Benning CM 2-1 User manual

BENNING CM 2-1
Operating manual
Translation of the German original version
5191 / 07/2021 en

Legal notice
5191 / 07/2021 enBENNING CM 2-12
Legal notice
Notes concerning the documentation
Ensure that the applicable documentation is used for this product. For safe handling, knowledge
that is provided in these instructions is required.
The product may only be handled while following this documentation, particularly the safety
instructions and warnings it contains. The personnel must be qualified for the respective task
and have the capability to recognise risks and prevent possible dangers.
Manufacturer and holder of rights
BENNING Elektrotechnik und Elektronik GmbH&Co.KG
Münsterstraße135–137
46397 Bocholt
Germany
Phone: +492871/93‑0
E-Mail: [email protected]
Internet: www.benning.de
Commercial register Coesfeld HRA No. 4661
Copyright
© 2021, BENNING Elektrotechnik und Elektronik GmbH&Co.KG
All rights reserved.
This document – particularly all of the contents, texts, photographs and graphics that it contains
– are protected by copyright.
No part of this documentation or the associated contents may be reproduced or edited, copied
or distributed using electronic media in any form (printed, photocopied or using any other
method) without express written permission.
Disclaimer
The contents of the documentation has been checked to ensure that it corresponds to the
hardware and software described. Nevertheless, deviations cannot be ruled out, so Benning
cannot guarantee complete correspondence. The contents of this documentation are checked
at regular intervals, and any corrections that are needed are contained in the versions that
follow.
General non-discrimination
Benning is aware of the importance of language with regard to the equality of men and women,
and endeavours to take this into account at all times. To improve readability, we have refrained
from consistently using differentiating formulations.

Table of contents
Table of contents
1 Introduction................................................................................................................................................7
1.1 General notes........................................................................................................................7
1.2 History ...................................................................................................................................8
1.3 Service & support..................................................................................................................9
2 Safety........................................................................................................................................................10
2.1 Warning system ..................................................................................................................10
2.2 Standards applied ...............................................................................................................10
2.3 Symbols used......................................................................................................................11
2.4 Intended use .......................................................................................................................12
2.5 Special types of risks ..........................................................................................................14
3 Scope of delivery.....................................................................................................................................15
4 Device description...................................................................................................................................17
4.1 Device structure ..................................................................................................................17
4.2 Functions.............................................................................................................................20
4.2.1 “ACHFR/ DCAZERO” key ................................................................................................20
4.2.2 “HOLD / MIN MAX” key.......................................................................................................21
4.2.3 Further setting options ........................................................................................................21
4.3 Measuring ranges ...............................................................................................................22
4.3.1 Voltage ranges ....................................................................................................................23
4.3.2 Current ranges ....................................................................................................................24
4.3.3 Resistance ranges ..............................................................................................................24
4.3.4 Continuity test .....................................................................................................................24
4.3.5 Diode test ............................................................................................................................25
4.3.6 Capacitance ranges ............................................................................................................25
4.3.7 Frequency ranges ...............................................................................................................25
5 Operation..................................................................................................................................................26
5.1 Requirements for tests and measurements ........................................................................26
5.2 Connecting the safety measuring lines ...............................................................................27
5.3 Voltage or frequency measurement ....................................................................................28
5.4 Current or frequency measurement ....................................................................................30
5.5 Resistance measurement ...................................................................................................31
5.6 Continuity testing.................................................................................................................32
5.7 Capacitance measurement .................................................................................................32
5.8 Diode testing .......................................................................................................................33
5.9 Voltage indicator .................................................................................................................33
5.9.1 Non-contact phase testing ..................................................................................................34
5191 / 07/2021 en BENNING CM 2-1 3

Table of contents
5.9.2 External conductor or phase testing....................................................................................35
6 Maintenance.............................................................................................................................................36
6.1 Maintenance schedule ........................................................................................................36
6.2 Making the device free of voltage .......................................................................................36
6.3 Cleaning the device.............................................................................................................37
6.4 Replacing the batteries .......................................................................................................38
6.5 Calibrating the device..........................................................................................................38
7 Technical data..........................................................................................................................................39
8 Disposal and environmental protection ................................................................................................40
Index .........................................................................................................................................................41
5191 / 07/2021 enBENNING CM 2-14

Table of figures
Table of figures
Figure 1 BENNINGCFlex1 ....................................................................................................................... 15
Figure 2 BENNINGTA1............................................................................................................................ 15
Figure 3 BENNINGTA2............................................................................................................................ 16
Figure 4 BENNINGTA3............................................................................................................................ 16
Figure 5 Ø 4mm measuring lines with 2mm measuring probe ................................................................ 16
Figure 6 BENNING CM 2‑1 device structure ............................................................................................. 17
Figure 7 Rotary switch ............................................................................................................................... 18
Figure 8 Digital display............................................................................................................................... 19
Figure 9 “MODE” function .......................................................................................................................... 20
Figure 10 AC voltage or frequency measurement ....................................................................................... 28
Figure 11 DC voltage measurement ............................................................................................................ 29
Figure 12 Current or frequency measurement............................................................................................. 30
Figure 13 Resistance, capacitance measurement, continuity or diode testing ............................................ 31
Figure 14 Non-contact phase testing ........................................................................................................... 34
Figure 15 Battery replacement (exemplary)................................................................................................. 38
5191 / 07/2021 en BENNING CM 2-1 5

List of tables
List of tables
Table 1 History.......................................................................................................................................... 8
Table 2 Symbols on the device................................................................................................................. 11
Table 3 Symbols used in the operating manual........................................................................................ 11
Table 4 Low-pass filter.............................................................................................................................. 20
Table 5 AC voltage ranges (V-AC) ........................................................................................................... 23
Table 6 DC voltage ranges (V-DC)........................................................................................................... 23
Table 7 Voltage ranges (LoZ, AutoV) ....................................................................................................... 23
Table 8 AC ranges (A-AC)........................................................................................................................ 24
Table 9 DC ranges (A-DC)........................................................................................................................ 24
Table 10 Resistance ranges (Ω) ................................................................................................................. 24
Table 11 Continuity test .............................................................................................................................. 24
Table 12 Diode test..................................................................................................................................... 25
Table 13 Capacitance ranges (μF) ............................................................................................................. 25
Table 14 Frequency ranges (Hz) ................................................................................................................ 25
Table 15 Maintenance schedule................................................................................................................. 36
Table 16 Technical data ............................................................................................................................. 39
5191 / 07/2021 enBENNING CM 2-16

Introduction
1.1 General notes
5191 / 07/2021 en BENNING CM 2-1 7
1 Introduction
The TRUE RMS digital current clamp multimeter BENNINGCM2‑1 described here (in the
following only referred to as “device”) is intended for testing in circuits with a nominal voltage up
to a maximum of 600V‑AC or 600V‑DC. The device enables you to perform the following tests
and measurements:
• DC and AC voltage measurement
• DC and AC measurement
• Resistance measurement
• Diode and continuity test
• Capacitance measurement
• Frequency measurement
Further information
http://tms.benning.de/cm2‑1
On the Internet, you will find the following additional information directly at the specified link or
at www.benning.de (product search):
• Operating manual of the device in several languages
• Further information depending on the device (e.g. brochures, technical reports, FAQs)
1.1 General notes
Target group
This operating manual is intended for the following groups of people:
• Qualified electricians and electrotechnically trained personnel
Required basic knowledge
To understand these operating manual, you will need general knowledge of testing and
measuring equipment. Moreover, you will need basic knowledge of the following issues:
• General electrical engineering
Purpose of the operating manual
This operating manual describes the device and provide you information about how to handle it.
Keep this operating manual in a safe place for later use. Read this operating manual before
handling the device and follow the instructions.

1.2 History
Introduction
5191 / 07/2021 enBENNING CM 2-18
NOTE
Disclaimer of liability
Please make sure that any person using the device has read and understood the instructions of
this operating manual before handling the device and that the instructions are adhered to in all
points. Non-observance of this operating manual might result in product damage, property
damage and/or personal injury.
Benning assumes no liability for damage and malfunctions resulting from the failure to observe
the instructions in this operating manual.
The devices are subject to continuous further development. Benning reserves the right to make
changes to the device’s design, configuration and technology. The information in this operating
manual corresponds to the state of technical knowledge at the time of printing. For this reason,
no claims for certain device characteristics can be derived from the contents of this operating
manual.
Information in this operating manual can be changed at any time without prior notice. Benning is
not obligated to make amendments to this operating manual or to keep it up to date.
Direct any technical questions to Technical Support [}page9].
Trademarks
All trade marks that are used are the property of their respective owners, even if they are not
separately marked as such.
1.2 History
Release number Amendments
07/2021 • Initial release
Table1: History

Introduction
1.3 Service & support
5191 / 07/2021 en BENNING CM 2-1 9
1.3 Service & support
Please contact your specialty retailer or the BENNINGServiceCenter for any repair or service
work that might be required.
Technical support
Please contact our Technicalsupport for technical questions on handling the device.
Phone: +49287193-555
Fax: +49287193‑6555
E-Mail: [email protected]
Internet: www.benning.de
Returns management
Easily and conveniently use the BENNING returns portal for a quick and smooth returns
processing:
https://www.benning.de/service-de/retourenabwicklung.html
Phone: +49287193-554
E-Mail: [email protected]
Return address
BENNING Elektrotechnik und Elektronik GmbH & Co. KG
Retourenmanagement
Robert-Bosch-Str. 20
D - 46397 Bocholt

2.1 Warning system
Safety
5191 / 07/2021 enBENNING CM 2-110
2 Safety
2.1 Warning system
This operating manual contains notes that must be taken into consideration for your personal
safety and in order to avoid injuries and damage to property. Warnings about your personal
safety and to prevent personal injuries are marked with a warning triangle. Warnings on sole
prevention of material damage are shown without a warning triangle. The warnings are shown
in descending order depending on the hazard level as follows.
DANGER
Extremely dangerous situation for humans
If you do not pay attention to this warning, irreversible or deadly injuries will occur.
WARNING
Hazard to humans
If you do not pay attention to this warning, irreversible or deadly injuries could occur.
CAUTION
Minor hazard to humans
If you do not pay attention to this warning, minor or moderate injuries could occur.
NOTICE
Danger to property, not to persons
If you do not pay attention to this warning, material damage could occur.
If multiple hazard levels occur, the warning for the highest respective hazard level will be used.
In addition, a warning about personal injuries can also include a warning about material
damage.
2.2 Standards applied
The device has been built and tested in compliance with the following standards and has left the
factory in perfectly safe condition.
• IEC/ DINEN61010-1 (VDE0411‑1)
• IEC/ DINEN61010-2‑032 (VDE0411‑2‑032)
• IEC/ DINEN61010-2-033 (VDE0411‑2‑033)
• IEC/ DINEN 61010-031 (VDE0411‑031)

Safety
2.3 Symbols used
5191 / 07/2021 en BENNING CM 2-1 11
2.3 Symbols used
Symbols on the device
Symbol Meaning
Application around and removal from hazardous live conductors is
permitted.
Please observe the information provided in this operating manual in
order to avoid dangers.
Warning of electrical danger! Please observe the information provided
in this operating manual in order to avoid dangers.
CATII Measuring categoryII is applicable to testing and measuring circuits
which are directly connected to user connections (e.g. sockets) of the
low-voltage mains installation.
CATIII Measuring categoryIII is applicable to testing and measuring circuits
connected to the distribution circuit of the low-voltage mains installation
of a building.
CATIV Measuring categoryIV is applicable to testing and measuring circuits
connected to the feeding point of the low-voltage mains installation of a
building.
The device complies with EUdirectives.
At the end of product life, dispose of the unserviceable device via
appropriate collecting facilities provided in your community.
The device is provided with protective insulation (protection classII).
Please observe the operating manual.
(DC) direct voltage or direct current
(AC) alternating voltage or alternating current
Earth (voltage to earth)
Table2: Symbols on the device
Symbols used in the operating manual
Symbol Meaning
General warning
Warning of electric voltage!
Table3: Symbols used in the operating manual

2.4 Intended use
Safety
5191 / 07/2021 enBENNING CM 2-112
2.4 Intended use
Only use the device within the framework of the corresponding technical data. Any operating
conditions that deviate from this shall be considered as improper use. Solely the user of the
device shall be liable for any resulting damage.
In particular, note the following:
• In case of improper use, the liability and warranty claims become void. Solely the user of the
device shall be liable for any damage resulting from improper use. Uses not complying with
the intended use include e.g.:
– Use of components, accessories, spare or replacement parts that have not been
released and approved for the respective application by Benning
– Non-observance, manipulation, changes or misuse of the operating manual or the
instructions and notes contained therein
– Any form of misuse of the device
– Any use other than or beyond that described in this operating manual
• Warranty and liability claims are generally excluded if damage is due to force majeure.
• If any prescribed services are not performed regularly or not on time according to
manufacturer specifications during the warranty period, a decision about a warranty claim
can only be made once the findings are available.
Direct any questions to Technical Support [}page9].
Using the device
Please observe the following basic obligations when using the device:
• The device may only be used in a technically perfect and safe condition. Always check the
device for damages before using it.
• Make sure the personnel using the device is qualified for the respective task.
• Observe relevant regulations on occupational safety and health as well as those on
environmental protection.
• The device may only be used in dry environments.
• Use the device only in electric circuits of overvoltage categoryIII with a conductor for a
maximum of 600V or overvoltage categoryIV with a conductor for a maximum of 300V to
earth.
• Use suitable (approved) safety measuring lines. For measurements in electric circuits of
overvoltage categoryIII orIV, the protruding conductive part of a contact tip of the safety
measuring line must not be longer than 4mm. Before measuring, attach the enclosed
protective caps onto the contact tips (marked with CATIII and CATIV).
• In order to detect a dangerous voltage and to prevent any danger, always measure a
present voltage first without low-pass filter (without high-frequency suppression “HFR”).
• In order to prevent danger due to incorrect measurements, replace discharged batteries
immediately.

Safety
2.4 Intended use
5191 / 07/2021 en BENNING CM 2-1 13
WARNING
Dangerous voltage
Danger to life or serious injury is possible due to contact with high electric voltage in case of
incorrect operation.
• Do not touch the bare measuring probe tips of the safety measuring lines.
• Connect the safety measuring lines to the correspondingly marked measuring jacks of the
device and check them for tight fit.
• Only use approved safety measuring lines.
• Attach the protective caps to the contact tips of the safety measuring lines (circuits of
overvoltage category CATIII orIV).
WARNING
Opening the device
Danger to life or serious injury is possible due to contact with high electric voltage when opening
the device. The device might get damaged.
• Make sure that the device is free of voltage before opening the battery compartment.
• Do not open the device (except for the battery compartment).
• Please contact your specialty retailer or the returns management for any repairs [}page9].
Securing the device
If the device is not in a technically perfect and operationally safe condition, safe operation is no
longer guaranteed. Make sure that the following measures are taken:
• Switch off the device.
• Remove the device from the measuring point.
• Secure the device against unintentional operation.
The following characteristics indicate that safe operation is no longer guaranteed:
• The device (housing or safety measuring lines) shows visible damage or is damp/wet.
• The insulation of the safety measuring lines is damaged.
• The device does not work properly in compliance with regulations (e.g. errors during
measurements).
• The device shows recognisable consequences of prolonged storage under inadmissible
conditions.
• The device shows recognisable consequences of extraordinary stress due to transport.

2.5 Special types of risks
Safety
5191 / 07/2021 enBENNING CM 2-114
2.5 Special types of risks
DANGER
Bare conductors or main line carriers
Danger to life or serious injury is possible due to contact with high electric voltage when working
with bare conductors or main line carriers.
• Please observe relevant regulations on occupational safety and health.
• If necessary, use appropriate protective equipment.
WARNING
Dangerous voltage
Danger to life or serious injury is possible due to contact with high electric voltage when working
on live components or equipment. Even low voltages from 30V‑AC and 60V‑DC on can be
dangerous to human life!
• Please observe relevant regulations on occupational safety and health.
• If necessary, use appropriate protective equipment.

Scope of delivery
2.5 Special types of risks
5191 / 07/2021 en BENNING CM 2-1 15
3 Scope of delivery
The scope of delivery of the device includes the following components:
• 1x TRUERMS digital current clamp multimeter BENNINGCM2‑1
• Safety measuring lines (item no.: 044145):
– 1x safety measuring line (red, l=1.4m)
– 1x safety measuring line (black, l=1.4m)
• 1x compact protective pouch
• 2x 1.5V micro batteries (AAA/ IECLR03)
• 1x operating manual
Optional accessories
• Flexible AC current transformer BENNINGCFlex1 (item no.: 044068)
ACrange: 30A/ 300A/ 3 000A
Figure1: BENNINGCFlex1
• Set of safety measuring lines BENNINGTA1 (item no.: 044124)
Ø 4mm alligator clips, 2‑piece, red/ black, professional version, CATIII 1 000V, 36A
Figure2: BENNINGTA1

2.5 Special types of risks
Scope of delivery
5191 / 07/2021 enBENNING CM 2-116
• Set of safety measuring lines BENNINGTA2 (item no.: 044125)
Set of Ø 4mm measuring lines, 6‑piece, red/ black, professional version, consisting of:
– Measuring lines (silicone) (CATIII 1 000V)
– Test probes (4mm measuring probe, CATII 1 000V)
– Alligator clips (CATIII 1 000V)
Figure3: BENNINGTA2
• Set of safety measuring lines BENNINGTA3 (item no.: 044126)
Set of Ø 4mm measuring lines, 8‑piece, red/ black, professional version, CATIII 1 000V,
consisting of:
– Measuring lines (silicone)
– Test probes (slender measuring probe)
– Grabber clips
– Alligator clips
Figure4: BENNINGTA3
• Set of Ø4mm safety measuring lines with 2mm measuring probe (item no.: 044146)
Ø4mm measuring lines, 2‑piece, red/ black, L=1.40m, with 2mm measuring probe,
CATIV 600V/ CATIII 1 000V (with protective caps), CATII 1 000V (without protective
caps)
Figure5: Ø 4mm measuring lines with 2mm measuring probe

Device description
4.1 Device structure
5191 / 07/2021 en BENNING CM 2-1 17
4 Device description
4.1 Device structure
1
2
3
4
5
6
7
8
9
Figure6: BENNING CM 2‑1 device structure
1 Measuring clamp (for clamping the
conductor)
2 “ACHFR/ DCAZERO” key
3 “HOLD/ MINMAX” key 4 Rotary switch
5 Digital display 6 “+” jack
7 COM jack 8 Opening lever
9 Current clamp bulge (protection against
contact with conductor)
Rear panel of the device
• Battery compartment with battery compartment cover
The device is powered by two 1.5V micro batteries (AAA/ IECLR03).
• 2 labels on the battery compartment cover (notes and information about the device)
• Serial number (label)

4.1 Device structure
Device description
5191 / 07/2021 enBENNING CM 2-118
Rotary switch
You can set the desired test or measurement by means of the rotary switch.
12
34
5
6
Figure7: Rotary switch
1 Current or frequency measurement 2 Resistance, capacitance measurement,
continuity or diode testing
3 Setting of the rotary switch 4 Voltage measurement or voltage
indicator
5 Device switched off 6 Voltage or frequency measurement

Device description
4.1 Device structure
5191 / 07/2021 en BENNING CM 2-1 19
Digital display
The digital display is divided into different sections:
• Display of the currently set function and unit
• Display range: 4‑digit liquid crystal display (LCD) with a font size of 14mm and decimal
points. The highest display value is 4 000digits.
• Battery status: Indicates the state of charge of the batteries (max. 3segments). The
batteries are discharged as soon as all segments have disappeared and the symbol is
flashing. When switching it on, the device additionally displays the battery status:
“FULL” (full), “HALF” (half) or “Lo” (low).
• Polarity display (automatic): Indicates a polarity contrary to the jack definition with “-”.
• Dangerous contact voltage (symbol is flashing)
The nominal measuring rate of the device is 2measurements per second for the digital display.
By means of a light sensor, the display illumination switches on automatically in dark lighting
conditions.
1
2
3
4
5
Figure8: Digital display
1 Display of functions and units 2 Display range
3 Battery status 4 Polarity
5 Dangerous contact voltage

4.2 Functions
Device description
5191 / 07/2021 enBENNING CM 2-120
4.2 Functions
Use the rotary switch to switch the device on (desired measuring function) or off (“OFF”).
The device confirms each operation of keys and the rotary switch with an acoustic signal.
Invalid keystrokes are confirmed with a double beep. The device switches off automatically after
approx. 20minutes (APO, Auto-Power-Off). To switch the device back on, first set the rotary
switch to switch position “OFF” and then set the desired measuring function.
4.2.1 “ACHFR/ DCAZERO” key
The “ACHFR/ DCAZERO” key has three functions.
“MODE” function
Press the “ACHFR/ DCAZERO” key to select the second, third or fourth function of the
respective rotary switch position.
Figure9: “MODE” function
“HFR(AC)” function (low-pass filter)
The “HFR(AC)” function is intended to connect a low-pass filter (high-frequency suppression)
during AC current or AC voltage measurement. With this low-pass filter, it is possible to filter out
high-frequency pulses, e.g. on pulsed motor drives.
Press and hold the “ACHFR/ DCAZERO” key for approx.2s to enable or disable the function.
With the function being enabled, the “HFR” symbol appears on the digital display.
The limiting frequency (-3dB) of the filter is fg=800Hz. When reaching the limiting
frequencyfg, the displayed value is lower by a factor of 0.707 than the actual value without
filter.
Without low-pass filter With low-pass filter
Table4: Low-pass filter