Compliance West HT-2800 Service manual

HT-2800

Dielectric Withstand Tester

0-2800 Volts DC Output

Instruction Manual

COMPLIANCE

WESTUSA

Dear Customer:

Congratulations! Compliance West USA is proud to present you
with your Dielectric Withstand Tester. Your instrument features
a groundbreaking logic-controlled circuit design and ergonomic
front panel and represents the latest in high voltage production
line testing.

To fully appreciate all the features of your new meter, we
suggest that you take a few moments to review this manual.
Compliance West USA stands by your instrument with a full one­year warranty and a loaner instrument policy. If the need arises,
please don't hesitate to call on us.

Thank you for your trust and confidence.

Rev. 2.4 August 20, 2007 i

Table of Contents

An Introduction to Dielectric Withstand Testing with the HT-2800..................................................................1

Safety Precautions......................................................................................................................................1

Test Personnel.............................................................................................................................1

Testing Area................................................................................................................................1

Safety Techniques ......................................................................................................................2

Using the HT-2800 Dielectric Withstand Tester....................................................................................2

Continuity Check .........................................................................................................................2

Ground Check Failures ...............................................................................................2

Defeating the Ground Check.....................................................................................3

Leakage Test................................................................................................................................3

Leakage Current Failures............................................................................................4

High Voltage Dielectric Withstand Test ..................................................................................4

High Voltage Dielectric Withstand Test Failures...................................................4

High Voltage Discharge.............................................................................................4

Testing Equipment with non-Standard Plugs or Pigtail Operation......................................4

Introduction and Specifications................................................................................................................................5

Introduction.................................................................................................................................................5

Specifications...............................................................................................................................................5

Operation ......................................................................................................................................................................7

Setting up your Tester ................................................................................................................................7

AC Line Voltage Requirements.................................................................................................................7

Fuse Replacement.......................................................................................................................................7

Front and Rear Panel Features ..................................................................................................................7

Initial Checkout Procedure.........................................................................................................................12

Setting up the HT-2800 for Production Line Testing.............................................................................13

Factory Settings..........................................................................................................................13

Adjustment of the Leakage Current Level ...............................................................................13

Adjustment of the High Voltage Ramp Time ..........................................................................14

Adjustment of the High Voltage Level....................................................................................14

Adjustment of the High Voltage Test Duration.....................................................................15

Setting the Ground Check Switch.............................................................................................15

Operating Techniques................................................................................................................................16

Daily Operation Test ...................................................................................................................16

Testing ..........................................................................................................................................16

Test Verification procedure when using the HTT-1 function checker:...............16

Test Verification procedure when NOT using the HTT-1 function

checker:.........................................................................................................................16

Test results...................................................................................................................................17

Hipot Pass....................................................................................................................17

Red LED/Buzzer...........................................................................................................17

Technical Assistance.................................................................................................................................................19

Maintenance and Calibration....................................................................................................................................21

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Introduction.................................................................................................................................................21

Service Information.....................................................................................................................................21

General Maintenance..................................................................................................................................21

Interior Access............................................................................................................................21

Calibration Access......................................................................................................21

Cleaning........................................................................................................................................22

Performance Test .........................................................................................................................................22

Calibration Procedure .................................................................................................................................23

Voltage Calibration Adjustment................................................................................................23

Continuity Calibration Adjustment..........................................................................................24

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Section 1

An Introduction to Dielectric Withstand Testing with the HT-2800

The continuity test/dielectric withstand test is a production line test which is recognized by safety
agencies worldwide as a valid criterion of safe assembly of end-use equipment. The test ensures that the
primary circuit power and ground conductors were properly wired and connected for safe operation. It also
applies a high-voltage potential between power and ground conductors to make sure that no unintentional
leakage or arcing paths exist between power and ground. The test consists of a continuity check, a leakage
current check and a high voltage check. It is non-destructive to the equipment under test, and can be
accomplished in a short time.

Safety Precautions

The dielectric withstand test generates voltages of up to 2800 volts dc at potentially lethal current
levels. Currents of as little as 5 mA at 120 volts can cause death, and the HT-2800 is capable of generating 5
mA at up to 2800 volts. Because there is no zero volts crossing point as there is for ac voltage, dc voltage is
considered the more dangerous of the two. It is more likely that a person will be thrown clear or be able to
extricate himself from ac because of the zero crossing. The HT-2800 has been designed to minimize exposure
to high voltages. However, the potential for serious injury or death exists and personnel should be aware
when they conduct this test.

Test Personnel

Personnel require special training to conduct the dielectric withstand test. They should
understand electrical fundamentals clearly, and be aware that high voltage is adept and creative at
completing a path to ground. Instructions should include a warning against any metal jewelry. Operators
should not allow others in the testing area, especially when tests are being conducted. Organization is to be
stressed. The operator should keep the area free of unused leads and equipment.

Testing Area

The area used for conducting the dielectric withstand test should be as remote as possible from
normal productio n line activities. Only personnel actually conducting the test should be allowed in the area,
and it should be taped or roped off to preclude casual entry by other employees. In addition, the area
should be marked "WARNING - HIGH VOLTAGE TESTING" or the equivalent to warn others of the nature
of the testing taking place.
The bench being used should be non-conductive, and any exposed metal parts should be tied
together and grounded. If a conductive surface must be used, it should be grounded.
Because of sparking during a dielectric test failure, it is not safe to conduct dielectric withstand
tests in combustible atmospheres.

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It is imperative that a good ground be provided to the HT-2800. Before connecting the HT-2800,
ensure that a low-resistance gro und is provided by the building wiring. If the HT-2800 is used on a high­resistance grounding circuit, dangerous high voltages may be present to the operator. In addition, the
power to the Testing Area should be provided with an easily reached shutoff switch which can be actuated
by personnel outside the Area if needed.

Safety Techniques

The high voltage circuit of the HT-2800 can be shut off at any time by pressing the RESET button.

The HT-2800 has been provided with a Reset switch to provide an unarmed "Standby" setting
when it is energized, but idle. When the red RESET button is lit. the tester will not provide high voltage
until the RESET Button and the TEST Button have been pressed in order. To prevent inadvertent
operation, the operator should be instructed not to press the RESET Button until the test is ready.
The HT-2800 is equipped with a Ground Continuity Check which will not allow high voltage to be
applied if the Test Return Lead is not properly connected. This is an important safety feature and should
not be defeated unless two wire products are being tested. In that event, it is imperative that the operator
make absolutely sure the Test Return Lead is properly connected to the equipment being tested. If the lead
is not properly connected, a dielectric withstand test failure may energize exposed dead metal of the
equipment being tested. Additionally, the HT-2800 may not recognize the failure. The test will continue for
its normal length of time, and the HT-2800 may show a "PASS".
The HT-2800 has been designed for one-touch operation with the right hand. If possible, it should
be set up to the left and in front of the equipment under test. The equipment under test should be
connected to the HT-2800 and then left alone by the operator. After the operator is clear of the Tester and
the equipment under test, he should press the RESET Button, then the TEST Button, with his right hand.
This will allow the greatest separation between the operator and the test being conducted.
The HT-2800 is designed to bleed the high voltage away after the test has concluded. In order to
ensure that any voltage present in the equipment being tested has been completely bled away, the operator
should not unplug the equipment under test from the HT-2800 unti l the front panel meter reads zero volts.

Using the HT-2800 Dielectric Withstand Tester

The dielectric withstand test involves high voltage and caution should be exercised when using
the Tester. The Tester's return lead is connected to ground potential and when properly connected to the
equipment being tested, it will guard against the operator contacting high voltage. Always make sure the
return lead is firmly connected to exposed dead metal. In the sections below, the three tests are discussed.

Continuity Check

The continuity check ensures that the grounding pin of the power supply cord is properly
connected to the exposed dead metal of the chassis. If this connection is absent, the exposed dead metal of
your product could be at line potential indefinitely after an internal wiring fault, causing risk of shock to
anyone touching it.
If the green Ground OK LED lights and the test continues, the connection between the grounding
pin and the exposed dead metal of the equipment being tested has a resistance of below three ohms*.

Ground Check Failures

If the red Ground Open LED lights, the buzzer sounds, and the test is terminated. The connection
between the grounding pin of the attachment plug cap and the exposed dead metal of the chassis has a
resistance of greater than three ohms*. This indicates a problem with the connection of the HT-2800 to the
equipment being tested, or that the ground connection in the equipment being tested is defective. The
connection to the tester should be checked by removing the Test Return Lead clip from the equipment

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under test and reconnecting it, taking care to make a good connection. The unit should then be retested. If
a failing result is repeated, the connection between the power supply cord ground pin and the chassis of the
equipment being tested should be checked and reworked until a passing result is obtained.
In some cases where the leakage current of the equipment under test is high, but still within the
testing parameters of the HT-2800, and the ground continuity of the chassis at the point of attachment of
the Test Return Lead clip is marginal (within 1% of the three ohm failing point), the ground continuity test
light may trigger after the test has commenced. This is due to the high leakage current appearing as a
voltage across the resistance of the grounding connection, which influences the continuity check. (The
continuity check is monitored continuously during the entire test sequence by the HT-2800 for safety
reasons.) We recommend that this result still be treated as a failure. The high resistance ground path
should be checked and reworked before shipment.

*Special calibrations available by internal adjustment. Must be performed by qualified service personnel. See Sec. 5.

Defeating the Ground Check

The continuity check can only be conducted on equipment using a three wire grounded power
supply cord. Some equipment, such as most portable lamps and all double insulated tools, have only a two
wire power supply cord, so the continuity test cannot be conducted.
Please note that defeating the continuity check should not be done except when necessary to test

two-wire devices. The continuity check feature provides an extra level of operator safety because high
voltage will not be applied if the Test Return Lead is not properly connected to the exposed dead metal of the
equipment being tested. If the Test Return Lead is not properly connected, a dielectric withstand failure
may energize exposed dead metal. Additionally, the HT-2800 may not recognize the failure. The test will
continue for its normal length of time, and the HT-2800 may show a "PASS".

To allow the HT-2800 to test equipment using a two wire power supply cord, the continuity check
can be defeated by turning the rear panel Ground Check switch Off. To remind the operator that the
continuity check is not being conducted, both the Ground OK and Ground Open LED's are lit continuously
during each test. When testing with the Ground Check switch Off, the operator must ensure that the Test
Return Lead is properly connected to exposed dead metal of the equipment being tested for safety and to
ensure that the HT-2800 properly reports all failures.

Leakage Test

The HT-2800 leakage test uses a separate low-frequency transformer circuit to check for excessive
leakage between primary power components and ground. There is not a specific leakage current level
pass/fail requirement at this time for most equipment. However, higher than normal leakage current on a
particular part may indicate an assembly or component problem in the primary circuit.
The leakage current is also monitored by the HT-2800 to ensure that excessive leakage does not
keep the Tester from developing full voltage required for the high voltage test. The HT-2800 will provide full
voltage at any leakage current level up to 5 mA. The leakage current trip level is adjustable on the rear
panel.
The leakage test is conducted by shorting the power and neutral conductors of the power supply
cord and applying high voltage between them and the exposed dead metal of the chassis of the equipment
being tested.
Excessive leakage current is not grounds for failure of the dielectric withstand test. Leakage
current is a normal result of capacitance in the primary circuit between neutral or line conductors and
ground. Because the HT-2800 uses dc voltage, the capacitance will not be apparent, and in non-motorized
equipment, high leakage currents should not normally be anticipated. (In dielectric tests of some larger
electric motors, leakage currents of as high as 95 mA are considered acceptable by safety agencies.)
However, higher than normal leakage currents for a particular example should not be ignored. This indicates
problems of low resistance up to a short circuit between line/neutral and ground, and failures should be
investigated. Failure modes are discussed below.

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If the green Full Voltage LED lights and the test continues, the leakage current was below the level
set by the rear panel adjustment.

Leakage Current Failures

If the red Excess Leakage LED lights, the buzzer sounds, and the test is terminated. The leakage
current delivered to the equipment being tested was over the amount set by the rear panel adjustment. If
other equipment of the same type routinely passes this test, there may be a problem with the primary circuit
of the example being tested. The unit should be checked and reworked if necessary.

High Voltage Dielectric Withstand Test

This test checks for insulation system breakdowns between the primary and ground circuits. The
HT-2800 uses a separate high-frequency transformer circuit to check for and detect arc breakdowns.
The dielectric withstand test is conducted by shorting the line and neutral conductors of the power
supply cord and applying high voltage between them and the exposed dead metal of the chassis of the
equipment being tested. The duration of the test is controlled by the test time control on the back panel.
The test time is counted from the time the Full Voltage LED is lit to the completion of the test.
If the green Hipot Pass LED lights, the test cycle has been successfully completed. The equipment
under test is in accordance with the preset test parameters. The HT-2800 is ready to test the next piece of
equipment.

High Voltage Dielectric Withstand Test Failures

If the red Hipot Fail LED lights, a problem has been found with the insulation system between
primary and ground. The equipment under test should be examined, reworked and successfully tested
before being shipped.

High Voltage Discharge

The HT-2800 has an internal resistor bank designed to discharge the high voltage after completion
of the dielectric withstand test. The equipment being tested should remain connected to the HT-2800 until
the voltage has discharged to a safe level to protect the operator and also to ensure that there is no energy
stored in the tested equipment.

Testing Equipment with non-Standard Plugs or Pigtail Operation

The front panel of the HT-2800 is provided with a NEMA Type 5-15R receptacle, suitable for
testing cord -equipped single -phase products designed for use on a 15 amp branch circuit in North America.
For other types of products, a different receptacle type or pigtail leads may be required. Various adapters
and pigtail leads are available from Compliance West USA, or you can make your own. If tests of this type
are contemplated, call us for information.

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