METREL MD 9272 User manual

MD 9272 Leakage Clamp Meter with Power
Functions
MD 9272
Instruction manual
Bedienungsanleitung
Version 2.2.11; Code 20 752 381

2
Distributor:
METREL d.o.o.
Ljubljanska cesta 77
1354 Horjul
SLOVENIA
E-mail: [email protected]
web site: http://www.metrel.si/
Metrel GmbH
Mess und Prüftechnik
Orchideenstrasse 24
90542 Eckental -Brand
Germany
E-mail: [email protected]
Internet: http://www.metrel.de/
Metrel UK Ltd.
Test & Measurement
Unit 16, 1st Qtr Business Park
Blenheim Road
Epsom
Surrey
KT19 9QN,
Great Britain
E-mail: [email protected]
Internet: http://www.metrel.co.uk

3
Mark on your equipment certifies that it meets requirements of all
subjected EU regulations.
Die Kennzeichnung auf Ihrem Gerät bestätigt, dass es den Anforderungen
aller geltenden EU-Vorschriften entspricht.
Oznaka na tej opremi potrjuje, da ta oprema ustreza zahtevam vseh EU
Hereby, Metrel d.d. declares that the MD 9272 is in compliance with
subjected EU directive. The full text of the EU declaration of conformity is
available at the following internet address http://www.metrel.si/DoC.
Hiermit erklärt Metrel d.d., dass der MD 9272 den geltenden EU-
Richtlinien entspricht. Der vollständige Text der EU-
Konformitätserklärung ist unter der folgenden Internetadresse
https://www.metrel.si/DoC verfügbar.
Metrel d. d. izjavlja, da je MD 9272 v skladu z direktivo EU. Polno besedilo
https://www.metrel.si/DoC.
Mark on your equipment certifies that it meets requirements of all
subjected UK regulations.
Hereby, Metrel d.d. declares that the MD 9272 is in compliance with
subjected UK regulations. The full text of the UK declaration of conformity
is available at the following internet address https://www.metrel.si/UK-
DoC.
© 2023 METREL
The trade names Metrel®, Smartec®, Eurotest®, Auto Sequence®are trademarks registered in
Europe and other countries.
No part of this publication may be reproduced or utilized in any form or by any means without
permission in writing from METREL.

MD 9272 Leakage Clamp Meter Contents/Inhalt/Vsebina
4
Contents/Inhalt/Vsebina
English
1. General Instructions............................................................................................................5
2. Instrument Description .......................................................................................................7
3. Description of Functions ................................................................................................... 12
4. Data Hold and Recording Mode.........................................................................................18
5. Technical Specifications.................................................................................................... 19
6. Maintenance .....................................................................................................................23
7. Limited Warranty..............................................................................................................24
Deutch
1. Allgemeine Anweisungen..................................................................................................25
2. Gerätebeschreibung ..........................................................................................................27
3. Beschreibung der Funktionen............................................................................................32
4. Datenspeicherungsmodus.................................................................................................39
5. Technische Daten..............................................................................................................40
6. Wartung............................................................................................................................44
7. Begrenzte Gewährleistung ................................................................................................45
Slovensko
1. ...............................................................................................................46
2. Opis instrumenta ..............................................................................................................48
3. Opis funkcij .......................................................................................................................52
4. .............................................................................................58
5. ................................................................................................................59
6. .......................................................................................................................62
7. Garancijska izjava..............................................................................................................63

MD 9272 Leakage Clamp Meter General Instructions
5
1. General Instructions
This instrument has been designed in accordance with IEC 61010 series standards that regulate
safetyrequirementsfortheelectronicmeasuringequipmentandcurrentmeasuringclamps.The
user manual shall be read carefully in order to get the best results from this equipment. Safety
instructions shall always be followed.
Safety measures
General
Iftheclamp-meterisusedinamannernotspecifiedinthis ,theprotection
provided by the equipment may be impaired!
This equipment can be used to carry out measurements in the CAT.III1600V
environment.
When using this clamp meter, the user should comply with all the safety measures
regarding:
-Protection against the electric current hazards.
-Protection of the clamp A-meter against incorrect use.
-Protection against electric shock hazard.
For operator security, only the test probes supplied with the instrument shall be used.
Do not use the clamp-meter and its accessories ifany damage is detected!
During use
Before carrying out any measurements, the instrument shall be warmed up for at least
30 seconds.
If the clamp-meter is used near any high level noise source, the screen might become
unstable or there may appear errors in display.
The maximum limits of the input value shown in the technical specification tables shall
not be exceeded in order to avoid damage to the equipment.
The rotary switch shall be in the correct position before starting a new measurement.
Exerciseextremecautionwhenworkingnearbareconductorsorbus-bars.Anyaccidental
contact with the bare conductor may cause an electric shock.
Work carefully with voltages higher than 60 VDC. or 30 VACrms to avoid a risk of electric
shock.
The test probe(s) shall be disconnected from the circuit that is being tested before
changing the function.
During measurement fingers shall always be kept behind the protection guard (check
point 2 of this manual)
The battery shall be changed when the symbol is shown in order to avoid incorrect
measurement readings.
(1): Measurement protective category III covers measurements performed in the building
installation. Examples are measurements on distribution boards, circuit-breakers, wiring,
including cables, bus-bars, junction boxes, switches, socket-outlets in the fixed installation,
equipment for industrial use, and some other equipment, for example, stationary motors with
permanent connection to thefixed installation.

MD 9272 Leakage Clamp Meter General Instructions
6
Symbols
The symbols used in this manual and in the equipment are as follows:
Warning: check the instruction manual. Any incorrect use may cause damage to the
equipment or itscomponents.
Earth.
Complies with European Union Directives.
Complies with UK regulations.
This equipment hasdouble insulation.
Allows use with dangerous voltage conductors.
Instructions
Before openingthe equipment,theinstrumentshallbedisconnectedfrom anysourceof
electricity supply and it shall be ensured that the operator is free from static electricity,
as this could damage or destroy the internal components.
Before using this equipment it shall be checked for proper operation; by turning the
rotaryswitchtoAorVpositionandverification ofa doublebeep andthe display activity.
Any adjustment, repair or maintenance work on the clamp A-meter must only be carried
out by a qualified person, always taking into account theinstructions in this manual.
operation of the equipment, and with the risks implied. This person should be trained
and authorized to charge and discharge energy from the circuits and the equipment in
accordance with established practice.
When the equipment is open, some internal components can retain dangerous power,
even after the equipment has been disconnected from the mains or battery electricity
supply.
In the case of abnormaloperation and/or performance, the equipment shall not be used
until it has been repaired and verified.
The batteryshallberemoved fromtheclamp-meter ifitisnot goingto beused foralong
period, and shall not be stored at a high temperature or in a humid environment.
WARNING
This equipment is designed according to EMC standards for portable measuring and test
instruments. Regardless, it is recommended to disconnect the test leads during clamp
measurements, as a high radiofrequency electromagnetic field might be present, which can
negatively affect the accuracy of the measurement.

MD 9272 Leakage Clamp Meter Instrument Description
7
2.Instrument Description
Become familiar with the equipment
1 Transformer jaws
2 Protection ring
3 Jaw opening trigger
4Function switch
5Keypad
6LCD display
7Terminals
Transformer clamps
Capture alternating current flowing through theconductor. Direct current cannot be measured.
Keyboard
The keyboard consists of four push buttons. Table 1 describes the function of each one.
1
2
3
5
4
6
7

MD 9272 Leakage Clamp Meter Instrument Description
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Table 1. Keyboard
Key
Use
Function
F Function
Any position of the
rotary switch
Function selection key. Depending on the
rotary switch position, the functions will vary
(refer to chapter 3).
Pressing this button cycles through the
various functions.
Hz
A and V, in the RMS
function only
Pressed for more than 2 s, alternates the
second display information from THD to Hz.
H Hold
Any position of the
rotary switch in all
the functions except
in PEAK function
When pressed the memory mode is activated
and the value on screen kept from updating.
Pressed again, the MAX mode is activated for
the register of maximum values.
Next pressed, the MIN mode is activated for
the register ofminimum values.
Pressed again returns to the normal mode.
Light
Any position of the
rotary switch, in all
the functions
With a long press of the key (more than 2 s)
the LCD screen back illumination is turned
on. 30 s after any button was pressed,it
switches off automatically.
Auto
A and V, in the RMS
function only
Cycles through manual ranges until the
Autorange is active again.
+
A and V in the
harmonic
measurement
function
Increases the number ofharmonics to be
measured.
AC/DC
V, in the RMS
function only
Alternates between VAC. and VDC
measurements.
-
A and V in the
harmonic
measurement
function
Decreases the number of harmonics to be
measured.
Table 2. Rotary switch positions
Position
Function
OFF
OFF position.
A
Measurement of AC current up to 100 A.
V
Measurement of AC or DC voltage up to 600 V.
W
Measurement of power of up to 60 kVA, with limit at 100 A and
600 V.

MD 9272 Leakage Clamp Meter Instrument Description
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LCD Screen
Data hold indication.
Maximum reading indication.
Minimum reading indication.
PEAK
Peak function, this is the fast sampling for maximum value of the
measured quantity, whether voltage or current.
Measurement of the phase angle of the current inreference to the
voltage.
Indicates that the current is in front comparedto the voltage.
Indicates that the current is behind compared to the voltage.
Indication of loss, possibly due to insulation defects, only in the mA
measurement mode.
Indication of loss, possibly due to insulation defects and accumulation
of non-linear loads, only in the mA measurement mode.
Indication of loss, possibly due to a high accumulation of non-linear
loads, only in the mA measurement mode.
Indication that themeasured magnitude is expressed as a true effective
value.
CF
Crest factor measurement function is active for the given mode (V or A).
AC
AC input indication.
DC
DC input indication.
mA, A
Milliamperes, Amperes.
V
Volts.
VAr, kVAr
Reactive Volt amperes, Reactive Kilovolt amperes. Reactive power
measuring units.
VA, kVA
Volt amperes, Kilovolt amperes. Apparent powermeasuring units.
W, kW
Watts, Kilowatts. Active power measuring units.
%
Measurement of a percent value.

MD 9272 Leakage Clamp Meter Instrument Description
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THD
Total harmonic distortion ratio
PF
Power factor.
HARMONIC
Indication of the measured harmonic.
Hz
Hertz, frequency measurement unit.
Indication that range is selected automatically.
Full battery.
Medium battery.
Low battery.
Battery is close to be discharged
Input
Table 3: Input
Measuring power Measuring current Measuring voltage
Standby Mode
Iftheclamp-meterisnotusedforaperiodof15minutes,thescreenwillgoblankandtheclamp-
meter will go into standby mode. To wake the clamp-meter from standby mode, the rotary
switch needs to be turned to the OFF position and then back to the function to reactive the
screen.
Input
Description
COM
Input received by the black test probe as common reference.
V
Input received by the red test probe for the voltage and power
measurements.

MD 9272 Leakage Clamp Meter Instrument Description
11
Accessories
Test probes
Batteries (2 AA 1,5V batteries)
Instruction manual
Carrying Case

MD 9272 Leakage Clamp Meter Description of Functions
12
3.Description of Functions
Measuring mA, A and V
The following sections explain the functions available in the current (mAand A) and voltage (V)
measurement mode (positions of the rotary switch in mA, A and V). To select the desired
function the Fkey shall be pressed repeatedly. For current measurements (mA, A), it is
recommended to
TRMS value measurement
Inthis function,we canseethemeasurement oftheeffectivevalueof thecurrent orthevoltage
together with a second reading: the THD (total harmonic distortion ratio) or the frequency of
measured signal. The THD is a ratio of the higher frequency components in the signal to the
essential component (at 50 Hz or 60 Hz) expressed in percentage. A high THD value indicates
high distortion of the measured signal whilst a 0%THD indicates that the measured signal
wavelength is a pure sinusoid.
In this mode data hold is possible as well asthe registering the maximum and minimum values
using the Hkey.
Frequency measurement
In this function, the frequency of the measured signal is displayed. Press the Fbutton for more
than 2 s in the TRMS measurement mode to enter frequency measurement mode. To return to
THD, press the same button again during more than 2 s.

MD 9272 Leakage Clamp Meter Description of Functions
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Intelligent loss analysis (mA measurement only)
The clamp A-meter includes an algorithm that determines the cause of the current loss. This
mode is enabled only when current is measured in the mA range and TRMS measurement is
selected. In the TRMS measurement function, one or two icons will be shown on the screen
informing of the possible reasons for the loss.
This icon indicates that the loss is possibly due to a defect in the
equipment insulation.
These two icons indicate that the loss may be partially due to
defects in the insulation and partially to the accumulation of non-
linear loads.
Thisiconindicatesthata lossispossiblydueto ahighaccumulation
of non-linear loads.
Harmonic analysis
Theclamp-metermeasuresharmoniccontentofthe signalupto19th component, displaying the
effective value and the harmonic number. A harmonic is a multiple of the network base
frequency. If, for example, the 3rd harmonic is measured on a 50 Hz network frequency, this
means measuring the magnitude (current or voltage) of the 150 Hz component.
In this function, the measurement of the effective value of any harmonic in the range of 1 to 19
range is executed. Initially displayed is the harmonic 1,but this can be modified using the +and
-keys.Thedisplayshowstheeffectivevaluetogetherwiththeharmonicnumber(tothebottom
of the screen).
In this mode, data hold and registering of maximum and minimum values is possible by using
the Hkey.
Harmonic analysis (percentage values)
Harmonics can be measured (1 through to 19) as a percentage of the fundamental (the 1st)
harmonic, also called the fundamental frequency. Initially the harmonic 1 is displayed but this
canbechangedusingthe+and-keys.Thedisplayshowsthepercentofeffectivevaluetogether

MD 9272 Leakage Clamp Meter Description of Functions
14
with the harmonic number (at the bottom of the screen).
In this mode data retention and registering of maximum and minimum values is possible by
using the Hkey.
Crest factor
Measures value of crest factor of the input signal. The crest factor is the ratio of the peak and
the effective (or TRMS) value of a waveform. For a sinusoidal wave the crest value is 1.41. The
greater the difference between the peak and efficient RMS value, the higher the crest factor is.
In this mode, data hold and registering of maximum and minimum values is possible by using
the Hkey.
Peak hold
In this function, the peak value of the waveform is shown. The peak value is the highest
measured value of the signal waveform and is usually higher than the effective value (also
known as the TRMS value). E.g. for a perfect sinusoidal signal the peak value is 1.41 times the
effective value. Peak hold is executed with a faster sampling rate than other measurements,
catching pulses as shortas 25 µs.

MD 9272 Leakage Clamp Meter Description of Functions
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DC measurement (Voltage only)
Inthisfunction,theDCvalueofthewaveformisshown.ThismodeisenteredbypresstheAC/DC
buttonintheTRMSmeasurementfunctionscreen.TochangebacktoAC,pressthesamebutton
again.
Manual range selection
By pressing the Auto button, the range mode changes from autorange to the different manual
ranges available. This function can be used in V and A mode. When the autorange is not active,
the icon is off.

MD 9272 Leakage Clamp Meter Description of Functions
16
Measuring Power
In the following sections, the functions available in the power measuring mode (position W of
the rotary switch) will be explained. To select the desired function the Fkey must be pressed
repeatedly.
Active power measurement
In this function themeasurement of active power together withthe measurement of thepower
factor are shown on the screen. If the load is inductive, the symbol will appear on the
screen and if the load is capacitive, the symbol will appear on screen.
In this function, the position of the voltage terminals and the jaw is taken into account; the red
terminal should be connected to the line terminal and the jaw should be connected so that the
current flows toward load in the direction indicated on the jaw. In this mode, data hold and
registering of maximum and minimum values is possible by using the Hkey.
Reactive Power Measurement
In this function the measurement of reactive power is shown together with the measurement
ofthepowerfactor.Ifthe loadis inductive,thesymbol willappearonthescreenandifthe
load is capacitive, the symbol will appear on screen.
In this function, the position of the voltage terminals and the jaw is taken into account; the red
terminal should be connected to the line terminal and the jaw should be connected so that the

MD 9272 Leakage Clamp Meter Description of Functions
17
current flows toward load in the direction indicated on the jaw. In this mode, data hold and
registering of maximum and minimum values is possible by using the Hkey.
Apparent Power Measurement
In this functionthe measurementof theapparentpower togetherwiththe measurement ofthe
power factor are shown. If the load is inductive, the symbol will appear on the screen and
if the load is capacitive, the symbol will appear on screen.
In this mode data hold and registering of maximum and minimum values by using the Hkey is
possible.
Phase difference measurement
In this function the phase difference measurement between the voltage and the current is
shown in degrees. The position of the voltage terminals and the jaw should be taken into
account: the phase line should be connected to line (red) terminal and the jaw should be
connectedsothatthecurrentflowstowardstheloadinthedirectionindicatedonthejaw.Ifthis
is not the case the phase angle difference shown will not be correct.

MD 9272 Leakage Clamp Meter Data Hold and Recording Mode
18
4.Data Hold and Recording Mode
To access the data hold mode, press the Hkey. By pressing the key repeatedly the HOLD, MAX
and MIN modes can be selected. The three recording modes are available in all the measuring
functions except in the peak measurement.
HOLD Mode
In this mode, last measured value is frozen on the screen. The symbol also appears on the
screen.
MAX Mode
In this mode, the maximum value measured is shown since mode activation is displayed. The
symbol is on. Before using this function, the clamp-meter should be connected properly
(see section 3).
When recording the value, the difference between the peak value and the maximum value
should be taken into account: the maximum value holds the highest measured value on the
screen, whilst the peak value shows the highest absolute value of the waveform.
MIN Mode
In this mode, the minimum measured value is shown on the screen. The symbol will be
shown. Before using this function, the clamp should be connected properly (see section 3)

MD 9272 Leakage Clamp Meter Technical Specifications
19
5.Technical Specifications
General specifications
Environment conditions:
Measurement Category: clamp-meter
CAT III 600V
Measurement Category Test Lead
CAT III 600V
Maximum Current1
100 A
Pollution degree
2
Operation
Indoor
Altitude
< 2000 m
Operation temperature
0 ºC 40 ºC (<80 % H.R., <10 ºC without
condensation)
Storage temperature
10 ºC 60 ºC (<70 % H.R., extract batteries)
Temperature coefficient:
0.1 (of specified precision) / ºC (<18 º C or >28 º C)
Functioning principle:
Sampling of signal at high speed
Data update on screen:
twice a second
Screen:
3 3/4 + 3 digits LCD screen
Range selection:
Automatic and manual selection
Over-range indication:
-0L- is shown on the LCD screen, fast beep
Polarity indication:
-
E.M.C.:
Emission: Class B
Immunity: Portable test and measurement
equipment
Meets EN 61326-1:2013, EN 61326-2-2:2013
Safety:
Meets EN 61010-1:2010, EN 61010-2-32:2012, EN
61010-2-033:2012, EN 61010-031:2015
Power supply:
3 V
Type of batteries:
2 x 1,5 VAA,alkaline batteries
Consumption:
5 mA average, depending on function.
Duration of the batteries:
200 - 400 h. (batteries 2000 mAh)
Dimensions:
185 mm x 62mm x 42 mm
Weight:
Aprox. 210 g (without battery)

MD 9272 Leakage Clamp Meter Technical Specifications
20
(1) This equipment cannot be exposed to currents above the limit.
Measurement specifications
Current and voltage
Automatic ranging within the same function.
TRMS value
Function
Range
Resolution
Accuracy
mA,
A
40 mA
0.01 mA
± 0.8 % ofreading ±3 digits
400 mA
0.1 mA
± 0.8 % ofreading ±3 digits
4 A
0.001 A
± 0.8 % ofreading ±3 digits
40 A
0.01 A
± 1 % ofreading ± 3 digits
80 A
0.1 A
± 1.2 % ofreading ±3 digits
100 A
0.1 A
± 5 % of reading
V
40 V
0.01 V
± 0.5 % of reading ± 4 digits
400 V
0.1 V
± 0.5 % of reading ± 2 digits
600 V
1 V
± 0.5 % of reading ± 2 digits
THD
0.1 %
± 2 % of reading ± 3 digits
100
1 %
± 2 %of reading ± 3digits
Note: the specifications are valid for waveforms with fundamental frequency between 45 Hz
and 65 Hz and crest factor < 3.
DC voltage
V
40 V
0.01 V
± 0.5 % of reading ± 4 digits
400 V
0.1 V
± 0.5 % of reading ± 2 digits
600 V
1 V
± 0.5 % of reading ± 2 digits
Frequency
Hz
45 - 100 Hz
0.1 Hz
± 0.1 % ± 2 digits
Note: The instrument is designed to measure power supply voltage and current signals in the
range of 45 70 Hz and observes them as first harmonic. If the measured signal has a
frequency greater than 70 Hz, the instrument will understand it as a higher harmonic.
Note: Frequency is measured at voltages higher than 15% of the range or 0.3 V (whichever is
higher). Manually change the range to a
frequency while the signal is higher than 0.3 V.