For standard nema mg 1 motors of 5 hp and lower rating, renewal is typically more time and cost effective than overhaul. Electric motor testing explained the electricity forum. Menzel electric motor test field in berlin offers the latest test engineering for manufacturerindependent motor tests up to. Testing and commissioning procedure for electrical installation 1. This article describes ac electrical motor troubleshooting. Information, editorials and tech tips for you to use. Motordoc llc provides electrical machinery, electrical reliability and industrialcommercial consulting and training as well as the first continuous monitoring electrical and current signature analysis system and esa data collection systems. Electric motors have had a reputation for being a mix of science and magic. It provides information on procedures and testing of major electrical equipments to be followed during testing by engineers and also furnish evidence that an electrical equipmentdevice is free of inherent flaws or faults. When a bad motor winding cannot be found by a physical inspection, many times an ohmmeter may show that there is a defective winding. Although stationary test measure primarily exhaust noise, this test has been designed to pass quiet vehicles those which test below a specified limit and fail those that exceed a certain sound level limit. 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.
Inspection, testing and commissioning of electrical. Test for direct shorts in the motors power windings in. The ansineta standard for maintenance testing specifications for electrical power equipment and systems was developed for use by those responsible for the continued operation of existing electrical. The speed of an ac motor depends on the frequency of the input power and the number of poles for which the motor is wound. For good insulation, the resistance usually reads in the megohm range. Small motors, in particular, have become essential tools of convenience, for instance inside of car seats. So when a motor fails to operate it may not be obvious what the problem is. Induction motor testing and evaluation summary as energy costs rise, more emphasis is being placed on determining the health of large inductive motors.
Jul 01, 2015 basic motor testing with multimeters and ammeters july 1, 2015 by david herres 12 comments when an electric motor fails to start, runs intermittently, runs hot, or continually trips its overcurrent device, there my be a variety of causes. Test results of surge protection devices shall be in accordance with procedures for testing of lv surge arresters. Guide for the use of electric motor testing methods based on iec 6003421 p ll determined from residual loss 8. Some of the more common electrical tests and procedures include. The windings are marked with tags u1 and u2, v1 and v2, w1 and w2. Industrial productivity training manual, 1996 annual iac directors meeting, rutger s. Electric motor testing electrical engineering centre. The megger will help to detect areas of deteriorating insulation where the windings may soon short. Rather, it presents a sampling of many diverse activities for the interest of electrical, electronic, and. The page top photo was taken of of an oil burner electric motor not an air conditioning blower fan motor or pump motor, but youll see that all of these electric motors look a lot alike. Knowledge of the basics together with powerful new test equipment vastly simplifies the job.
Testing of the electric vehicle in driving cycles fig. The test should also be performed after a motor is serviced. The former translates position, speed, or force acceleration or torque commands to the signals needed to move the motor. Electric motors consume 78% of all electrical energy in industrial processes, 43% of electrical energy in commercial buildings and 37% of the electrical energy in residential environments. Jul 06, 2016 testing electric motors doesnt have to be a mystery. The test measurement data can be recorded on a test graph over time. Diagnose problems caused by damaged or failed harnesses, connectors, terminals and. The established documentation for the elimination and control of hazards is henceforth referred to as electrical safety procedure. Designconstruction related features in ac motors that lead to longer service life and. In such a case the motor insulation is shown to be weak by failing the surge test, yet has not become a welded, hard, or bolted short. This compilation is not intended as a complete survey of the field of electrical and electronic equipment testing. Section 7 of the ansineta standard for acceptance testing specifications for electrical.
To ensure the electrical motor condition is good or not,we must know how to testing it. Verify scribe on the rotor shaft is correct to indicate the magnetic center of the motor as applicable. Electro motor testing procedure free download as word doc. Ieee std 1122004, ieee standard test procedure for polyphase. Check for burnt, damage to body or cooling fan or shaft. Select, qualify and use proper electrical testing equipment and leads. It should be noted that the scope of motor testing depends upon the motor type and size, this being indicated on the inspection forms. Electrical inspection checklists this pdf contains 77 electrical inspection checklists taken from the 2014 electrical inspection manual with checklists. Does test procedures for electric motors are prescribed at. Yes, i would like to receive emails from motordoc llc. Standard for acceptance testing specifications for. The paper also describes a detailed procedure of design. Megger guide to electrical insulation testing pdf instrumart.
The megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. Measuaring motor insulation using hi pot tester 28012012 by lemau 1 comment when we need to evaluate the motor condition, hipot tester or high potential tester is the common equipment are used. This may cause severe problem to the load and entire system. 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. Minimum test value of motor insulation resistance is 1 meg ohm 1 m. Pdf electrical motor testing station with electromagnetic load. In addition to conventional squirrel cage rotor testing methods such as the growler test, also covered will be techniques such as the use of a core loss tester, high current excitation, and spectrum analysis of vibration.
The induction motor is visually inspected for o utside view such as rust, scratch, and bruise, coasting color and finish, description on name plate, mounting direction of terminal box and protection type of frame. However, on application electrical machinery may be type tested. Electric motor insulation testing with baker instruments. How to test a 3 phase motor windings with an ohmmeter. Subject to the rules for classification and construction of gl electrical machinery is not required to be type tested. Ieee std 1122004, ieee standard test procedure for.
Testing electric motors doesnt have to be a mystery. The electromagnetic load emulator ele is designed to be an adjustable load of an electric motor. Mar 29, 2019 check that the windings are not open or blown. The rate at which a motor moves is dependent on the signal that drives the motor. Introduction the procedures stated in this document cover the activities in preliminary tests and inspections, functional performance tests and the commissioning of newly completed installations and existing ones after major alteration. Standard for acceptance testing specifications for electrical. In order to properly test the motor you must remove. In the running configuration, the windings are joined with metal jumpers. Testing manual for electrical equipment nahed alhajeri 1and anantha madhavan 2 abstract.
Take a virtual tour through our load test field our test facility is one of the most uptodate test stations of its type. If shaft rotation is free and smooth, bearing is possibly in good condition, otherwise consider replacing. This document contains proprietary information of general electric company, usa and is furnished to its customer solely to assist that customer in the installation, testing, operating andor maintenance of the equipment described. Test results of motor starter equipment shall be in accordance with. As we know,a multimeter or ohm meter reading only can determine if a motor winding is open or shorted but cannot checked winding insulation condition. Ac electric motors best practice lifetime reliability solutions. Select ohms resistance on the multimeter and set for the 30,000ohm range. It very important device to made production smoothly. Motordoc llc provides industrial and commercial consulting, training and technology for electrical and mechanical system reliability.
Be sure to follow good safety measures to prevent electrical shock. The vast majority of the electricity used by an electric motor drive system is consumed by the electric motor. Modular construction to suit the clients test requirements and budget. Doe is not proposing any changes to the scope of applicability of the electric motor test procedure. Motor current monitoring and analysis mcsa is a straight forward tool to diagnosing problems with large inductive motors. For motors 25 hp or greater, record motor vibration measurements in accordance with the test equipment manufacturers instruction manual. Third party inspection for induction motor procedure. Can be combined with a dynamometer for load testing of motors.
The wire itself is usually copper or aluminum, which is known to be a good conductor of the electric current that powers your equipment. As shown below, the indicated terminal matrix blue lines shows the way the windings of a 3 phase motor should be tested with an ohmmeter. Complex, powerful tools, electric motors are critical components in a wide range of equipment and. These tests are performed to check the electrical or mechanical defects of the induction motor.
Many simple across the line singlephase and 3phase motors used in household appliances and industry respectively can be checked simply by changing the range of the ohm meter to the lowest offered r x 1, zeroing the meter again, and measuring the resistance between the leads of the motor. Improve the quality control of the project and simplify the procedures for engineers. This is video i want to show you about easy electric motor repair how to connect capacitor to washing machine dryer motor. All of us hope youll like our video clip concerning. Standard for testing specifications electrical power. A motor needs to be given electrical power to turn the motor. Electric motors performance analysis testing tool demonstration project, pacific.
How to test three phase ac motors learning electrical. Dropforged eyebolts per american society of testing materials a489 or equivalent must be used. Electric motor efficiency under variable frequencies and loads pdf r06004. Formwound stator coils for alternatingcurrent rotating electric machines, figure 1, page 8. Inspection and test procedures of rotating machinery, synchronous motors and generators on photo. How to check an electric motor if it is bad hunker. Do not lift both the motor and driven equipment with the motor lifting means. From this voltage the actual resistances of the windings are measured. The checklists are in pdf format and can be completed electronically or printed and used as hard copy. All steps are now treated the same as in the fuds test. Testing manual for electrical equipment requirements are fulfilled. Easy electric motor repair how to connect capacitor to. Uses same test instrument setup as lockedrotor test.
The first describes the testing of various electronic components, assemblies, and systems. Testing and commissioning procedure for electric motors eep. Although low voltage testing, such as the megohm test, is commonly used on electric motors, generators and windings, only high voltage testing can. Ul ul674 electric motors and generators for use in hazardous locations easa ar1001998 recommended practice for the repair of rotating electrical apparatus ieee ieee std. To obtain short circuit current and its power factor angle, block rotor test is performed on the motor. Ieee standard test procedure for polyphase induction motors and generators 3 park avenue, new york, ny 100165997, usa ieee power engineering society sponsored by the electric machinery committee 4 november 2004 print.
Electric motor testing is usuallly the first thing to be sacrificed when cutting back on operational expenses. This pdf contains 77 electrical inspection checklists taken from the 2014 electrical inspection manual with checklists. Electro motor testing procedure bearing mechanical. Designed to run the motor after rewind or servicing. Third party inspection for induction motor visual inspection. If manufacturers intend to test electrical machinery on their own responsibility, apart from compliance with other requirements type testing is conditional. Read online now motor rewinding procedure ebook pdf at our library. The current electric motor test procedure is at subpart b of 10 cfr part 431. The institute of electrical and electronics engineers, inc. This is important, because the highvoltage current in threephase systems is far more lethal than a mere lowvoltage shock received in residential setting.
Third party inspection for induction motor dimensional inspection. How to conduct the stationary sound test this is a summary of the sae j1287 jul98 stationary sound test procedure. Motor vibration shall be measured in a triaxial direction, i. As noted, this nopr also addresses the test procedure for electric motors in response to a petition for rulemaking. If the motor is nonstandard or has custom features, repair may be the only practical option. Troubleshooting with insulation resistance test instruments. The megger insulation tester is essentially a highrange resistance meter ohmmeter with a builtin directcurrent generator. 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. Check for shorts between the power wiring and ground.
We are constantly doing what everyone else just talks about. The three resistance readings of a threephase induction motor are compared. Ieee std 1122004 revision of ieee std 1121996 ieee standard test procedure for polyphase induction motors and generators sponsor electric. Rather, it presents a sampling of many diverse activities for the interest of electrical. Apply rated voltage and frequency with no mechanical load. Factory acceptance tests fat the routine tests shall be made with each electrical equipment and, whenever practicable. Test methods for determining the impact of motor condition on. The measuring procedure the measuring procedure has been based on the unece regulations 101 and within the scope requiring it to be detailed according to en 18211. Such a failure could result from a new operator in the winding department the hipot test a versatile test. Ansineta standard for acceptance testing specifications for electrical power equipment and systems are clearly identified in writing as the source of all such uses or reproductions.
For single phase motor testing we apply generally three test ntinuty test 2. See how to measure insulation resistance of electric motor running amps test with the motor running, check the full load amps fla with a suitable meter or preferably a clamp on meter and compare with the name plate fla. Using the megger to test a threephase motor is rather easy, though the safety hazards for this procedure are quite high. Inspection and test procedures for rotating machinery. Electric motor testing 07012011 by lemau 15 comments electrical motor is the common used in industry all over the world. Standard for maintenance testing specifications for electrical power equipment and systems is the most current revision of this document.
But smart companies understands is that what this means for maintenance programs is billions of dollars of lost revenue through increased motor repair costs, downtime, and waste in industrial and commercial companies. When a threephase supply is given to the coils, then the. Similarly the range of ammeter and voltmeter during blocked rotor test, 10a, 250v. How to test and check single phase electric motors learning. The first neta maintenance testing specifications for electrical power equipment and systems was published in 1975. Since 1989, revised editions of the maintenance testing specifications have been published in 1993, 1997, and 2001. To determine whether a 3 phase motor is still good or has gone bad, a simple ohmmeter test across the windings of the motor will reveal its true state of health. Measuaring motor insulation using hi pot tester electrical. Recommended test voltage the ideal situation for the surge test is to find the arcing turntoturn insulation failure. Model repair specifications for low voltage induction motors. Rtd circuits shall be in accordance with system design intent and machine protection device.
To perform an insulation spot test, apply the following procedure. In 2005, this document was approved for the first time as an american national standard. Testing can be conducted without interrupting the normal operation of the motor, and in fact should be performed when the motor is under a minimum of 70% load. The complete guide to electrical insulation testing.
Applicable to tata power operating and project sites which cover but not limited to plant premises, switchyards, substations, offices. The checklists are intended to help inspectors keep track of the numerous aspects of an electrical installation. Most repair shops will use a megger or a ground insulation tester. After dismantling motor unit that not pass electrical or testing we. Connect a megohmmeter to measure the resistance of each. Touch one lead to each motor power lead and the other to the metal motor casing. Motor current signature analysis mcsa is a proven and accepted method for determining the condition of a motors current carrying components. In this article we provide a diagnostic guide to determine and repair problems with electric motors. Whitelegg manufacture a large range of ac only or ac and dc test panels for electric motors. Test to obtain more reliable values ranges of both wattmeter should be 10a, 250v for blocked rotor test. Electric motor testing in seconds since its introduction in the nineteenth century, the electric motor has become a major force in industry.
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