Associated Research 7550DT Operation manual

RESEARCH, INC.
OPERATION AND SERVICE MANUAL
MODEL 7550DT and 7564SA
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7564SA
ELECTRICAL SAFETY
COMPLIANCE ANALYZER
IS
ASSOCIATED RESEARCH, INC.
905 CARRIAGE PARK AVENUE
LAKE BLUFF, IL., 60044-2248 U.S.A.
©PHONE: [phone]
FAX: [phone]
E-MAIL; [email protected]
http ://www. asresearch. com
FOR TECHNICAL ASSISTANCE
® PHONE: [phone]-TEST (8378)
Item # 37737

Certificate Nos 970924-07564100071
CERTIFICATE OP CALIBRATION
P.O. Nos 33911
Company5 OWL ENGINEERING,INC.
Model Nos 07564SAC
Serial Nos 100071
Temp.s 70 °F
Humidity: 50%RH
Calibration date: 09/24/97
Calibration dues 09/24/98
Associated Research, Inc. certifies that the instrument listed
above meets or exceeds published manufacturing specifications.
This instrument was calibrated using standards that are
traceable to the National Institute of Standards & Technology.
Calibration Notes
Instrument was calibrated according to manufacturer's
specification.
le following standards were used to calibrate this equipments
Asset No Manufacturer Model No Model Description Cal Date Next Cal. Measurement NIST Test No.
AR 144
AR 434
AR 434
AR 450
AR 481
AR 481
AR 484
AR 484
AR 517
AR 520
Cole - Parmer 3310-40
Fluke 8060A
Fluke 8060A
ARI 25220
ThermohygrcHTieter 05/19/97
Digital Multimeter 02/25/97
Digital Multimeter 02/25/97
Mi Hi Ohm Load 02/06/97
Hewlett Packard 34401A Digital Multimeter 12/17/96
Hewlett Packard 34401A Digital Multimeter 12/17/96
Ross Engineerin VD30-12.5Y-A Voltage Divider 05/22/97
Ross Engineerin VD30-12.5Y-A Voltage Divider 05/22/97
Hewlett Packard 34330A 30A Current Shunt 06/17/97
ARI DTF-10M13G 10M-13.1G Decade R 11/20/96
05/19/98
02/25/98
02/25/98
02/06/98
12/17/97
12/17/97
05/22/98
05/22/98
06/17/98
11/20/97
TEMPERATURE
DC CURRENT
AC CURRENT
RESISTANCE
DC VOLTAGE
AC VOLTAGE
AC VOLTAGE
DC VOLTAGE
AC CURRENT
RESISTANCE
711004
811/255765,251971,811/251992,811/25174
811/255765,251971,811/251992,811/25174
811/256216,251971,DC57,811/251741,811/
HP REF. CRN0005081
HP REF. CRN0005081
227129,738/255169, 811/255553
232596,811/256753, 811/257734-97
811/255765,251971,811/251992,811/25174
114171,10458-0142-10463
ite calibrateds 09/24/97 Calibrated Bys Victor Bogatov
905 Carriage Park Ave., Lake Bluff, Iliinois 60044 U.S.A. • Phone; [phone]
Fax: [phone] * E-mail: [email protected] * http://www.asresearch,com

5 YEAR WARRANTY POLICY
Associated Research, Inc., 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 and Technology (NIST).
Your new instrument is warranted to be free from defects in workmanship and
material for a period of (1) year from date of shipment. You must return the “Owners
Registration Card” provided within (15) days from receipt of your instrument.
AR recommends that your instrument be calibrated on a twelve month cycle.
Instruments purchased and used in the U.S. only, may have their warranty extended in one
year increments to a maximum of (5) years provided they are returned to AR at least
annually for calibration and inspection. The annual calibration and inspection must be
performed annually each and every year following receipt of instrument. Any instrument
not calibrated and inspected annually will not be eligible for extended warranty status. This
extended warranty is non-transferable and is offered only to the original purchaser.
A return material authorization (RMA) must be obtained from AR before returning
this instrument for warranty service. Please contact our Customer Support Center at
1~800”858”TEST (8378) to obtain an RMA number. It is important that the instrument is
packed in its original container for safe transport. If the original container in not available
please contact our customer support center for proper instructions on packaging.
Damages sustained as a result of improper packaging will not be honored. Transportation
costs for the return of the instrument for warranty service must be prepaid by the
customer. AR will assume the return freight costs when returning the instrument to the
customer. The return method will be at the discretion of Associated Research.
Except as provided herein, Associated Research 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.
Any non-authorized modifications, tampering or physical damage will void your
warranty. Elimination of any connections in the earth grounding system or by-passing any
safety systems will void this warranty. This warranty does not cover batteries or
accessories not of Associated Research manufacture. Parts used must be parts that are
recommended by AR as an acceptable specified part. Use of non-authorized parts in the
repair of this instrument will void the warranty.
ii

OPERATION AND SERVICE MANUAL
MODEL 7564SA QUADCHEK®!!
MODEL 7550DT HypotULTRA®!!
Electrical Safety Compliance Analyzers
AC/DC HIPOT WITH INSULATION RESISTANCE TESTER
AND IEEE-488 (GPIB) INTERFACE or RS-232
and
GROUND BOND TESTER on 7564SA
or
CONTINUITY TESTER on 7550DT
SERIAL NUMBER
© Associated Research, Inc., 1997
905 Carriage Park Avenue, Lake Bluff, Illinois, 60044-2248 U.S.A.
Item #37737
Printed June 22, 1997
Ver 1.01

TABLE OF CONTENTS
SECTION I OPERATORS MANUAL.1
SAFETY.2
INTRODUCTION.7
SPECIFICATIONS.13
WHAT’S NEW.20
CONTROLS.23
INSTALLATION.28
QUICK START.31
OPERATION.34
OPTIONS.76
SECTION II SERVICE MANUAL. 8 3
CALIBRATION.84
PARTS LIST.91
SCHEMATICS.92
IV

SECTION 1
OPERATORS MANUAL

ASSOCIATED
RESEARCH, INC.
SAFETY
SAFETY PRECAUTIONS REQUIRED FOR HIGH
VOLTAGE TESTING!
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.
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
WARNING I CONDITION, THAT COULD POSSIBLY CAUSE BODILY
INJURY OR DEATH.
CAUTION I
CALLS ATTENTION TO A PROCEDURE, PRACTICE, OR
CONDITION, THAT COULD POSSIBLY CAUSE DAMAGE
TO EQUIPMENT OR PERMANENT LOSS OF DATA.
2

SAFETY
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.
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 an Associated Research, Inc.
authorized service center.
ASSOCIATED RESEARCH, INC.
905 CARRIAGE PARK AVENUE
LAKE BLUFF, IL., 60044 -2248 U.S.A.
SPHONE; 1 [phone]
1 (800) 858-TEST (8378)
FAX; 1 [phone]
E-MAIL : [email protected]
http;/Av\vvv.asresearch.com
Service Interval
The instrument and its power cord, test leads, and accessories must be returned at least
once a year to an Associated Research authorized service center for calibration and
inspection of safety related components. Associated Research 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. Associated Research 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 Associated
Research with unsafe modifications will be returned to their original operating condition at
your expense.
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
3

ASSOCIATED
RESEARCH, INC.
SAFETY
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."
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 the event of an emergency,
anyone can cut off the power before entering the test area to offer assistance.
Work Area
Perform the tests on a nonconducting table or workbench, if possible. If you cannot avoid
using a conductive surface, be certain that it is securely grounded to a good earth ground
and insulate the high voltage connection 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, made of a non-conducting material such as
clear acrylic, such that the item being tested is within the guards or enclosure during the
test, and fit them with switches so that the tester will not operate unless the guards are in
place or the enclosure closed.
Keep the area clean and uncluttered. All test equipment and test leads not absolutely
necessary for the test should be removed from the test bench and put away. It should be
clear to both the operator and to any observers which product is being tested, and which
ones are waiting to be tested or have already been tested.
Do not perform Hipot tests in a combustible atmosphere or in any area where combustible
materials are present.
TEST OPERATOR
Qualifications
This instrument generates voltages and currents which can cause harmful or fatal electric
shock and must only be operated by a skilled worker trained in its use.
4

ASSOCIATED
RESEARCH, INC.
SAFETY
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 and therefore, current
from the high-voltage output will flow through any available ground path.
Safety Procedures
Operators should be thoroughly trained to follow these and all other applicable safety rules
and procedures before they begin a test. Defeating any safety system should be treated as
a serious offense and should result in severe penalties, such as removal from the Hipot
testing job, Allowing unauthorized personnel in the area during a test should also be dealt
with as a serious offense.
Press
Operators should not wear jewelry which could accidentally complete a circuit.
Medical Restrictions
This instrument should not be operated by personnel with heart ailments or devices such
as pacemakers.
TEST PROCEDURES
INEVER PERFORM A HIPOT TEST ON ENERGIZED CIRCUITRY OR EQUIPMENT!
If the instrument has an external safety ground connection be sure that this is connected.
Then Connect the return lead first for any test regardless of whether the item under test is
a sample of insulating material tested with electrodes, a component tested with the high
voltage test lead, or a cord-connected device with a two or three prong plug.
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 to be certain that they are proper and secure.
On Models 7550 DT and 7564SA the return lead of the instrument is not
grounded (earthed). This allows for the monitoring of very low leakage
levels of current. It is therefore important that the device under test is never grounded
(earthed) or the current meter will essentially be bypassed and you will get incorrect
current meter readings.
warningI
NEVER TOUCH THE ITEM UNDER TEST OR ANYTHING CONNECTED TO IT WHILE
HIGH VOLTAGE IS PRESENT DURING THE HIPOT TEST.
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.
CAUTION II
5

I, INC.
SAFETY
HOT STICK probes can be used to discharge any capacitance in the item under test as a
further safety precaution. A hot stick is a nonconducting rod about two feet long with a
metal probe at the end which 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 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.
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.

ASSOCIATED
RESEARCH, INC.
INTRODUCTION
GLOSSARY OF TERMS
(as used in this manual)
Alternating Current, AC: Current which reverses direction on a regular basis, commonly in the
U.S.A. 60 per second, in other countries 50 limes per second.
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 10^ ohm-cm or a surface resistivity of no
more than 10^ 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 10-^ ohm-cm.
Current: The movement of electrons through a conductor. Current is measured in amperes,
milliamperes, microamperes, nanoamperes, or picoamperes. Symbol = I
Dielectric: An insulating material which 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 which flows in one direction only. The source of direct current is said
to be polarized and has one terminal which is always at a higher potential than the other.
Hipot Tester: Common term for dielectric-withstand test equipment.
Hypot®: Registered trademark of Associated Research, Inc., for its dielectric-withstand test equipment.
Insulation: Gas, liquid or solid material which has a volume resistivity of at least 10^^ ohm-cm and is
used for the purpose of resisting current flow between conductors.
Insulation Resistance Tester; An instrument or a function of an instrument capable of measuring
resistance's in excess of 200 megohms. Usually employs a higher voltage power supply than used in
ohmmeters measuring up to 200 megohms.
Leakage; Ac or DC current flow through insulation and over its surfaces, and AC current flow through
a capacitance. Current flow is directly proportional to voltage. The insulation and/or capacitance is
thought of as a constant impedance, unless breakdown occurs.
Resistance: That properly of a substance which impedes current and results in the dissipation of power
in the form of heat. The practical unit of resistance is the ohm. Symbol - R
Trip Point: The minimum current flow required to cause an indication of unacceptable performance
during a dielectric voltage-wdthstand test.
Voltage; Electrical pressure, the force which causes current through an electrical conductor.
Symbol = V
7

I, INC.
INTRODUCTION
INTRODUCTION
The importance of testing... User safety
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 (lEC), the British Standards Institution (BSI), the Association of German
Electrical Engineers (VDE) and (TUV), the Japanese Standards Association (JSI). These
same agencies may also require that an insulation resistance test and high current ground
bond test be performed.
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.
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

[. INC.
INTRODUCTION
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.
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 1-800-858-TEST
(8378).
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.
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.
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 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,

ASSOCIATED
RESEARCH, INC.
INTRODUCTION
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,
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.
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
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.
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 have
failure shut off circuitry which will indicate failure almost immediately if the total
10