English User's Manual

User's Guide
Multifunction Voltage Tester
Model VT10
Congratulations on your purchase of the Extech VT10 Multifunction Voltage Tester. The VT10
measures AC Voltage to 600V and DC Voltage to 400V with LED indicators, and LEDs for positive and
negative polarity. Additional features include audible continuity beeper, low impedance mode for
eliminating phantom voltages, and a built-in flashlight to illuminate test connections during
measurements This device is shipped fully tested and calibrated and, with proper use, will provide
years of reliable service. Please visit our website (www.extech.com) to check for the latest version of
this User Guide, Product Updates, and Customer Support.
International 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
Safety Precautions
Improper use of this meter can cause damage, shock, injury or death. Read and understand
this manual before use.
Ensure that any covers or battery doors are properly closed and secured before use.
Inspect the condition of the test leads and the meter itself for any damage before use.
Do not exceed the rated input limits.
Use great care when taking measurements greater than 25VAC rms or 35VDC. These
voltages are considered a shock hazard.
Discharge capacitors and remove power from the DUT before Continuity tests.
Remove the batteries from the meter if the meter is to be stored for long periods.
Voltage measurement results on electrical outlets can be misleading because of the difficulty
in making a proper connection to the electrical contacts.
NEVER apply voltage to the meter that exceeds the specified maximum:
VAC, VDC, Continuity
Input Protection Limits
Maximum Input
600VAC: 30 second max
400VDC: 30 second max
USE EXTREME CAUTION when working with high voltages.
ALWAYS discharge filter capacitors in power supplies and disconnect the power when
making continuity tests.
ALWAYS disconnect the test leads before opening the cover to replace the battery.
NEVER operate the meter unless the battery cover is in place and fastened securely.
VT10-en-GB_V4.3 12/14
Test Probe (-)
Test Probe (+)
LED voltage level indicators
LED (AC voltage indicator)
LED (low impedance test indicator)
LED (phase sequence direction indicators)
LED (continuity indicator)
LED (AC/DC +V/-V polarity voltage indicators)
10. Low impedance button (+)
11. Flashlight button
12. Battery cover
13. Low impedance button (-)
VT10-en-GB_V4.3 12/14
Always test the meter on a known live circuit before taking measurements
Voltage Measurement
1. Note: The voltage tester will turn on automatically when voltages higher than
4.5V AC/DC are detected.
2. Touch the positive (+) and negative (-) test leads to the device or circuit under
3. If the voltage is higher than 4.5V AC/DC, the voltage level LEDs will light and
display the reading.
For AC voltages, the LED and the “AC” LEDs will light in the display. For DC
voltages, the “+V” or “-V” LED will light to indicate polarity. In addition, when
negative DC voltages are measured, the continuity LED will light and the audible
alert will sound.
Note: The measurement time should not exceed 30 seconds. After 30 seconds the
meter should be allowed to cool for 10 minutes.
Single Lead AC Voltage Detection
To check for the presence of voltage (between 100V and 600V) using only the
positive test lead (+), touch the lead to the device or circuit under test. If voltage is
present, the LED will light.
Note: In this mode, the actual voltage is not displayed; only the presence of voltage
is detected.
Low Impedance Voltage Measurement
Due to the lowered internal impedance, capacitive voltage is suppressed
so that the reading shows the actual voltage applied. This can be used to
quickly identify phantom voltages.
Hold the two test tips on the measuring points to be tested.
Press the two low impedance test buttons simultaneously.
The Low Impedance LED will light and the applied voltage will
be displayed on the LEDs.
Note: The maximum duty cycle in this mode is 5 seconds for
voltages up to 250V. Allow 10 minutes between each reading.
Note: Measuring from hot to ground may trip any GFCI equipped
Continuity Test
The tester can measure resistance and alert the user if the resistance value is less than 400kΩ.
1. Before taking a continuity test, make sure that power to the device or circuit under test is off
and that all capacitors are discharged.
2. Touch the test tips to the device under test.
If the resistance is less than 400kΩ, the tester will sound an audible alert and the
continuity LED will light.
VT10-en-GB_V4.3 12/14
Press and hold the
button to turn the flashlight on. Release the button to turn the flashlight off.
3-Phase Rotation
The 3-phase rotation function indicates whether the 3 phase AC lines or mains are live and also
identifies the phase orientation of the three wires before attaching them to a motor or other equipment.
The phase sequence will determine the direction (Clockwise or Counter-clockwise) a motor will rotate
when connected.
To determine clockwise rotation (P1-P2-P3)
Touch probe L1 to any one of the three AC mains. Label this phase P1.
Touch probe L2 to the other two phases. One phase will indicate “L” and one will indicate
Label the phase that indicates “R” as P2.
Touch probe L1 to phase P2 and touch probe L2 to the remaining unlabeled AC main wire.
The “R” icon will illuminate. Label this phase P3.
The clockwise sequence P1-P2-P3 (also known as 1-2-3 or R-S-T) has been identified.
To determine a counterclockwise rotation exchange the “L” and “R” in the procedure.
P1 P2 P3
P1 P2 P3
P1 P2 P3
VT10-en-GB_V4.3 12/14
Battery replacement
1. Disconnect the meter from any test device or circuit before opening the
2. Loosen the recessed Phillips head screw at the bottom of the tester. Do
not remove the screw.
3. Hold the meter and pull the lower portion of the meter off until the
batteries are exposed.
4. Replace the two ‘AAA’ batteries observing polarity and dispose of the old
batteries properly.
5. Slide the meter back together and replace the screw.
All EU users are legally bound by the battery ordinance to return all used batteries to
collection points in your community or wherever batteries / accumulators are sold!
Disposal in the household garbage is prohibited!
Cleaning and Storage
Before cleaning the tester, ensure that the test leads are not connected to any circuit or device. Wipe
the meter only with a damp cloth as needed. Do not apply abrasives, solvents, or other cleaners to the
surface of the meter. Store with the battery removed and avoid extreme temperature and humidity.
VT10-en-GB_V4.3 12/14
Voltage LED steps
AC: 24, 48, 120, 208, 240, 277, 480, 600
DC: 6, 12, 24, 36, 48, 110, 220, 400
ACV frequency range
LED enable input voltage
>4.5V AC/DC
-30% to 0% of the indication
Range selection
Max measuring current
≤1.2mA (600VAC); ≤1.0mA (400VDC)
Display delay
LED indication <0.1s
Input Impedance
1MΩ (approx)
Continuity test
Range 0 to 400kΩ, guaranteed on < 50kΩ; <10µA test current;
Low impedance test
12-250VAC/DC; impedance <6kΩ;
Operation time
30 seconds on / 10 minutes off duty cycle
Power supply
2 x “AAA” 1.5V alkaline batteries, 50mA max
Battery life
Approx. 8 hours of continuous use typical
Operating Temperature
-10 to 55 C (14 to 131 F)
Storage Temperature
-30 to 60 C (-22 to 140 F)
Operating Humidity
10 to 85% RH (non-condensing)
Operating Altitude
2000m (7000 ft.) maximum
This meter is intended for origin of installation use and protected,
against the users, by double insulation per EN61243-3:2010 CATIII
600V and CAT IV 600V.
CE, IP64
240 x 78 x 40mm (9.4 x 3 x 1.6”)
260g (9.2oz)
Copyright © 2014 FLIR Systems, Inc. All rights reserved including the right of reproduction in whole or in part in any form www.extech.com 7
VT10-en-GB_V4.3 12/14