Extech Instruments VT30 User manual

User's Guide
LCD Multifunction Voltage Tester
Model VT30

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Introduction
Congratulations on your purchase of the Extech VT30 Multifunction Voltage Tester. The
VT30 measures AC voltage to 480V and DC Voltage to 690V with LCD readout, stepped
voltage bargraph indicator, and LEDs for positive and negative polarity. Additional
features include audible continuity beeper, low impedance test for eliminating phantom
voltages, and a built-in flashlight to illuminate test connections during measurements.
This meter is shipped fully tested and with proper use will provide years of reliable
service.
Safety
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
1. Improper use of this meter can cause damage, shock, injury or death. Read and
understand this manual before use.
2. Ensure that any covers or battery doors are properly closed and secured before use.
3. Inspect the condition of the test leads and the meter itself for any damage before use.
4. Do not exceed the rated input limits.
5. Use great care when taking measurements greater than 25VAC rms or 35VDC. These
voltages are considered a shock hazard.
6. Discharge capacitors and remove power from the DUT before Continuity tests.
7. Remove the batteries from the meter if the meter is to be stored for long periods.
8. Voltage measurement results on electrical outlets can be misleading because of the
difficulty in making a proper connection to the electrical contacts.
Safety Instructions
This meter has been designed for safe use, but must be operated with caution. The rules
listed below must be carefully followed for safe operation.
1. NEVER apply voltage to the meter that exceeds the specified maximum:
Input Protection Limits
Function Maximum Input
VAC, VDC, Continuity 480VAC, 690VDC
Low Impedance 3s<400V AC/690V DC
2. USE EXTREME CAUTION when working with high voltages.
3. ALWAYS discharge filter capacitors in power supplies and disconnect the power when
making continuity tests.
4. ALWAYS disconnect the test leads before opening the cover to replace the battery.
5. NEVER operate the meter unless the battery cover is in place and fastened securely.

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Description
1. Test Probe L1 (-)
2. Test Probe L2 (+)
3. Flashlight
4. LCD display
5. LED (AC voltage indicator [between 100 to 480V])
6. LED (low impedance test)
7. LED (continuity)
8. Low impedance test button (L2)
9. Flashlight button
10. Battery cover
11. Low impedance test button (L1)

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Operation
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 (L2) and negative (L1) test leads to the device or
circuit under test.
3. If the voltage is higher than 4.5V AC/DC, the LCD will light and
display the reading. The stepped voltage bargraph scale in the
display will also indicate the reading.
4. For AC voltages, the LED will light and the “AC” icon will appear in
the display. For DC voltages, the “DC” icon will be displayed. If the
DC voltage is negative, a minus sign will be displayed before the
digital readout.
Single Lead AC Voltage Detection
To check for the presence of voltage (between 100V and 480V)
using only the positive test lead (L2), 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.
1. Hold the two test tips on the measuring points to be
tested.
2. Press the two low impedance test buttons
simultaneously.
3. The Low Impedance LED will light and the applied
voltage will be displayed on the LCD.
Note: The maximum duty cycle in this mode is 5 seconds for
voltages up to 250V and 3 seconds for voltages up to
690V. Allow 10 minutes between each reading.
Note: Measuring from hot to ground may trip any GFCI equipped circuits.

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Continuity Test
The tester can measure resistance and alert the user if the resistance value is less than
200kΩ.
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.
3. If the resistance is less than 200kΩ, the tester will sound an audible alert; the LCD will
display “000”, and the continuity LED will light.
Flashlight
Press and hold the button to turn the flashlight on. Release the button to turn the flashlight off. After the
button is released, the light will turn off after 12 seconds (approx).
Maintenance
Battery replacement
1. The
BAT
icon will appear in the lower right of the display
when the battery voltage becomes low. Replace the batteries
when this appears.
2. Disconnect the meter from any test device or circuit before
opening the tester.
3. Loosen the recessed Phillips head screw at the bottom of the
tester. Do not remove the screw.
4. Hold the meter and pull the lower portion of the meter off until
the batteries are exposed.
5. Replace the two ‘AAA’ batteries observing polarity and
dispose of the old batteries properly.
6. Slide the meter back together and replace the screw.
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.

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Specifications
LCD display 1999 counts (3-1/2 digits) with bargraph and backlight
Resolution 1 Volt
AC Voltage range 0 to 480V
ACV frequency range 50/60Hz
DC Voltage range 0 to 690V
Accuracy ACV ±(1.5%rdg + 5d); DCV ±(1.0%rdg + 3d)
Range selection Automatic
Max measuring current ≤1.0mA (400VAC); ≤1.5mA (690VDC)
Response time Updates 2-3 times/sec
Input Impedance 1MΩ(approx)
Continuity test Range 0 to 200kΩ, guaranteed on < 50kΩ; <5µA test
current
Overvoltage protection 480VAC/690VDC
Low impedance test 12-250VAC/DC; impedance <6kΩ;
LCD enable input voltage >4.5V AC/DC
Operation time: 5s<250V AC/DC
Power supply 2 x “AAA” 1.5V alkaline batteries
Battery life Approx. 8 hours continuous use typical
Operating Temperature 14 to 131oF (-10 to 55oC)
Storage Temperature -22 to 140oF (-30 to 60oC)
Operating Humidity 10 to 85% RH (non-condensing)
Safety This meter is intended for origin of installation use and
protected, against the users, by double insulation per
EN61243-3 and IEC61243-3 to Category IV 600V and
Category III 1000V; Pollution Degree 2.
Approvals CE, IP64
Dimensions 9.4 x 3 x 1.6” (240 x 78 x 40mm)
Weight 9.2oz (260g)

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Support Hotline [phone]
Tech support: Ext. 200; Email: [e-mail]
Repair/Returns: Ext. 210; Email: [email protected]
Product specifications subject to change without notice
For the latest version of this User’s Guide, Software updates, and other
up-to-the-minute product information, visit our website: www.extech.com
Extech Instruments Corporation, 285 Bear Hill Rd., Waltham, MA 02451
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 on 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
[phone] ext. 210 for authorization or visit our website at 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.
Calibration and Repair Services
Extech offers repair and calibration services for the products we sell. Extech also provides
NIST certification for most products. Call the Customer Service Department for information
on calibration services available for this product. Extech recommends that annual
calibrations be performed to verify meter performance and accuracy.
Copyright ©2006 Extech Instruments Corporation
All rights reserved including the right of reproduction in whole or in part in any form.