New testing approach matches real world conditions traditional motor testing methods the traditional method for measuring electric motor performance and efficiency is well defined, but the process can be costly to setup and difficult to apply in working processes. Dc motor fault zone analysis is a vital part of any dc motor maintenance program. The goal here is to describe the testing at a level above the physical attributes, such as temperature, pressure, force, and so on, but below the level of a final. Product testing methods for industrial hardware products.
Input power considerations provides the questions needed when evaluating the voltage and. The process is noninvasive, requiring only that a current transformer ampprobe or. This final thesis will mostly be dedicated to induction motors but also to synchronous permanent magnet and reluctance motors. Even that this method exhibits numerous advantages such as the elimination of electrical distortions and influence of supplying voltage low quality. Our electric motor testing training course teaches students the leading cause of motor failure. 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. 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. Here we will see a detailed article related to the starting methods of threephase induction motor. Ieee test procedure for poly phase induction motors and. The motor was a squirrel cage induction motor, tefv. Induction motor efficiency test methods ieee journals. Oct 28, 2015 in direct method of testing the generator or motor is put on full load and whole of the power developed by it is wasted. Ieee std 1122004 revision of ieee std 1121996 ieee standard test procedure for polyphase induction motors and generators sponsor electric machinery committee of the ieee power engineering society.
Contactors perform the switching action in the starter to connect and disconnect the power supply to the motor. Improving motor reliability through static and dynamic testing by noah bethel static motor testing is a wellknown means to comprehensively test electric motors. Knowing some basic methods and techniques along with having a. Induction motor starting methods bright hub engineering. Testing of dc machines dc motor and dc generator categories dc generator, dc motor, electrical machines there are several tests that are conducted for testing a dc machine generator or motor to judge its performance.
Mar 29, 2019 check that the windings are not open or blown. Pdf this paper describes a set of tests carried out on an induction motor for a 75. It very important device to made production smoothly. Naturally, the bearing temperature will increase by passing the time. Testing of dc machines can be broadly classified as. Simple, lowcost dynamometer setup for motor testing part 1. Yes, i would like to receive emails from motordoc llc. However, if a motor cannot be shutdown even the best static equipment becomes ineffective. Implementing a predictive maintenance program takes a pm program to the next level. Megger guide to electrical insulation testing pdf instrumart.
If manufacturers intend to test electrical machinery on their own responsibility, apart from compliance with other requirements type testing is conditional. Ieee std 1122004, ieee standard test procedure for. Explain starting methods of 3 phase induction motor. Test methods for determining the impact of motor condition on. These tests include a simple ac withstand test and diagnostic testing like tan deltapower. This compilation is not intended as a complete survey of the field of electrical and electronic equipment testing. Pure dc motor performance efficiency curve figure 2. In addition to conventional squirrel cage rotor testing methods such as the growler test, also covered will be. Dc motor analysis a leader in electric motor testing. For most shore facility applications, this is the case.
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. Subject to the rules for classification and construction of gl electrical machinery is not required to be type tested. The megger tester applies a high voltage to a system for a prescribed length of time, measuring the leakage current through the insulation. This measurement is expressed as resistance and, when tested periodically, can be used to graph and evaluate the condition of a motor s overall insulation over time. If any particular phase fails the continuity test, your motor is probably burnt. Motor testing methods based on iec 6003421 p ll determined from residual loss 8.
Electric motor testing training certified electricity forum. Motordoc llc case studies and expert witness cases. How to test three phase ac motors learning electrical. Timeresistance testing method this method is fairly independent of temperature and often. The lighting distribution panels are the source for singlephase power supply. Electric motor testing electrical engineering centre. A dynamometer is a testing device that helps engineers collect data for various mechanical loading conditions that a motor or engine might encounter in a. Technical note starting methods for ac motors reducing electrical and mechanical stress at startup the starting current of an ac motor can vary from 3 to 7 times the nominal current.
That is, with the same test connections and with the same test voltage applied for the same length of time. There are two types of induction motors, one with wound type rotor, also called slipring motor and another one with squirrelcage rotor. If the current is above the rated current for the motor, the contactor will be tripped automatically to disconnect the motor from the supply. Consider the working of a motor for a better understanding of these indicators. 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. The main purpose of the information that will be presented here is to describe many of the available tests that can be utilized under these different circumstances. Table il presents the various test methods included in. Induction motor testing and evaluation plant services.
Improving motor reliability through static and dynamic testing. The first describes the testing of various electronic components, assemblies, and systems. Each phase to phase must have a continuity if winding is ok. If a machine produces too much heat then it can affect the insulation of the machine and ultimately it can cause the breakdown of the machine. Dc motor analysis pdma a leader in electric motor testing.
By far the most commonly used ac motor is the induction motor. Let us assume that the threephase supply given to the motor has a phase sequence of ryb, then the motor. Dec 30, 2018 testing of induction motor december 30, 2018 february 24, 2012 by electrical4u demand of energy is growing day by day and along with it cost of energy rising abruptly, so now it is necessary that the health of large motors which consumes maximum power should be taken care off. There are different methods that can be used for software testing. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s.
Pdf testing and analysis of induction motor electrical faults. The electrician or maintenance person must have this skill to determine the electrical motor condition,defected or cannot use anymore. In this method, the dc machine is loaded directly by means of a brake applied to a water cooled pulley coupled to the shaft of the machine. Dec 30, 2018 the load testing of dc machine is needed to determine the rating of a machine. Review of testing methods for fullload temperature rise testing of induction machines. To ensure the electrical motor condition is good or not,we must know how to testing it. However, on application electrical machinery may be type tested. Pdf this paper describes a set of tests carried out on an induction motor for a 75 kw escalator. What really matters is the trend in readings over a time period, showing lessening resistance and warning of coming problems. The speed of an induction motor is given as n 120fp 1s. The technique of testing without having any knowledge of the interior workings of the application is called blackbox testing.
Two methods of reduced voltage starting are star delta starting and autotransformer stating. Induction motor efficiency test methods ieee xplore. For this motors, we require three phase power supply, whereas thus three phase power must be supplied in a sequence. Understanding insulation resistance testing pdf 0712 technical assistance 800 34391. And unexpectded motor failures cost a company hundreds of thousands of. Testing and commissioning procedure for electric motors eep. Jul 06, 2016 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. Information, editorials and tech tips for you to use. Ieee std 1122004 revision of ieee std 1121996 ieee standard test procedure for polyphase induction motors and generators sponsor electric. Our 2day electric motor testing training course introduces students to the basics of online and offline motor testing techniques. The computer based no load and blocked rotor test method are costlier and the electrical parameters cannot be visualized by programmable logic. Situations like these have fueled the popularity of dynamic testing. In many cases, the singlephase motors on board a ship will be wired into the lighting distribution panels. The testing of rotating electrical machine for constructional and electrical requirement can be verified without disassembling the machine.
When we run a machine, then some energy is lost in the machine, which converts into the heat and cause temperature rise. If youre interested in hardware product testing methods in general, youll want to check out our white paper. Preliminary tests generally are done using the ubiquitous multimeter. Electrical motor is the common used in industry all over the world. Electric motor drives are significant to the overall energy requirements of the country and the world. Visual inspection and electrical testing of the armature and fields give the maintenance personnel an understanding of the condition of the motor. They can be quite different for one motor or machine tested three days in a row, yet not mean bad insulation.
Rules for classification and construction vi additional rules. The majority of these electric motors are squirrel cage induction motors, and it is to the efficiency testing of these motors that this paper is directed. Testing of dc motor, dc motor testing direct and indirect. Ieee std 1122004, ieee standard test procedure for polyphase. Three phase induction motor or ac motor is started by itself but we require some starter or other methods for proper starting and controlling induction motor. Following tests are carried out on three phase induction motor to check the essential requirements which are likely to vary during production. The main methods employed for speed control of induction motors are as follows. This is because a large amount of energy is required to magnetise the motor enough to overcome the inertia the system has at standstill. Testing of machines is used for finding losses, efficiency and temperature rise. The goal here is to describe the testing at a level above the physical attributes, such as temperature, pressure, force, and so on, but below the level of a final assembly inside of which the electric motor resides. The complete guide to electrical insulation testing. This chapter briefly describes the methods available.
Motor current signature analysis mcsa is a proven and ac cepted method for determining the condition of a motors current carrying components. 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. Testing of dc motor, dc motor testing direct and indirect method october 28, 2015 admin 0 comments. A number of diagnostic tools, such as clampon ammeters, temperature sensors, a megger or oscilloscope, can help illuminate the problem. Motor current signature analysis mcsa is a proven and accepted method for determining the condition of a motor s current carrying components. Motor current signature analysis mcsa is a proven and accepted method for determining the condition of a motors current carrying components. Prakasam and others published testing and analysis. Iec 6003421 specifies rules concerning efficiency testing methods and iec 6003430 defines efficiency classes for a wide range of electric motors connected. It should be noted that the scope of motor testing depends upon the motor type and size, this being indicated on the inspection forms. Using a multimeter, check the continuity of motor winding from phase to phase u to v, v to w, w to u. Testing can be conducted without inter rupting the normal operation of the motor, and in fact should be performed when the motor is under a minimum of 70% load. In practice, as you will see in the test methods described below, you.
The comparative environmental impacts of motor rewinding vs. The direct tests can be used only on small machines. The induction motor shall run at the rated voltage and frequency, and each bearing temperature is measured periodically. Motor vibration shall be measured in a triaxial direction, i. The temperature rise should not be bo more than specified value in the induction motor testing procedure or motor datasheet. Motor testing equipment newer more contemporary instruments make testing even easier.
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