Martindale Electric CM55 User manual

CM55
AC CLAMP METER
InstructIon
Manual

ALWAYS READ THESE INSTRUCTIONS BEFORE PROCEEDING
Thank you for buying one of our products. For safety and a full understanding
of its benefits please read this manual before use. Technical support is
available from [phone] and [email protected]
CONTENTS
1 Safety Information 1
1.1 Meaning of Symbols and Markings 1
1.2 Precautions 2
2 Introduction 5
2.1 Inspection 5
2.2 Description 5
2.3 Accessories 5
2.4 Battery Installation 5
3 Operation 6
3.1 General 6
3.2 Low Battery Indication 6
3.3 Description of Clamp Meter Elements 6
3.4 Description of Press Buttons 7
3.5 Description of LCD Symbols 7
3.6 Auto Power Off 7
3.7 Display Hold 8
3.8 Use of the TL16 Test Leads 8
3.9 AC Current Measurements 8
3.10 AC Voltage Measurements 9
3.11 DC Voltage Measurements 9
3.12 Resistance Measurements and Continuity Testing 9
4 Maintenance 10
4.1 Battery Replacement 10
4.2 Test Lead Replacement 10
4.3 Calibration 11
4.4 Cleaning 11
4.5 Repair & Service 11
4.6 Storage Conditions 12
5 Warranty 13
Measurement Categories 14
Specifications

1. SAFETY INFORMATION: Always read before proceeding.
REMEMBER: SAFETY IS NO ACCIDENT
These instructions contain both information and warnings that are
necessary for the safe operation and maintenance of this product. It is
recommended that you read the instructions carefully and ensure that the
contents are fully understood. Failure to understand and to comply with
the warnings and instructions can result in serious injury, damage or even
death.
Particular attention should be paid to the Warnings, Precautions and
Technical Specications.
Please keep these instructions for future reference. Updated instructions
and product information are available at: www.martindale-electric.co.uk
1.1 Meaning of Symbols and Markings
Caution - risk of danger & refer to instructions
Caution - risk of electric shock
Equipment protected by double or reinforced insulation
(Class II)
Application around and removal from hazardous live
conductors is permitted.
CAT II (Measurement Category II) is applicable to test and measuring
equipment connected directly to utilization points (socket outlets
and similar points) of the
low-voltage MAINS installation.
CAT III (Measurement Category III) is applicable to test and measuring
equipment connected to the distribution part of the building’s
low-voltage MAINS installation.
1

2
CAT IV (Measurement Category IV) is applicable to test and
measuring equipment connected at the source of the building’s
low-voltage MAINS installation.
For further information on measurement categories see page 14
or visit www.martindale-electric.co.uk/measurement_categories.
php
Equipment complies with relevant directives
Equipment complies with relevant UK Conformity
Assessed marking
End of life disposal of this equipment should be in
accordance with relevant directives
1.2 Precautions
This product has been designed with your safety in mind, but please pay
attention to the following warnings and cautions before use.
Warnings
In order to avoid the danger of electrical shock, it is important that proper
safety measures are taken when working with voltages exceeding the extra
low voltage (ELV) limit of 50V AC RMS or 120V DC.
Where applicable other safety measures such as the use of protective
gloves, goggles etc. should be employed.
The clamp meter must only be used by a skilled and competent person
who is familiar with the relevant regulations, the safety risks involved and
the consequent normal safe working practices, and under the conditions
and for the purposes for which it has been constructed and specified.

3
Before each use the clamp meter and any associated test leads and
accessories should be examined for damage, cracks, cuts or scratches.
Do not use if damaged in any way.
Make sure the clamp meter and test leads are dry, clean and free from
dust, grease and moisture while in use to avoid the danger from electric
shock due to surface leakage.
Always test this unit on an appropriate proving device or a known good
voltage source before and after using it to determine if a hazardous voltage
exists in a circuit to be tested. Do not use the unit if it does not function
correctly during proving.
Measuring / testing for a voltage / current that exceeds the specified limits
of the unit may damage the unit and may expose the operator to a shock
hazard. Always check the unit’s specified limits before use.
If the clamp meter is used in a manner not specified by
Martindale Electric, the protection provided by the clamp meter may be
impaired.
As a clamp meter or multimeter the unit must only be used on CAT III
and CAT II installations up to 600V to earth, and within the operating
temperature and humidity range specified.
If the removable probe tip caps are not fitted to the probes of the test
leads, their measurement category becomes CAT II 1000V, and they must
not be used on CAT III or CAT IV installations to avoid the risk of shorting
high energy circuits and arc flash.

When this unit is used in combination with test leads, the measurement
category of the combination is the lower measurement category of either
this unit or the test leads used. Likewise if test lead accessories such as
crocodile clips are also used, the measurement category will be the lowest
measurement category in that combination.
Do not use if the battery compartment cover is not fitted.
When using test leads, always keep your fingers behind the finger guard
on the test lead probe.
When positioning the clamp jaws around a hazardous live conductor
always keep your fingers behind the clamp safety protection barrier.
When making current measurements using the clamps, disconnect the test
leads from the clamp meter terminals.
Cautions
Avoid severe mechanical shock or vibration and extreme temperature.
When using test leads avoid excessive stresses to the cable entry points at
the probe and 4mm plug connector.
To avoid possible corrosion from leaking batteries, remove the batteries
when the unit is not in use for an extended period.
4

2. INTRODUCTION
2.1 Inspection
Examine the shipping carton for any sign of damage. Inspect the unit and
any accessories for damage. If there is any damage then consult your
distributor immediately.
2.2 Description
The Martindale CM55 has the following measurement functions:
• AC current to 400A
• AC/DC voltage to 600V
• Resistance to 400Ω
• Continuity with audible indication
Further functions are:
• Display hold
• Auto power off
• Auto ranging on AC & DC Voltage and AC current functions
2.3 Accessories
The CM55 comes with the following accessories:
• Carrying case
• Set of TL16 test leads
• 2 x 1.5V AAA batteries
• Instructions
2.4 Battery Installation
Refer to section 4.1 (Battery Replacement) for the battery installation
instructions.
5

3. OPERATION
3.1 General
If the clamp meter displays OL then the measurement limits of the range
have been exceeded.
3.2 Low Battery Indication
If the symbol is displayed, the batteries need replacing as
measurement accuracy can no longer be guaranteed (see section 4.1
Battery Replacement).
3.3 Description of Clamp Meter Elements
Figure 1
1
Clamp current
sensing jaws
2
Clamp safety
protection barrier
3 Clamp trigger
4
Rotary function
selector switch
5 Hold button
6
Liquid crystal
display
7
COM input
terminal
8
Positive input
terminal
6

3.4 Description of Press Buttons
HOLD Selects display hold
3.5 Description of LCD Symbols
Indicates low battery
AUTO Indicates auto ranging
HOLD Display hold is activated
Auto power off is activated
A, V, ΩUnits of measurement being displayed
Indicates AC measurement
Indicates DC measurement
Continuity function is selected
3.6 Auto Power Off
If the clamp meter is inactive for a period of 10 minutes it will automatically
power off. If any button is pressed after the clamp meter has automatically
powered off, the clamp meter will turn back on.
To disable the auto power off function, press the HOLD button at the same
time as turning the rotary switch from OFF to any position. Press the HOLD
button again and the symbol will no longer be displayed on the LCD.
7

3.7 Display Hold
To hold a displayed value, press the HOLD button. The LCD will display
HOLD. Press again to exit display hold.
3.8 Use of the TL16 Test Leads
Before use, always check the continuity of the test leads.
Where access to test points may require extended probe tips, the probe tip
caps may be removed by gently pulling them forward until they unclip from
the probe body.
CAT III 1000V
CAT IV 600V
CAT II 1000V ONLY
DO NOT USE ON
CAT III or CAT IV
installations
3.9 AC Current Measurements
1. Set the rotary switch to the
A
position.
2. Taking all necessary safety precautions, press the clamp meter trigger
to open the clamp jaws, position the jaws around the conductor to be
meaured, and release the trigger to close the jaws.
3. Position the clamp meter so the conductor is central within the
clamp jaws.
4. Read the measured ac current from the display.
Note: Clamping around more than one conductor will result in an incorrect
measurement.
8

3.10 AC Voltage Measurements
1. Connect the black test lead to the COM terminal and the red test lead to
the terminal.
2. Set the rotary switch to the
V
position.
3. Taking all necessary safety precautions connect the test leads to the
circuit being measured and read the measured ac voltage from
the display.
3.11 DC Voltage Measurements
1. Connect the black test lead to the COM terminal and the red test lead to
the terminal.
2. Set the rotary switch to the
V
position.
3. Taking all necessary safety precautions connect the test leads to the
circuit being measured and read the measured dc voltage from
the display.
3.12 Resistance Measurements and Continuity Testing
1.Connect the black test lead to the COM terminal and the red test lead to
the terminal.
2.Set the rotary switch to the Ω position.
3. Taking all necessary safety precautions connect the test leads to the
circuit being measured and read the measured resistance from
the display.
If the resistance is <25Ω, the buzzer will sound continuously.
9

4. MAINTENANCE
4.1 Battery Replacement
To avoid shock or injury, disconnect the clamp meter from any
external circuits and remove the test leads before proceeding.
Referring to figure 2, the battery compartment is underneath the unit and
can be accessed by removing the screw and lifting off the cover.
Fit 2 new 1.5V, AAA alkaline batteries (IEC LR03, NEDA 24A) observing
correct polarity.
Replace the battery compartment cover and screw.
Note: Do not mix old and new batteries.
4.2 Test Lead Replacement
If the test leads become damaged they should be replaced.
The replacement test leads must have the same (or better)
overvoltage category rating as the TL16 test leads supplied.
Figure 2
10

4.3 Calibration
To maintain the integrity of measurements made using your instrument,
Martindale Electric recommends that it is returned at least once a year to
an approved Calibration Laboratory for recalibration and certification.
Martindale Electric is pleased to offer you this service.
Please contact our Service Department for details.
Email: [email protected]
Tel: [phone]
4.4 Cleaning
To reduce the risk of surface leakage, this instrument must be kept
in a clean condition.
Prior to cleaning, ensure that the instrument is disconnected from
any voltage source.
If contamination is found, clean with a damp soft cloth and if necessary
a mild detergent or alcohol. Do not use abrasives, abrasive solvents, or
detergents which can cause damage to the unit. If a mild detergent is
used, the unit should subsequently be thoroughly cleaned with a water
dampened soft cloth. After cleaning, dry and allow to remain in a dry
environment for 2 hours before use.
4.5 Repair & Service
There are no user serviceable parts in this unit other than those that
may be described in section 4. Return to Martindale Electric if faulty. Our
service department will quote promptly to repair any fault that occurs
outside the guarantee period.
Before the unit is returned, please ensure that you have checked the unit,
batteries, leads and for poor connections.
11

4.6 Storage Conditions
The instrument should be kept in warm dry conditions away from direct
sources of heat or sunlight, and in such a manner as to preserve the
working life of the unit. It is strongly advised that the unit is not kept in a
tool box where other tools may damage it.
12

5. WARRANTY AND LIMITATION OF LIABILITY
This Martindale product is warranted to be free from defects in material
and workmanship under normal use and service. The warranty period is
2 years and begins on the date of receipt by the end user. This warranty
extends only to the original buyer or end-user customer, and does not
apply to fuses, disposable batteries, test leads or to any product which, in
Martindale’s opinion, has been misused, altered, neglected, contaminated,
or damaged by accident or abnormal conditions of operation, handling or
storage.
Martindale authorised resellers shall extend this warranty on new and unused
products to end-user customers only but have no authority to extend a greater
or different warranty on behalf of Martindale.
Martindale’s warranty obligation is limited, at Martindale’s option, to refund
of the purchase price, free of charge repair, or replacement of a defective
product which is returned to Martindale within the warranty period.
This warranty is the buyer’s sole and exclusive remedy and is in lieu of
all other warranties, expressed or implied, including but not limited to any
implied warranty of merchantability or fitness for a particular purpose.
Martindale shall not be liable for any special, indirect, incidental or
consequential damages or losses, including loss of data, arising from any
cause or theory.
Since some jurisdictions do not allow limitation of the term of an implied
warranty, or exclusion or limitation of incidental or consequential damages, the
limitations and exclusions of this warranty may not apply to every buyer. If any
part of any provision of this warranty is held invalid or unenforceable by a court
or other decision-maker of competent jurisdiction, such holding will not affect
the validity or enforceability of any other provision or other part of that provision.
Nothing in this statement reduces your statutory rights.
13

CAT Ratings
BS EN61010-1 Installation Categories
(CAT ratings) define the risks from
hazardous transient impulses and
potentially lethal short circuit currents
on the mains supply system based on
where you are working.
Voltage Ratings
Test equipment used for measuring
mains circuits will have a CAT rating
to show where it can be used. Each
category also has a voltage rating
to show the maximum safe phase to
earth system voltage, normally 50V,
100V, 150V, 300V, 600V or 1000V.
Stay safe - Match your test
equipment safety rating to the
installation category.
CAT II: Socket outlets and similar
points of the mains installation.
CAT III: The distribution part of the
building’s mains installation.
CAT IV: The supply side source of the
building’s mains installation.
Testers, leads and accessories all
need safety ratings equivalent to, or
higher than the installation category
and voltage rating for the location
to be safe.
MEASUREMENT CATEGORIES
OVER OR
UNDER
GROUND
PV
ARRAY
*MAIN
ISOLATOR
SWITCH
L1 (L2, L3)
N
PV
ARRAY
DISTRIBUTION
BOARD
LOW-VOLTAGE
SUPPLY SOURCE
CAT III CAT IICAT IV
Tarrif Meter
Service fuse
Circuit Breakers
6
6
Lighting
Generation Meter
Socket Wiring
Socket Outlet
Plug-in Lamps
Electrical Appliances
1
1
2
2
5
5
4
4
14

ELECTRICAL
All specified accuracies are at 23°C ± 5°C,
<80% RH for 1 year.
Temperature coefficient:
add 0.1 x (specified accuracy) per °C.
(0°C to 18°C, 28°C to 40°C).
All accuracies below are expressed as
± (percentage of reading + digits)
DC Voltage
Range Resolution Input impedance Accuracy
400V 0.1V 1MΩ 1.0% + 3
600V 1V
Overload protection: 660V DC or AC rms
AC Voltage
Range Resolution Input impedance Accuracy
(50 to 400Hz)
400V 0.1V 1MΩ 1.2% + 3
600V 1V
Overload protection: 660V DC or AC rms
Specication
CM55
AC Clamp Meter

AC Current
Range Resolution Accuracy
(50 to 60Hz) (60 to 400Hz)
40A 0.01A
1.9% + 3 3.0% + 5
400A 0.1A
Overload protection: 660A DC or AC rms
Resistance and Continuity
Range Resolution Open circuit
voltage
Accuracy
Audible
indication
400 Ω 1Ω -1.5V dc
1.0% + 2 <25Ω
Overload protection: 600V DC or AC rms
GENERAL
Display: 3¾ digit liquid crystal display with maximum reading 3999
Sample rate 2 times/sec
Polarity: Automatic, positive implied, ‘-‘ for negative polarity indication
Overrange: (OL) is displayed
Power: 2 x 1.5V, AAA alkaline batteries (IEC LR03, NEDA 24A)
Battery life (alkaline): 500 hours typical for ACV and ACA ranges
800 hours typical for DCV and Ω ranges
Low battery indication: symbol is displayed
Auto power off: after 10 minutes
Jaw opening capability: 25.4mm
Dimensions: 203 x 75 x 32mm
Weight: 262g approx, including batteries
Includes: carrying case, set of TL16 test leads, 2 x 1.5V AAA batteries,
instructions
Specication
CM55
AC Clamp Meter

ENVIRONMENTAL
Location: Indoor use only, or outdoor use in dry weather conditions
Temperature & Humidity:
(Operating): 0°C to 40°C <80% R.H., non-condensing
(Storage): -10°C to 60°C < 70% R.H., batteries removed
Altitude: up to 2000m
Pollution degree: 2
SAFETY
Conforms to: BS EN 61010-1, BS EN 61010-2-032, CAT III 600V, CAT IV
300V. Class II, double insulation.
EMC
Conforms to: BS EN 61326-1
SPECIFICATION FOR TL16 TEST LEADS
Maximum voltage: 1000V AC/DC
Maximum current: 10A continuous
Connector: 4mm banana plug with fixed shroud
Environmental
Temperature: (Operating & Storage): 0°C to 40°C
Altitude: up to 2000m
Pollution degree: 2
Safety
Conforms to: BS EN 61010-031, CAT IV 600V, CAT III 1000V, 10A
(probe tip covers fitted), CAT II 1000V, 10A (probe tip covers removed)
Class II, double insulation
Specication
CM55
AC Clamp Meter

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Due to policy of continuous development, Martindale Electric reserves the right to alter
equipment specification and description outlined in this document without prior notice.
No part of this document shall be deemed to be part of any contract for the equipment
unless specifically referred to as an inclusion within such contract. © 2023 Martindale
Electric Co. Ltd. Registered in England No. 3387451. LITCM55
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Ver. D1.0
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Watford WD24 4PP. T: [phone] F: [phone]
www.martindale-electric.co.uk [email protected]