Moulded test vessels give repeatable results with lock in precision electrode gap setting adjustment wheels. Megger s motor and generator testers ensure the correct phase connection in one of our easytouse testers. This is not a commonly used test step voltage test method in this test, the operator applies two or more test voltages in steps. To effectively test the motor, you must disconnect the field coils where possible. The minimum and maximum ir insulation resistance values can be found in the megger manual. Pd scan firmware files follow instructions in user guide to update firmware. To be able to follow this instruction, you will need a megger. During any maintenance inspections, be sure the motor shaft will not rotate. Step 3 crank the handle for about a minute, and notice the resistance reading. Megger guide to electrical insulation testing pdf instrumart. A protocol involving voltage level, time duration, intervals between tests and connection methods must be composed, taking into account the type and size of the equipment, its value and role in the production process and other factors. Disconnect the power cables from the main terminals 1l1, 3l2, and 5l3 and the motor cables from terminals 2t1, 4t2 and 6t3. What is the procedure for testing insulation resistance in.
The test measures the insulation resistance between the phases andor between phase and ground. The mto210 transformer ohmmeter is a lineoperated, fieldportable instrument designed specifically to measure the dc resistance of all types of magnetic windings safely and accurately. Coils ii, iii, and iv are permanently connected and cannot be separated. Pictures used in the checklist are generic and may not be indicative of your specific configuration.
M valley forge corporate center 2621 van buren avenue norristown, pa 19403 u. Megger s automatic laboratory oil test sets perform accurate breakdown voltage tests on mineral, ester and silicon insulating liquids. Motors that are to be used in flammable andor explosive atmospheres must display the csa listed logo. The megger powerdb is a powerful software package providing data management for each of your acceptance and maintenance testing jobs. Using the megger to test a threephase motor is rather easy, though the safety hazards for this procedure are quite high. Both testers incorporate a guard terminal to eliminate the effects of surface leakage in the item under test, thus ensuring accurate measurements. Megger regularly audits the performance of distribution partners to ensure they meet standards for technical proficiency and customer support. How to use a megger to measure and test motor insulation. Be sure to follow good safety measures to prevent electrical shock. Submersible motor megger testing meggers, or megohmeters, are often used by service personnel or sophisticated end users as an immediate trouble shooting device.
Place one megger probe to the any mounting bolt on the breaker box to test for grounding continuity, then touch the other probe to a motor terminal. Pd test of insulating materials and electronic components. This enables you to perform the following insulation tests. Test interphase resistance by disconnecting the leads from each terminal with a flathead screwdriver, then touch any two terminals with the two probes.
Megger is the industry leader in relay testing, having developed the first softwaredriven protective relay test system in 1984, and continuing to provide models from computercontrolled to manually operated test sets in portable and laboratory styles for every relay testing need. Electrical testing usually consists of insulation resistance. Megger and bridge test of motor cr4 discussion thread. Any voltage larger than this may stress the cable and cause premature failure. Delta4000 series is a fully automatic 12 kv insulation power factor dissipation factor tan delta test set designed for condition assessment of electrical insulation in high voltage apparatus such as transformers, bushings, circuit breakers, cables, lightning arresters, and rotating machinery. Enclosed in a tough case it is both smaller and lighter than its predecessor making it even easier to carry and store. Megger s automatic portable oil test sets perform accurate breakdown voltage tests on mineral, ester and silicon insulating liquids.
Rpm insulation systems evaluation and maintenance guidelines. Reverse side of card at right is used to record the test data. The reporting device that is additionally meant to create and render reports in the web will consistently be there to build the reports that you requirement for your framework. Before performing any motor maintenance procedure, be sure that the equipment connected to the motor shaft cannot cause shaft rotation. When the insulation is in good shape, the 60second reading is higher that the 30second reading. Curve b shows same values corrected to 20c see page 22, giving a definite downward trend toward an unsafe condition. How to megger a motor also known as an insulation test. Opening a specific record shows detailed information about the job, such as type of service, order date, sales contact, and invoice information. Offering cat iv, the mit1025 is compact, light 10 kv insulation resistance tester for the diagnostic testing and maintenance of high voltage electrical equipment. The result obtained is a voltage value usually expressed in kilovolts kv. The correct settings, connection procedures, test durations and safety precautions must be implemented to avoid damaging the equipment or possible electrocutions. Insulation resistance testing is a nondestructive test procedure. Threephase dualvoltage motor insulation resistance testing.
Certain tasks identified as optional or if equipped refer to an optional motor test which may or may not be applicable to other ranges of motors. You can trust an authorised megger distributor to help you choose the right test equipment. To do this for delta connected 9lead motors, remove the wirenuts from 4 and 7, 5 and 8, and 6 and 9. Simple data entry of electrical test results and installation details. A passion for the business of test and measurement over 100 years ago in 1885 to be precise sydney evershed. A guide to diagnostic insulation testing above 1 kv. To properly test this type of motor, remove the wirenuts joining leads 4 and 7, 5 and 8, and 6 and 9. Here we are showing you one verified brand new motor vs one that has been taken out of service. In part 1 have been presented some tests as insulation resistance megger and pi. At this level it is important to use test equipment that will minimize errors introduced by the test lead resistance andor contact resistance between the probe and the material being tested. Megger has developed its free formfiller software as part of the companys longterm commitment to making life easier and more profitable for electrical contractors by. In this video you will find out how to test 3phase induction motor.
The test voltage is the rated voltage of the cable the linetoline voltage. Motor slip rated speed is on the motor nameplate caveat. For good insulation, the resistance usually reads in the megohm range. If you cant find your desired data sheet below please contact us were always happy to help out. Megger mit525 insulation resistance tester manual pdf instrumart. Jul 25, 2018 in hand operated megger electromagnetic induction effect is used to produce the test voltage i. Megger multiphase test system smrt46 megger multiphase. This is particularly the case with solid insulated coaxial cable.
Apr 09, 2017 a megger is used to verify the integrity of the insulation for safety reasons. Test record card pack of 20 6111216 black test lead with large alligator clip 6220295 red test lead with large alligator clip 6220586 green test lead with large alligator clip 6220587 set of test leads with fused prods fpk5 v a. This is an insulation test commonly referred to as megging, to megger, or to meg a motor. The transparent, shielded lid is a key feature enabling users to see what is happening within the test chamber. If the resistance is higher than the maximum display range, the megger will display the symbol on the left side of the screen. Pc install is for remote operation of a wide range of megger test instruments including freja, rtms, smrt and stvi. Deepwell pumps and provisional megger testing of the marflex pump motors prior to each discharge. For the detailed technical specification of them please refer to the respective data sheets. A dc motor whose poles are made of permanent magnets is known as permanent magnet dc pmdc motor. We are testing the motors insulation, more specifically between the motor windings and the motor casing. For test voltages above volt, it is most likely that a partial discharge type of test setup using an ac test voltage is better. We supply a broad range of megger programma instruments.
Specific service conditions for these motors are defined in nfpa 70 nec article 500. The test voltage is connected to the hv terminal and the current is measured at the lv terminal. Mit1025 10 kv diagnostic insulation resistance tester megger. Megger working principle types history uses of megger. In order to measure the insulation resistance in electrical wiring and electrical motors, electricians use the megohmmeter, also known as a megger.
Megger has developed its free formfiller software as part of the companys longterm commitment to making life easier and more profitable for electrical contractors by providing unrivalled products and support. One of the sctm working conditions is related to motor. As the voltage increases in external circuit the deflection of pointer increases and deflection. You can then perform the following insulation resistance tests. Condition monitoring visual oil analysismegger test marflex. The test voltage selected for this type of test is less than 5 kv, and is applied for up to one minute, or until the measured insulation resistance value stabilizes.
Please find all available data sheets listed below. This is important, because the highvoltage current in threephase systems is far more lethal than a mere lowvoltage shock received in residential setting. Megger insulation testers mit over 5 kv the industrial tester range megger mit1025 insulation tester. The stator of the motor serves as a return path for the magnetic flux. With the pd scan, megger offers a lightweight, robust and portable pd scanner that can quickly inspect various type of equipment for partial discharge signals. Some unknown facts was presented at the 2020 neta powertest conference in chicago, il. Megger makes electrical test equipment to help you install, improve efficiency and extend the life of assets and cable networks at high, medium and low voltage. Test methods timeresistant tests dielectric absorption ratio dar the ratio of 60 seconds30 seconds less than 1 failed 1. The motor under test must be powered down and disconnected from all equipment and wiring not included in the test. The megger mit400 series insulation and continuity testers. I cover the different test methods, an analogy on how insulation testing works, safety and the use of insulation test equipment. Note that the wyeconnected 9lead motor s internal connections vary from the delta motor.
When motors driving centrifugal loads are replaced, actual motor speed should remain the same higher motor speeds can increase energy use c 2006, success by design voltage most threephase motors operate at 460 volts some motors run on 230v, 200v, or. Figure 2 shows how a 60second test would appear for good and bad insulation. Insulation resistance testing of low voltage cables in the. Threephase dualvoltage motors are used for most daytoday operations in todays industrial plants. The complete guide to electrical insulation testing. From power station to plug, megger test equipment helps you maintain the electrical network, monitor its condition and maintain supply to your customers.
Delivered in onsite case with 1 operating manual, 2 elbowedstraight pvc. This article takes an indepth look at the transformer turns ratio test, some of the challenges associated with interpreting test results, and unknown facts related to test. Note that the wyeconnected 9lead motors internal connections vary from the delta motor. Testing the thyristors step by step before disconnecting the cables mark them. A low resistance measurement is typically a measurement below 1. The wide range of features also makes the mit400 series ideal for maintenance technicians and. Ttr310, ttr31047 highvoltage equipment read the entire manual before operating.
Every electric wire in a facility, whether its in a motor, generator, cable, switch, transformer, or whatever is. Download the zip file and directly unzip it to a clean thumb drive. Insulation resistance testing of low voltage cables in the field. The test icon will appear in the bottom right corner until the test is complete. Unfortunately, megger results are not appropriate for use as a passfail determination due to the many variables and judgments involved. Applications the bm11d and bm21 test the insulation resistance of. Where as in electronic type megger battery are used to produce the testing voltage. Electricians motor and generator testing equipment megger. Connect the megger hot lead to a motor winding lead. Onboard install files are for freja, rtms, smrt and stvi local device installation. Customer and contract information is quickly sorted and searched. Moulded test vessels give repeatable results in the field and laboratory with lock in precision electrode gap setting adjustment wheels. How to test a threephase motor with a megger hunker.
It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. Figure 1 shows a simplified measuring circuit diagram of the delta 4000 test set measuring a twowinding transformer in ust test mode. Formfiller is a manual entry portable appliance documentation software. Jul 06, 2016 the test generally applies between 100 and 5,000 v or more.
Insulation resistance testing guide chauvin arnoux. In addition, the elapsed time of the test is displayed constantly removing the need for separate timer. Megger offers a range of lead sets and clips of various sizes and electrical characteristics for use with mit5102, mit5202 and mit10202 insulation resistance testers, enabling the user to. Megger portable 60 kv and 80 kv oil test sets are the lightest on the market ranging from 16 kg to 23. Figure 4typical record of insulation resistance of a mill motor. Connect the megger ground lead to the same ground plane the motor is connected to. Highvoltage power cables large motor generator windings line and substation transformers.
Delta4000 series 12 kv insulation diagnostic system megger. The magnets are radially magnetized and are mounted on the inner periphery of the cylindrical steel stator. The megger technical library provides access to a range of additional content and resources such as technical guides, application notes and more. The megger insulation tester is essentially a highrange resistance meter ohmmeter with a builtin directcurrent generator. It can test transformers and rotating machine windings and perform lowcurrent resistance measurements on connections, contacts and control circuits. Megger multiphase test system smrt46 megger multiphase relay test system n small, rugged, lightweight and powerful n operate with or without a computer n intuitive manual operation with smart touch view interface n high current, high power output 60 amps300 va rms per phase n 4 voltage channels, 3 current channels, with convertible voltage. Figure 3typical scale on the megger insulation tester. Due to heat, vibration, and limited space, the insulation on motor windings is the weak link.
Electrical test equipment power station to plug megger. My view about testing small motor windings is that a 500 volt dc megger is what is required. The megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. If the load can cause shaft rotation, disconnect the load from the motor. In using the megger, a bit of a learning curve is involved. Dielectric testing may be destructive in the event of a fault, depending on the test. It differs from an ohmmeter in that, unlike the ohmmeter, it is able to measure resistances in ohm values of more than one million. If a fraction of current flows, it can be measured by these highly sensitive meters. This is an insulation test of motor windings, commonly referred to as megging, to megger, or to meg a motor.
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