User Guide
1Φ/3Φ 1000 Amp True RMS Power Clamp-On
Model 380976
380976 V3.2 4/11
2
Introduction
Congratulations on your purchase of the Extech 380976 Power Clamp-On Meter. This device
measures 1Φ/3Φ Power (True, Apparent, and Reactive), Horsepower, Phase Angle, True RMS
Current/Voltage, Resistance, Capacitance, Frequency, & Temperature. Power measurements can
be achieved on 3- or 4-wire configurations. Please read the entire manual to get the most from the
meter’s wide array of capabilities. This meter is shipped fully tested and calibrated and, with
proper use, will provide years of reliable service.
Table of Contents
Warranty .................................................................................................................................. 3
Safety Information ..................................................................................................................3
Meter Description ................................................................................................................... 4
AC + DC Voltage Measurements ........................................................................................... 5
AC Current Measurements .................................................................................................... 5
1Φ KW, KVA, KVAR, Power Factor & Phase Angle Measurement ..................................... 6
3Φ 3-Wire KW, HP, KVA, KVAR, Power Factor & Phase Angle Measurement.................. 7
3Φ 4-Wire KW, HP, KVA, KVAR, Power Factor & Phase Angle Measurement................ 10
Resistance and Audible Continuity Measurements .......................................................... 13
Capacitance Measurements ................................................................................................ 14
Diode Tests ........................................................................................................................... 14
Temperature Measurements................................................................................................ 14
AC and DC µA Current Measurements ............................................................................... 14
Meter Control Keys............................................................................................................... 15
Automatic Sleep Mode and Battery Replacement ............................................................. 16
Specifications ....................................................................................................................... 17
Calibration, Repair, and Technical Support Services ....................................................... 20
380976 V3.2 4/11
3
Warranty
EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts
and workmanship for one year from date of shipment (a six month limited warranty applies to
sensors and cables). If it should become necessary to return the instrument for service during or
beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210
for authorization or visit our website www.extech.com for contact information. A Return
Authorization (RA) number must be issued before any product is returned to Extech. The sender is
responsible for shipping charges, freight, insurance and proper packaging to prevent damage in
transit. This warranty does not apply to defects resulting from action of the user such as misuse,
improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized
modification. Extech specifically disclaims any implied warranties or merchantability or fitness for a
specific purpose and will not be liable for any direct, indirect, incidental or consequential damages.
Extech's total liability is limited to repair or replacement of the product. The warranty set forth above
is inclusive and no other warranty, whether written or oral, is expressed or implied.
Safety Information
• Read the following safety information carefully before attempting to operate or service the
meter.
• To avoid damage to the instrument do not exceed the maximum input limits shown in the
technical specifications.
• Do not use the meter or test leads if they appear damaged.
• Use extreme caution when working around bare conductors or bus bars. Accidental contact
with the conductor could result in electric shock.
• Use the meter only as specified in this manual; otherwise, the protection provided by the
meter may be impaired.
• Read the operating instructions before use and follow all safety information.
• Use caution when working with voltages above 60VDC or 30VAC RMS. Such voltages
represent a shock hazard.
• Before taking resistance measurements or testing continuity, disconnect the circuit under test
from the main power supply and remove all loads from the circuit.
Safety symbols
Caution! Refer to this manual before using the meter.
Dangerous voltages.
Meter is protected throughout by double insulation or
reinforced insulation.
When servicing, use only specified replacement parts.
Complies with EN-61010-1, IEC 1010-2-32
380976 V3.2 4/11
4
Meter Description
1. Transformer Jaws
2. Jaw opening trigger
3. Data Hold & MX/MN button
4. Function Selector
5. Range button
6. Temperature input jack
7. LCD Display
8. ‘COM’ input jack
9. ‘V’ input jack
10.
Ω
µA
input jack
380976 V3.2 4/11
5
Measurements
AC + DC Voltage Measurements
WARNING
The maximum input is 600V. Do no attempt voltage measurements above this limit. Exceeding
this limit could cause electrical shock and damage to the meter.
1. Set the rotary switch to the ‘
V’ position.
2. Insert the test leads into the meter’s input jacks. (Black to
‘COM’ and Red to ‘V’)
3. Connect the test leads to the measured circuit.
4. The meter will automatically detect and display AC or DC
voltage. The meter will also automatically select the
appropriate range.
5. Read the voltage (main display) and frequency (upper,
smaller display digits) on the LCD.
NOTE: The sensitivity for Automatic AC/DC Voltage detection is
1V.
Voltage below 1V may indicate DC.
NOTE: The sensitivity for voltage measurements is 1.2V and the frequency range is 40Hz to 1
KHz. If the frequency is less than 40Hz the LCD may display ‘Hz’.
AC Current Measurements
1. Set the rotary switch to the "~A" position.
2. Press the Trigger to open the jaw.
3. Fully enclose the conductor that is being measured in the jaw. No gap should exist between the
two jaw halves. The conductor under test must be a single wire; if there are multiple wires in a
cable the conductor must first be isolated (see diagram below).
4. The meter selects the range automatically.
5. Read the measured current (main display) and frequency (upper display) on the LCD.
NOTE: The sensitivity for current measurements is 6A and the frequency range is 40Hz to
400Hz. If the frequency is less than 40Hz the LCD may display ‘Hz’.
380976 V3.2 4/11
6
AC Power Measurements
1Φ KW, KVA, KVAR, Power Factor & Phase Angle Measurement
1. Set the rotary switch to the ‘KW/KVA’
position.
2. Insert the test leads to the meter as
follows: Black to ‘COM’ and Red to ‘V’.
3. Connect the black lead to the neutral line.
4. Connect the red lead to the power line
and clamp onto the same lead to which
the red lead is connected.
5. The meter selects the best range
automatically.
6. Select the desired display combination
using the RANGE key. Press RANGE to
scroll through the following combination displays:
kW and HP (horsepower)
kW and PF (power factor)
kW and KVAR (reactive power)
KVA and phase angle (θ)
V and A
Note that LEAD and LAG icons are also displayed on the LCD to inform the user that the voltage is
leading or lagging the current with regard to phase.
Note: Allow 2 seconds after each RANGE key press for the meter to update the display.
1 HP = 746 Watts
PF
KW
KVA
=
= cosθ
KVA (Apparent Power) = (V*A) / 1000
KVAR (Reactive Power) =
(KVA) (KW)
22
−
= KVA * sinθ
NOTES
1. The ‘+’ sign printed on the meter must face the power source for best accuracy.
2. If the device under test is a switching mode power supply, the KW, PF, and Phase angle
measurements may not be accurate.
Loading...