Extech Extech 380942 Manual

Model 380942

INSTRUCTION MANUAL

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99 Washington Street
Melrose, MA 02176
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True RMS AC/DC 30A Mini Clamp-on Meter

• True RMS AC Current and Voltage

• Measure low current with high resolution to 0.1mA AC and 1mA DC

• Auto Power Off

• One touch DCA zero adjust

• MIN/MAX and Data Hold functions

• 0.9” (23mm) Jaw diameter

Introduction

Congratulations on your purchase of Extech’s DC/AC Clamp Meter. This professional meter,
with proper care, will provide years of safe reliable service.

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

FAX [phone] - TestEquipmentDepot.com

Specifications

General Specifications

Display 3-3/4 (4000 count) Digit LCD with 40 segment bargraph
Functions ACA, DCA, ACV, DCV
Polarity Minus sign ( - ) indicates negative polarity
Current sensor Hall effect sensor type
Overload indication Left blinking digit
DCA zero adjust One touch zero key
Display rate 2 readings/second (20 readings/second for bargraph)
Battery Two 1.5V AA batteries
Operating conditions 40F to 1220F (-100C to 500C); < 85% Relative Humidity
Storage conditions - 40F to 1400F (-200C to 600C); < 75% Relative Humidity
Altitude Operate at less than 2000 meters. Indoor use only.
Power consumption Approximately 10mA DC
Weight 6.2 oz. (190g) including battery
Dimensions 7.2 x 2.5 x 1.4” (183 x 63.6 x 35.6mm) (HWD)
Jaw opening 0.9” (23mm)
Standards IEC 1010 Category III 300V, Category II 600V

Range Specifications

Function Range Resolution Accuracy Overload

4000mA 1mA 40A DC DC Current
30A 10mA

AC Current

(True RMS)

DC Voltage 400V 0.1V ± (1.0% + 2d) 1000V DC

(True RMS)

50/60Hz 40 to 100Hz
400mA 0.1mA ±(1.5% + 5d) ±(2.0% + 5d) 40A AC
50/60Hz 40 to 1kHz
4000mA 1mA ±(2.5% + 5d) ±(3.0% + 5d) 40A AC
30A 10mA ±(2.0% + 5d) ±(2.5% + 5d) 100A AC

50/60Hz 40 to 1kHz AC Voltage
400V 0.1V ±(1.5% + 4d) ±(2.0% + 5d) 800V AC

± (2.0% + 3d)

protect

100A DC

Specification Notes

AC Voltage and Current Crest Factor: < 3

AC / DC Voltage Input Impedance: 10MΩ

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Meter Description

1. Current sense jaw

2. Measurement Trigger

3. Function switch

4. Data HOLD key

5. MAX / MIN key

Safety Symbols and Information

Caution ! Refer to the explanation in this Manual

!

Caution ! Risk of electric shock

6. One-touch DCA ZERO key

7. LCD Display

8. Positive input terminal for V, HZ and Ω

9. COM terminal

Earth (Ground)

This meter has been designed to be safe in use, but the operator must use caution in its
operation. The rules listed below should be carefully followed for safe operation.

1. NEVER apply voltage or current to the meter that exceeds the specified maximum:

2. USE EXTREME CAUTION when working with high voltages.

3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above
earth ground.

4. ALWAYS turn off the power and disconnect the test leads before opening the back to
replace the fuse or batteries.

5. NEVER operate the meter unless the back cover and the battery/fuse door are in place
and fastened securely.

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Ver. 1.6 03/2005

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

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Operation

AC Current Measurements (True RMS)

WARNING: To avoid electric shock, disconnect the test leads from the meter before

making current measurements.

1) Set the Function switch to the 400mA, 4000mA, or 30A AC
range.

2) Press the jaw trigger and clamp around, fully enclosing a
single conductor. Do not allow a gap between the two halves
of the jaw. Refer to the diagram at right for the correct way to
enclose a single conductor.

3) Read the ACA value on the LCD.

DC Current Measurements

WARNING: To avoid electric shock, disconnect the test leads from the meter before

making current measurements.

1) Set the Function switch to the mA or 30A DC range.

2) Press the DCA zero key to null the meter display.

3) Press the Trigger to open the current sense Jaw.

4) Fully enclose the conductor to be measured. Do not allow a gap between the two
halves of the jaw.

5) Read the DCA value on the LCD.

AC Voltage Measurements (True RMS)

WARNING: To avoid electric shock or damage to the meter, do not make any voltage

measurements that exceed the maximum specified limits.

1) Set the Function switch to the 400V AC position.

2) Insert the test leads to the meter as follows: Red lead to “V” terminal; Black lead to the
COM input.

3) Connect the test leads to the circuit or device under test.

4) Read the ACV value on the LCD.

Yes

No

DC Voltage Measurements

WARNING: To avoid electric shock or damage to the meter, do not make any voltage

measurements that exceed the maximum specified limits.

1) Set the Function switch to the 400V DC position.

2) Insert the test leads to the meter as follows: Red lead to “V” terminal; Black lead to the
COM input.

3) Connect the test leads to the circuit or device under test.

4) Read the DCV value on the LCD.

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Ver. 1.6 03/2005

Advanced Features

Relative Measurements

1) Press the ZERO key. The displayed reading will zero and the word ZERO will appear
on the upper portion of the LCD.

2) All subsequent measurements will now be displayed with respect to the zeroed
reading. For example, if a 20A reading is zeroed and a 30A reading is subsequently
measured, the LCD will display 10A.

3) To return to normal operation, press and hold the ZERO key for 2 seconds until the
word ZERO switches off.

4) Note that Relative mode is not available if MIN/MAX mode is enabled.

Data Hold

To freeze the current reading on the LCD, press the Data Hold key. The word HOLD will
appear on the LCD while the meter is in the Data Hold mode. To release the Data Hold
function and return the meter to normal operation, press the Data Hold key again. The
word HOLD will switch off.

MIN/MAX Readings

Pressing the MIN/MAX key allows the meter to display the highest and then the lowest
readings encountered. Press the MIN/MAX key once to view the minimum reading, press it
again to view the maximum reading. Note that the meter will only change its displayed
reading when a measurement is taken higher than the previous MAX or lower than the
previous MIN readings. The HOLD display icon (along with the MIN or MAX icon) will
appear on the LCD in MIN/MAX mode. Pressing the MIN/MAX key a 3
meter to normal operation.

Auto Power Off

To extend battery life, the meter will auto power off after 30 minutes of operation. To
resume operation, either turn the meter OFF and then ON again, or press the HOLD
button. To disable the auto power off function, press down the “HOLD” key while turning
the meter on.

rd

time returns the

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5

Ver. 1.6 03/2005

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

FAX [phone] - TestEquipmentDepot.com