Extech Instruments 38394 User manual

User's Manual
Digital AC/DC Clamp Meter
Model 38394
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com
Back to the Extech 38394 Product Info Page

38394 V2.1 03/2002
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INTRODUCTION
Congratulations on your purchase of Extech’s 38394 AC/DC Clamp Meter. This clamp meter
measures AC/DC Current to 600A, DC/AC Voltage, Resistance, Frequency, and Continuity.
Proper use and care of this meter will yield years of reliable service.
SAFETY
Safety Symbols
This symbol, adjacent to another symbol or terminal, indicates the user must
refer to the manual for further information.
This symbol, adjacent to a terminal, indicates that, under normal use, hazardous
voltages may be present
Double insulation
WARNING: This indicates that a potentially hazardous condition which, if not avoided,
could result in death or serious injury.
CAUTION: This indicates that a potentially hazardous condition which, if not avoided,
could result in injury or damage to the meter.
Safety Precautions
WARNING: Improper use of this meter can cause damage, shock, injury or death. Read and
understand this user's manual before operating the meter.
1. Always remove the test leads before making current measurements.
2. Always remove the test leads before replacing the batteries.
3. Inspect the condition of the jaws, test leads and the meter for any damage before
operating the meter. Repair any damage or replace meter before use.
4. Do not exceed the maximum rated input limits.
5. Use great care when making measurements, especially when the voltages are
greater than 25VAC rms or 35VDC. These voltages are considered a shock hazard.
6. Always discharge capacitors and remove power from the dut before performing
Resistance or Continuity tests.
7. Remove the batteries from the meter if the meter is to be stored for long periods.
8. Ensure that the selected meter function matches the measurement to be taken
9. If the measured current is higher than the range selected for long periods,
overheating may occur compromising the safety and the operation of the meter’s
internal circuits
10. To avoid discharge risks and erroneous readings, do not measure current on high
voltage conductors (>600V)

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SPECIFICATIONS
Function Range Accuracy
240.0A ±(2% rdg + 5d)
(AC @ 50/60Hz)
AC/DC Current
600A ±(2% rdg + 8d)
AC Voltage 2.400V, 24.00V, 240.0V, 600.0V ±(1.2% rdg + 5d)
(AC @ 50/60Hz)
240.0mV ±(0.5% rdg +2d)DC Voltage
2.400V, 24.00V, 240.0V, 600V ±(1.0% rdg + 2d)
240.0Ω, 2.400kΩ24.00kΩ, 240.0kΩ±(1% rdg + 5d)
2.400MΩ±(2% rdg + 2d)
Resistance
24.00MΩ±(3.5% rdg + 5d)
Frequency (≥5V) 50.00Hz, 500.0Hz, 5.000kHz, 50.00kHz,
100.0kHz
±(1% rdg + 5d)
Continuity Audible tone <40Ωapproximately
Function
Maximum
Input Function
Maximum
Input
V DC/AC 600V DC or
AC Peak
Frequency 250V DC or AC peak
Input Limits
A DC/AC 600A DC/AC,
fused
Resistance 400V DC or AC peak
(<10 seconds)
Conductor Size: 1.18" (30mm) maximum
Battery type: 2 x 1.5V AA
Range Selection: Automatic ranging
Display: 5000 Count LCD
Overload Indication: "OL"
Low Battery Indication: Battery icon
Environmental conditions Installation Category II, Pollution degree 2,
Altitude: 2000 meters, Indoor use only
Operating Temperature/Humidity 32º to 122ºF (0oC to 50oC) / <80% RH
Storage Temperature/Humidity 14º to 140ºF (-10oC to 60oC) / <80% RH
Dimensions 7.0x4.2x1.3” (178x64x33mm)
Weight 8.3 oz. (230g)
Zero Adjust Uses REL (Relative) push button
Diode Short/Open, Good/Defect Test
Sample Time 0.35 sec approximately.
Input Impedance 10MΩ for ACV & DCV
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com

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METER DESCRIPTION
Front panel
1. Current Jaws
2. Jaw opening trigger
3. Rotary function switch
4. REL key
5. DATA HOLD key
6. Function key
7. Range key
8. LCD display
9. COM & V/Ωinput jacks
Symbols and Units of measure
AC Current or Voltage
DC Voltage
•))) Continuity
Diode test
Hold Display Data Hold
Auto Auto Range
Low Battery icon
V Volt (voltage)
Ω Ohm (resistance)
A Amp (current)
REL Relative Mode
Hz, KHz Frequency

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OPERATING INSTRUCTIONS
AC/DC Current Measurements
WARNING: Ensure that the test leads are disconnected from
the meter before making current clamp
measurements.
1. Set the Function switch to the 600A range.
2. Press the FUNC key to select AC or DC (the AC/DC icons
will toggle on the LCD with each key press).
3. Press the trigger to open jaw. Fully enclose one conductor
to be measured.
4. The clamp meter will display reading and automatically
select the proper range
AC/DC Voltage Measurements
1. Set the Function Switch to the Vposition.
2. Press the FUNC key to select AC or DC Voltage. The
meter will display the selected unit of measure (AC or DC)
on the left side of the LCD.
3. Insert the black test lead to the COM input jack and the
red test lead to the Vjack.
4. Connect the test leads in PARALLEL with the circuit to be measured.
5. Read the measured value from the LCD display.
Manual Range
This meter is automatic ranging. However, the range can be manually held and
selected. To manual hold the range, press the RANGE key until the desired display
range is selected. The units of measure and decimal positioning will change with each
press of the RANGE key.
Resistance Measurements
CAUTION: Before taking any in-circuit resistance measurements, remove power from the
circuit under test and discharge all capacitors.
1. Insert the black test lead to the COM input jack and the red test lead to the Ωinput
jack.
2. Set the Function switch to the •))) Ωposition, press the FUNC key if necessary
to display the Ω icon.
3. Connect the test leads to the device under test and read the measured value on
the LCD display.
Continuity Test
CAUTION: Before taking measurements, remove power from circuit under test and
discharge all capacitors
1. Insert the black test lead to the COM input jack and the red test lead to the Ωinput
jack.
2. Set the Function switch to the •))) Ωposition.
3. Press the FUNC key until the “•)))” icon appears on the upper right-hand portion of
the LCD.
4. Connect the test lead tips to the device to be measured.
5. If the resistance is < 40Ω(approx.) a tone will sound.

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Frequency Measurements
CAUTION: Before taking any in-circuit measurements, remove power from the circuit
under test and discharge all capacitors.
1. Insert the black test lead to the COM input jack and the red test lead to the VΩ
input jack.
2. Set the Function switch to the Hz position.
3. Connect the test lead tips to the device under test.
4. Read the measured value from the LCD display.
Diode Test
CAUTION: Before taking measurements, remove power from circuit under test and
discharge all capacitors
1. Insert the black test lead to the COM input jack and the red test lead to the V/Ω
input jack
2. Set the Function switch to the •))) Ωposition
3. Press the FUNC key until the “ “ icon appears on the upper right-hand side of
the LCD.
4. Connect the test lead tips to the device to be measured
5. Note the displayed reading
6. Reverse the test lead polarity by swapping the red and black lead connection. Note
this reading also.
a. If one reading displays a value and the other reading displays “OL”, the
diode is good
b. If both readings display “OL”, the device is open
c. If both readings are very small or 0, the device is shorted
Data Hold
Press the HOLD key momentarily to freeze the present reading on the LCD. Hold will
appear in the display. Press the Hkey again to return to normal operation.
Relative Mode
The Relative mode permits the user to store a reference reading and compare all
subsequent readings to the stored reference value. Subsequent readings will display a
value that is the difference between the actual reading and the stored value.
1. Press the REL key when the desired valued is displayed on the meter. This
becomes the stored reference.
2. Take measurements and note that the meter displays the actual reading minus the
reference reading.
3. Press the REL key to return to normal operation.
Using Relative Mode to zero the meter
Press the REL key to zero the meter. Ensure that the test leads and clamp jaw are not
connected to any circuit while doing so. The display will read zero and all subsequent
readings will be displayed relative to zero. Zero as often as necessary.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com