Extech CA250 - Manual

User’s Guide Model CA250

400A AC/DC Current Clamp-on MultiMeter Adaptor

CA250-en-EU_V1.5 8/14

Introduction

Congratulations on your purchase of
the Extech CA250 400 Amp AC/DC
Clamp-On MultiMeter Adaptor. With
this clamp adaptor, a current can be
measured by simply clamping around
a single conductor. The adaptor
outputs an mV signal that is
proportional to the measured current
and displayed on a DMM. Careful use of this device will provide years of
reliable service.

Specifications

Measurement Ranges 0 to 40 Amps AC/DC

0 to 400 Amps AC/DC

Adaptor Output

10mV/Amp on the 0 to 40A range
1mV/Amp on the 0 to 400A range

Frequency range

50/60Hz

Safety

EN61010-1 and IEC61010-1 2nd Edition (2001)
to Category III 600V and Category IV 300V;
Pollution Degree 2 in accordance with IEC 664
indoor use.

Standards

CC

Accuracy

0 to 40A ± (2.5% + 0.1A)
0 to 400A ± (2.8% + 0.5A)

Jaw size

30mm (1.2")

Operating Conditions

0 to 50

o

C (32 to 122

o

F) < 70% RH

Storage Conditions

-20 to 70

o

C (-4 to 158

o

F) < 80% RH

Battery

2 – 1.5V “AAA”

Dimensions/Weight

146 x 60 x 32mm (5.8 x 2.3 x 1.3");
226g (8oz)

Safety

Safety Symbols

This symbol, adjacent to another symbol or terminal,
indicates the user must refer to the manual for further
information.

This symbol indicates that double insulation is used.

WARNING

: This indicates that a potentially hazardous condition which,

if not avoided, could result in death or serious injury.

Safety Precautions

1.

WARNING

: Improper use of this meter can cause damage, shock,

injury or death. Read and understand this manual before operating
the meter.

2.

Inspect the condition of the test leads and the meter itself for any
damage before operating the meter. Repair or replace any damage
before use.

3.

Do not use on non-insulated conductors at voltages greater than
600VAC rms or DC.

You, as the end user, are legally bound (

EU Battery

ordinance

) to return all used batteries,

disposal in the

household garbage is prohibited!

You can hand over your

used batteries / accumulators at collection points in your
community or wherever batteries / accumulators are sold!

Disposal:

Follow the valid legal stipulations in respect of the

disposal of the device at the end of its lifecycle

Current Measurements

NOTE:

This device has a 30-minute automatic shut-off feature

1. Set

the

DMM

range to

AC mV

when measuring AC amps and

DC

mV

when measuring DC amps or to the lowest voltage range.

2.

Connect the RED test lead to the DMM '+' Voltage terminal and
the BLACK lead to the '-' COM terminal.

3.

Set the adaptor to the 40A (AC or DC) or the 400A (AC or DC)
range.

4.

Press the Jaw Trigger to open the jaw and clamp around a single
conductor.

5.

The unit will output an AC or DC voltage proportional to the
measured current. (40A range:10mV/A, 400A range:1mV/A)

6.

Read the voltage on the DMM display and interpret as
current.(direct mV to A on the 400A range, divide by 10 on the
40A range)

1. Read

mV

2.

Set to AC or DC mV

3. Voltage

Input

4. NCV

detector

5. NCV

indicator

6.

DC Zero adjust

DC Zero

A hysteresis voltage may appear when the clamp is set to the DC
position. With no conductor in the jaw, adjust the DC Zero adjust until
the DMM display indicates zero. If the voltage is beyond the range of
the zero adjust, snap the jaw open and shut several times to clear the
hysteresis. Set

DMM

to

DC mV

range.

Note:

Verify the zero or re-zero the unit prior to all DC current

measurements and range changes.

Note:

DC current measurements are polarity sensitive. Reverse the

conductor direction in the jaw to change the polarity.

Note

: Do not apply voltage to the clamp adaptor’s test leads

Note

: Clamp a single conductor only, do not clamp the hot and neutral

simultaneously.

Note

: The clamp jaws must be fully closed for proper measurements.

On large conductors or line splitters, make sure there is no gap
between the upper and lower jaw.

Non-Contact AC Voltage Measurements

1. Touch the probe tip to the hot conductor or hold next to the hot

side of the electrical outlet.

2. If AC voltage is present, the detector LED will illuminate.

Copyright

©

2014

FLIR

Systems,

Inc.

All

rights

reserved

including

the

right

of

reproduction

in

whole

or

in

part

in

any

form

ISO

‐

9001

Certified

www.extech.com

X

WARNING:

Risk of Electrocution. Before use, always test the

Voltage Detector on a known live circuit to verify proper operation

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