Extech Instruments 380385 User manual

User's Manual
10KV Digital High Voltage Insulation Tester
Model 380385

380385 V1.5 3/04
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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 (click on Contact Extech and go to Service Department to request an
RA number). 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.
Introduction
Congratulations on your purchase of the Extech High Voltage Insulation Tester. This
device has four pre-set voltage test ranges (up to 10kV) and measures insulation
resistance to 500GΩ. Other voltage test values can be selected using the ±500V step
buttons. This professional meter, with proper care, will provide years of safe reliable
service.
Safety
1. Circuits under test must be de-energized and isolated before connections are made.
2. Circuit connections must not be touched during a test.
3. After insulation tests, capacitors must be discharged.
4. Test leads (including alligator clips) must be in good working order, clean and without
broken or cracked insulation.
5. When servicing, use only specified replacement parts.
6. Environmental conditions:
•Indoor use only; Installation category III 300V
•Pollution degree 2
•Altitude up to 2000 meters
•Relative Humidity 80% max.; Temperature 0 to 40oC
International Safety Symbols
Caution, refer to this manual before using this meter
Dangerous Voltages; risk of electric shock
Meter is protected throughout by double or reinforced insulation

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Specifications
General specifications
Display 2 x 20 character alphanumeric multi-function dot matrix
Range selection 20 ranges in 500V steps with automatic ranging.
Preset buttons for 1KV, 2.5KV, 5KV, and 10KV
Bargraph Displays voltage ramp, soak, and decay
Automatic discharge After automatic & manual stop or upon completion of test
Low battery indicator "Replace battery" displayed when battery voltage is low
Power source Eight 1.5V ‘C’ cells; Battery life 40 hrs (no load at 10kV)
Auto Power off After 5 minutes of inactivity
EnersaveTM mode Shorter test time to conserve battery life
Test Leads Supplied. RED (length = 108”) with GREEN guard lead.
BLACK lead is 42”.
Operating conditions 32 to 104oF (0 to 40oC); < 80% RH
Storage conditions 14 to 140oF (-10 to 60oC); < 80% RH
Dimensions 13 x 10.2 x 6.3” (330 x 260 x 160mm)
Weight 7.9 lbs (3.6kg)
Range Specifications
DC Test
Voltages
Resistance
Ranges (in GΩ)
Short Circuit
Current
Accuracy Resolution
0.5KV 25
1KV 50
1.5KV 75
2KV 100
100mA
2.5KV 125
3KV 150
3.5KV 175
4KV 200
4.5KV 225
5KV 250
120mA
5.5KV 275
6KV 300
6.5KV 325
7KV 350
7.5V 375
8KV 400
8.5KV 425
9KV 450
9.5KV 475
170mA
10KV 500 360mA
± (3% + 2d)
1MΩ
Note: Voltage Regulation is +20% -5% unless current limited.

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Meter Description
1. Test lead jacks
2. Dot Matrix Display
3. Keypad
4. Battery compartment (on bottom)
5. Test lead compartment latch
Preparation
Warning: Ensure that the circuit under test does not include devices or components that
can be damaged by 10KVDC; such devices include power factor correction capacitors, low
voltage mineral insulated cables, electronic light dimmers, ballasts and starters for
fluorescent lamps.
Connecting the Test Leads to the meter
The Black (Earth), Red (Line), and Green (Guard) test leads connect to the meter
directly above the dot matrix display (the meter jacks are color coded). NOTE: The Green
(Guard) lead is attached to the Red lead and should be used (refer to applications section
next).
Connecting the Test Leads to the device under test
The Black (Earth) lead is connected to the conductive material. The Red (Line) and
Green (Guard) leads are connected to insulating, sheathing, and covering material as
shown in the following applications section.
1
2
3
4
5

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Operation
Powering the meter
Press the ON button to turn the unit on. Press the OFF button to turn the unit off.
Insulation Resistance Measurements
Warning: The circuit under test must be completely de-energized and isolated before
making test connections.
1. After turning the unit on, the display will prompt the user
to select a test voltage (diagram at right).
2. Select the test voltage by pressing one of the preset
voltage buttons (1KV, 2.5KV, 5KV, 10KV) or by pressing the Voltage Adjust buttons
(500+, 500-) to step through the available test voltages in 500V steps.
3. The resistance range for the selected voltage is indicated on the dot matrix display as
shown above.
4. Press the TEST START / STOP button again.
5. The display will prompt the user to connect the leads.
Press the TEST START/STOP button to start testing.
6. The elapsed test time appears on the upper line (right
hand side) of the display. The resistance reading is shown on the upper left hand side
of the display. The lower line shows the test voltage in bargraph format (see diagram
at right).
7. The HOLD icon will appear in place of the bargraph
when the test is complete and the voltage has been
discharged.
WARNING: DO NOT REMOVE THE TEST LEADS BEFORE THE HOLD DISPLAY
APPEARS.
8. The meter automatically discharges the system at the end of the test.
9. The meter automatically powers down after 5 minutes.
The EnersaveTM Mode
EnersaveTM mode conserves battery life by performing a relatively short test (10 seconds).
The EnersaveTM mode is the default test mode. To bypass this mode and run a longer test
(100 seconds max), press and hold the TEST button for 3 seconds when starting a test.
Bargraph Voltage Display
The bargraph represents the voltage present on the test leads as it rises, soaks, and
decays. The bargraph appears on the lower left of the dot matrix display during a test.
Automatic Under/Over Range Resistance Detect
If the display shows the message “LOW MΩ”, the test should be interrupted immediately
by pressing the TEST button. This message indicates that the insulation under test has
broken down and the meter is trying to inject a high potential onto a short circuit. If ‘HIGH’
appears, it is likely that the test configuration is open. Check the test set-up then test
again.
Elapsed Timer
The test duration is indicated on the display. This is particularly useful in determining
whether an insulating material under test will break down in a given amount of time.
Select Voltage:
250000MΩV = 5000V
Connect Leads . . . .
. . . . . . Press TEST
R=9.998M
Ω
6.8s
0> ██████ <500V

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Manual Test STOP
To stop a test in progress, press the TEST button. The test will immediately end and the
system will automatically discharge.
Automatic Test STOP
When in the default EnersaveTM mode, the test automatically stops after approx. 10
seconds. The test automatically stops after approx. 100 seconds if the meter is not in the
EnersaveTM mode.
Live Circuit Warning
If the test leads are connected to a live circuit (approx. 500V), a warning beeper will sound
and the meter will display “Live Warning…Circuit Live…”. In this case, correct the problem
and retest.
Automatic Discharge
At the end of a test, the meter automatically discharges the high voltage. The automatic
discharge status is reflected on the display. During discharge the beeper will sound and,
when completely discharged, the HOLD icon appears on the display.
Applications
Measuring Power Tools and Small Appliances
For small appliances, connect the Black (EARTH) lead to conductors and the Red (LINE)
lead to insulating material.
For single or double insulated power tools, one lead should be connected to the device’s
chuck, blade, etc. and the other lead to one of the AC power cord conductors (test both
conductors in turn). Refer to the power tool application diagram below.
Testing Motors
AC Motors
Disconnect the motor from the line by:
a. Disconnecting the wires from the
motor terminals or
b. Opening the main switch
If the main switch is opened, and the
motor also has a motor-starter, then
the starter must be held in the ON position. With the main switch opened, the measured
resistance will include the resistance of the motor wire and all other components between
the motor and the main switch. If a weakness is indicated, the motor and other
components should be checked individually. If the motor is disconnected at the motor
terminals, connect the RED lead to the grounded motor housing and the BLACK lead to
one of the motor leads.
AC
Plug For 2 or 3 prong plugs, connect the
RED lead to one conductor at a time
Connect the BLACK
lead to the chuck
Connect RED lead
to grounded housing
Connect BLACK lead
to the motor leads

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DC Motors
1. Disconnect the motor from the line.
2. To test the brush rigging, field coils and armature, connect the RED lead to the
grounded motor housing and the BLACK lead to the brush on the commutator.
3. If the resistance measurement indicates a weakness, raise the brushes off of the
commutator and separately test the armature, field coils and brush rigging by
connecting one lead to each individually, leaving the other connected to the grounded
motor housing. This also applies to DC Generators.
Testing Single Conductor Cables
1. Completely disconnect the cable
under test from its source and
destination.
2. Connect the test leads to the
cable as shown at right.
Testing Multi Conductor Cables
1. Completely disconnect the cable under test from its source and destination.
2. Refer to the diagrams below for three possible tests.
Transformer Testing
Transformer tests are performed with the transformer completely disconnected from the
line and the load. Note that the case ground should not be removed.
The five tests listed below will completely test a single-phase transformer. Note that at
least 1 minute should be allowed
between each test.
1. High voltage winding to low voltage
winding and ground
2. Low voltage winding to high
voltage winding and ground
3. High voltage winding to low voltage
winding (pictured at right)
4. High voltage winding to ground
5. Low voltage winding to ground
Core Insulation Sheath Covering
EARTH GUARD LINE
Testing one conductor to
all of the conductors Testing one conductor
to earth One conductor to all
minus ground
EARTH
LINE
LINE
EARTH
GUARD
GUARD
LINE
EARTH
Connect the
BLACK lead here Connect the
RED lead here

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
Support Hotline [phone]
Tech support: Ext. 200; Email: [email protected]
Repair/Returns: Ext. 210; Email: [email protected]
Website: www.extech.com
Maintenance
Battery Replacement
When ‘REPLACE BATTERY’ appears on the display, replace the eight 1.5V ‘C’ batteries.
1. Ensure that the meter is powered down and that the test leads are not connected
2. Close the instrument cover and turn the instrument upside down
3. Remove the screw located on the bottom of the meter
4. Remove the battery compartment cover
5. Replace the eight batteries ensuring proper polarity
6. Affix the rear cover and secure the rear screw
Cleaning
Periodically wipe the case with a dry cloth. Do not use solvents or abrasives to clean this
instrument.
Repair and Calibration
Extech offers complete repair and calibration services for all of the products we sell. For
periodic calibration, NIST certification or repair of any Extech product, call customer
service for details on services available. Extech recommends that calibration be performed
on an annual basis to insure calibration integrity.
Copyright ©2002 Extech Instruments Corporation. All rights reserved
including the right of reproduction in whole or in part in any form.