Hipot test procedure pdf

Ammeter clear test a lowvoltage test using a 60 hz 125v ac power. Hipot testing is an abbreviation for high potential testing a category of electrical tests used to verify the. Hipot test voltages high potential test electrom instruments. Performed by stressing the insulation of the product far.

A minor disadvantage of the ac hipot tester is that if the circuit under. Perform the test as instructed to make best use of vlf technology. High voltage is applied from the mains input lines to the chassis of the product. Vlf hipot test voltages are provided by the ieee 400. Hilo programmable during test time lo can be set to off during hipot test hi can be set to off during ir test indication. Bring dc voltage up to prescribed test level in equal steps.

In the last few years, hipot and continuity tests have resulted in the highest failure rates of any measurements we make. Understand that each step in the work plan must be executed as planned. The test connection arrangement is shown in figure 2 c. Cirris hipot testers are designed to be as safe as practically possible.

The productionline hipot test, however, is a test of the manufacturing process to determine whether the construction of a production unit is about the same as the construction of the unit that was subjected to type testing. The dielectric withstand hipot test in compliance magazine. The dc voltage potential in the windings is rapidly raised to a predetermined level, or raised in steps up to this level, depending on what test method is used. If a vlf test is too low in voltage andor too short in duration, more harm than good may result. Designed to verify that the insulation of a product is adequate enough to withstand high voltage. Image you are bathing in bath tube, suddenly drier in operating dropping into bath tube, the current flows from drier through your body to ground under this situation. The choice of the right method and the most appropriate instrument before moving on to the main hipot testing techniques, menu. This discussion will also focus on testing of stator windings and not on testing individual bars or coils. Sentry plus series hipot testers instruction manual. Some say because ac more readily ionizes air than dc, dc is a less stressful test. The hipotronics hd11s tester supplies the needed voltage and measures the current leakage.

This test is similar to tests 1 and 2, but as applied to a three phase transformer for phase identification and phase continuity check. Ipctm650 embedded devices test methods subcommittee. With an ac hipot test, a long ramp time is usu ally not required except with certain sensitive devices. It is the data behind the hipot test that can help manufacturers ensure the product is safe and consistent. Inadequate creepage and clearance distances introduced during the manufacturing process. Nrtl standards generally specify two separate testing categories. Acceptable procedures for conducting hipot testing, although varying slightly in technique, have been standardized as either a withstand test or a timeleaking current test. This technical article provides general guidelines for high potential hipot dc testing of mv power cables. Test button this is a momentary contact switch used to start a test. Such testing can be conducted as an acceptance test for new installations or as. Electrical safety testing reference guide touch area.

In the boost or voltage withstand test process, as a result of short circuit, flashover, breakdown, such as over current, the current trip of relay protection, automatic voltage regulator power that test materials are not up to standard, at this time regulator should be back to zero, cutting off power supply, inspect the test products. Hipot testing procedure for withstand testing of hv coax. The hipot test the dielectric voltagewithstand test is commonly known as the hipot test. A dielectric strength test, commonly called a hipot test, dielectric withstand, or high potential, is a stress test of the insulation of a device under test dut.

All tests made following cable installation and during the warranty period must be performed in accordance with the applicable specifications. Ac hipot testing there are no widely accepted test standards for ac hipot testing of cables, and power frequency ac hipot testing of cable systems is rarely performed. Ac hipot tests 15 dc hipot tests 15 arcing 16 line regulation 17 load regulation 17 ramping 18 minmax current detection 18 ground continuity test 18 polarization test 19 ground bond test 19 insulation resistance test 20 measurement procedure 21 dielectric absorption 21 charging current 21 leakage current 21 leakage current test 22. Reverse side of card at right is used to record the test data. Ac testing also has the advantages of checking both polarities of voltage and of not needing to discharge the dut after testing is complete. High potential testing hipot testing can be conducted with a dc potential or ac potential and can be applied as a type 1, withstand test or a type 2, diagnostic test. Testing of high voltage cables manual horizon power 1st edition february 20 prepared by field practices. Connection setup for a vlf cable connecting a vlf test instrument to a cable refer to ieee 400. The hipot test is usually a 100% production line test and can be performed using either an ac or a dc voltage. Recently, there was a discussion in the ieee email safety forum about the relationship between the hipot test current, leakage current, and insulation resistance. Timely conducted testing procedures can help notice the loss of cable insulation integrity, spot signs of its deterioration caused by aging, and therefore prevent.

A dielectric voltagewithstand test, usually referred to as a hipot test, stresses the insulation of a product beyond what it would encounter during normal operation to be certain of the units safety, even under uncommon circumstances. A dc hipot test should be used only when a vlf test set is not available. To reset the system for the next test, press and release this button. Electrical safety testing reference guide power sources. In this video we discuss the basics of hipot testing.

Hipot test is short name of high potential high voltage test and it is also known as dielectric withstand test. Early commercial hipot testers were actually not much. Hipot test makes surety of no current will flow from one point to another point. The hertz signal test, when performed by industrial tests, incexpert engineers, has proved to be a extremely successful testing procedure, in terms of eliminating any possible deteriorating damage. Hipot test current, leakage current and insulation resistance. I n particular, the question was whether the hipot test and the insulation resistance test could be combined into a single measurement. Curve b shows same values corrected to 20c see page 22, giving a definite downward trend toward an unsafe condition.

The complete guide to electrical insulation testing. Hipot testing has long been a standard procedure for assuring the electrical safety of electronic equipment. Testing of high voltage cables manual horizon power. A few simple steps ensure testing takes place safely when potentially lethal voltages and currents are involved in the testing process. The surest way to weed out bad cables and accessories is to just perform a simple ac hipot test, just like we do with vacuum bottles, arrestors, hot sticks, switchgear bus and insulators, etc. Ideas for improving hipot safety cirris systems corp. The test setup and procedures are identical for both ac and dc hipot tests. This means that if the cable temperature is increased due to having been subjected to substantial load. Safety, operation, and procedure instructions for the pts.

Dry testing transformer series is produced, it is completely changed by the backward state of old test transformer stupid, big and heavy, it can produce our matching mounted on a highvoltage silicon stack to provide dc highvoltage test power supply, with a control box,automatic protection microammeters, gap and other ancillary equipment. As a manufacturer or test operator, its up to you to ensure you have the proper knowledge and training to use high voltage equipment. It was not clear why the higher voltage test was being applied but the test lab was adamant that it was correct. Hipot test is short name of high potential high voltage teat and it also known as dielectric withstand test. A hipot test checks that no current flows between points where there should be no current. Timely conducted testing procedures can help notice the loss of cable insulation integrity, spot signs of its deterioration caused by aging, and therefore prevent cable failure. The description of these tests will not apply to watercooled stator windings since the test procedure and analysis differ for watercooled units. Better and easier setup for production line hipot testing. Cable types, design, and associated insulation faults. High potential hipot cable system testing can be performed using dc, ac or very low frequency ac also known as vlf test voltage. If a display fails the onesecond test method, redo the test using the sixtysecond etl test outlined below, as required by article 36 of ul standard 1433. Please accepts pass results for the following four hipot test methods. Test button this is a momentary contact switch used to. Vlf hipot test is the preferred method of highpotential testing and should be used whenever a vlf test set is available.

Once partial discharge is triggered in a defect under the test voltage, enough time must be allowed to permit the pd to create an electrical tree and grow to failure. Sep 03, 2015 hipot test is short name of high potential high voltage test and it is also known as dielectric withstand test. In some ways a hipot test is the opposite of a continuity test 2872008 i am tasked to setup a test procedure to conduct dielectric withstand test on a 480v 3phase system. Regardless of your specific interest in safety testing, it is important for you to have a. Some say because ac more readily ionizes air than dc, ac is a more sensitive test.

Hipot testing has long been a standard procedure for assuring the electrical safety. Hipot test makes surety of no current will flow from one point to another point hipot test is the opposite of a continuity test. The dc hipot withstand test is a passfail test that has been applied to all types of cable and accessories. Guidelines for high potential hipot dc testing of medium. Ac testing, however, does have some disad vantages. Dielectric withstand or hipot test the dielectric voltagewithstand test, or hipot high potential test, is designed to stress the insulation of your product far beyond what it will encounter during normal use.

Below are hipot test voltages for both dc hipot and ac hipot tests. The hipot test procedure described in figure 3 will be discussed first. A low voltage is applied from the chassis of the product to the ground pin to determine if the appropriate amount of current flows. Repeat this test procedure for all circuit phase conductors testing each phase to. Ac voltage test setup and procedure setup for onesecond and sixtysecond ac voltage test methods. The vlf test instrument should be solidly grounded before connecting up any cables. Hipot testing shall not be conducted on test specimens that have previously been exposed to high voltage levels or other similar testing. Before working with an electrical safety test station, you need to make sure you are a qualified operator according to osha guidelines1. This is primarily due to the availability of other test methods and the high levels of power consumption. Join us as we take you to our whiteboard where we give you a visual diagram of the hipot.

Some passed initially, then failed later in functional testing. How dc hipot works dc voltage is applied to open disconnected windings by the hipot tester or motor analyzer. Complete tests 1 and 2 for each winding of a threephase transformer individually with the remaining windings kept open. Hold the full test voltage for not less than 10 minutes or more than 15 minutes. Since the insulation draws relatively low current the hertz test set is much smaller than its 60hz counterparts. The dielectric voltage withstand test page 2 the dielectric voltage withstand test is an integral part of the product safety evaluation of electrical and electronic devices, and provides manufacturers with important information regarding the quality and appropriateness of the chosen insulation system. The assumption is that if the insulation can withstand the significantly higher voltage for a given time it will be able to. Such a test applies a voltage to the dut that is much higher than normal operating voltage. Performed by stressing the insulation of the product far beyond what it would encounter during normal use. There are always things you can do to increase the safety and reduce the risk a hipot test might present. Understanding hipot certification testing electronic design. The choice of the right method and the most appropriate instrument before moving on to the main hipot testing techniques, it is. Equipment to be used by trained personnel only this operator manual contains instructions for the operation of a high voltage power source.

The use of the product highvoltage test, the familiar with the specification, but also to strictly enforce the state standards and procedures. At the nrtl, the unit passed every test except the hipot test, which was a bit of a surprise since the unit. Continuity test checks surety of current flows easily from one point to another point while hipot test checks surety of current would not flow from one point to another point and turn up the voltage really high just to make sure no current will flow. Other models in the 800 series follow a similar testing procedure, but today im demonstrate testing on a 15kv. Nov 26, 2018 a few simple steps ensure testing takes place safely when potentially lethal voltages and currents are involved in the testing process. Connect output of test set to conductorterminal to be tested and connect ground terminal of test set to ground. Figure 3typical scale on the megger insulation tester. Shari richardson is a director of engineering and the lead engineer on all medical applications at quadtech. Figure 4typical record of insulation resistance of a mill motor.

If the hipot does not have a complete circuit, it cannot discharge the dut at the end of the test. These notes are all available for download in adobe pdf format. A ground continuity test assures the ground wire of a product is intact. Dc hipot tester hipot test procedure electrom instruments. Before moving on to the main hipot testing techniques, it is important to introduce the basic information on power cables, namely their types and typical structure. Low voltage directive provides structure and procedure of product safety test. Ieee std 400 provides additional information on dc testing and evaluation of the insulation of shielded power cable systems. Hipot testing is an abbreviation for high potential testing a category of electrical tests used to verify the effectiveness of electrical insulation in transformers, motors, printed circuit boards, electrical sub. Hipot test procedure pdf various cable testing methods. To figure out what could cause such failures, i decided to current limit the hipot tester with a highvoltage series resistor. Jul 31, 2017 some say because ac more readily ionizes air than dc, ac is a more sensitive test.

Withstand or hipot cable testing withstand or hipot testing is used to evaluate the condition of cable insulation during installation, acceptance, or maintenance testing. Jan 16, 2014 this unit is our 880pl dc hipot tester. Hipot test is the most common type of electrical safety test. This button may also be used to abort a test in progress. This page is about using ac hipot testing, but you may find you have a specification in ac vrms even though your tester only has dc hipot testing. Dc voltage is applied to open disconnected windings by the hipot tester or motor analyzer. Yes the cable may fail under test if it has a severe defect, but thats the point of the test. Vlf cable test voltage ieee standard high voltage inc. This problem is solved using vlf technology, the well recognized alternative to using large, heavy, costly, and high in power draw 5060 hz power frequency. Hipot testing procedure for withstand testing of hv coax cabling using the vitrek 955i.

Hipot testing has long been a standard procedure for assuring the electrical safety compliance of electronic equipment. Hipot setup and testing for hipotronics hd103 and hd106 acdc voltage testers. Oct 31, 2017 recently, there was a discussion in the ieee email safety forum about the relationship between the hipot test current, leakage current, and insulation resistance. At the common test voltages used for electronic products, in the range of volts to 3500 volts rms or so, there is no conclusive evidence that either is the better test. After having verified that the test procedure was correct and that the supply was correctly installed, an investigation of the test voltage found that the voltage applied was in excess of 1,500vac, but not at the 3kv or 4kv level. The usual thing to do is to convert the ac specification to vpeak and.