The motor and phase rotation tester permits the electrical contractor or industrial maintenance electrician to permanently connect and tape the terminals of the motor being installed, without having to first energize the motor by a temporary hookup from a power source, if available, to determine motor rotation. Megger makes electrical test equipment to help you install, improve efficiency and extend the life. The generator can be handcranked or lineoperated to develop a high dc voltage which causes a small current through and over surfaces of the insulation being tested fig. Section 7 of the ansineta standard for acceptance testing specifications for electrical power equipment and systems may be reproduced and used on a cut and paste basis for the particular type of equipment to be tested. The unit performs excitation, ratio and polarity test by providing a variable output voltage up to 1600 v ac. Megger leads are connected to lv and hv bushing studs to measure insulation resistance ir value in between the lv and hv windings. Each phase to phase must have a continuity if winding is ok. Jul 06, 2016 the test generally applies between 100 and 5,000 v or more. The megger is capable of applying different voltages, and the level should be coordinated with the type of equipment under test and the scope of the inquiry. This is important, because the highvoltage current in threephase systems is far more lethal than a mere lowvoltage shock received in residential setting.
You do this by using a high voltage and looking for voltage leaking through the insulation. Figure 2 typical megger test instrument hookup to measure insulation resistance. This is an insulation test of motor windings, commonly referred to as megging, to megger, or to meg a motor. So when the individual component test lists are merged, a thoughtful and smart overall test recommendation for transformers emerges. How to megger a motor also known as an insulation test. This procedure provides the minimum guidelines and acceptance criteria necessary to ensure that you perform meggering safely and consistently. One of the reasons that it is still such a popular option is because it is nondestructive. Oct 19, 2015 how to meg a motor with a megohmeter checking motor condition. The leads used for connecting megger testing with the circuit should be fault free and the two connecting leads should have electrical continuity. Ieee std 1122004, ieee standard test procedure for polyphase. The three lines leading to the right of the test set are for direct attachment to energized ac power systems up to 600 volts to determine the system phase sequence. The test is generally conducted by applying between 100 and 5,000 v or more. Threephase dualvoltage motor insulation resistance testing. If you are referring to a megohm meter, it is a test of the insulation properties of such things as electric wiring, motor windings and high power antenna mounts.
Insulation resistance testing guide chauvin arnoux. To accomplish this, a test procedure should be established and used consistently over time. In this video you will find out how to test 3phase induction motor. 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. Established in the late 1800s, the company has been designing and making test and measurement instruments that perform electrical measurements for. Threephase dualvoltage motor insulation resistance testing threephase dualvoltage motors are used for most daytoday operations in todays industrial plants. 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. Megger makes electrical test equipment to help you install, improve efficiency and extend the life of electrical assets and cable networks at high, medium and. The megger 560000 series motor and phase rotation tester is used to determine system phase sequence, motor rotation, and transformer polarity in electrical systems and motor installations. What happens is a dc voltage is applied to the device or winding under test. Be sure to follow good safety measures to prevent electrical shock.
I have not personally ever used a megger but from what i understand that type of test would be very time consuming or am i. Jun 22, 2018 but the megger provides a much higher voltage rather than the ohm meters typical threevolt test voltage derived from an internal battery. It will calculate the rated knee point in compliance with ieee c57. Jul 25, 2018 in hand operated megger electromagnetic induction effect is used to produce the test voltage i. Megger products help you install, improve efficiency, reduce cost and extend the life of your or your customers electrical assets.
Using the megger to test a threephase motor is rather easy, though the safety hazards for this procedure are quite high. Once you start to record your readings, you will be able to compare them with the output readings that the device should have based on the manufacturers specifications. This standard provides the basic test procedure for evaluating the performance of a. How to test three phase ac motors learning electrical.
It should always be kept in mind that, technically, this test should always be addresses or called insulation test. The megger brand is already strong and highly respected in the industry, but in these times of digital transformation, megger wishes to further elevate the depth of relation with our customers to truly standout. Regular insulation resistance testing is one of the most cost effective, non destructive methods of identifying ageing in electrical equipment. 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. We are testing the motors insulation, more specifically between the motor windings and the motor casing. This method will ensure that the separate windings. Have anyone hear of a hi megger testing residential circuits as part of their home inspection. Rotate the end shaft approximately 30 degrees and test the motor again. Insulation testing technical guides megger insulation. Low resistance ohmmeters for electricians testers megger. Figure 4typical record of insulation resistance of a mill motor. If any particular phase fails the continuity test, your motor is probably burnt. Battery testing guide 5 battery types there are several main types of battery technologies with subtypes.
As the voltage increases in external circuit the deflection of pointer increases and deflection. Insulation resistance testing of low voltage cables in the field. An important benefit is that the data entry screens are exactly the same as the printed reports, which greatly simplifies interpretation of the test results. Megger mct1605 test is a lightweight, portable unit for shop and field testing of current transformers using ieee c57. If you think you have what it takes to help us realise our ambitions, we would love to hear. Megger testing of residential circuits inspectionnews. The correct settings, connection procedures, test durations and safety precautions must be implemented to avoid damaging the equipment or possible electrocutions. This analog meter has a fourposition knob to select the test to be made and features a push button to start the test. Electricians motor and generator testing equipment megger. Our products are complemented by bespoke software that records all measurements and data, easing the process of information management. The megger test is a method of testing making use of an insulation. Call us today for a quote at 8003533411 or send us a message.
Perform this procedure a number of times as most dc motors use a carbon brush and copper commutator to conduct the electrical power to the armature. Megger 560060 phase and motor rotation test 5060h tequipment. Megger has offered a 10 kv insulation resistance tester since 2001. In the off position, both the meter and the battery are disconnected from all circuits. Ieee std 1122004, ieee standard test procedure for. Megger working principle types history uses of megger. The megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
The complete guide to electrical insulation testing. The procedure of insulation resistance test or megger test are given below. How to test a threephase motor with a megger hunker. Isbn 07389785 ss95211 no part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. It is checked by touching the free ends of the leads together while the megger button is pressed on to check for zero. The above variables should be controlled as much as possible to promote accurate insulation resistance measurement data. This is certainly not a new test, and has been in use for a number of years.
Digital microohmeters and dlros measure contact resistance of switch and circuit breakers, aircraft frame bonds, and rail and pipeline bonds just to name a few of the applications. Any voltage larger than this may stress the cable and cause premature failure. The certificates can also be customised to include, for example, the users business logo and contact details. To properly test this type of motor, remove the wirenuts joining leads 4 and 7, 5 and 8, and 6 and 9.
Electrical test equipment power station to plug megger. If the resistance of the insulation is high, the pointer of the moving coil deflects towards the infinity, and if it is low, then the pointer indicates zero. Megger testing procedures ieee electrical code issues. Megger testing of busses, mccs, and distribution panels. Operators must compose a protocol involving voltage level, time duration, intervals between tests and. The megger insulation tester is essentially a highrange resistance meter ohmmeter with a builtin directcurrent generator. Close to 400 predefined test forms are provided in powerdb covering many types of electrical apparatus such as bushings, batteries, cables, generators, transformers, relays and motors.
Calibration service since 1982 jm test systems has been providing nist traceable calibrations to our customers. Test interphase resistance by disconnecting the leads from each terminal. Standard for acceptance testing specifications for. From megger, these highly accurate, easy to operate instruments measure resistance with resolution as fine as 0. Megger guide to electrical insulation testing pdf instrumart. 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. But the megger provides a much higher voltage rather than the ohm meters typical threevolt test voltage derived from an internal battery. In hand operated megger electromagnetic induction effect is used to produce the test voltage i. The goal is to determine if the insulation of a wire has been compromised. It is an insulation test to see is the insulation has been injured in any way to cause a short circuit when normal power is applied to it.
I have not personally ever used a megger but from what i understand that type of test would be very time consuming or am i missing something. What are the possible results of a the megger test. A catalogue, for quick reference, of the range of megger test instruments for the maintenance of electrical power systems. Electrical test equipment application solutions from megger. Ieee std 1122004 revision of ieee std 1121996 ieee standard test procedure for polyphase induction motors and generators sponsor electric. Where as in electronic type megger battery are used to produce the testing voltage. The test voltage is the rated voltage of the cable the linetoline voltage. This current usually at an applied voltage of 500 volts or more is measured by the ohmmeter, which has. In using the megger, a bit of a learning curve is involved. Some units may also incorporate a hand generator to. Delivered in onsite case with 1 operating manual, 2 elbowedstraight pvc leads 1. The following sections of the ansineta standard for acceptance testing specifications for.
Megger designs and manufactures portable electric test equipment. Jul 17, 2017 release the push button on the megger or stop the cranking of the meter. These motors run conveyor belts, pumps, fans, and many other applications. Curve b shows same values corrected to 20c see page 22, giving a definite downward trend toward an unsafe condition.
The selector switch connects a dsize dry cell into the circuit when the rotation of a motor or the polarity of a transformer is being checked. Insulation resistance testing of low voltage cables in the. For good insulation, the resistance usually reads in the megohm range. The test measures the insulation resistance between the phases andor between phase and ground. On my megger there are 3 ranges 300v, 750v, and volts. For three phase motors, connection type is either star y or delta ac motor winding continuity test using a multimeter, check the continuity of motor winding from phase to phase u to v, v to w, w to u. The megger 560060 motor and phase rotation tester permits the electrical contractor or industrial maintenance electrician to permanently connect and tape the terminals of the motor being installed, without having to first energize the motor by a temporary hookup from a power source, if available, to determine motor rotation. How to meg a motor with a megohmeter checking motor condition. A guide to diagnostic insulation testing above 1 kv euroindex.
Reverse side of card at right is used to record the test data. Figure 3typical scale on the megger insulation tester. First we will disconnect all the line and neutral terminals of the transformer. Weve assembled helpful technical guides on insulation testing from leading manufacturers in the field. Crank the handle for about a minute, and notice the resistance reading. As some transformer tests are better suited as commissioning and diagnostic tests, the reason for testing e. A fourposition switch selects the test to be made system phase sequence, motor rotation and transformer polarity. 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. How to use a megger to measure and test motor insulation. Com reference manual applications guide delta 4000 12 kv insulation diagnostic system zmah02e. Insulation resistance testing is a nondestructive test procedure. The megger is the instrument uses for measuring the resistance of the insulation.
The purpose of this procedure is to provide instructions for performing insulation resistance megger testing of busses, motor control centers mccs, and distribution panels. If a fraction of current flows, it can be measured by these highly sensitive meters. Jm test systems is a stocking distributor of megger products. Hi, ive been asked to find an ieee or equivalent test procedure for meggering from the tleads in an mcc cubicle to the motor in the field. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. For each system, megger has the product best suited to conducting a comprehensive diagnostic insulation test. Motors are susceptible to the gradual failure of their insulation resistance. The purpose of the guard terminal on insulation testers.
Find here insulation testing and continuity, power protection, power transformer testing, power cable infrastructure, cable fault location, general electrical test. Megger is a brand name and not a test description although mostly, the equipment being used for this test is branded megger. Jm test systems has the megger 560060 motor and phase rotation tester for purchase and for rent. Ieee std 432000 recommends a procedure for measuring insulation resistance of armature. The motor under test must be powered down and disconnected from all equipment and wiring not included in the test.