Guidelines for high potential hipot dc testing of medium. But unlike dc hipot testing, the ieee standard does not caution that vlf hipot testing may not provide meaningful information. The 19053 provides 8 scan channels for ir measurement, and the 19054 provides 4 scan channels for ir measurement in a single compact unit. Safety guidelines for hipot testing and setting up a safe. Concerns associated with dc testing dc hipot testing is believed to be harmless to new solid dielectric cables as their insulation is. Why engineers prefer vlf hipot testing protec blog. Following points summarize difference between ac hipot test and dc hipot test. The chroma hipot tester 19070 series provides 2 models to choose from. All tests made following cable installation and during the warranty period must be performed in accordance with the applicable specifications. G 12kv dc ir hipot tester 40 dedicated function test instruments 41 milliohmmeters 41 megohmmeters 41 digibridge component testers 41 precision lcr meters 41 appendix a 43 nationally recognized testing laboratories nrtls and standards organizations 44 product safety standards 45. Hipot setup and testing for hipotronics hd103 and hd106 ac dc voltage testers overview to ensure your own personal safety and the safety of your coworkers, and to be sure that our displays are suitably tested to ensure customer safety, it is essential that you understand the proper setup and use of our hipot testers. Dc hipot test uses dc voltage where as ac hipot test uses ac voltage at 5060 hz frequency. Jan 16, 2014 dc hipots can be used for the following testing applications.
Therefore, if a test of an installed motor in a plant fails above peak operating voltage, it does not mean that. A cable will be subjected to multiple tests in its lifetime including a series of tests beginning at the factory and potentially continuing throughout the lifespan of the cable. Hvis combination high voltage dc proof testers and hv megohmmeters are available in field portable and benchtop models for testing dielectric strength and insulation resistance with a single instrument. The okonite company technical news engineering information the ofessional engineer frequency of field hipot testing when discussing field dc hipot testing of medium voltage epr and xlpe insulated cables, two questions that always come up are. Meanwhile, your heart palpitation unregulated and blood pressure falling down causes tragedy cant be redeemed. Most safety standards allow the user to disconnect the y capacitors prior to testing or, alternatively, to use a dc hipot tester. Electrical safety testing reference guide power sources. Sentry plus series hipot testers instruction manual. Dec 01, 2011 most safety standards allow the user to disconnect the y capacitors prior to testing or, alternatively, to use a dc hipot tester. Although, there remains one clear advantage to the vlf hipot testing method compared to the dc hipot testing method, the ieee standard does not caution that vlf hipot testing may not provide meaningful information.
Cable testing revision 1 june 2, 2011 page 2 of 8 cable testing testing represents an integral part in the life of a cable. Dc hipot test passfail analysis a dc hipot test is done at a voltage higher than the peak operating voltage of the device under test dut, where peak voltage rms voltage x 1. Vlf hipot testing vlf hipot test has the same advantages as dc hipot testers they are relatively small and light weight. The megger test is performed by applying an elevated dc voltage to the conductor and measuring the current.
Hipot testing of kbs ac and dc drives most of our ac and dc drives are listed by underwriters laboratory or ul. Thus, a dc hipot test voltage is often derived from a typical ac hipot test voltage which is proven to work well. Ieee, epri, cea, and others have denounced dc testing for years, with the ieee having written a new test standard for vlf that is soon to be implemented. More importantly, it does not warn that vlf hipot testing is likely to cause damage to certain field aged cables. Dc dielectric withstand testing of modular and manufactured homes has. The ultimate guide to manufactured home testing hipot. Electrical safety testing of modular homes is a complex business, but weve set out to help you simplify this application with our ultimate guide to manufactured home testing.
It is important to understand the difference between the nature of ac and dc voltagecurrent. Safety, operation, and procedure instructions for the pts series of dc hipotmegohmmeters danger lethal voltages. The test voltages to be used vary depending upon whether the device or circuit is low or high voltage, a primary or control circuit and whether tested at the factory or in the field. Hipot test standards dc hipot test analysis electrom. Electrical safety testing reference guide touch area. High voltage pts75 75kv dc hipot with megohmmeter megger cb360 dc cb120 dc dc circuit breaker test sets high voltage vlf65e 65kv vlf tester hipotronics 100hvt 100kv 5kva ac hipot. Dc voltage used in hipot test is higher compare to ac hipot testing. Many people assign too much mystery to vlf testing. Dc hipot test uses higher voltage compare to ac hipot test. We are here to help you with your testing equipment needs.
Dc testing as an acceptance test on newly installed extruded dielectrics, and almost all of the recommended practices have abandoned the use of dc testing for maintenance purposes, or particularly when the cable has reached service age is over five years of age. However, if a dc hipot test is used on an ac circuit, the hipot voltage should be two times the peak 2 x 1. When vacuum breakers first came out, many companies were using the dc hipot method to test their bottles, but it soon became apparent after the first bottle or two that something was amiss. Performed by stressing the insulation of the product far beyond what it would encounter during normal use.
Overpotential or hipot tests are frequently applied to. Although the sentry plus unit is designed with full attention to operator safety, serious hazards could occur if the instrument is used improperly and these safety instructions are not followed. Differences both ac and dc hipot tests have inherent advantages and disadvantages which are evident depending on the product being tested. Pts series portable the pts series can perform high voltage dc hipotproof and current leakage testing as well as resistance measurement. Cable types, design, and associated insulation faults. The dc hipot tester would not indicate the failure of a unit even with high y capacitors because the y capacitors see the voltage but dont pass any current. 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. This electrical test equipment is available for rent, lease, or purchase from protec equipment resources. Stein aok technologies iris power engineering electric power research institue toronto, ontario mississauga, ontario palo alto, california abstract. A vlf hipot or very low frequency is a test done to detect defects. Ac hipot testing ac high potential tests are conducted at voltages above the normal system voltage for a short time. One of the requirements of ul 508 is that all ac and dc drives pass a high voltage dielectric withstand test, commonly called the hipot test. Hipot testing has long been a standard procedure for assuring the electrical safety compliance of electronic equipment. Some of the process failures that can be detected by a productionline hipot test include, a transformer wound in such a way that creepage and clearance have been reduced.
Hipot test voltages high potential test electrom instruments. 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. Posted by protec tech team on saturday, december 4, 2010. Such a failure could result from a new operator in the winding department the hipot test a versatile test. Safety, operation, and procedure instructions for the pts. Nov 26, 2018 a few simple steps ensure testing takes place safely when potentially lethal voltages and currents are involved in the testing process. This technical article provides general guidelines for high potential hipot dc testing of mv power cables. Equipment to be used by trained personnel only this operator manual contains instructions for the operation of a high voltage power source.
In 1996, the insulated conductor industry determined that dc withstand testing of the plastic xlpe insulation systems either in the cable factory as a routine production test or after installation as the higher voltage proof test was detrimental to the life of the insulation and therefore discontinued recommending dc testing. A dc hipot unit is relatively easy to control, provides accurate leakage current data, and is relatively small and light weight. The best voltage for a dc hipot is normally higher than the ac test voltage by a factor of 1. Designed to verify that the insulation of a product is adequate enough to withstand high voltage. The test can be done at various times such as acceptance of new cable installation, maintenance testing to track insulation degradation and as a pre and post test for splicing existing cables to new ones. So, in hipot testing, voltage is increased to cause leaking or arcing between exposed wires or cables, which helps to catch errors that otherwise would be missed. A product that would be tested at 1500v ac would be tested at 2121v dc. Dc ir hipot testing and insulation resistance ir measurements.
In dc voltage test and leakage current test, as long as the high voltage silicon stack is installed on the high voltage output terminal, the dc high voltage can be obtained, and its amplitude is 1. G 2520 ac dc hipot tester 38 g 2530 ac dc ir hipot tester 38 guardian 6000 series g 6000 electrical safety analyzer 39. The good news is a dc hipot can be used to test vacuum bottles. Dc hipots can be used for the following testing applications. Below are hipot test voltages for both dc hipot and ac hipot tests. Dielectric testing reasons dielectric testing is intended to check the integrity of the insulation for two basic reasons.
Dc high potential testing dc hipot testing purpose dc hipot testing is used for proof testing shielded cables 5kv to 46kv in the field. Dc hipot cons the conventional dc hipot is a potentially destructive test similar to what was described under ac hipot pros and cons. The sentry plus series hipot tester can provide an output voltage as high as 6000v dc 5000v ac to the external device under test dut. The purpose of this paper is to explain the fundamentals of each test and the theory behind dielectric testing, and to compare behavior of dielectric breakdowns in ac and dc tests. Hipot test is the most common type of electrical safety test. Ac hipot test vs dc hipot testdifference between ac hipot.
Tutorial on safety standard compliance for hipot testing. A dc hipot test can usually be substituted for an ac hipot test. Ac and dc testing capability dc testing capability 5 kv ac 6 kv dc 15 kv dc values up to 1,000,000 m. Understanding hipot certification testing electronic design. Dc hipot pros and cons in regards to the pros and cons lists below, the pro or con applies to all methods of dc hipot testing unless the type of dc test is listed in parenthesis beside the pro or con. Dc hipot testing methods for using dc hipot testing of cables were developed in the early 1900s, primarily for testing laminated cable systems such as paper insulated lead covered cable types.