Canada 18060109th ave edmonton, alberta t5s 2k2 canada tel. When using current measurement to determine motor load, it is important that correction be made for the operating power factor. The premise for motor operation is that if you can create a. By observing a few essential rules, you will ensure problemfree operation for many years. Slip is the ratio between the slip speed and synchronous speed. The nated n1n3 motor mechanics qualification is a qualification from level s n1n3 focussing on the theory of motor mechanics in motor trade and diesel theory. Phasethis represents the number of ac power lines supplying the motor. Read and download ebook previous diesel trade theory n3 question papers and solutions pdf at public ebook library previ. Record the readings of all the meters, connected in the circuit.
As its name indicates stator is a stationary part of induction motor. It will lead to know more than the people staring at you. Themotorisallowedtorunatnoload,andissuppliedwithvarious voltages at nofcmal frequency,rangingfrom 25 percentabove normaltoa value at which the motorwill just. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Report 191 n1 n3 carlyn van hinsbergen 20181012t10. Three phase motors and alternators flashcards quizlet. A stator winding is placed in the stator of induction motor and the three phase supply is given to it. The fact that the three voltage change polarity at regular intervals. Single phase series motor, theory of operation performance and application, shcrage motor.
An induction motor can therefore be made without electrical connections to the rotor. In this work a conventional three phase squirrelcage type induction motor with specifications 10 hp, 415v, stardelta connected and 4 poles is chosen for comparison with our motor, which is designed for good efficiency. In the case of three phase ac alternating current operation, the most widely used motor is a 3 phase induction motor, as this type of motor does not require an additional starting device. The operating principle of the induction motor can be briefly explained as, when balanced three. The major difference between them is that transformer is static in nature i. The reference design manual describes basic motor theory, the system design concept. Motors have been described as a transformer with a rotating secondary.
You should also make a dc measurement of stator winding linetoline resistance. These types of motors are known as selfstarting induction motors. The following examples show the rating plates for two motors with a motor shaft output of 4 kw and the respective connection circuits on a threephase ac network. The stator carries a 3 phase winding called stator winding while the rotor carries a shortcircuited winding called rotor winding only the stator winding is fed from the 3 phase supply. Generally three phase induction motor is treated as rotating transformer. Wiring diagram book a1 15 b1 b2 16 18 b3 a2 b1 b3 15 supply voltage 16 18 l m h 2 levels b2 l1 f u 1 460 v f u 2 l2 l3 gnd h1 h3 h2 h4 f u 3 x1a f u 4 f u 5 x2a r. Like any electric motor, a 3 phase induction motor has a stator and a rotor. Electrical trade theory n3 march 2014 question paper. Read and download ebook n2 motor trade theory pdf at public ebook library n2 motor trade theory pdf download. An ac function can represent either a power source or a signal source with the shape of an ac waveform generally following that of a mathematical sinusoid being defined as. Pdf in industries, electric motors contribute a major percentage of electrical loads, and by.
We thank you for making this choice, and would ask you to read the contents of this manual. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the explanations to suit the intended reader. Quantity of heat q for a change in temperature q m c t kj for a change of phase q m. Even now, there are many sources to learning, reading a photo album nevertheless becomes the first complementary as a good way. If in the input circuit, correct the single phase condition.
N1 electrical trade theory n2 electrical trade theory revision n1 electrical trade theory 1. It brings important information for the operation of various types of. Training guidelines from the commercial nuclear power. Electrical trade theory n2 question paper 25 march or. Three phase ac motor theory motors have been described as a transformer with a rotating secondary. Calculate the output power of the motor from the given information. Installation and maintenance threephase induction motors. Revision on exam type questions, on 3 phase transformer calculations. Classification of types of construction, mounting arrangements and terminal box position im code. Please select below folders, where you can access previous exam papers that have been grouped per subject. Record all nameplate information for the induction motor. An induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. For this example, refer to the motor equivalent circuit and calculations described above.
N2 electrical engineering question papers and memorandums. A 3 phase, y connected, 460 volt line to line, 25 horsepower, 60 hz, 8 pole induction motor has the following constants, in ohms per phase referred to the stator. Single phase induction motor, theory of operation double revolving field theory, equivalent circuit, determination of parameters methods of starting, split phase starting, repulsion starting, shaded pole starting, performance characteristics. Pdf construction of three phase linear induction motor. If the copper ring is moved away from the end of the permanent magnet, the direction of force will reverse and become attractive rather than repulsive followup question. For this example we have to shift the result by n 3 bits. Microsoft word n3 electrical trade theory november 2016 memorandum. Basic principle of operation of threephase induction machine. From the data obtained from the noload test, we can determine the values for the series circuit elements r.
Drm092, 3phase ac induction vector control drive with single. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Draw a circuit diagram of a splitphase motor that has one capacitor which is permanently connected during operation. Draw a circuit diagram of a split phase motor that has one capacitor which is permanently connected during operation. The arrangement of the stator windings around the inside of the motor. N2 electrical trade theory class activities mathematics n3 april 2018 question. There are three speed control motor product groups. Bookmark file pdf n2 electrical engineering question papers and memorandums.
N3 electrical trade theory november 2016 memorandum. Theory and analysis of three phase induction motor using written pole technology kishor s. Efficiency classes of singlespeed threephase cage induction motors. Measure the resistance per phase of the stator winding, following ohm. Pdf the performance of a 3phase induction machine under. Motor trade theory n3 11040673 5 april 2016 xpaper 9. Currentrated load current in amps is at nameplate horsepower hp with nameplate voltage and frequency. If a single phase condition exists, correct the problem. The ac speed control motor unit that uses the most popular singlephase capacitorrun induction motor, the small and highly efficient brushless dc motor unit. Speed control methods of various types of speed control. Motors, generators, and transformers are similar in that their basic principle of operation involves induction. Draw the single phase subcircuit that adheres to wiring code regulations.
Transformers in this video we show you how to answer electrical trade theory n2 transformers questions. Torquespeed characteristics of three phase squirrel cage. Variable voltage variable frequency vf control theory an induction motor compared to a dc motor has some major advantages such as absence of brushes, commutator segments, rugged construction, being cheap, lesser maintenance requirements and smaller. An induction motors rotor can be either wound type or squirrelcage type. The fact that the voltage in a three phase system are 120 degrees out of phase with each other. Tecowestinghouse motor company po box 227 786800277 5100 n. Theory and analysis of three phase induction motor using. An alternating function or ac waveform on the other hand is defined as one that varies in both magnitude and direction in more or less an even manner with respect to time making it a bidirectional waveform. Electrical engineering three phase induction motor objective types question and answer in hindi electrical engineering three phase induction motor objective types question and. There are two basic reasons for the use of singlephase motors rather than 3phase motors.
Designing of three phase squirrel cage induction motor for. This qualification meets the academic requirements for you to write your trade test once you have aquired the required practical hours. One single phase wattmeter plus miscellaneous apparatus as needed. Stator is made up of number of stampings in which different slots are. Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and. Always have an expert check the motor windings to determine whether the single phasing occurred in the input circuit or in the motor windings. The rotor is often called a squirrel cage because it consists of a circular network of bars and rings that look a bit like a cage connected to an axle.
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