Testing of electric motors - pdf

Electric motor repair, model repair specifications for low voltage motors, and motor repair tech brief were produced by the u. Bearings are located at both ends of the motor which are sometimes called bell housings or end bells. It may have the ability to ramp up the motor speed gradually during startup. A complete and definitive source for the design, manufacture, application and testing of small electric motors less than ten horsepower engine design engineers, test.

Additionally, does small electric motors test procedures at subpart x of part 431 reference. This test can be done in your own workshop using simple hand tools and a specialized electric testing device. Backed by 150 years of experience, simotics motors are unrivaled when it comes to reliability, ruggedness. Companies across the globe trust our reliability solutions, products, and services. Ieee std 1122004, ieee standard test procedure for polyphase. It may have the ability to ramp up the motor speed. With its 14 different test methods the allinone motoranalyzer2 offers almost everything for testing all types of motors like induction, synchronous, single phase.

It should be noted that the scope of motor testing depends upon the motor type and size, this being indicated on the inspection forms. There might be controls to reverse the motor direction or thermal sensors to shut down the motor. This might result in unexpected motor failures when critical services from such motors are required affecting availability of plants. Review of electrical tests to assess motor windings. Information on the introduction of new testing standards, efficiency classes, labels and minimum energy performance standards meps for electric motors in global markets. The basic steps in ascertaining the health of a threephase ac motor are given below. If you need custom test equipment to test your electric motor or just have a question about automated test of electric motors, reach out here to start the discussion. Actually voltage or current unbalance will produce too much heat thus damaging the motors. Electric motor testing 07012011 by lemau 15 comments electrical motor is the common used in industry all over the world. Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. Use the phillips screwdriver to unscrew the set screws of the connections.

Select ohms resistance on the multimeter and set for the 30,000ohm range. From this voltage the actual resistances of the windings are measured. The following standards are widely used for efficiency testing of motors at manufacturers test facilities and laboratories. The first describes the testing of various electronic components, assemblies, and systems. The bearings allow the shaft or rotor assembly to turn freely and smoothly in the frame. Testing of single phase motors is pretty easy if certain basic steps are followed. A megger is able to measure highvoltage resistance values. Model repair specifications for low voltage induction motors. Inspection and test procedures for rotating machinery. How to test and check single phase electric motors learning. 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.

Jul 17, 2017 check for shorts between the power wiring and ground. Ieee std 1122004, ieee standard test procedure for. Test methods for determining the impact of motor condition on. It is therefore used in starter motors of cars and elevator motors p. Crank the handle for about a minute, and notice the resistance reading. Dc motor fault zone analysis is a vital part of any dc motor maintenance program. Guide for the use of electric motor testing methods based on iec 6003421 p ll determined from residual loss 8. Doe is also proposing to clarify several values used for testing small electric motors. The phase relation between the rotor and stator magnetic field i. We look at different motor types, methods for testing them, which megohmmeters to.

Ac motor testing performed with pdma mce offline tester resistive imbalance during this test a dc voltage is applied to the motor. Implementing a predictive maintenance program takes a pm program to the next level. A motor placed in storage may or may not work, regardless of its physical. Knowledge of the basics together with powerful new test. Testers for electric motors and all kinds of windings schleich. Motordoc llc provides electrical machinery, electrical reliability and industrialcommercial consulting and training as well as the first continuous monitoring electrical and current signature analysis. How to check an electric motor if it is bad hunker. 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. But smart companies understands is that what this means for maintenance. Electric motor testing is usuallly the first thing to be sacrificed when cutting back on operational expenses.

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. The objective of any ac motor test is to determine the health status of the motor. Check to make sure there are exposed wire ends on the wires. Backed by 150 years of experience, simotics motors are unrivaled when it comes to reliability, ruggedness, compactness, efficiency, and performance. Many electric motor failures are caused by bearing failures. In many circumstances, energy efficiency can mean the difference between profitability and financial losses. How to test a 3phase motor is discussed in this article. Visual inspection and electrical testing of the armature and fields give the maintenance personnel an understanding of the condition of the motor. The proposed modifications to the test procedures for small electric motors and electric motors adopted in this nopr incorporate testing methods contained in certain sections of the following commercial standard. As we know, an electric motor plays a vital role in every sector of the industry, and also in a wide range of applications. And, since motors consume such a significant portion of energy in industry.

Jul 06, 2016 testing electric motors doesnt have to be a mystery. This compilation is not intended as a complete survey of the field of electrical and electronic equipment testing. If youre interested in other info on custom automated test systems, check out our automated test systems resources. So when a motor fails to operate it may not be obvious what the problem is. Electric motor impulse testing electric motor impulse testing is an integral part of predictive maintenance of electrical motors. Mar 29, 2019 check that the windings are not open or blown. Standard methods for determining losses and efficiency from tests. By testing the condition of motorgenerator circuits, we can help diagnose potential issues that could cause a failure during future operations and prevent it. It should be noted that the scope of motor testing depends upon the motor type and size, this. 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. Request for information and comments in the following sections, doe has identified a variety of.

Review of electrical tests to assess motor windings vicki warren and greg stone iris power engineering 1 westside drive, unit 2 toronto, ontario m9c 1b2 abstract surveys have shown that rotor and stator. To ensure the electrical motor condition is good or not,we must know how to testing it. Megger guide to electrical insulation testing pdf instrumart. For good insulation, the resistance usually reads in the megohm range. 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. Yes, i would like to receive emails from motordoc llc. The electric motor operation is based on the following points. In many circumstances, energy efficiency can mean the. Test for direct shorts in the motor s power windings in. Motor vibration shall be measured in a triaxial direction, i. Pdf electrical motor testing station with electromagnetic load.

Oct 19, 2015 how to troubleshoot 3 phase 240 or 480 volts any motor 3 leads 6 leads or 9 leads duration. The basic steps in ascertaining the health of any motor are given below a general inspections b earth continuity and resistance test c power supply test. The three resistance readings of a threephase induction motor are compared and calculated to obtain the resistive imbalance. The megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. What is however common to them all is that they have a start winding, a run winding.

The megger insulation tester is essentially a highrange resistance meter ohmmeter with a builtin directcurrent generator. Low voltage ac motors for line and converter operation. Through the following questions the influence that extensive impulse testing has on a motor is investigated. Touch one lead to each motor power lead and the other to the metal motor casing. For a three phase motor, insulation resistance is usually measured between each motor winding or phase and between each motor phase and motor frame earth using an insulation tester or megger. Rated values specified for testing small electric motors. 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. How to test and check single phase electric motors custom search. A general inspections b earth continuity and resistance test. Synchronous motors and generators procedures index 1.

Insulation resistance failure of an electric motor is one of the first signs that the motor is about to fail. New testing approach matches real world conditions the efficient use of electricity is not just a nice to have. At least one of the two magnetic field is generated by a solenoid carrying a current. Motor current monitoring and analysis mcsa is a straight forward tool to diagnosing problems with large inductive motors. Ieee std 1122004 revision of ieee std 1121996 ieee standard test procedure for polyphase induction motors and generators sponsor electric. Industries of today use threephase motors widely in highpower applications. How to test a threephase motor with a megger hunker. Post a question or comment about installing a hardstart capacitor to get. How to test three phase ac motors learning electrical. Threephase power, introduced by inventor nikoa tesla, uses a polyphase system of alternating current to supply power to large motors and. Youll find case studies, white papers, webinars, and. Dc motor analysis a leader in electric motor testing. Motordoc llc provides industrial and commercial consulting, training and technology for electrical and mechanical system reliability. Different types of electric motors and their applications.

Electric motor testing explained the electricity forum. Introduction to electric motor system diagnostics the reliability and energy consumption of electric motors and the systems they drive has a direct financial impact to industrial and commercial. Electric motors are used in many different machines and i am sure it is really important to be sure that they are working properly. The testing of rotating electrical machine for constructional and electrical requirement can be verified without disassembling the machine. The wire itself is usually copper or aluminum, which is known to be a good conductor of the electric current that powers your equipment. It is recommended that the recommended tests be performed. Department of energys office of industrial technologies oit with input. An introduction to electric motors stmicroelectronics. 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. What is however common to them all is that they have a start winding, a run winding, and a common connection between them as shown below. Pdf the aim of this paper is to present the station for electrical motor testing with its potentials.

Malloy can provide an electronic pdf copy of these results for the as found and as left conditions of the electric circuits. Electric motor testing electrical engineering centre. Test interphase resistance by disconnecting the leads from each terminal. It very important device to made production smoothly. Electric motors have had a reputation for being a mix of science and magic. Induction motor testing and evaluation summary as energy costs rise, more emphasis is being placed on determining the health of large inductive motors. There are a variety of types of electric motors are available in the market. 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. Testing electric motors doesnt have to be a mystery. When an electric motor fails to start, runs intermittently, runs hot, or continually trips its overcurrent device, there my be a variety of causes. Determining electric motor load and efficiency share this article pauline gill pauline gill is.

Mechanical energy what is an electric motor an electric motor is a device converting electrical energy into mechanical energy usually a torque. Simotics industrial electric motors provide you with the optimum solution for every application. One of the electric motors that i have hasnt been used for a while, so it. By testing the condition of motorgenerator circuits, we can help diagnose. 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. Remove the wire connections leading from the motor to the dc battery. 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. When a motor fails, it is often difficult to see why it failed just by looking at it. As with all testing and inspections, the motor name plate provides valuable information that will help to ascertain the true health of the motor. The following are recommended electric motor testing tasks. Pdma corporation is the leader in the field of predictive maintenance, condition monitoring applications, and the development of electric motor test equipment for motor circuit analysis.

Testing and commissioning procedure for electric motors eep. Threephase dualvoltage motor insulation resistance testing. Sometimes the trouble lies within the power supply, including branch circuit conductors or motor controller. Information, editorials and tech tips for you to use. Minimum test value of motor insulation resistance is 1 meg ohm 1 m. Knowledge of the basics together with powerful new test equipment vastly simplifies the job. The purpose of these guidelines is to provide standards for offline motor testing for low and medium voltage electric motors.