Extech Electronics 7611 User manual

7611
LINE LEAKAGE TESTER
OPERATION MANUAL
EV 1.11
Printed Dec. 2005

WARRANTY POLICY
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 (1) year 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.
Any unauthorized modification, tampering with or physical damage to this instrument
will render your warranty void. Elimination of any connection in the earth grounding
system or by-passing any safety system will void this warranty. This warranty does not
cover accessories not of Extech Electronics Co., Ltd. manufacture. Parts used must be
parts that are recommended by Extech Electronics Co. Ltd. as an acceptable specified
part. Use of non-authorized parts in the repair of this instrument will void the warranty.
Extech Electronics Co., Ltd. recommends that your instrument be calibrated on a twelve
month cycle.
Except as provided herein, Extech Electronics Co., Ltd. makes no warranties to the
purchaser of this instrument. All other warranties, express or implied are hereby excluded,
disclaimed and waived.

Index
Chapter 1 : Introduction ……………………………………1
Chapter 2 : Specifications …………………………………..10
Chapter 3 : Front And Rear Panels ……………………….13
Chapter 4 : Installation …………………………………….18
Chapter 5 : Quick Start …………………………………….20
Chapter 6 : General Setup Procedures ……………………23
Chapter 7 : Test Parameter Setup Procedures ……………25
Chapter 8 : System Parameter Setup ………………………30
Chapter 9 : Operation Procedure ………………………….34
Chapter 10 : LCD Displayed Messages ……………………37
Chapter 11 : Remote Operation ……………………………40
Chapter 12 : RS232 & GPIB Interface …………………….42
Chapter 13 : Options ………………………………………..50
Chapter 14 : Calibration Procedures ………………………52

INTRODUCTION
1
CHAPTER 1 : INTRODUCTION
1.1 GENERAL:
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 (110 or
220) and the correct fuse is installed.
1.1.1 SAFETY SYMBOLS:
INSTRUCTION MANUAL SYMBOL. PLEASE REFER TO THE
INSTRUCTION MANUAL FOR SPECIFIC WARNING OR
CAUTION INFORMATION TO AVOID PERSONAL INJURY OR
DAMAGE TO THE PRODUCT
INDICATES HAZARDOUS VOLTAGES MAY BE PRESENT.
CHASSIS GROUND SYMBOL.
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.
WARNING
CAUTION

INTRODUCTION
2
1.1.2 WARNING:
A Hipot produces voltages and currents which 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.
1.1.3 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. Any external cleaning should be done with a clean dry or slightly damp cloth.
Avoid the use of cleaning agents or chemicals to prevent any foreign liquid from
entering the cabinet through ventilation holes or damaging controls and switches, also
some chemicals may damage plastic parts or lettering. Schematics, when provided, are
for reference only. Any replacement cables and high voltage components should be
acquired directly from Associated Research, Inc. Refer servicing to a Extech Electronics
Co., Ltd. authorized service center.
Service Interval
The instrument and its power cord, test leads, and accessories must be returned at least
once a year to a Extech Electronics Co., Ltd. authorized service center for calibration and
inspection of safety related components. Extech Electronics Co., Ltd. will not be held
liable for injuries suffered if the instrument is not returned for its annual safety check and
maintained properly.
User Modifications
Unauthorized user modifications will void your warranty. Extech Electronics Co., Ltd.
will not be responsible for any injuries sustained due to unauthorized equipment
modifications or use of parts not specified by Associated Research. Instruments returned
to Extech Electronics Co., Ltd. with unsafe modifications will be returned to their
original operating condition at your expense.
1.1.4 OPERATING, STORAGE AND SHIPMENT ENVIRONMENT
Operating Environment
This instrument may be operated in temperatures from 0° - 40° C. and relative humidity
of 20 to 80%, altitude 2000 meters (6560 feet)
.
Storage Environment
This instrument may be stored or shipped in environments with the following limits:
Temperature......................... -40° to 75°C
Altitude..........................….. 7,620 meters (25,000 feet)
The instrument should also be protected against temperature extremes, which may cause
condensation within the instrument.

INTRODUCTION
3
Shipment Environment
Original Packaging: Please retain all original packaging materials that you originally
received. If you are returning your instrument to us for servicing please repackage the
instrument in its original container. Please enclose the instrument with all options,
accessories and test leads. Indicate the nature of the problem or type of service needed.
Also, please mark the container "FRAGILE" to insure proper handling.
Other Packaging: If you do not have the original packaging materials please follow these
guidelines:
1). Wrap the instrument in a bubble pack or similar foam. Enclose the same information
as above.
2). Use a strong double-wall container that is made for shipping instrumentation. 350 lb.
test material is adequate.
3). Use a layer of shock-absorbing material 70 to 100 mm (3 to 4 inch) thick around all
sides of the instrument. Protect the control panel with cardboard.
4). Seal the container securely.
5). Mark the container "FRAGILE" to insure proper handling.

INTRODUCTION
4
1.2 Product Safety Testing
The importance of testing... User safety
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), the
Association of German Electrical Engineers (VDE) and (TÜV), the Japanese Standards
Association (JSI). These same agencies may also require that an insulation resistance test
and high current ground bond test be performed.
1.3 Line Leakage Testing
The Line Leakage test is one of many product safety tests which 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, and Applied 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 which 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.
The Model 7611 Line Leakage Tester provides 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 which is designed to simulate

INTRODUCTION
5
the impedance of the human body , this circuit is called the Measuring Device (MD).
The instrument has five different MD circuits, selectable through the menu, which are
representative circuits designed to simulate the impedances 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 on the Measuring Devices differ depending upon the type of
test being performed as well as the maximum allowable leakage current. Leakage current
measurements are performed on products under both 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 built in switching matrix interface allows the 7611 to be
interconnected with other AR safety testers to form a complete safety testing system.
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.
1.4 The Dielectric Withstand (Hipot) 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.
The most common applications of the dielectric-withstand test are:
•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 varies with each product, but basically, during a dielectric voltage
- withstand test, an electrical devise is exposed to a voltage significantly higher than it
normally encounters. The high voltage is continued for a given period of time.

INTRODUCTION
6
During the test, all "stray" current flow to ground is measured. If, during the time the
component is tested, stray current flow remains within specified limits, the device is
assumed to be 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 on each
and 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.
1.5 Advantages and Disadvantages of AC Testing and DC Testing....
Please check with the Compliance Agency you are working with to see which of the two
type 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. If you are unsure which specification you must
comply with please contact our CUSTOMER SUPPORT GROUP at 02-26943030.
Many safety agency specifications allow either AC 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.
1.5.1 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 when AC is applied to a capacitive load.
1.5.2 AC testing advantages
1. 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 at AC
voltages and AC hipot testing offers the advantage of stressing the insulation

INTRODUCTION
7
alternately in both polarities which more closely simulates stresses the product will
see in real use.
2. 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.
3. 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.
1.5.3 AC testing disadvantages
1. A key 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.
2. 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.
1.5.4 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.
1.5.5 DC testing advantages
1. 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.
2. The other advantage to DC testing is that since the charging current only needs to be
applied momentarily 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.
1.5.6 DC testing disadvantages
1. 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

INTRODUCTION
8
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.
2. Since a DC hipot does charge the item under test it becomes necessary to discharge
the item after the test.
3. 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 a key reason that some safety agencies do not accept DC testing as an
alternative to AC.
4. 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 The 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, TÜV 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.
1.6.1 TYPES OF FAILURES DETECTABLE ONLY WITH A HIPOT
TEST
•Weak Insulating Materials

INTRODUCTION
9
•Pinholes in Insulation
•Inadequate Spacing of Components
•Pinched Insulation
1.7 The 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 the event 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, TÜV, VDE, BABT and others,
have requirements calling out this test. This test should not be confused with simple low
current continuity tests that are also commonly called out in some safety agency
specifications. A low current test merely indicates that there is a safety ground
connection, it does not completely test the integrity of that connection.
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 SHOULD HAVE ANY QUESTIONS RELATING TO THE OPERATION
OF YOUR INSTRUMENT CALL 886-2-26943030 IN TAIWAN.

SPECIFICATIONS
10
CHAPTER 2 : SPECIFICATIONS
2.1 Functional Specifications of 7611
CURRENT MEASUREMENT
Frequency Range DC – 1MHz
CMRR >40 dB @1MHz, differential mode
Input Impedance/Capacitance >1MΩ/ <200pf
LEAKAGE CURRENT
Range Resolution Accuracy (DC - 200KHz) Accuracy(10KHz - 1MHz)
0.0-999.9, µA 0.1 ±(1.5% of reading+5counts) ±(5% of reading+5counts)
1000-6000, µA 1 ±(1.5% of reading+2counts) ±(5% of reading+5counts)
LINE VOLTAGE MEASUREMENT
Range 0-300Vac
Resolution 0.1V
Accuracy ±(1% of reading +2counts)
DUT
30 –300 VACInput Power Rating
Single Phase Unblanced(One Hot or Line conductor and One Neutral)
Current Capatcity 30 A
Production 32 A ,Short current, Response Time < 600ms
SETTINGS
High/Low Trip, µA 0 - 6000µA (0=OFF), Resolution 1µA
Delay Time, second 0, 1.0-999.9s (0=Continuous), Resolution 0.1s
MEASURING DEVICES CIRCUIT
MD A UL 544 Non Patient、UL484、IEC60598
MD B UL 544 Patient Care
MD C IEC60601-1, UL2601-1, EN60601-1
MD D UL1563
MD E UL 60950, IEC60950, IEC61010-1, IEC60335-1,IEC60990
MD F External MD
GENERAL
Input Voltage 115/230 Vac ±15%, 50/60Hz ±5%, Fuse 2A/250V Slow-Blow fuse

SPECIFICATIONS
11
PLC Remote Control Input ：Test, Reset, Memory 1, 2 ,3
Output --- Pass, Fail, Processing
Memory 10 Memories, 8 step/memory
Display 16×2 LCD with back light
Key Lock To prevent unauthorized alteration of the test Parameters
Calibration Build-in software and external calibrated meters
Interface GPIB/ RS232 (option)
Alarm Volume Setting Range:0-9; 0=OFF, 1 is softest volume, 9 is loudest volume
Environment 0 – 40°C, 20 – 80%RH
Dimension 430(W) × 89(H) × 400(D) mm
Net Weight 7.5 Kg.
STANDARD ACCESSORY
1102 ×2
1761 ×1
1906 ×1

SPECIFICATIONS
12
2.2 KEY FEATURES & BENEFITS SUMMARY
FEATURES BENEFITS
Provides 8 of the most common
safety tests
No need to manually set up the test or to switch test
leads around.
The 5 most common measuring
devices are built-in and can be
selected through software control
A versatile tester that can be set-up to meet
multiple specifications without the need for
complicated external connections, or the need for
separate instruments.
Fully complies with the latest
European Norms
Complies with the latest EN such as the Low
Voltage Directive and Medical Directive.
Programmable security password
system
Avoids tampering with settings by only allowing
authorized personnel with a user programmable
security password to change test parameters.
Front panel calibration All calibration is done through a simple user
interface from the front panel. No need to open the
instrument.
PLC, RS-232 or GPIB Control Provides flexibility for semi-automatic or automatic
operation with a choice of communication
protocols which provides the capability for easy
test data storage.
Microprocessor control with software
menuing
Microprocessor control allows for many advanced
features such as automatic testing, memories and
software control.
External measurement circuit One external measurement circuit is provided for
measurement of other devices.
Separate current trip points for each
test
Each test can have a separate trip point for failure
analysis.
50 Memories for test storage Storage of test set-ups so parameters only need to
be entered once then memorized.
Complete with software driver National Instruments LabVIEWsoftware driver
is provided for automated applications to ease the
testing process.
Ranges from DC to 1 MHz Complies with even the 1 MHz specification for
IEC testing.

FRONT AND REAR PANELS
13
CHAPTER 3 : FRONT AND REAR PANELS
3.1 FRONT PANEL DESCRIPTION
1. POWER SWITCH: Rocker-style switch with international ON ( l) and OFF (O)
markings.
2. RESET BUTTON: This is a momentary contact switch. If a failure condition
occurs during a test you will need to reset the system to shut off the alarm and to
signal the system that you are aware of a failure condition before you can proceed to
the next test or change any of the set-up parameters. This switch also serves as an
abort signal to stop any test in progress controlled by the Line Leakage Tester.
3. TEST SWITCH: This is a momentary contact switch. Press the green button to
activate the leakage test which is set up in the memory location shown on the display.
The switch will also illuminate to indicate a pass condition at the end of the test.
4. TRIP: Use this key to set the trip current level for each step.

FRONT AND REAR PANELS
14
5. LINE: Use this key to activate the NEUTRAL, REVERSE, and GROUND relays to
set up the steps within each memory for the single fault and normal conditions.
6. MD CIRCUIT: Use this key to select the Measuring Device (MD) circuit A through
F to simulate different body impedances. This setting will vary depending upon the
standard to which the product is being tested. The Line Leakage Tester has 5 internal
MD circuits A-E which are shown below and 1 external measuring device which can
be added if a new requirement is needed.
MD = A
UL 544 MEDICAL EQUIPMENT
Non patient equipment.
MD = B
UL 544 MEDICAL EQUIPMENT
Patient care equipment.
MD = C
IEC 601-1, UL 2601, EN 60601-1,
MEDICAL EQUIPMENT
MD = D
UL 1563 Electric Spas,
Equipment Assemblies and
Associated Equipment
MD = E
IEC 1010, UL 3101, IEC 950, UL 1950, EN 60950 LABORATORY EQUIPMENT,
INFORMATION TECHNOLOGY
7. DELAY: Use this key to program the delay time for making the leakage
measurement for each step.
8. PROBE:
Use this key to select the location of the MD circuit for the type of test being
performed. G-L indicates the MD is connected to measure the leakage current in the
earth ground conductor in the line cord back to the system neutral, an EARTH
LEAKAGE TEST. PH-L indicates the MD is connected between the PROBE-HIGH (PH)
terminal # 27 on the instrument which should be connected to the ENCLOSURE of the
DUT through the system neutral, an ENCLOSURE LEAKAGE TEST. PH-PLindicates
the MD is connected between the PHand the PROBE-LO (PL) terminal # 26 on the
instrument which allow the operator to connect the MD between APPLIED PARTS.
9. CONNECT: Use this key to sequence one step to the next step. The display will
indicate M1-1_. The underbar indicates that step 1 is connected to step 2.
10. DATA ENTRY KEYS: Use these keys to input numeric parameters followed by the
ENTER key. Also used to recall test parameters stored in memory 0-9.
11. STEP: Use this key to select one of the 8 locations contained within each memory.
The step button will cycle through the steps as indicated on the display in the Set
Screen. M1-1, M1-2, M1-3, etc.