................................................14
3. SPECIFICATIONS ............................................................................. 15
3.1 Reference Conditions.........................................................................15
3.2 Electrical.............................................................................................15
3.2.1 Frequency Measurements ....................................................15
3.2.2 Voltage Measurements .........................................................15
3.2.3 DC Resistance Measurements .............................................16
3.2.4 AC Earth/Ground Resistance Measurements.......................17
3.2.5 Soil Resistivity Measurement ρ ............................................18
3.3 Data Storage......................................................................................20
3.4 Power.................................................................................................20
3.5 Mechanical.........................................................................................21
3.6 Environmental ....................................................................................21
3.7 Safety.................................................................................................21
4. OPERATION..................................................................................... 22
4.1 General Operating Instructions ..........................................................22
4.1.1 Automatic Mode....................................................................22
4.1.2 Manual (Expert) Mode ..........................................................22
4.2 Instrument Conguration (SET-UP mode) .........................................23
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4 Ground Resistance Tester Model 6470-B
5. AUTOMATIC MODE .......................................................................... 24
5.1 Switching the Test Voltage .................................................................24
5.2 Resistance Measurement mΩ (2-Wire)..............................................24
5.2.1 Lead Compensation Measurement ......................................25
5.2.2 Alarm Function......................................................................26
5.3 Resistance Measurement mΩ (4-Wire)..............................................27
5.4 Earth/Ground Measurement (3-Pole).................................................28
5.4.1 62% Method..........................................................................28
5.4.2 Full Method ...........................................................................30
5.4.3 Recommendations for a Reliable Measurement...................31
5.5 Earth/Ground Measurement (4-Pole).................................................32
5.6 Soil Resistivity Measurements (ρPosition) ........................................34
5.6.1 Advantages/Disadvantages of Wenner & Schlumberger......34
5.6.2 Changing the Measurement Method.....................................35
5.6.3 Programming the Distance for Electrode Placement............35
5.6.4 Wenner Method ....................................................................36
5.6.5 Schlumberger Method...........................................................37
6. MANUAL MODE............................................................................... 39
6.1 Switching the Test Voltage .................................................................39
6.2 Measurement Frequency Selection ...................................................40
6.3 Manual Settings for mΩ Measurements ............................................40
6.3.1 Continuity Test ......................................................................41
6.4 3-Pole Earth/Ground Measurements & Coupling ................................ 41
6.4.1 3-Pole Earth/Ground Measurements ....................................41
6.4.2 Earth/Ground Coupling Measurements ................................41
6.5 4-Pole Earth/Ground Measurements .................................................43
6.6 Soil Resistivity Measurements ...........................................................43
6.7 Smoothing..........................................................................................43
7. MEMORY FUNCTION........................................................................ 44
7.1 Saving Measurements into Memory...................................................44
7.2 Recalling Measurements from Memory .............................................45
7.3 Erasing Measurements from Memory................................................45
7.3.1 Erasing All Measurements ....................................................45
7.3.2 Erasing Selective Measurements .........................................45
DATAVIEW®SOFTWARE....................................................................... 47
8.1 Installing DataView®................................................................................................................................... 47
8.2 Connecting the Model 6470-B to your Computer...............................51
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Ground Resistance Tester Model 6470-B 5
8.3 Establishing Communication to the Instrument..................................51
8.4 The Ground Tester Control Panel ......................................................52
8.5 Conguring the Instrument.................................................................53
8.5.1 DC Continuity Test ..............................................................54
8.5.2 3-Pole Ground Resistance Test ..........................................55
8.5.3 4-Pole Ground Resistance ..................................................56
8.5.4 4-Pole Soil Resistivity .........................................................57
8.6 Tools Menu.........................................................................................58
8.6.1 Tools > Options .....................................................................58
8.6.2 Tools > Colors .......................................................................58
8.6.3 Tools > Recover Data ...........................................................58
8.7 Starting a Test ....................................................................................58
8.8 Downloading Data to Database .........................................................58
8.8.1 Session Properties................................................................59
8.9 Exporting the Report to a PDF File ..................................................60
MAINTENANCE ................................................................................... 61
9.1 Maintenance.....................................................................................61
9.2 Cleaning...........................................................................................61
9.3 Fuse Replacement...........................................................................61
9.4 Recharging the Battery ....................................................................62
9.5 Replacing the Battery.......................................................................63
TROUBLESHOOTING ............................................................................ 65
10.1 Error Reporting.................................................................................65
10.1.1 Electrode Resistance Too High.............................................65
10.1.2 Out of Range.........................................................................65
10.1.3 Misconnection ......................................................................65
10.1.4 Out of Limits Indicators .........................................................66
10.1.5 Error Messages.....................................................................67
GLOSSARY OF TERMS......................................................................... 68
Basic Terminologies ....................................................................................68
Glossary ......................................................................................................69
Limited Warranty .........................................................................................73
Warranty Repairs ........................................................................................73
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6 Ground Resistance Tester Model 6470-B
CHAPTER 1
INTRODUCTION
WARNING
These safety warnings are provided to ensure the safety of personnel.
Please read and comply with these precautions:
• This instrument is protected from accidental voltages of not more than
50V with respect to earth in measurement CAT IV. The guaranteed level
of protection of this equipment may be compromised if used in a manner
not specied by the manufacturer.
• Safety is the responsibility of the operator.
• All metal objects or wires connected to the electrical system should be
assumed to be lethal until tested. Grounding systems are no exception.
• Never exceed the maximum rated voltage and current, and the mea-
surement category.
• Never exceed the protection limits, and always comply with the condi-
tions and place of use, indicated in the specications.
• Do not use the instrument or its accessories if they appear damaged.
• Use accessories that have overvoltage category and service voltages
greater than or equal to those of the instrument (CAT IV 50V). Use only
accessories that comply with safety standards (IEC 61010-2-031 & 32).
• Wear the appropriate protective gear (insulating boots and gloves).
• Check that no terminal is connected and the switch is set to OFF before
opening the device.
• Use only the charging unit supplied with the instrument to recharge the
battery.
• Troubleshooting and metrological verication procedures must only be
performed by qualied, approved personnel, or the factory.
• NOTE:The potentials on the various rods used for an earth measurement
may be different if a nearby electrical installation is defective or certain
weather conditions prevail (thunderstorms). It is up to the operator
to decide whether to continue or postpone measurements in these
situations.
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Ground Resistance Tester Model 6470-B 7
1.1 International Electrical Symbols
Signifies that the instrument is protected by double or reinforced insulation.
This symbol on the instrument indicates a WARNING that the operator must
refer to the user manual for instructions before operating the instrument. In
this manual, the symbol preceding instructions indicates that if the instructions
are not followed, bodily injury, installation/sample and/or product damage may
result.
Risk of electric shock. The voltage at the parts marked with this symbol may be
dangerous.
Ground/Earth symbol
In conformity with WEEE 2002/96/EC
1.2 Definition of Measurement Categories
CATII: For measurements performed on circuits directly connected to the electrical
distribution system. Examples are measurements on household appliances or
portable tools.
CATIII: For measurements performed in the building installation at the distribution level
such as on hardwired equipment in xed installation and circuit breakers.
CATIV:For measurements performed at the primary electrical supply (<1000V) such
as on primary overcurrent protection devices, ripple control units, or meters.
1.3 Receiving Your Shipment
Upon receiving your shipment, make sure that the contents are consistent with the
packing list. Notify your distributor of any missing items. If the equipment appears
to be damaged, le a claim immediately with the carrier and notify your distributor
at once, giving a detailed description of any damage. Save the damaged packing
container to substantiate your claim.
1.4 Ordering Information
Ground Resistance Tester Model 6470-B.....................................Cat. #2135.01
Includes carrying bag, 110/240V power adapter with US power cord, optical USB cable,
rechargeable NiMH battery pack, and a USB stick with DataView®software, ground tester
workbook and user manual.
Ground Resistance Tester Model 6470-B Kit (150 ft) ..................Cat. #2135.02
Includes meter, two carrying bags, two 150 ft color-coded leads on spools (red/blue), one 30
ft lead (green), two 5 ft color-coded leads (red/blue), 110/240V power adapter with US power
cord, optical USB cable, two T-shaped auxiliary ground electrodes, set of ve spaded lugs,
one 100 ft tape measure, rechargeable NiMH battery pack, and a USB stick with DataView®
software, ground tester workbook and user manual.
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8 Ground Resistance Tester Model 6470-B
Ground Resistance Tester Model 6470-B Kit (300 ft) ..................Cat. #2135.03
Includes meter, two carrying bags, two 300 ft color-coded leads on spools (red/blue), two 100
ft color-coded leads (hand-tied, green/black), two 5 ft color-coded leads (red/blue), 110/240V
power adapter with US power cord, optical USB cable, four T-shaped auxiliary ground
electrodes, set of ve spaded lugs, one 100 ft tape measure, rechargeable NiMH battery
pack, and a USB stick with DataView®software, ground tester workbook and user manual.
Ground Resistance Tester Model 6470-B Kit (500 ft) ..................Cat. #2135.04
Includes meter, two carrying bags, two 500 ft color-coded leads on spools (red/blue), two
100 ft color-coded leads (hand-tied, green/black), one 30 ft lead (green), two 5 ft color-
coded leads (red/blue), 110/240V power adapter with US power cord, optical USB cable,
four T-shaped auxiliary ground electrodes, set of ve spaded lugs, one 100 ft tape measure,
rechargeable NiMH battery pack, and a USB stick with DataView®software, ground tester
workbook and user manual.
1.4.1 Kits, Accessories and Replacement Parts
Test Kit for 3-Pole (3-Point) Testing (150 ft) .................................Cat. #2135.35
Includes one carrying bag, two 150 ft color-coded leads on spools (red/blue), one 30 ft lead
(green), two 5 ft color-coded leads (red/blue), two T-shaped auxiliary ground electrodes, set
of ve spaded lugs and one 100 ft tape measure.
Test Kit for 4-Pole (4-Point) Testing (300 ft) .................................Cat. #2135.36
Includes one carrying bag, two 300 ft color-coded leads on spools (red/blue), two 100 ft color-
coded leads (hand-tied, green/black), two 5 ft color-coded leads (red/blue), four T-shaped
auxiliary ground electrodes, set of ve spaded lugs and one 100 ft tape measure.
Test Kit for 4-Pole (4-Point) Testing (500 ft) .................................Cat. #2135.37
Includes one carrying bag, two 500 ft color-coded leads on spools (red/blue), two 100 ft
color-coded leads (hand-tied, green/black), one 30 ft lead (green), two 5 ft color-coded leads
(red/blue), four T-shaped auxiliary ground electrodes, set of ve spaded lugs and one 100 ft
tape measure.
Test Kit for 3-Pole (3-Point) Testing
(Supplemental for 4-Pole (4-Point) Testing) .............................................Cat. #2135.38
Includes one carrying bag, two 100 ft color-coded leads (hand-tied, green/black), one 30 ft
lead (green), two T-shaped auxiliary ground electrodes, set of ve spaded lugs and one 100
ft tape measure.
Extra Large Classic Tool Bag ...........................................................Cat. #2133.73
Tape Measure (100 ft) ......................................................................Cat. #2130.60
Ground Tester DVD/Workbook Set...................................................Cat. #2130.64
Set of Two, 14.5" T-shaped Auxiliary Ground Electrodes .................Cat. #2135.39
Replacement - Carrying Bag for Meter.............................................Cat. #2135.40
Optical USB Cable............................................................................Cat. #2135.41
Inverter – 12VDC to 120VAC 200 Watt for vehicle use ......................Cat. #2135.43
Replacement - Fuse, set of 5, 0.63A 250V 5x10 1.5kA....................Cat. #2135.81
Rechargeable NiMH 9.6V Battery Pack ...........................................Cat. #2960.21
Replacement - Power Adapter 110/240V & Power Cord 115V US...Cat. #5000.13
Power Cord 115V US .......................................................................Cat. #5000.14
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Ground Resistance Tester Model 6470-B 9
CHAPTER 2
PRODUCT FEATURES
2.1 Description
The Digital Ground Resistance Tester Model 6470-B is a portable measurement
instrument designed to measure Ground Resistance, Soil Resistivity (two methods
– Wenner and Schlumberger), Bonding Resistance (DC Resistance 2-Wire and
4-Wire Kelvin sensing) and Earth Coupling resistance. This direct reading tester
measures from 0.01 to 99.99kΩ and is auto-ranging, automatically seeking out the
optimum measurement range and test current.
Easy-to-use – simply connect the leads, select the test mode, press Start and read
the results. Up to 512 test results can be stored in internal memory for later recall
to the display or downloaded to a PC via DataView®software.
The large LCD is easy-to-read and indicates ground electrode resistance, test
voltage, current and frequency as well as individual electrode resistance, battery
status and more.
The Model 6470-B is CAT IV rated to 50V and is over voltage protected to more
than 250VAC against accidental connection to live circuits. The voltage is also dis-
played on screen. In the event of a system fault, the Model 6470-B can withstand
250VAC.
Additional features of the Model 6470-B include a heavy-duty eld case sealed
against dust and water when closed (the test button is also sealed against the
elements); manual and automatic test frequency selection from 40 to 513Hz; user
selectable 3-Pole (3-Point) Fall of Potential or 4-Pole (4-Point) Soil Resistivity test
methods and user selectable 2-Wire or 4-Wire Bond Resistance test method.
The Model 6470-B is powered by 9.6V, 3.5 Ah NiMH rechargeable batteries. An
external recharger powered from 120/230V 50/60Hz is included and provides for
testing while recharging. The Model 6470-B can also be vehicle powered from an
optional 12V battery adapter.
The Ground Resistance Tester Model 6470-B is rugged, easy-to-use and ideal for
maintenance crews performing numerous tests. It exceeds mechanical and safety
specications for shock, vibration and drop tests per IEC standards. The adjust-
able test frequency provides for rejection of high levels of interference, allowing it
to be used under difcult conditions such as high stray currents that normally affect
accuracy.
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10 Ground Resistance Tester Model 6470-B
2.2 Key Features
• 2- and 4-Wire Bond Resistance/Continuity measurement (DC Resistance) with
automatic polarity reversal
• 3-Pole (3-Point) Fall-of-Potential measurement with manual or automatic
frequency selection
• 4-Pole (4-Point) Fall-of-Potential measurement for very low resistance
measurements with manual and automatic frequency selection and automatic
lead compensation.
• 4-Pole (4-Point) Soil Resistivity measurement with automatic calculation of
Rho (ρ) and user selection of the Wenner or Schlumberger test method
• 3-Pole (3-Point) Earth Coupling measurement
• Manual and automatic frequency scan from 40 to 513Hz for optimum test ac-
curacy in electrically noisy environments
• Selectable test voltage of 16 or 32V up to 250mA of test current
• Auto-off power management
• Automatic recognition of all electrode connections and their resistance value
• Stores up to 512 complete test results in internal memory
• Optically isolated USB communication
• Remote set up and operation of all measurements using DataView®software
supplied
• Automatic report generation
• Rechargeable NiMH batteries from wall charger or vehicle power
• Rugged dustproof and rainproof eld case – IP54 rated in closed position
• Grounding standards IEC 61557 parts 4 and 5 compliant
• Includes DataView® software for data storage, real-time display, analysis, re-
port generation and system conguration
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Ground Resistance Tester Model 6470-B 11
2.3 Control Features
mΩ
Ω
Ω
GROUND TESTER
MODEL 6470-B
3
2
1
4
5
6
10
7
9
8
Figure 2-1
Item Description
1Backlit LCD Display (see §2.4)
2Battery charging connector
3Input terminal H (Z) - auxiliary electrode
4Input terminal S (Y) - auxiliary electrode
5Input terminal ES (Xv) - auxiliary electrode
6Input terminal E (X) - grounding electrode under test
7Six program/function buttons (see §2.5)
8Optical interface connector for connection to a computer
9Range selection switch
10 Start/Stop button
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12 Ground Resistance Tester Model 6470-B
2.4 Display
The Model 6470-B’s display is a custom 256 segment multi-line backlit LCD.
External voltages will be displayed only on the small displays (A2 and A3)
without the view of the main display (A1). This helps to rapidly recognize that
these are measurements of external voltages.
Backlight: The backlight turns ON automatically when entering a function and
turns OFF after the function is complete. Press the DISPLAY button to turn it back
on.
In the Set-up mode (Instrument Configuration § 4.) pressing the DISPLAY
button also selects the next configurable parameter.
A1
A2
A3
Figure 2-2
A1 Top main display
A2 Middle small display
A3 Bottom small display
Warning buzzer is activated
Communication port active
Indicates the battery charge condition; the segments represent the energy
Indicates that the secondary function of a button will be used
External voltage present - this symbol is activated when the instrument
measures voltages above 60Vp
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Ground Resistance Tester Model 6470-B 13
Indicates that the measurement is running in State 2 or instrument is
working
MANUAL Indicates MANUAL mode - the user has to stop the measurement, other-
wise the measurement keeps on running
AUTO
Indicates AUTO mode - measurement stops immediately after all results
are available. In AUTO mode, the measurement frequency is automatically
adjusted to the best available disturbance voltage rejection.
Symbol not used in Model 6470-B
Indicates the 2-Wire DC resistance; calculates the offset of the cable
resistance into the result (5Ωmax for offset value)
Symbol not used in Model 6470-B
Symbol not used in Model 6470-B
Symbol not used in Model 6470-B
Symbolizes the soil resistivity value (Rho): W or S indicates respectively
that Wenner or Schlumberger method is used for the measurement
(changed by the Hz/OPTIONS button)
ALARM Indicates the alarm is activated. An audible alarm will sound if the value
measured is above the limit defined in the SET-UP mode.
REMOTE
Indicates the instrument is controlled remotely by the RS-232/USB inter-
face. In this mode, all of the buttons and the rotary switch are inactive,
except switching to the OFF position.
MEM Indicates that there is recorded data in memory
MR Memory recall - displayed as long as this state is active
NOISE
If blinking, indicates the measurement had a disturbance at the moment
the measurement was started.
DISTANCE
If blinking, indicates the value is ready to be overwritten with a new value
or that a new value will be entered instead of “- - -”. If more than one
value has to be entered, the CHANGE  button moves to the next one.
CONFIG Indicates that the blinking value of AUTO/MANUAL mode, frequency, volt-
age or DC current direction can be changed.
SMOOTH Optional with a push on the 2nd button - sets a digital filter active
SWEEP Symbol not used in Model 6470-B
FREQUENCY Indicates the test frequency
OBJ:TEST Memory address
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14 Ground Resistance Tester Model 6470-B
2.5 Button Functions
START/STOP
Starts a measurement and compensates for lead resistance (§ 5.2.1).
A short push (<2s) enables a faster measurement because there is no
measurement of the auxiliary rod resistances.
A long push (>2s) - until the second beep occurs - enables the measure-
ment of all auxiliary rod resistances.
Measurement stops automatically (AUTO) or is stopped by pressing this
button again (MANUAL).
Selects the second function highlighted in yellow under the buttons.
Increases or decreases the value of the flashing parameter displayed or
selects the next parameter. Press the button for a longer time to increase
the change of value speed at a faster rate.
Selects the parameter to be modified or moves the cursor to the right.
MEM/MR MEM: Stores measurements to memory (§ 7)
MR: Retrieves measurements from memory.
DISPLAY/
SMOOTH
DISPLAY: Displays all parameters of a measurement.
SMOOTH: Smooths the display of measurement providing a more
stable result.
Hz/OPTIONS/
DISTANCE
Hz/OPTIONS: Enables configuration of measurement functions.
DISTANCE: Available for soil resistivity and V potential measurements. It
allows the setting of values of distances used for Rho (ρ) calculation.
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Ground Resistance Tester Model 6470-B 15
CHAPTER 3
SPECIFICATIONS
3.1 Reference Conditions
Influencing Parameters Reference Values
Temperature 68°F ± 5.5°F (20°C ± 3°C)
Relative Humidity 45 to 55% RH
Power Supply 9 to 11.2V
Frequency Range of Input Signal 0 to 440Hz
Capacitance Parallel to Input Resistance 0 uF
Electric Field <1 V/m
Magnetic Field < 40 A/m
In the following sections, the intrinsic error is dened under the reference condi-
tions and the operating error under the operating conditions in accordance with
IEC 61557 (1.4 and 5).
3.2 Electrical
3.2.1 Frequency Measurements
MeasuringMethod: Digital with a sampling frequency of 4028Hz, low pass, FFT.
The frequency of the strongest spectral component is displayed.
MeasuringRate:Display updates approx. 3 times per s.
Measurement Range 5 to 450Hz
Resolution 1Hz
Operating error ± 2Hz
Min. input voltage 10mV
3.2.2 Voltage Measurements
Overvoltages up to 75Vrms are displayed as ">65V". Permanent overvoltages
between 70 and 75V at terminals H (Z) and E (X) can cause overheating of the
overvoltage protection varistor.
Voltages of more than 75Vrms lead to error message 31 (excessive external
voltage) or 32 (voltage measurement overrange).
If terminals H (Z) and E (X) are put into contact with the line voltage, the protection
fuse will blow.
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16 Ground Resistance Tester Model 6470-B
External Voltage Measurements
MeasuringMethod:Digital by sampling at 4028Hz, low pass lter, FFT.
The frequency of the strongest spectral component is displayed.
MeasuringRate: Display updates approx. 3 times per s.
Measured Range 0.00 to 9.99V 10 to 65V
Resolution 0.01V 0.1V
Intrinsic error ± (2% + 1ct)
Operating error ± (5% + 1ct)
Input impedance ZH-E, ZS-E (ZS-ES) 1.2MΩ
Operating frequency DC and 15 to 440Hz
3.2.3 DC Resistance Measurements
MeasuringMethod:Voltage/Current measurement (Standard EN 61557 part 4)
Nominal Output Voltage: 16VDC (if resistance < 22Ωthe output voltage is
reduced to 10VDC)
MaxOutputCurrent:> 200mADC for resistances < 20Ω
MaxOverload(permanent):50Vrms (protection up to 250V is guaranteed)
MaxInductiveLoad:2 H
MaxInterferingVoltage:60Vpeak > 10Hz
TimeforAutoRangeSelecting:approx 5 s
MeasuringTime:8 s with automatic polarity inversion
MeasuringRate:3 per s in manual mode
LeadCompensation:Possible from 0 to 5Ω
AlarmSetting:“>” or “<” from 1 to 999Ω(max 3 digits)
2-Pole mΩmeasurement
Measurement
Range
0.12 to
9.99Ω
10.0 to
99.9Ω
100 to
999Ω
1.00 to
9.99kΩ
10.0 to
99.9kΩ
Resolution 0.01Ω0.1Ω1Ω10Ω100Ω
Intrinsic error ± (2% + 2cts)
Operating error ± (5% + 3cts)
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Ground Resistance Tester Model 6470-B 17
4-Pole mΩmeasurement
Measurement
Range
0.020 to
9.999Ω
10.00 to
99.99Ω
100.0 to
999.9Ω
1.000 to
9.999kΩ
10.00 to
99.99kΩ
Resolution 0.001Ω0.01Ω0.1Ω1Ω10Ω
Intrinsic error ± (2% + 2cts)
Operating error ± (5% + 5cts)
3.2.4 AC Earth/Ground Resistance Measurements
MeasuringMethod: Voltage/Current measurement (EN 61557 part 5)
OpenCircuitVoltage: 16 or 32Vrms square wave (if current > 240mA the output
voltage is reduced to 10Vrms)
TestFrequency: Selectable from 41 to 513Hz (see table in § 6.2)
ShortCircuitCurrent: > 200mAAC
NoiseSuppression:> 80 dB for frequencies 20% or more above or below the
test frequency
Max.Overload:250Vrms
Max. Value for RH& RS:100kΩ
MeasuringTime: ShortpushonSTART:approx. 7 s for rst value of REat
128Hz, then 3 measurements per s.
LongpushonSTART: approx. 15 s for rst value of REat
128Hz, then 3 measurements per s.
The following error indications refer to reference conditions with a test voltage of
32V, test frequency of 128Hz, RHand RS= 1kΩ, no external voltage.
The operating error of AC resistance measurements can be less than that speci-
ed for voltage or current because frequency characteristics of the voltage channel
are matched to those of the current channel.
Measurement of auxiliary electrodes RH, RS, RES, RE
Measurement
Range
0.14 to
9.99Ω
10.0 to
99.9Ω
100 to
999Ω
1.00 to
9.99kΩ
10.0 to
99.9kΩ
Resolution 0.1Ω0.1Ω1Ω10Ω100Ω
Operating error ± (10% + 2cts)
The START button must be pressed for more than 2 s. For frequencies between
41 and 256Hz, the resistance of the auxiliary earth electrodes is measured at the
test frequency set. At higher frequencies the resistance is measured at 256Hz.
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18 Ground Resistance Tester Model 6470-B
3-Pole earth resistance measurement RE
Measurement
Range
0.09 to
9.99Ω
10.0 to
99.9Ω
100 to
999Ω
1.00 to
9.99kΩ
10.0 to
99.9kΩ
Resolution 0.01Ω0.1Ω1Ω10Ω100Ω
Intrinsic error ± (2% + 1ct)
Operating conditions: RE< 3 x RH, UOUT = 32V Operating error for RE
Values for RH, RSand REFrequency (Hz)
(RH+ RS) / RE
< 3000
RH≥0Ω, Rs ≤3kΩ41 to 513 ± (3% + 2cts)
RH> 3kΩ, Rs ≤30kΩ41 to 513 ± (10% + 2cts)
(RH+ RS) / RE
< 5000 RH> 30kΩ, Rs < 100kΩ41 to 128 ± (10% + 3cts)
Note: For a test voltage UOUT of 16V, halve the value for RH.
4-Pole earth resistance measurement RE
Measurement
Range
0.011 to
9999Ω
10.00 to
99.99Ω
100.0 to
999.9Ω
1.000 to
9.999kΩ
10.00 to
99.99kΩ
Resolution 0.001Ω0.01Ω0.1Ω1Ω10Ω
Intrinsic error ± (2% + 1ct)
Operating conditions: RE< 3 x RH, UOUT = 32V Operating error for RE
Values for RH, RSand REFrequency (Hz)
(RH+ RS) / RE
< 3000
RH≥0Ω, Rs ≤3kΩ41 to 513 ± (3% + 2cts)
RH> 3kΩ, Rs ≤30kΩ41 to 513 ± (10% + 2cts)
(RH+ RS) / RE
< 5000 RH> 30kΩ, Rs < 100kΩ41 to 128 ± (10% + 3cts)
Note:With a test voltage UOUT of 16V, halve the value of RH.
3.2.5 Soil Resistivity Measurement ρ
MeasuringMethod: Voltage/Current measurement (EN 61557 part 5)
OpenCircuitVoltage: 16 or 32Vrms square wave
TestFrequency: Selectable from 41 to 128Hz (see table in § 6.2)
ShortCircuitCurrent: > 200mAAC
NoiseSuppression:> 80 dB for frequencies 20% or more above or below the
test frequency
Max.Overload:250Vrms
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