What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy to mechanical energy, and vice versa. Be sure such technicians observe standard safety precautions including. Almost 3040% of all reported induction motor failures falls in this category. The fundamental laws associated with the relationship between electricity and magnetism were derived from experiments conducted by several key scientists in the 1800s. These motors are suitable for all general applications where an open machine is not applicable due to severe environments such as excessive dirt, dust andor moisture. Motor will make a humming noise and the circuit breaker or fuse will trip. Be trained in the proper care and use of protective equipment such as rubber. Accidentally these are also uncertain parameters when the machine is released from production. A 3 phase induction motor can be used for different applications with various speed and load requirements. The 3phase induction motor is used in the larger horsepower application above 1 hp while the singlephase ac motors were used in the. The types of induction motor depend upon the input supply. An indepth troubleshooting guide to help you with your ac electric motor issues. Motor current monitoring and analysis mcsa is a straight forward tool to diagnosing problems with large inductive motors. Traditional design of cage rotor induction motors ronald g.
Eee page 5 it is usually for large 3 phase induction motors. Diagnostics of rotor and stator problems in industrial induction motors by fang duan b. Induction motor fault heading fault causes remedies induction motor a no supply voltage b driven equipment jam c motor shaft jammed. The induction motor drives can provide high productivity with energy efficiency in different industrial applications and are the basis for modern. Induction motor parameters locked rotor test the locked rotor. Installation and maintenance threephase induction motors.
It has been more than a century since the principle of the operation of induction motors was discovered. Induction motors a stolp 12610 threephase f electrical frequency the magnetic flux inside the motor rotates at the synchronous speed. Pdf on may 3, 2019, ahmed m t ibraheem alnaib and others published singlephase induction motors find, read and cite all the research you need on researchgate. No responsible discussion of electrical equipment maintenance would be complete without first covering the need to maintain a safe working environment. There are two types of induction motors, one is named as single phase induction motor, while the second one is named as 3 phase induction motor. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. In the present day, induction motors consume between 90 to 95 percent of the motor energy used in industry. Be trained and authorized to perform the service, maintenance or repair of the motor. Several additional components are necessary to operate the singlephase motor.
Because it is a capacitortype induction motor, it has a high power factor and runs with a low noise level caution. Induction motor do not possess the above mentioned problems, they have. Singlephase motors have only two power source supply lines connected. Process performance and general performance motors. Induction motors continued to evolve in form and use. Wind pushes the blades of the turbine, spinning a shaft attached to magnets. In this article, we take a look at common operational problems for threephase ac induction motors, how to diagnose them and how to fix them. Like generators, motors a have problems with armature reaction.
Basic design and theory of operation the alternating current ac induction motor is one of the most rugged and most widely used machines in. Induction motor problems and solutions pdf 3 phase induction motor pdf three phase induction motor the wound rotor induction motor speed control of induction motor three phase induction motor diagram blocked circle diagram of an induction motor speed control of induction motor by vf method single phase induction motor pdf free download speed control of three phase induction motor with. Introduction to induction motor the engineering projects. One singlephase wattmeter plus miscellaneous apparatus as needed. To illustrate the simplicity of the ac induction motor. Fault diagnostics of electrical ac machines literature survey marian negrea. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Diagnostics of rotor and stator problems in industrial. Magnetism and induction a motor converts electrical energy into mechanical energy ac alternating current reverses poles of electromagnetic coil 120 times per sec 60hz coils wound into the stator of the motor create rotating magnetic field magnetic field passing through the conductors of the rotor induces current to flow.
Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. Sample troubleshooting chart 3phase induction motor 20k pdf. Sep 27, 2016 induction motor is an ac electric motor, having a stator and a rotor just like other motors, but the working principle is a little different which would be discussed further. The acoustic noise in induction motors has three main sources. The table below gives the commonly encountered problems in 3 phase squirrel cage induction motors, cause of problems and what remedy to apply to bring the motor back to production. Single phase induction motor 1introduction the singlephase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Rotor has winding, same as stator and the end of each phase is connected to a slip ring. This troubleshooting guide can also be applied to other types of three phase induction motors. Synchronous and asynchronous electromechanicalsystems dr. You should also make a dc measurement of stator winding linetoline resistance.
The parameters of equivalent circuit of induction machines are crucial when considering advanced control techniques i. Unit 16 electric motors washington state university. Pdf the effect of bearing currents in inverter driven induction motors has been investigated and reported for about ten years. 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. Induction motors and transformers both im and transformer works on the principle of induced voltage transformer.
Induction motors make up the majority of the load in many industries. Troubleshooting capacitor motors is similar to troubleshooting splitphase motors. Maintenance and troubleshooting three phase induction motor. Other motors that are included are 1phase induction motors, permanent synchronous motors and synchronous reluctance motors. There must be no vibration, twisting, misalignment etc. Synchronous and asynchronous electricmotors the electric motor is an electromechanical continuous energy conversion equipment that converts electrical energy into electrical energy mechanical energy. Therefore, motor troubleshooting involves the entire system, not just the. This standard specification describes the requirements for the contractor to overhaul ashore in a suitable repair facility an alternating current ac induction or synchronous motor removed from a coast guard vessel. The only additional device to be considered is the capacitor. Model repair specifications for low voltage induction motors. Here we are giving you only overview on 3 phases induction motor. Model repair specifications for low voltage induction motors these model repair specifications are intended to cover routine repair and rewind of lowvoltage randomwound threephase ac squirrel cage induction motors.
The rotor of an induction motor can be a squirrel cage rotor or wound type rotor. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. Ac motors, single phase induction motors,permanent splitcapacitor motor. The motor is mounted in a test rig that allows one to control the torque applied to the motor shaft and to measure both rpm and torque. They also generate counter emf as a result of their motion.
Fri, feb 09 by troubles with the induction motors are generally divided into two categories. Pdf troubleshooting and fixing of inverter driven induction motor. Finally, references 1118 are indicative of current research approaches and issues in induction motor load modeling in power systems. The most common ways, to manually determine induction motor. Iron loss stator core power transferred to rotor via magnetic field of air gap i2r loss in stator winding i2r loss in rotor winding iron loss in. Troubleshooting capacitor motors a capacitor motor is a splitphase motor with the addition of one or two capacitors.
Nov 03, 2019 there are basically two types of induction motor. If it doesnt its either the brushes or the windings that are. The induction motor cannot make a quickreversal run because of the torque acting in the opposite direction. For maximum motor life, the cause of overheating should be identified and eliminated. Maintenance and troubleshooting of electric motors. Troubleshooting problems on your ac motor is relatively straightforward, and providing you have reasonable doityourself abilities, repairing it is not too difficult. The industry is becoming increasingly aware of the. The ac induction motor is the most used electrical motor in industrial applications worldwide. Transfer of the induction motor to the ups system after power failure. The induction motor is made up of the stator, or stationary windings, and the rotor. All we need to do is to keep daxis stator current constant.
Induction motors were invented by nikola tesla in 1888 while he was a college student. The very first thing that you should do before starting any type of maintenance on a motor is a visual inspection, a lot of times the trouble can be found just by looking, because if the problem is that bad then it should be very obvious by observation. In phase wounded rotor always double layer, distributed windings are used in alternators even the stator has two phases. Also the foundation of pump a foundation of motor pump must be rigid and secure to provide adequate support.
Pdf transfer of the induction motor to the ups system after. Induction motors induce a current into an electromagnetic rotor in order to create rotation. Types, losses in induction motors, motor efficiency, factors affecting motor performance, rewinding and motor replacement issues, energy saving opportunities with energy efficient motors. The first industrial motors of this type were constructed at the end of the nineteenth century and soon gained the favor of users who appreciated their raggedness, simplicity and relatively low manufacturing cost compared to dc commutator motors. In the first part of our presentation, we are going to discuss. Teco totally enclosed fan cooled squirrelcage induction motors are designed, manufactured and tested to meet or exceed the latest nema, ieee, csa and other international standards. The starting mechanism of the singlephase induction motor is mainly an additional stator winding start auxiliary winding as shown in figure 3. The start winding can have a series capacitor andor a centrifugal switch. You should also make a dc measurement of stator winding linetoline resistance using a dmm. Telecommunication engineering, southwest jiaotong university, china, 2005 thesis submitted for the degree of masters of engineering science in school of electrical and electronic engineering the university of adelaide, australia august 2010. Therefore stop the induction motor once, change the wire connections and make a reverse run. Overload relays take the motor off during full load operation. When the motor is connected to a singlephase power supply, the main winding carries an alternating current. Induction motors despite the fact that the threephase motor has more phases than the singlephase motor, the singlephase motor is a much more complex machine.
The keys to successful motor operation include a total understanding of the application, then choosing the proper type of motor for the application. Motion and temperature heat control are paramount in energy. All about motors 88 motor protection selection aids the eaton selector slide enables you to determine quickly and reliably which motor starter is the most suitable for the application concerned. An electrical motor is a device that has brought about one of the biggest advancements in the fields of engineering and technology ever since the invention. Capacitors give the motor more starting andor running torque. One is the electrical faults, such as the various faults of switches, buttons, fuses, electric brushes, stator winding, rotor, starting equipment and so. Nema mg1 motors that have the iecex designation have also been.
To build an ac permanent capacitor splitphase induction motor. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the. Problems and premature failures often indicate input power system troubles, poor or deteriorating mechanical installations, or malfunctions in the driven machinery. Motivated by the need of energyefficiency improvements, process optimization, softstart capability and numerous other environmental benefits, it may be desirable to operate induction motors for many applications at continuously adjustable speeds. Fall 2005 ee595s electric drive systems 36 the plan continued achieving 14. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. Pdf literature survey fault diagnostics of electrical ac machines. For motors falling outside this description, the more comprehensive model specifications below are recommended. As indicated in the troubleshooting sections, overheating results from a variety of different motor problems. Although dc motors possess good control characteristics and ruggedness, their performance and applications in wider areas is inhibited due to sparking and commutation problems. Induction motor testing and evaluation summary as energy costs rise, more emphasis is being placed on determining the health of large inductive motors. Single phase induction motors arenot a selfstarting motor, and three phase induction motor are a selfstarting motor. I previously covered how dc motors work, but ac induction motors are actually much more useful for homemade machines such as bandsaws. For this only the operating voltage, the motor rating, the various shortcircuit ratings and coordination types are.
A 480v, 60 hz, 6pole, threephase, deltaconnected induction motor has the following parameters. Introduction symmetrical components analysis of unbalanced modes of. Tips for troubleshooting electric motors understanding the nuances of various motor types is essential when servicing or installing such units b y d e n n i s b u s h a fter more than 100 years of use, with an ever increasing installed base, there are probably few aspects of an electric motors. In an induction motor, the electric current in the rotor needed to produce torque is obtained via electromagnetic induction from the rotating magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. The first are the most commonly chosen induction motors for demanding industrial uses and cover frame sizes 63 450, or 0.
Relevant standards motors shipped with this installation instruction have been designed and built to the following standards to the latest revision. Figure below summarizes losses in induction motors. Motor guide february 2014 low voltage motors motor guide. Troubleshooting techniques help keep ac induction motors. Electric energy and induction motors the level of prosperity of a community is related to its capability to produce goods and services.
There are single phase induction motors and three phase induction motors. Crossreferences lessons in electric circuits, volume 2, chapter. Determining electric motor load and efficiency most likely your operations motors account for a large part of your monthly electric bill. Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. Far too often motors are mismatchedor oversizedfor the load they are intended to serve, or have been rewound multiple times. Allow only qualified personnel to perform troubleshooting and maintenance of motors. It was the wicked and insane genius nikola tesla who invented them. Before troubleshooting the 3 phase induction motor, we must have to know about the 3 phase induction motor, star delta starter and its connection diagram.