To test a cable with a megger, you connect one probe to the outside of the cable and, with the power turned off, you touch the probe to the conducting wire at the point of connection. Weve assembled helpful technical guides on insulation testing from leading manufacturers in the field. Ieee std 432000 recommends a procedure for measuring insulation resistance of armature and field windings in rotating. It is checked by touching the free ends of the leads together while the megger button is pressed on to check for zero. The purpose of this procedure is to provide instructions for performing insulation resistance megger testing of busses, motor control centers mccs, and distribution panels. The megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. Since 1989, revised editions of the maintenance testing specifications have been published in 1993, 1997, and 2001. Insulation testing technical guides megger insulation. Megger working principle types history uses of megger. The purpose of this procedure is to provide instructions for performing insulation resistance megger testing of transformers. 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. Could someone briefly explain to me the difference between meggering and hipot testing of cables.
The megger is the instrument uses for measuring the resistance of the insulation. Cable testing and diagnostics provides information about the cables global condition e. Motors are susceptible to the gradual failure of their insulation resistance. Electrical test equipment power station to plug megger. From power station to plug, megger test equipment helps you maintain the electrical network, monitor its condition and maintain supply to your customers. Ieee recommended practice for testing insulation resistance of rotating machinery 1. I know that meggering involves placing a dc current, usually no more than 2 times the rated ac voltage, between the cable and ground to test the insulation resistance. Megger safety precautions when you use a megger, you could be injured or damage equipment you are working on if the following minimum safety precautions are not observed. The megger technical library provides access to a range of additional content and resources such as technical guides, application notes and more. 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. Megger test procedure manufactured goods electromagnetism.
You will find that the megger test, or insulation resistance test, is going to be useful in a host of different situations and for different purposes. In an industrial facility, the recommended procedure is to perform periodic tests and record the results so that damaging trends can be detected and. Megger and power factor windings, bushing and arrestors. View and download megger det14c user manual online. The device is being used since 1889, popularity raised during 1920s since the long back device is same in its uses and purpose of testing, few real improvements appeared in recent years with its design and quality of. Megger download manager software free download megger.
Tm5611559334 navfac p8634 to35c234632 note low insulation resistance may be caused by dirt or excessive moisture. Mto3xx series leads are interchangeable with the megger. Vi repeat the procedure to test subsequent conductors with respect to conductors 2, 3, 4 etc. This document will focus only on the tests that are of importance for field installers which are described as installation and maintenance tests. Com reference manual applications guide delta 4000 12 kv insulation diagnostic system zmah02e. The first neta maintenance testing specifications for electrical power equipment and systems was published in 1975. We would like to show you a description here but the site wont allow us. Location a location b it arefor the purpose of guidance. Insulation failure may be caused by wrong voltages, induced voltages caused by opening field circuits too quickly, oil and grease, high temperatures or excessive vibration. Megger testing procedures ieee electrical code issues. 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 low voltage. In 2005, this document was approved for the first time as an american national standard. Free opensource download manager and accelerator supporting video conversion.
Megger testing of busses, mccs, and distribution panels. Megger supplies graph paper which makes it easy to plot megohms. Standard for testing specifications electrical power. View and download megger det3ta user manual online. Threephase dualvoltage motor insulation resistance testing threephase dualvoltage motors are used for most daytoday operations in todays industrial plants. Connect the megger ground lead to the same ground plane the motor is connected to. The leads used for connecting megger testing with the circuit should be fault free and the two connecting leads should have electrical continuity.
Insulation resistance testing of low voltage cables in the. Electricity networks have had to become more flexible, reacting more quickly to the changes and needs of higher performance. Standard for acceptance testing specifications for. A megger is an ohmmeter that measures resistance in the megohm scale. Megger tests condition of electrical insulation the insulation resistance meter test method for determining the condition of electrical insulation has been widely used for many years as a general nondestructive test method.
The w orld s best selling electric f loor he ating br and waru i sa. How to interpret megohmmeter readings by tim walsh hunker may earn compensation through affiliate links in this story. Insulation resistance test or megger test procedures with circuit. If the insulation fails to meet the test standards, the generator may be dried out by heat from a. It will be possible to detect leaks on bad motors, generators, transformers, and many other devices. The megger insulation tester is essentially a highrange resistance meter ohmmeter with a builtin directcurrent generator. Threephase dualvoltage motor insulation resistance testing. Testing manual for electrical equipment nahed alhajeri 1and anantha madhavan 2 abstract quality assurance qa refers to a program for the systematic monitoring and evaluation of the various aspects of a project, service, or facility to ensure that standards of quality are being met. It also deteriorates due to the presence of electrical and mechanical stress. What is the procedure for testing insulation resistance in. For the detailed technical specification of them please refer to the respective data sheets. We supply a broad range of megger programma instruments.
Prior to installation in the test assembly, meggering tests were performed on all conductors in the. If you find that the readings are incorrect, it could mean one of several things. For good insulation, the resistance usually reads in the megohm range. These motors run conveyor belts, pumps, fans, and many other applications. Your complete software solution for managing, analysing and logging measurement data and cable data. Megger has offered a 10 kv insulation resistance tester since 2001. What are the possible results of a the megger test.
The pat400 series from megger is a new generation of downloading portable. Megger guide to electrical insulation testing pdf instrumart. Connect the megger hot lead to a motor winding lead. Megger recommends that the bite 3 be made part of a. Megger download software included allowing further analysis and storage data. Use meggers on highresistance measurements only such as insulation measurements. How does a megger test measure insulation resistance. This procedure provides minimum guidelines and acceptance criteria necessary to ensure meggering is performed safely and consistently. Free download manager is a powerful opensource downloading application that has millions of loyal users all over the world. Any help would be m megger testing procedures ieee electrical code issues engtips. Electrical test equipment application solutions from megger. Some tests and procedures may be performed by specialists during the assembly phase. Please find all available data sheets listed below. This demand for flexibility is especially true where multiple generation sources occur, such as the intermittent power from renewables like solar and wind energy.