Martindale Electric CM51A User Manual

CM51A CLAMP METER

INSTRUCTION
MANUAL

MARTINDALE

ELECTRIC

Trusted by Professionals

1. Press the POWER key to turn on the
clamp meter.

2. Open the clamp head and clamp
onto a single conductor. NOTE: If two
or three conductors are clamped at the
same time, the measurement cannot
be made.

1. If the BAT symbol is displayed on
the LCD then replace the battery.

2. Turn off the power.

3. Referring to figure 3 unscrew the
battery cover retaining screw
and slide off the battery cover.

4. Replace the 3V type CR2032 battery.
Note: Ensure correct polarity.

5. Replace the battery cover and
retaining screw.

MARTINDALE

ELECTRIC

Trusted by Professionals

SAFETY INFORMATION

Always read before proceeding.

WARNING

These instructions contain both information and warnings that are
necessary for the safe operation and maintenance of the clamp
meter. It is recommended that you read the instructions carefully
and ensure that the contents are fully understood. Failure to
understand the instructions and to comply with the warnings and
instructions contained herein can result in serious injury, damage
or even death.

In order to avoid the danger of electrical shock, it is important that
proper safety measures are taken when working with voltages
exceeding 30 V AC rms, 42 V AC peak or 60 V DC.

This clamp meter must only be used under the conditions and for
the purposes for which it has been constructed. Particular attention
should be paid to the safety instructions, the technical
specifications and the use of the clamp meter in dry surroundings.

Always check the clamp meter is in good working order before use and
that there are no signs of damage to the unit. Do not use if damaged.

SYMBOLS

~

AC (alternating current)

Earth ground

Safety information (refer to the manual)

Double insulated

1. INTRODUCTION

1.1 Features

1. Auto-ranging (40 A and 300 A) and pocket-sized, compact body.

2. Large, 4000 count LCD.

3. Display Hold.

4. Auto Power Off.

5. Safety Design. CE mark approved.

1.2 Unpacking and Inspection

Before unpacking the unit, examine the shipping carton for any sign of
damage. Unpack and inspect the clamp meter and accessories for any
damage.

If any damage is found or accessories are missing then consult your
distributor immediately.

Check that the following accessories are included.

1. Carrying case.

2. Instruction manual.

2. SPECIFICATION

2.1 General Specifications

DISPLAY:
Numeric Display: 33/4digit, 4000 count LCD, maximum reading 4000,

12mm high.

Unit & Symbols: ~, A, DH, BAT, AUTO, APO & decimal point.

Operating principle: Dual Slope Integration.
Range selection: Autoranging.
Overange indication: OL symbol is shown.
Battery warning: BAT symbol is shown.
Sampling rate: 2.5 times per second.
Display hold: Displays are held by DH key.
Overload protection: AC current; 400A AC (300V Line) for one minute.
Operating temperature & humidity: 0°C to 40°C, less than 80% RH.
Storage temperature & humidity: -10°C to 50°C, less than 70% RH.
Temperature coefficient: 0.1 x specified accuracy / °C for 0°C to 18°C

& 28°C to 40°C.
Dielectric strength: 3.7kV AC for one minute (between case & metal
parts).

Safety: EN 61010-1, EN 61010-2-032 Overvoltage Cat. III 300V, Class II.
EMC: EN 50082-1:01.92 & EN 55022:08.94 + A1:05.95 + A2:97
Power consumption: Approx. 5mW (100 hours continuous operation).
Power supply: One 3V CR2032 battery.
Auto power off: Power turns off automatically after 12 minutes.
Conductor diameters: Maximum 27mm
Dimensions & weight: 150 x 52 x 24mm, 110 grams.

2.2 Measurement Specifications

AC Current (~A) Average Rectification

Frequency Response: 50~60Hz. 0~0.4A add 5dgt
40Hz ~500Hz, add 1.5% to above accuracy.

3. FUNCTIONAL DESCRIPTION

3.1 LCD

3.2 Power

Press this key to turn power on. Press again to turn off.

3.3 DH Key (Display Hold)

Press this key to hold the displayed valve (‘DH’ shows). Press again to
release display.

3.4 Clamp Head

When measuring AC current, open the clamp head and clamp on to
the single conductor to be monitored.

NOTE: If two or three conductors are clamped at a time, the
measurement cannot be made.

3.5 Finger Guard

For safety, finger tips must not go beyond the Finger Guard.

4. PRECAUTIONS

WARNING

Before use check the clamp meter for cracks or any other damage, and
make sure the clamp meter is free from dust, grease and moisture.

WARNING

When using the clamp meter always keep your fingers behind the
finger guard.

WARNING

The maximum allowable line voltage of the conductor being measured
is 300V AC rms.

CAUTION

Do not measure current > 300A rms.

CAUTION

Avoid severe mechanical shock or vibration, extreme temperature or
very strong magnetic fields.

CAUTION

Remove the battery when not in use for an extended period to avoid
corrosion from leaking battery electrolyte.

5. OPERATION

5.1 Preparation for Use

Instruction Manual

Read this instruction manual completely before proceeding, paying
particular attention to the safety warnings and precautions.

Battery

A 3V type CR2032 battery is installed in the instrument. If the BAT
symbol is displayed on the LCD replace the battery. (Refer to 6.1
Battery Replacement).

Overrange Indication

If the measured current exceeds 430 A AC the OL symbol appears on
the LCD.

Auto Power Off

12 minutes after the last operation of the POWER/DH button the clamp
meter will automatically turn off. In this condition there is <0.01 mW
power consumption.

5.2 AC Current (~A) Measurement

WARNING
The maximum allowable voltage of the conductor being measured
is 300 V AC rms.

Do not measure current > 300 A rms.

Always keep your fingers behind the finger guard.

3. Read the measured current on the LCD.

4. Display Hold is available by pressing the DH key.

5. When measurements are finished, remove the clamp head from the
conductor. Press the POWER key for longer than two seconds to turn
off the power.

6. MAINTENANCE

6.1 Battery Replacement

WARNING

Remove the clamp head from the circuit being measured before
removing the battery cover.

6.2 Cleaning

After removal from any live circuits the clamp meter may be cleaned
using a soft damp cloth. Do not polish the clamp meter casing or use
abrasives, solvents, cleaning fluid, gasoline, benzene etc. If necessary
use silicon oil or anti-static fluid.

6.3 Repair & Service

If the clamp meter is not operating correctly, check the following before
returning the unit to the distributor for repair:

1. Check the battery connection.

2. Check the battery is installed with the correct polarity.

3. Check the condition of the battery.

6.4 Calibration

It is recommended that the clamp meter is calibrated every 12 months
and/or after repair.

6.5 Storage Conditions

The clamp meter 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 camp meter. It is strongly advised that the clamp
meter is not kept in a tool box where other tools may damage it.

FINGER GUARD

LCD

CLAMP HEAD

POWER DH KEY

~: Alternating Current (AC)
BAT: Battery Warning
AUTO: Autoranging
DH: Display Hold
A: Amperes
APO: Auto Power Off

Range Resolution Accuracy Max. Input Current

40.00A 10mA
±1.8%rdg±5dgt 300A (Max. 300V)

300.0A 100mA

Martindale Electric Company Limited

Metrohm House, Imperial Park, Imperial Way, Watford,

Tel: [phone] Fax: [phone]

Registered in England No. 3387451. LITCM51A Rev 1

Hertfordshire, WD24 4PP, UK

E-mail:[e-mail]

Website: www.martindale-electric.co.uk

© Martindale Electric Company Ltd. 2016