AEMC 6418 User manual

ENGLISH
User Manual
■
GROUND TESTER
6418

2Clamp-On Ground Tester Model 6418
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 N.I.S.T. 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. For recalibration, please use
our calibration services. Refer to our repair and
calibration section at www.aemc.com.
Serial #:
Catalog #: 2141.03
Model #: 6418
Please fill in the appropriate date as indicated:
Date Received:
Date Calibration Due:
Chauvin Arnoux®, Inc.
d.b.a AEMC®Instruments
www.aemc.com

Clamp-On Ground Tester Model 6418 3
Table of Contents
PRECAUTIONS FOR USE ..................................................... 5
1. INTRODUCTION ................................................................... 7
1.1. Function Keys .................................................................. 8
1.2. Display ............................................................................. 8
1.3. Inserting Batteries............................................................ 9
1.4. Date and Time Setup....................................................... 9
2. OPERATION .................................................................... 10
2.1. General .......................................................................... 10
2.2. Impedance and Current Measurement.......................... 10
2.3. Current Measurement.................................................... 12
2.4. Configuring (Set-up) .......................................................13
2.5. Errors ............................................................................. 15
2.6. Automatic Stop .............................................................. 15
2.7. Storage .......................................................................... 16
3. TECHNICAL CHARACTERISTICS ................................. 18
3.1. General Reference Conditions ...................................... 18
3.2. Electrical Characteristics ............................................... 18
3.3. Influences ...................................................................... 19
3.4. Power Supply................................................................. 22
3.5. Environmental Conditions.............................................. 22
3.6. Mechanical Characteristics............................................ 22
3.7. Compliance with International Standards ...................... 23
3.8. Electromagnetic Compatibility (EMC)............................ 23
4. MAINTENANCE............................................................. 24
4.1. Cleaning......................................................................... 24
4.2. Battery Replacement ..................................................... 24
LIMITED WARRANTY .......................................................... 26

4Clamp-On Ground Tester Model 6418
Thank you for purchasing the AEMC Clamp-On Ground Tester Model
6418.
For best results from your instrument and for your safety, read the
enclosed operating instructions carefully and comply with the
precautions for use. These products must be only used by qualified and
trained users.
WARNING, risk of DANGER! The operator must refer to these
instructions whenever this danger symbol appears.
Equipment is protected by double insulation.
Battery.
Application or withdrawal authorized on conductors carrying
dangerous voltages. Type A current sensor per IEC 61010-2-
032.
Useful information or tip to read.
The product has been declared recyclable after analysis of its
life cycle in accordance with the ISO14040 standard.
Guarantees conformity with European directives and with
regulations covering EMC.
In the European Union, the product must undergo selective
disposal for the recycling of electric and electronic material, in
compliance with Directive WEEE 2002/96/EC.
Definition of Measurement Categories (CAT)
CAT IV Measurement category IV corresponds to measurements taken
at the source of low-voltage installations.
Example: power feeders, counters and protection devices.
CAT III Measurement category III corresponds to measurements on
building installations.
Example: distribution panel, circuit-breakers, machines or fixed
industrial devices.
CAT II Measurement category II corresponds to measurements
taken on circuits directly connected to low-voltage
installations.
Example: power supply to domestic electrical appliances
and portable tools.

Clamp-On Ground Tester Model 6418 5
PRECAUTIONS FOR USE
This instrument is compliant with safety standard IEC 61010-2-032, for
voltages up to 100V in category IV or 150V in category III. Failure to
observe the safety instructions may result in electric shock, fire,
explosion, and destruction of the instrument and of the installations.
The operator and/or the responsible authority must carefully read and
clearly understand the various precautions to be taken in use. The
operator and/or the responsible authority must carefully read and
clearly understand the various precautions to be taken in use. Sound
knowledge and a keen awareness of electrical hazards are essential
when using this instrument.
If you use this instrument other than as specified, the protection it
provides may be compromised, thereby endangering you.
The safety of any system in which this instrument might be
incorporated is the responsibility of the integrator of the system.
Do not use the clamp above its rated frequency, since this might
cause it to overheat dangerously.
Do not use the instrument on networks of which the voltage or
category exceeds those mentioned.
Observe the environmental conditions of use.
Do not use the instrument if it seems to be damaged, incomplete, or
poorly closed.
Before each use, check the condition of the insulation on the housing.
Any item of which the insulation is deteriorated (even partially) must
be set aside for repair or scrapping.
Before using your instrument, check that it is perfectly dry. If it is wet,
it must be thoroughly dried before it can be connected or used.
When handling the instrument, keep your fingers behind the physical
guard.
Avoid impacts on the measurement head, in particular the air gap.
Keep the surfaces of the air gap clean; even a little dirt can cause the
clamp to malfunction.
Use personal protection equipment systematically.
All troubleshooting and metrological checks must be done by
competent accredited personnel.

6Clamp-On Ground Tester Model 6418
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, file 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.
Ordering Information
Clamp-On Ground Tester Model 6418..............................Cat. #2141.03
Includes hard carrying case, 5
Ω calibration loop, four 1.5V AA batteries,
wrist strap, Bluetooth adapter, multilingual safety sheet, Quick Start
Guide, and USB drive containing User Manual.
Replacement Parts
Hard Carrying Case ..........................................................Cat. #2141.52
5 Ω Calibration Loop .........................................................Cat. #2141.51
For the accessories and replacement parts, visit our web site:
www.aemc.com

Clamp-On Ground Tester Model 6418 7
1. INTRODUCTION
The simple-to-use Clamp-On Ground Tester Model 6418 makes ground
impedance measurements in a parallel earth network, such as power
distribution poles and overhead ground conductors. These
measurements are simpler to perform than traditional measurements
with two auxiliary rods.
The Model 6418 can make accurate low value ground impedances
measurements and AC current measurements. Its large oblong
measurement head can clamp around bars up to 1.18 x 1.57” (30 x
40mm). Its memory function records measurements for later viewing.
The instrument’s OLED (Organic Light Emitting Diode) display screen is
easy to read, even in direct sunlight.

8Clamp-On Ground Tester Model 6418
1.1. FUNCTION KEYS
As a general rule, functions shown in white on the keys are available
when the switch is set to Ω+A or A. The yellow arrow keys (▲, ▼ and
►) are available when the switch is set to MR or SET-UP.
Key Function
Switch the display unit backlighting ON and OFF.
MEM
Record the measurement displayed.
HOLD
Freeze/unfreeze the display of the measurement.
▲
▼
Browse in:
SET-UP menu and change the value of the parameter
selected.
Memory read (MR).
►
When switch is set to:
Ω+A or A: a long press on ► activates/deactivates the
audible signal.
SET-UP: ► browses in the menu and confirms the changes
made.
MR: ► toggles the display between the measurement and
the date/time.
1.2. DISPLAY
When the measurement exceeds the limits of the measurement range,
the instrument displays OR.

Clamp-On Ground Tester Model 6418 9
1.3. INSERTING BATTERIES
Refer to §4.2.
1.4. DATE AND TIME SETUP
The first time you turn ON the instrument by turning the switch to Ω+A,
the instrument prompts you to set the date.
The year blinks, indicating it can
be edited. Set it using the ▲ and
▼ keys.
Then press the ► key; the month
blinks. Set it using ▲ and ▼.
Press ►. The date blinks; set it
using ▲ and ▼ and confirm by
pressing ►.
The instrument then displays the
time format. Choose 24h or 12h (A
or P) using ▲ and ▼.
Confirm by pressing ►. The
hours reading blinks. Set it
using ▲ and ▼ and confirm
by pressing ►.
The minutes reading blinks. Set
it using ▲ and ▼ and confirm
with ►.

10 Clamp-On Ground Tester Model 6418
2. OPERATION
2.1. GENERAL
When turned ON, the instrument performs self-calibration. The jaws of
the clamp must therefore be closed and not clamped around any
conductor.
If the instrument fails to complete self-calibration, the error message Err.
CAL is displayed. If this happens, turn the instrument OFF and ensure
the air gaps are clean. Then turn the instrument ON.
2.2. IMPEDANCE AND CURRENT MEASUREMENT
Set the
switch to
Ω+A.
Press the trigger to open the jaws,
and clamp around the conductor
that is part of the ground system
to be measured.
When the jaws are open, the
symbol
is displayed and the
instrument cannot make a
measurement.

Clamp-On Ground Tester Model 6418 11
2.2.1. CONNECTION
The ground electrode to be measured (RX) is in a series/parallel
arrangement with other ground electrodes via the earth impedance (ZE)
and physical connection to other resistance paths (ZS). The measured
impedance will be slightly greater than RXassuming the downstream
impedance is very low. For example: If RXis 21Ωand ZS/R1-Rnis
effectively 0.6Ω, the Model 6418 will read 21.6Ω.
During the impedance measurement, the instrument emits an
intermittent audible “beeping” signal. This is caused by the
measurement frequency that flows in the measurement head.
The sound can vary as a function of the frequency and amplitude
of the current measured. This sound is normal and cannot be
eliminated.
2.2.2. FREEZING AND/OR STORING A MEASUREMENT
When the measurement has stabilized, you can press the HOLD key to
freeze it and/or MEM to record it.

12 Clamp-On Ground Tester Model 6418
2.2.3. AUTO-HOLD FUNCTION
The AUTO-HOLD function (see §2.4), freezes the measurement
automatically when the jaws of the clamp are opened. This can be useful
when you have only one hand free to make a measurement.
2.2.4 ALARMS
To facilitate making measurements, you can program an alarm on the
impedance measurement (see §2.4) and/or the current measurement
(see §2.4). You can then be aware whether the measurement is
acceptable without looking at the display.
The alarm indicator on the display
blinks and the instrument emits a
continuous audible signal.
To eliminate the audible signal, press
and hold the ► key.
If you set alarms on both the
impedance and the current, and both
alarm thresholds are exceeded, the
alarm on the current has priority.
2.3. CURRENT MEASUREMENT
The current measurement alone is identical to the current measurement
with the impedance measurement.
Set the switch to
A.
Press the trigger to open the jaws of the clamp and
clamp the conductor in which the current to be
measured flows.

Clamp-On Ground Tester Model 6418 13
When the measurement has stabilized, you can press the HOLD key to
freeze it and/or MEM to record it in memory. You can also use the
AUTO-HOLD function (see §2.4) to freeze the measurement
automatically when the clamp jaws are opened. This can be useful when
you have only one hand free to make a measurement. To facilitate
making measurements, you can configure an alarm on the current
measurement value (see §2.4).
2.4. CONFIGURATION (SET-UP)
Set the switch to SET-UP.
Use the ▼ and ▲ keys to scroll through the screens of the SET-UP
menu.
CLR (erase memory) menu.
Press the ► key to enter the CLR menu.
To cancel, press ►.
To erase all records, press and hold the ▲ and ▼ keys
simultaneously. The instrument emits 5 audible beeps before
erasing the memory.
SND menu (activation of the sound).
Press ► to enter the SND menu. Use ▲ and ▼ to display or
hide the symbol.
When is displayed, the instrument emits an audible
signal when keys are pressed and when alarm thresholds are
crossed.
Confirm by pressing ►.
During the measurements (when the switch is set to Ω+A or
A), a long press on ► activates/deactivates the audible
signal.
STOP menu (automatic standby).
Press ► to enter the STOP menu. Use ▲ and ▼ to display
or hide the symbol (permanent operation).
When is displayed, automatic switching of the instrument to
standby at the end of 5 minutes is disabled. Confirm by
pressing ►.
ALΩ menu (impedance alarm).
Press ► to enter the ALΩ menu. Use ▲ and ▼ to scroll
through the display:
: no impedance alarm.
: impedance alarm activates when impedance >10Ω.
: impedance alarm activates when impedance <10Ω.
Press ►; the alarm threshold blinks. Set it using ▲ and ▼.
Acceptable values are between 1 and 199Ω. A long press
scrolls the values faster.
Confirm by pressing ►.

14 Clamp-On Ground Tester Model 6418
AL A menu (current alarm).
Press ► to enter the AL A menu. Use ▲ and ▼ to scroll
through the display:
: no current measurement alarm.
: current alarm activates when current >30mA.
Press ►; the alarm threshold blink. Set it using ▲ and ▼.
Acceptable values are between 1mA and 20.0A. A long press
scrolls the values faster.
Press ► to confirm.
DATE menu (setting of the date)
Press ► to enter the DATE menu. Use ▲ and ▼ to set the
year. Press ►; the month setting blinks. Set it using ▲ and
▼.
Do the same for the day setting and confirm with the ► key.
For a more detailed procedure, see §1.4.
HOUR menu (setting of the time)
Press ► to enter the HOUR menu. Use ▲ and ▼to choose
24h or 12h (A or P) form. Press ►; the hours setting blinks.
Set this using ▲and ▼. Press ►; the minutes setting blinks.
Set this using ▲ and ▼; confirm by pressing ►.
For a more detailed procedure, see §1.4.
HOLD menu (activation of the AUTO-HOLD function)
Press ►to enter the AUTO-HOLD menu. Use ▲and ▼to display
or hide the symbol. When this symbol is displayed, the
AUTO-HOLD function is activated. In this mode, when the
measurement is stable, it is frozen when the clamp is opened.
Confirm by pressing ►.
VER menu (display of the software version)
Press ► to display the software version number.
Press ▼ to display the instrument serial number.
CAL menu (not used)

Clamp-On Ground Tester Model 6418 15
2.5. ERRORS
During the measurement, the instrument reports any errors.
Display of the NOISE symbol during the impedance
measurement indicates that the current (>5A) or voltage
(ZxI> 25V) is too high, making the accuracy of the
displayed measurement uncertain.
When the current exceeds 10A, the impedance
measurement is not displayed (dashes appear in the
measurement field).
When the impedance measurement is >1200Ω, the
instrument displays OR.
When the current measurement is >20A, the
instrument so indicates.
When the impedance measurement is <1Ω, the display
alternately indicates the measured value and LOOP,
indicating the value is very low for a valid ground
impedance measurement and most likely indicates the
measurement is through a wire loop rather than through
the earth.
2.6. AUTOMATIC STOP
After 5 minutes of inactivity, the instrument enters to standby mode.
Press any key or turn the switch to any setting to exit standby. The
instrument restarts without repeating the calibration procedure if it has not
been on standby for more than 15 minutes. It is possible to disable
automatic standby; refer to §2.4 (STOP menu). The symbol is then
displayed.

16 Clamp-On Ground Tester Model 6418
2.7. STORAGE
2.7.1. RECORDING A MEASUREMENT
To record a measurement, press the MEM key.
You can first press the HOLD key to freeze the measurement.
To record a measurement, the batteries must not be
discharged (the symbol must not be displayed).
The measurement is
recorded in the memory slot
of which the number is
displayed (in this example,
slot number 2).
It is recorded with all
accompanying information:
date and time
any alarms and their
status (triggered or not)
any errors (NOISE, OR,
LOOP)
ancillary displays (HOLD,
)
2.7.2. VIEWING RECORDINGS
Set the
switch to MR.
The instrument displays the last measurement
recorded. Press ► to display the date and time.
Use ▲ and ▼ to scroll through all of the recorded measurements.

Clamp-On Ground Tester Model 6418 17
2.7.3. ERASING ALL RECORDINGS
Set the switch to SET-UP.,
then follow the procedure
described in §2.4 in the CLR
menu.
When you return to the MR
setting, the instrument
indicates that the memory is
empty.
2.7.4. MEMORY FULL
You can record up to 300 measurements (numbered from 0 to 299).
If youcontinue recording, measurement number 300 overwrites
measurement number 0, measurement 301 overwrites measurement 1,
and so on.
The instrument reports this by alternately displaying FULL and the
memory slot number.
You can continue in this way up to number 9999, at which point
recording becomes disabled and you must erase the memory to be able
to resume recording.

18 Clamp-On Ground Tester Model 6418
3. TECHNICAL CHARACTERISTICS
3.1. GENERAL REFERENCE CONDITIONS
Quantities of influence
Reference values
Temperature
73 ±5°F (23 ±3°C)
Relative humidity
50 ±10%RH
Supply voltage
6 ±0.2V
Electric field
<1V/m
Magnetic field
<40A/m
Operating position
clamp horizontal
Position of the conductor in the jaws
centered
Adjacent conductors carrying current in
impedance measurement
At least 3.9” (10cm)
Magnetic mass
At least 3.9” (10cm)
Frequency
50Hz, sinusoidal
Level of distortion
<0.5%
Current present in impedance measurement
0mA
The intrinsic uncertainty is the error defined under the conditions of
reference.
The operational uncertainty is the intrinsic uncertainty plus the
variation of the quantities of influence (position, supply voltage,
temperature) as defined in standard IEC 61557. The uncertainties are
expressed as a percentage of the reading (R) and as a number of
display counts (ct): ±(a%R+# ct).
3.2. ELECTRICAL CHARACTERISTICS
3.2.1. IMPEDANCE MEASUREMENTS
Particular conditions of reference
Inductance in series with the resistance: zero.
Specified
measurement
range
0.010 to
0.099Ω
0.10 to
0.99Ω
1.0 to
49.9Ω
50 to
149Ω
Resolution (ct) 1 mΩ 10 mΩ 100 mΩ 1 Ω
Intrinsic
uncertainty (δ)
± (1.5%R +
0.01Ω)
± (1.5%R + 2
ct)
± (1.5%R +
2 ct)
± (2.5%
R +
2 ct)
No-load voltage ≤ 45 mV to 2083 Hz

Clamp-On Ground Tester Model 6418 19
Specified
measurement
range
150 to
245Ω
250 to 440Ω 450 to
640Ω
650 to
1200Ω
Resolution (ct) 5 Ω 10 Ω 10 Ω 50 Ω
Intrinsic
uncertainty (δ)
± (5%R +
2 ct)
± (10%R +
2 ct)
± (15%R +
2 ct)
± (20%R
+ 2 ct)
No-load voltage ≤ 45 mV to 2083 Hz
3.2.2 CURRENT MEASUREMENTS
Particular conditions of reference
Frequency of the signal 47 to 800Hz
Specified
measurement
range
0.500 to
9.950mA
10.00 to
99.90mA
100.0 to
299.0mA
0.300 to
2.990A
Resolution (ct)
50 µA
100 µA
1 mA
10 mA
Intrinsic
uncertainty (δ)
± (2%R +
200 µA)
± (2%R + 1 ct)
± (2%R +
1 ct)
± (2%R +
1 ct)
Specified measurement range 3.00 to 20.00 A
Resolution (ct)
100 mA
Intrinsic uncertainty (
δ
)
± (2%R + 1 ct)
Beyond 20A and 800Hz, the clamp may overheat dangerously.
3.2.3. STORAGE
Number of records: 300.
3.3. INFLUENCES
Z = impedance
I = current
δ= intrinsic uncertainty given in §3.2.
ct = resolution given in §3.2.

20 Clamp-On Ground Tester Model 6418
Impedance measurement:
Quantities of
influence
Range of
influence
Influence
Typical
Maximum
Temperature
-4 to 131°F (-20 to
+ 55 °C)
0.5 δ/ 10°C ± ct 1.5 δ/ 10°C + ct
Relative
humidity
10 to 90% RH
1 δ± ct 2 δ± ct
Supply
voltage
4 to 6.5 V
0.05 δ± ct 0.1 δ± ct
Position of
conductor
from the edge to
the center
Z < 450 Ω
0.2 δ± ct
Z ≥450 Ω
0.5
δ
± ct
Z < 450 Ω
0.4 δ± ct
Z ≥450 Ω
1
δ
± ct
Position of
clamp +/- 180° Z < 450 Ω
0.25 δ± ct
Z ≥450 Ω
0.5
δ
± ct
Z < 450 Ω
0.5 δ± ct
Z ≥450 Ω
1
δ
± ct
Proximity to
magnetic
mass
Sheet steel
1mm thick
against air gap
0.1 δ± ct 0.5 δ± ct
Magnetic field
50/60Hz
30 A/m 0.05 δ± ct 0.1 δ± ct
Adjacent
conductor I < 40A
Z < 250 Ω
0.25
δ
± ct
Z ≥250 Ω
0.4
δ
± ct
Z < 250 Ω
0.5
δ
± ct
Z ≥250 Ω
0.8
δ
± ct
Leakage
current in the
grounding
system from
50 to 60Hz
I <10 A. ZxI
<75 V
Z <
100 Ω
Z x I <
20 V
0.5 δ± ct 1 δ± ct
20 V ≤Z x
I < 40 V
1 δ± ct 3 δ± ct
40 V ≤
Z x I
2 δ± ct 4 δ± ct
Z ≥100 Ω
0.5
δ
± ct
1
δ
± ct
Ground
inductance
0 to 500 µH
Instrument displays Z at measurement frequency
(2083Hz)