Extech Instruments 7470 User manual

High Withstand Voltage Tester
EXTECH Electronics Co., Ltd.
11F-1, No. 408, Ruiguang Rd., Neihu District,
Taipei 114, Taiwan
PHONE: [phone]
FAX: [phone]
Website: http://www.extech-electronics.com
EV 1.02
MODEL 7470 (10KV AC ONLY HIPOT)
MODEL 7472 (12KV DC ONLY HIPOT)
MODEL 7473 (20KV AC ONLY HIPOT)
MODEL 7474 (20KV DC ONLY HIPOT)
Operation Manual

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CONTENT
1. INTRODUCTION.................................................................................................1
1.1. Warranty Policies......................................................................................................1
1.2. Safety Symbols.........................................................................................................2
1.3. Glossary of Terms (As used in this manual).............................................................2
1.4. Safety........................................................................................................................4
1.5. Introduction to Product Safety Testing......................................................................8
1.6. The Different Types of Safety Tests .........................................................................9
1.7. Key Features and Benefits:.....................................................................................14
2. GETTING STARTED.........................................................................................17
2.1. Unpacking and Inspection.......................................................................................17
2.2. Installation...............................................................................................................19
3. SPECIFICATIONS AND CONTROLS ...............................................................21
3.1. Functional Specifications........................................................................................21
3.1.1 7470 Functional Specifications ..........................................................................21
3.1.2 7472 Functional Specifications ..........................................................................22
3.1.3 7473 Functional Specifications ..........................................................................23
3.1.4 7474 Functional Specifications ..........................................................................24
3.1.5 General Specifications.......................................................................................25
3.2 Instrument Controls............................................................................................26
3.3 Quickstart...........................................................................................................29
4. SYSTEM SETTINGS.........................................................................................32
4.1. SETUP Key Parameters.........................................................................................32
4.2. LOCK/LOCAL Key..................................................................................................36
4.3. Password Setting....................................................................................................36
5. TEST PARAMETERS SETUP PROCEDURES.................................................38
5.1. Test Parameters .....................................................................................................38
5.2. Setting Up Tests.....................................................................................................39
5.3. Reviewing Test Results ..........................................................................................44
5.4. Default Test Parameters.........................................................................................44
6. OPERATING INSTRUCTIONS..........................................................................45
6.1. Preparation and Instrument Connections................................................................45
6.2. Power Up................................................................................................................45
6.3. Settings Screen ......................................................................................................45
6.4. Metering..................................................................................................................46
6.5. Performing a Test...................................................................................................46
7. DISPLAYED MESSAGES .................................................................................49
7.1. Running Test Messages all units............................................................................49

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7.2. Additional Displayed messages for DC units..........................................................51
7.3. BUS Remote message ...........................................................................................51
7.4. Fatal Error...............................................................................................................52
7.5. Output Error............................................................................................................52
8. CONNECTION OF REMOTE I/O.......................................................................53
8.1. Signal Outputs on Remote I/O................................................................................53
8.2. Signal Inputs of Remote I/O and Memory Access ..................................................54
9. BUS REMOTE INTERFACE GPIB / RS-232 (OPTION)....................................56
9.1. GPIB Messages......................................................................................................56
9.2. Functions................................................................................................................56
9.3. Signals and Lines ...................................................................................................56
9.4. GPIB Connector......................................................................................................57
9.5. GPIB Address.........................................................................................................57
9.6. Interface Functions.................................................................................................58
9.7. RS-232 Interface.....................................................................................................58
9.8. GPIB / RS-232 Interface Command List.................................................................59
9.9. Example of Communicating Over the GPIB Bus.....................................................67
9.10. Non Volatile Memory.............................................................................................68
9.11. BUS Remote message .........................................................................................68
10. OPTIONS ........................................................................................................69
11. CALIBRATION PROCEDURE.........................................................................72
11.1. Required Calibration Equipment...........................................................................72
11.2. Calibration Initialization.........................................................................................72
11.3. Calibration Procedure...........................................................................................72

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1. Introduction
1.1. Warranty Policies
EXTECH ELECTRONICS CO., LTD., certifies that the instrument listed in this manual
meets or exceeds published manufacturing specifications. This instrument was
calibrated using standards that are traceable to the National Institute of Standards
Taiwan.
Your new instrument is warranted to be free from defects in workmanship and material
for a period of (2) years from date of shipment. During the warranty period, you must
return the instrument to Extech Electronics Co., or its branches or its authorized
distributor for repair. Extech Electronics Co., reserves the right to use its discretion on
replacing the faulty parts or replacing the assembly or the whole unit.
Follow below states, EXTECH will void your warranty.
· Operate under non-normal , contrived omission, or accidental calamity (including,
temblor, floods, rebellion, and fire etc.)
· Any non-authorized modifications, tampering or physical damage.
· Elimination of any connections in the earth grounding system or bypassing any safety
systems.
· Use of non-authorized parts in the repair of this instrument. Parts used must be parts
that are recommended by EXTECH as an acceptable specified part.
This warranty does not cover accessories not of EXTECH manufacture.
Except as provided herein, EXTECH makes no warranties to the purchaser of this
instrument and all other warranties, express or implied (including, without limitation,
merchantability or fitness for a particular purpose) are hereby excluded, disclaimed and
waived.
EXTECH recommends that your instrument be calibrated on a twelve month cycle.

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1.2. Safety Symbols
1.2.1. Product Marking Symbols
Product will be marked with this symbol when it is necessary to refer to the
operation and service manual in order to prevent injury or equipment damage.
Product will be marked with this symbol when hazardous voltages may be
present.
Product will be marked with this symbol at connections that require earth
grounding.
1.2.2. Caution and Warning Symbols
Calls attention to a procedure, practice, or condition that could
possibly cause bodily injury or death.
Calls attention to a procedure, practice, or condition that could
possibly cause damage to equipment or permanent loss of data
1.3. Glossary of Terms (As used in this manual)
Alternating Current, AC: Current that reverses direction on a regular basis, commonly in the
U.S.A. 60 per second, in other countries 50 times per second.
Arc: A partial momentary breakdown due to the force of a strong electric field on closely spaced
conductors, sometimes evidenced by corona or a luminous flashover.
Breakdown: The failure of insulation to effectively prevent the flow of current sometimes evidenced
by arcing. If voltage is gradually raised, breakdown will begin suddenly at a certain voltage level.
Current flow is not directly proportional to voltage. Once breakdown current has flown, especially for a
period of time, the next gradual application of voltage will often show breakdown beginning at a lower
voltage than initially.
Conductive: Having a volume resistivity of no more than 103 ohm-cm or a surface resistivity of no
more than 105 ohms per square.
Conductor: A solid or liquid material which has the ability to let current pass through it, and which
has a volume resistivity of no more than 103 ohm-cm.
Current: The movement of electrons through a conductor. Current is measured in amperes,

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milliamperes, microamperes, nanoamperes, or picoamperes. Symbol = I
Dielectric: An insulating material that is positioned between two conductive materials in such a way
that a charge or voltage may appear across the two conductive materials.
Direct Current, DC: Current that flows in one direction only. The source of direct current is said
to be polarized and has one terminal that is always at a higher potential than the other.
Frequency: The number of cycles an AC waveform repeats over time. Usually
given in Hertz (Hz).
Ground: Refers to the point of low potential in a circuit to which all other voltages are
referenced. May or may not be tied to the earth. Also referred to as Earth.
Hot: Used to refer to the test lead or output side of an instrument that is at high
potential.
Impedance: The property of capacitive or inductive items to limit certain frequencies.
Insulation: Gas, liquid or solid material which has a volume resistivity of at least 1012
Ω-cm and is used for the purpose of restricting current flow between conductors.
Leakage: AC or DC current flow through insulation and over its surfaces. Current
flow is directly proportional to voltage. The insulation is thought of as a constant
impedance unless breakdown occurs.
Neutral: The point of low potential in a circuit to which all other voltages are
referenced. Also known as Common.
Peak Current: The maximum amplitude of anAC current waveform. For a sinusoid,
1.414 x the RMS value.
Power: The amount of work performed by an energy source over time, given in Watts
(W).
PF (Power factor): Power Factor = W/VA where W =Watts (Real Power) and VA
=Volts xAmps (apparent power). It is important to note that the closer the power
factor is to "1" the more resistive the DUT is. The closer the power factor is to 0 the
more reactive (inductive or capacitive) the DUT is.
Reactive Current: The current component due to the reactive impedance of a load.
Also called imaginary current.
Real Current: The current component due to the resistance of a load.
Resistance: The property of a substance that impedes current and results in the
dissipation of power in the form of heat. The practical unit of resistance is the ohm (Ω).
Symbol = R

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747X Series produces
voltages and currents that
can cause harmful or fatal
electric shock. To prevent
accidental injury or death,
these safety procedures
must be strictly observed
when handling and using the
test instrument.
This instrument
meets UL
requirements for
audible and visual
failure indication.
SAFETY
Return: The path by which current returns to a source.
RMS: The Root Mean Squared value of a voltage or current waveform. An RMS
waveform delivers the same amount of energy to a load as a DC waveform of the same
value. For a sinusoid, the RMS value is .707 x the peak value.
Total Current: The vector sum of the real current component and the reactive current
component produced by an applied voltage.
VA: A rating of instantaneous power found by multiplying an instrument’s maximum
output current by its maximum output voltage.
Voltage: The force which causes current through an electrical conductor, given in
volts (V). Symbol = V
1.4. Safety
This product and its related documentation must be
reviewed for familiarization with safety markings and
instructions before operation.
This product is a Safety Class I instrument (provided with a
protective earth terminal).Before applying power verify that
the instrument is set to the correct line voltage (115 or 230)
and the correct fuse is installed.
This product carries an NRTL (Nationally Recognized
Testing Laboratory) and comes equipped with an audible
and visual failure indicator.
1.4.1. Service and Maintenance
User Service
To prevent electric shock do not remove the instrument cover.
There are no user serviceable parts inside. Routine
maintenance or cleaning of internal parts is not necessary.
Avoid the use of cleaning agents or chemicals on the instrument,
some chemicals may damage plastic parts or lettering. Any
external cleaning should be done with a clean dry or slightly
damp cloth. Schematics, when provided, are for reference only.
Any replacement cables and high voltage components should be
acquired directly from Extech Electronics Co., Ltd..

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ESD TESTING
Service Interval
The instrument, its power cord, test leads, and accessories must be returned at least
once a year to an Extech authorized service center for calibration and inspection of
safety related components. Extech will not be held liable for injuries suffered if the
instrument is not properly maintained and safety checked annually.
User Modifications
Unauthorized user modifications will void your warranty. Extech will not be
responsible for any injuries sustained due to unauthorized equipment modifications or
use of parts not specified by Extech. Instruments returned to Extech with unsafe
modifications will be returned to their original operating condition at the customers
expense.
1.4.2. Test Station
Location
Select an area away from the main stream of activity which employees do not walk
through in performing their normal duties. If this is not practical because of production
line flow, then the area should be roped off and marked for HIGH VOLTAGE TESTING.
No employees other than the test operators should be allowed inside.
If benches are placed back-to-back, be especially careful about the use of the bench
opposite the test station. Signs should be posted: “DANGER – HIGH VOLTAGE
TEST IN PROGRESS –UNAUTHORIZED PERSONNEL KEEP AWAY.”
Work Area
Perform the tests on a non-conducting table or workbench, if possible. If you cannot
avoid using a conductive surface, be certain that it is
connected to a good earth ground and the high
voltage connection is insulated from the grounded
surface.
There should not be any metal in the work area
between the operator and the location where products
being tested will be positioned. Any other metal in
the work area should be connected to a good ground,
never left “floating”.
Position the tester so the operator does not have to
reach over the product under test to activate or adjust the tester. If the product or
component being tested is small, it may be possible to construct guards or an
enclosure around the device to be tested. Construct the guards of a non-conducting
Electrical safety tests
should not be
performed in or around
ESD testing areas.
ESD methods should
not be employed during
electrical safety testing,
as this could cause a
hazardous condition for
equipment and test
operators.

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material such as clear acrylic, so that the item being tested is within the guards or
enclosure during the test. If possible, the guards or enclosure should also contain
safety switches that will not allow the tester to operate unless the guards are in place or
the enclosure closed.
Keep the area clean and uncluttered. All test equipment and test leads not necessary
for the test should be removed from the test bench and put away. It should be
apparent to both the operator and to any observers, the product that is being tested and
the product that is waiting to be tested, or has already been tested.
Do not perform Hipot tests in a combustible atmosphere or in any area where
combustible materials are present.
Power
Dielectric Voltage-Withstand Test Equipment must be connected to a good ground.
Be certain that the power wiring to the test bench is properly polarized and that the
proper low resistance bonding to ground is in place.
Power to the test station should be arranged so that it can be shut off by one
prominently marked switch located at the entrance to the test area. In case of an
emergency, anyone can cut off the power before entering the test area to offer
assistance.
1.4.3. Test Operator
This instrument generates voltages and currents that can cause
harmful or fatal electric shock and must only be operated by a
skilled worker trained in its use. The operator should understand the electrical
fundamentals of voltage, current, and resistance.
They should recognize that the test instrument is a variable high-voltage power supply
with the return circuit directly connected to earth ground, therefore, current from the
high-voltage output will flow through any available ground path.
Rules
Operators should be thoroughly trained to follow all national safety standard guidelines
for electrical safety testing in the workplace. Defeating any safety system should be
considered a serious offense with severe penalties. Allowing unauthorized personnel
in the area during a test should also be dealt with as a serious offense. Test operators
should be familiar with methods to properly discharge a device under test in case test
leads become disconnected during testing.
Refer to the following standards for more information:

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KEY SAFETY POINTS TO
REMEMBER
NFPA 70E
OSHA1910 subpart (S)
EN50191
Dress
Operators should not wear jewelry that could accidentally complete a circuit.
ESD protocols should not be observed while performing
electrical safety tests. Intentionally grounding the test operator
could lead to a harmful or fatal electric shock.
Medical Restrictions
Personnel with heart ailments or devices such as pacemakers should be informed that
the voltages and currents generated by the
instrument are very dangerous. If contacted
it may cause heart-related problems that a
person of good health may not experience.
Please have the test operator consult their
physician for recommendations.
1.4.4. Instrument Connections
Never perform a hipot test on energized circuitry or equipment.
The instrument is equipped with a safety ground connection, be sure that this
is connected to a good earth ground.
Always connect the return lead first, regardless of whether the item under test is a
sample of insulating material, a component tested with the high voltage test lead, or a
cord-connected device with a two or three prong plug. The return lead should be
connected first for any type of hipot testing.
Plug in the high voltage test lead only when it is being used. Handle its clip only by the
insulator---never touch the clip directly. Be certain that the operator has control
over any remote test switches connected to the Hipot. Double check the return and
high voltage connections from the Hipot and the Line, Neutral, Ground and Case
connections from the Line Leakage tester to be certain that they are proper and secure.
Keep unqualified and
unauthorized personnel away
from the test area.
Arrange the test station in a safe
and orderly manner.
In case of any problem, turn off
the high voltage first.

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1.4.5. Device Under Test
Never touch the Device Under Test (DUT) or anything connected
to it while high voltage is being applied by the hipot.
When testing with DC, always discharge the capacitance of the item under test and
anything the high voltage may have contacted–such as test fixtures–before handling it
or disconnecting the test leads.
HOT STICK probes can be used to discharge any capacitance in the device under test
as a further safety precaution. A hot stick is a non-conducting rod about two feet long
with a metal probe at the end that is connected to a wire. To discharge the device
under test, two hot sticks are required. First, connect both probe wires to a good earth
ground. Then touch one probe tip to the same place that the return lead was
connected. While holding the first probe in place, touch the second probe tip to the
same place where the high voltage lead was connected.
1.4.6. Key Safety Points to Remember
Keep unqualified and unauthorized personnel away from the test area.
Arrange the test station in a safe and orderly manner.
Never touch the product or connections during a test.
In case of any problem, turn off the high voltage first.
Properly discharge any item tested with DC before touching connections.
1.5. Introduction to Product Safety Testing
1.5.1. The Importance of Safety Testing
Product Safety Tests are specified during the design and development stages of a
product as well as in the production of the products to insure that it meets basic safety
requirements. These tests are designed to verify the safety of the electrical products
in that they do not jeopardize the safety of the people, domestic animals, and property
of anyone who may come in contact with these products. In an era of soaring liability
costs, original manufacturers of electrical and electronic products must make sure
every item is as safe as possible. All products must be designed and built to prevent
electric shock, even when users abuse the equipment or by-pass built in safety
features.
To meet recognized safety standards, one common test is the “dielectric
voltage-withstand test”. Safety agencies which require compliance safety testing at
both the initial product design stage and for routine production line testing include:
Underwriters Laboratories, Inc. (UL), the Canadian Standards Association (CSA), the
International Electrotechnical Commission (IEC), the British Standards Institution (BSI),

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the Association of German Electrical Engineers (VDE) and (TÜ V), the Japanese
Standards Association (JSI). These same agencies may also require that an
insulation resistance test and high current ground bond test be performed.
1.6. The Different Types of Safety Tests
1.6.1. Dielectric Withstand Test
The principle behind a dielectric voltage –withstand test is simple. If a product will
function when exposed to extremely adverse conditions, it can be assumed that the
product will function in normal operating circumstances.
Common Applications of the Dielectric Withstand Test:
Design (performance) testing: Determining design adequacy to meet service
conditions.
Production Line testing: Detecting defects in material or workmanship during
processing.
Acceptance testing: Proving minimum insulation requirements of purchased parts.
Repair Service testing: Determine reliability and safety of equipment repairs.
The specific technique used to apply the dielectric voltage –withstand test to each
product is different. During a dielectric voltage –withstand test, an electrical device is
exposed to a voltage significantly higher than it normally encounters, for a specified
duration of time.
During the test, all current flow from the high voltage output to the return is measured.
If, during the time the component is tested, the current flow remains within specified
limits, the device is assumed safe under normal conditions. The basic product design
and use of the insulating material will protect the user against electrical shock.
The equipment used for this test, a dielectric-withstand tester, is often called a “hipot”
(for high potential tester). The “rule of thumb” for testing is to subject the product to
twice its normal operating voltage, plus 1,000 volts.
However, specific products may be tested at much higher voltages than 2X operating
voltages + 1,000 volts. For example, a product designed to operate in the range
between 100 to 240 volts can be tested between 1,000 to 4,000 volts or higher. Most
“double insulated” products are tested at voltages much higher than the “rule of thumb”.
Testing during development and prototype stages is more stringent than production run
tests because the basic design of the product is being evaluated. Design tests usually
are performed on only a few samples of the product. Production tests are performed

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on every item as it comes off the production line.
The hipot tester must also maintain an output voltage between 100% and 120% of
specification. The output voltage of the hipot must have a sinusoidal waveform with a
frequency between 40 to 70 Hz and has a peak waveform value that is not less than 1.3
and not more than 1.5 times the root-mean-square value.
Types of Failures only detectable with a Hipot test
Weak Insulating Materials
Pinholes in Insulation
Inadequate Spacing of Components
Pinched Insulation
Dielectric Withstand Test; AC verses DC
Please check with the Compliance Agency you are working with to see which of the two
types of voltages you are authorized to use. In some cases, a Compliance Agency will
allow either AC or DC testing to be done. However, in other cases the Compliance
Agency only allows for an AC test.
Many safety agency specifications allow eitherAC or DC voltages to be used during the
hipot test. When this is the case, the manufacturer must make the decision on which
type of voltage to utilize. In order to do this it is important to understand the
advantages and the disadvantages of both AC and DC testing.
AC testing characteristics
Most items that are hipot tested have some amount of distributed capacitance. An AC
voltage cannot charge this capacitance so it continually reads the reactive current that
flows whenAC is applied to a capacitive load.
AC testing advantages
AC testing is generally much more accepted by safety agencies than DC testing. The
main reason for this is that most items being hipot tested will operate on AC voltages.
AC hipot testing offers the advantage of stressing the insulation alternately in both
polarities, which more closely simulates stresses the product will see in real use.
Since AC testing cannot charge a capacitive load the current reading remains
consistent from initial application of the voltage to the end of the test. Therefore, there
is no need to gradually bring up the voltage since there is no stabilization required to
monitor the current reading. This means that unless the product is sensitive to a
sudden application of voltage the operator can immediately apply full voltage and read
current without any wait time.

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Another advantage of AC testing is that since AC voltage cannot charge a load there is
no need to discharge the item under test after the test.
AC testing disadvantages
One disadvantage of AC testing surfaces when testing capacitive products. Again,
since AC cannot charge the item under test, reactive current is constantly flowing. In
many cases, the reactive component of the current can be much greater than the real
component due to actual leakage. This can make it very difficult to detect products
that have excessively high leakage current.
Another disadvantage of AC testing is that the hipot has to have the capability of
supplying reactive and leakage current continuously. This may require a current
output that is actually much higher than is really required to monitor leakage current
and in most cases is usually much higher than would be needed with DC testing. This
can present increased safety risks as operators are exposed to higher currents.
DC testing characteristics
During DC hipot testing the item under test is charged. The same test item
capacitance that causes reactive current in AC testing results in initial charging current
which exponentially drops to zero in DC testing.
DC testing advantages
Once the item under test is fully charged, the only current flowing is true leakage
current. This allows a DC hipot tester to clearly display only the true leakage of the
product under test.
Another advantage to DC testing is that the charging current only needs to be applied
momentarily. This means that the output power requirements of the DC hipot tester
can typically be much less than what would be required in an AC tester to test the same
product.
DC testing disadvantages
Unless the item being tested has virtually no capacitance, it is necessary to raise the
voltage gradually from zero to the full test voltage. The more capacitive the item the
more slowly the voltage must be raised. This is important since most DC hipots have
failure shut off circuitry which will indicate failure almost immediately if the total current
reaches the leakage threshold during the initial charging of the product under test.
Since a DC hipot does charge the item under test, it becomes necessary to discharge
the item after the test.
DC testing unlike AC testing only charges the insulation in one polarity. This becomes
a concern when testing products that will actually be used at AC voltages. This is an
important reason that some safety agencies do not accept DC testing as an alternative

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to AC.
When performing AC hipot tests the product under test is actually tested with peak
voltages that the hipot meter does not display. This is not the case with DC testing
since a sinewave is not generated when testing with direct current. In order to
compensate for this most safety agencies require that the equivalent DC test be
performed at higher voltages than the AC test. The multiplying factor is somewhat
inconsistent between agencies which can cause confusion concerning exactly what
equivalent DC test voltage is appropriate.
1.6.2. Insulation Resistance Test
Some “dielectric analyzers today come with a built in insulation resistance tester.
Typically, the IR function provides test voltages from 500 to 1,000 volts DC and
resistance ranges from kilohms to gigaohms. This function allows manufacturers to
comply with special compliance regulations. BABT, TÜ V and VDE are agencies that
may under certain conditions, require an IR test on the product before a Hipot test is
performed. This typically is not a production line test but a performance design test.
The insulation resistance test is very similar to the hipot test. Instead of the go/no go
indication that you get with a hipot test the IR test gives you an insulation value usually
in Megohms. Typically, the higher the insulation resistance value the better the
condition of the insulation. The connections to perform the IR test are the same as the
hipot test. The measured value represents the equivalent resistance of all the
insulation which exists between the two points and any component resistance which
might also be connected between the two points.
Although the IR test can be a predictor of insulation condition it does not replace the
need to perform a dielectric withstand test.
1.6.3. Ground Bond Test
The Ground Bonding test determines whether the safety ground circuit of the product
under test can adequately handle fault current if the product should ever become
defective. A low impedance ground system is critical in ensuring that in case of a
product failure, a circuit breaker on the input line will act quickly to protect the user from
any serious electrical shock.
International compliance agencies such as CSA, IEC, TÜ V, VDE, BABT and others,
have requirements calling out this test. This test should not be confused with low
current continuity tests that are also commonly called out in some safety agency
specifications. Alow current test merely indicates that there is a safety ground
connection. It does not completely test the integrity of that connection.

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Compliance agency requirements vary on how different products are to be tested.
Most specifications call for test currents of between 10 and 30 amps. Test voltages at
these currents are typically required to be less than 12 volts. Maximum allowable
resistance readings of the safety ground circuit are normally between 100 and 200
milliohms.
If you are testing a product that is terminated in a three-prong plug, you are required to
perform a continuity or ground bond test on the ground conductor to the chassis or
dead metal of the product.
1.6.4. Run Test
All manufacturers of a product that runs on line power normally need to run the DUT
(Device Under Test) after final safety testing so that they can verify the functionality of
their products. In addition to running the DUT to test its basic functionality many
customers also require some basic test data to be recorded while the DUT is powered
up. ARun Test System allows the product to be powered up immediately after the
safety tests are completed with a single connection to the DUT. Measurements that
are commonly made while the DUT is running can include Amperage, Voltage, Watts
and Power Factor.
1.6.5. Line Leakage Test
The Line Leakage test is one of many product safety tests that are normally specified
for electrical products by safety testing agencies such as Underwriters Laboratories (UL)
and the International Electrotechnical Committee (IEC). The line leakage
specifications vary as well as the method in which the measurements are taken
depending upon the application or function of a product and the standard to which the
product is being tested.
Current Leakage or Line Leakage tests are general terms that actually describe three
different types of tests. These tests are Earth Leakage Current, Enclosure Leakage
Current, andApplied Part Leakage Current. The main differences in these tests are in
the placement of the probe for the measuring device. The Earth Leakage Current is
the leakage current that flows through the ground conductor in the line cord back to
earth. The Enclosure Leakage Current is the current that flows from any enclosure
part through a person back to ground if it were contacted by a person. The Applied
Part Leakage Current or Patient Lead Leakage Current is any leakage that flows from
an applied part, between applied parts or into an applied part. The Applied Part
Leakage Current test is required only for medical equipment. All of these tests are
used to determine if products can be safely operated or handled without posing a shock
hazard to the user.
Line Leakage Testers provide the capability of meeting the line leakage test specified in
the following standards; UL 544, IEC 950, UL 1950, IEC 601-1, UL 2601, UL 1563, UL
3101, IEC 1010 and others. The Line Leakage test, is a test which measures the
leakage current of a product, through a circuit that is designed to simulate the
impedance of the human body. The simulation circuit is called the Measuring Device

14
(MD). The instrument has five different MD circuits, selectable through the menu,
which are representative circuits designed to simulate the impedance of the human
body under different conditions. The impedance of the human body will vary
depending upon point of contact, the surface area of the contact and the path the
current flows. For these reasons, the specifications of the Measuring Devices are
different depending upon the type of test being performed as well as the maximum
allowable leakage current. Leakage current measurements are performed on
products under normal conditions and single fault conditions as well as reversed
polarity. This simulates possible problems, which could occur if the product under test
is faulted or misused while the product is operating under high line conditions (110% of
the highest input voltage rating of the product).
Line Leakage tests are normally specified as “Type Tests” or “Design Tests” which are
performed during the development of the product. This helps verify that the design is
safe but it does not guarantee the safety of the products being produced on the
production line. The only way to be sure you are shipping safe products is to test each
product at the end of the production line. The user may perform a Leakage Current
test along with other common safety test such as Dielectric Withstand, Insulation
Resistance, and Ground Bond on the production line with a single connection to the
device under test.
1.7. Key Features and Benefits:
Patented SmartGFI®
The SmartGFI provides maximum operator
protection. If the circuit detects excessive leakage
to ground it shuts down the high voltage in less
than 1 millisecond. SmartGFI is automatically
activated if the DUT is not grounded. The operator
does not need to make the decision whether to
activate the SmartGFI.
Storage of up to 50 setups
Areal benefit for manufacturers that test different
products. The instrument can store 50 individual
memories that may be performed individually or
connected for a 50-step test.
RS-232 or GPIB interfaces
All the functions of the instruments can be
programmed over a RS-232, GPIB or printer
interface which makes them adaptable to any
automated production environment.
Line and Load regulation
Maintains the output voltage to within 1% of setting
even if the load or the line voltage varies. This
ensures that the test results remain consistent and
within safety agency requirements.
Digitally controlled arc
detection system
Allows the operator to select whether low-level
arcs should be detected and provides the operator
with the ability to digitally select and program

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multiple sensitivity levels.
No load setup of trip current
and output voltage
This provides the operator with an easy and safe
way to set trip currents and output voltages since
parameters are set without the high voltage
activated.
TUV & UL listing
This assures you that this instrument meets or
exceeds safety requirements to ensure operator
safety.
Automatic storage of test
program
High Withstand Voltage Tester powers up with the
parameters that were used during the last test to
avoid operator set-up errors.
All parameters for the setups
can be adjusted through a
simple menu driven program
The easy to follow setup screens ensure that the
operator correctly sets up all test parameters
Tamper proof front panel
controls
This makes it possible to limit user access to the
setup screens so that only authorized personnel
with a security code can change test parameters.
Electronic dwell settings
The electronic dwell control helps keep test results
consistent by ensuring that the test duration is the
same for each product tested.
PLC remote inputs and
outputs
The standard 9 pin interfaces provide outputs for
Pass, Fail, and Test in Process. Inputs include
Test, Interlock and Reset. Remote recall of memory
program #1, #2 and #3. This gives the user all the
basic remotes required to configure the High
Withstand Voltage Tester through simple PLC
relay control.
Software calibration control
High Withstand Voltage Tester is calibrated
through the front panel keypad. All calibration
information is stored in non-volatile memory This
allows High Withstand Voltage Tester to be
completely calibrated without removing any covers
and exposing the technician to hazardous
voltages.
User selectable output
voltage frequencies of 50 or
60 hertz
High Withstand Voltage Tester was designed for
the global market. This feature makes it simple
for the user to select the output frequency in the
AC hipot mode so that products can be tested at
the same frequency they will be used at.
Output voltage fine
adjustment
To make High Withstand Voltage Tester usable in
all types of applications, the operator can manually
bring the voltage up or down in 10 volt increments
by simply pressing the up and down arrow keys.
This makes it very easy to adjust the output

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voltage even while High Withstand Voltage Tester
is in the dwell mode so you can analyze test
results at different voltages.
Flashing high voltage
indicator
Aflashing LED located directly over the high
voltage terminal clearly indicates when high
voltage is active to provide maximum operator
safety.
User selectable input voltage
High Withstand Voltage Tester can be switched for
either 115 or 230 volt input operation through an
easy access rear panel mounted switch to allow it
to be used in any country.
Low-current sense
Monitors the minimum level of current flow, thus
ensuring that the DUT is properly connected and
that the hipot test is being performed.
Electronic ramping (up &
down)
Provides a gradual and timed method to increase
or decrease output voltage to the DUT minimizing
any damage from quick high voltage changes to
sensitive DUTs.