Solution At No-load , ( )( ) At Full-load , Problem #2 A 3-phase, 15 hp, 460 V, 4-pole, 60 Hz, 1728 rpm induction motor delivers full output power to a load connected to its shaft. Acceleration of the Motor • Example – Separately excited dc motor has a resistance of 1 ohm and generates 50V at a speed of 500 rpm. Series DC machines 4. stream Troubleshooting Electric Motor Problems Made Easy for You. 5 0 obj provide the student with practical information for winding, repaiT'ina, and troubleshooting alternat:ng current and direct current motors, and controllers. Read the following passages to understand more about recognizing and troubleshooting these problems. Separately-excited DC machines 2. 9 0 obj 3 0 obj Remove motor from load and inspect motor by itself.Verify that motor shaft is not bent. A 7.5-hp, 120-V series dc motor has an armature resistance of 0.2 Ω and a series field resistance of 0.16 Ω. around the world. endobj Inspect the motor for any obvious defects that would prevent safe testing such as: %PDF-1.5 3f) Alternator condenser failure (9) - … stream x�U�� 14 0 obj If the previous motor was a special design, a stock motor may not be able to duplicate the performance. Calculating Back EMF, Power and Torque for a DC Shunt Motor - Duration: ... How to Solve Any Series and Parallel Circuit Problem - Duration: 14:06. Compound-connected DC machines 5. Withthespeed endstream endobj 415 0 obj <> endobj 416 0 obj [/ICCBased 428 0 R] endobj 417 0 obj <> endobj 418 0 obj <>stream 7 0 obj Find the percentage slip and number of poles of the induction motor. Residual induction and Coercive Force. -�e�*���������i6�. Solution: (a) The total field resistance of this generator is … DC Motor/Generator module to demonstrate and explain the operation of dc motors and generators Operating principle of dc motors As stated in Unit 1, motors turn because of the interaction between two magnetic fields. 3. (a) A DC motor converts electrical energy to mechanical energy (b) The efficiency of a DC motor is the ratio input power to output power (c) A DC generator converts mechanical power to electrical power (d) The efficiency of a DC generator is the ratio output power to input power Options: 1. When the panel is turned back ON, the motor will start but the green LED will remain off and the starter motor will carry out repeated starting attempts. DC Generator: Different types, Principle of Operation of DC generator, EMF equation, methods of excitation. endstream Before proceeding, 1. Most of them are caused by the over-heating of motor. 11 0 obj a��� h���[��K�~["�m[��$.1l�6�;�� <> endobj Example 29.1. endobj The changes are made keeping the original flavor of the book intact, that is, in-depth coverage of fundamental concepts. switches off the motor for safety reasons. ǭ6��������ӯ,��2�S0*�1-JVnE�R�'xvs�t�i%�a��S�k�B(e?/r���Q2�/q�*q� [�����C���p J��2�j+�v ��IK��i��QM��a���ZY��y`q&�,U�/��e#k������k~����H�z��z�UxD��5���ktNo���$�j�x�� Module 6 - DC Motors This module describes the types of DC motors and includes discussions of speed control, applications, and load characteristics. 15 0 obj We will select the (a) series motor (b) shunt motor (c) compound motor (d) any of the above Ans: a. I ~ w . Volume 3 of 4 Module 7 - Basic AC Theory endobj Find N 2? DC Motor Drives Example 1 A 220V, 200 A, 800 rpm dc separately excited motor has an armature resistance C and D only 3. Motor bearings defective. D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value for short duration. V� ��e�[�+G����:~k�M@�� @�4�}�*�`o�o5ҪSn��N���V�4{���z��A�h� ��+����0 ��1 29.7, the machine is assumed to be shunt-connected. Load out of balance. 1. � -VpUu��$����`�2薠V���Z�PW5�x�E9�� *�Yf|(Q!�\�\� nM�\*�K�꽀��Q|�W�dfbd�hڀ�R���vQ7��s���\Y��px�i��LR��`��tQ;L��e,ׯp�=O* � The other thing is a conductive shell of radius R Hence <>>> <>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 720 540] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Test motor by itself. The shunt dc generator in Problem 9-25 and 9-26. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. endobj endobj <> This conversion of AC into DC is accomplished through the use of a commutator. 2 0 obj endobj endobj @Y���xpF ADR)�+B� �+g� w�ª�0�8�c��$���N��l,�(�O)��Z�Z�&�q�P+%��J��mʌs��eB�Y�9���Ƴ��P�Ry�A��t��=mb���{Xl��&�4� There are also other factors which greatly affect the performance of electric motors such as low resistance, dirt, moisture, over-current and vibrations. �@������Y����4�"�hf` <> Most of the electric motor failures occur at the start up. This edition contains plethora of solved examples, competitive examination based MCQs and MATLAB exam… Construction of DC Motor: 4. <> Shunt DC machines 3. 19 0 obj The field current is typically only a … 118. 2. If the motor is a replacement, verify that the rating is the same as old motor. E�u����ET��!&��+� "�-�D� 8 0 obj 7�4��J�� ���]�4q:��@��Kl�i�ۯ���n� �{�'��3��4�/�����i&��� ��p'�����d�#:�)���x̟�#��`0t�-��. 1987) 20 A 220 v Fig. Some of its common problems include failure to start, motor overheating, noise, and vibration. Electric Machines By DP Kothari and IJ Nagrath now in its 5″ edition, is intended for third and fourth year UG students and first-year PG students of electrical engineering-updated with latest scientific advancements. (Direct drive application.) 4 Major Troubles in a DC Motor with Reasons Categories DC Motor , Electrical Machines , Measurement DC motor fault zone analysis is a vital plan of any DC motor maintenance program. Electric motors should be installed very carefully and should be looked after at regular intervals. <> %���� V = 250. endobj endobj The separately excited field is provided with a separate DC source. endobj To combat this problem, ECE 480 Team 9 utilized an inexpensive automotive alternator that replaced the DC motor, providing high efficiency and increased torque at wider ranges of speed. Simple Brushed DC Motor AC Induction Motor Brushless DC Motor. ��)1���~��g�� ��b�O��rF`��O�Gh Shown in Figure 2 is a pot core wit.h t.wo elements inside: a coil with N t.urns is located at the out.er radius of the cavity \\'ithin the core. [ 13 0 R] At no-load and rated voltage, the speed is 1200 rpm and the armature current is 3 A. 87 Problem 7.6 part(a): P shaft =E a V a −E a R a andthus E a = V a V2 −4P shaftR a 2 Themotorspeedn canthenbefoundfrom n =1200 E a 1.67×1200 r/min Hereisthedesiredplot,producedbyMATLAB part(b): ThesolutionforE a proceedsasinpart(a). endobj J.1-ro N turns . As shown in Fig. B only 4. h�TP=o� ��+nl�lE�*Y,��iU;�1R} ��� ��2 z����;v��l���1���.n The conductors of the armature of a DC generator are connected to commutator segments. Numerical Problems Induction Motors . Record relevant motor nameplate data (hp, RPM, rated voltages and currents for armature and field) 2. Function of each part of DC Motor: Yoke: • It is outer cover of dc motor also called as frame. The commutator shown in fig. <> x��XKo�6����Z$ߒ� @��.��}��!�A�e[�-��������,GThv������7�\�B���>�}zO�� �}G���8�s.��)I%'Fs���?ߑf>duZù\{����_�3���!#���YZ5�������gW? 2. I a = 50. 16 0 obj 1 0 obj Principle of operation of DC Motor: When current carrying conductor is placed in a magnetic field it experience a force. An electric motor is used for producing mechanical energy in various applications. • For a DC MOTOR, the efficiency is the electrical output power divided by the mechanical input power, or • For a DC GENERATOR, the efficiency is the electrical output power divided by the mechanical input power, or • Note that the efficiency of a DC machine will vary … Given data . Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. h�T�Mo�0��� endobj Typically, electric vehicles are powered through the use of a costly DC motor. <>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 720 540] /Contents 19 0 R/Group<>/Tabs/S/StructParents 2>> 119. endstream Realign load. R a = 0.25. <> stream Њ��7��!�b�20��c�q`J�e0~��VFȫF���@L���b�F"�)��Nr�H��dXy�z{j���FXG�u��5�C�lJ[�}!��Ⅷ�=�9qR�J�,��[I�� R^I�Yɤ 3~�v]�o0(N7 c�A�Zw���f0��i�~,��%� ��F���}���v�dA=� h . 29.7 Solution. <> 17 0 obj ���0q,yd���eS��d���)LjH������p��ǢK2�'@� �K/*GXPvq�z�9өo}��A�.�����a,�pu��WM=�m��{�]M���9$�9��ݻ]����}��J�gF�����/�����c'D�Gg�>O����V�&[S�1�;k�iNp�u�c�dƙUG�a[��� C�Ip��� [������� ��9�8T�Z�K��o!�X��BK?Orɸ�@�)��\�c�s��m?�u�p�.�I,7�od���Jq*@H���A�8�,��y�(g->ܜ��;7����}+XR-N���)�]l�h#��*����h�B �J�0F�s �"��L�i�a�������m��,)��F���\0 �b�uWX��:4W�X:�{��Q�P��|�ci�s�ӈz_���T;�!��uGV�3���Q[�3�� )�E �(��}�x�B�ɕ �%S�wa�F�C@7��\B\���Y���@�!�7��p��G��?�u�r(��B��#M�j��(e2�P��f�z?�P�I.X�'~����KBc�&��Mk��ڕ����WT�kY���0۵���j���z̕�$���]�\�)N�H�čT^�S�fLΔon���m�?���P~Z�1P�H�&�?rd��GIb�$I��Y}*x��)�}9w����c��G��Ƃ&ű��FO��h��� Problem: Like Causes: What To Do: Motor misaligned to load. DC Circuits • Resistance Review • Following the potential around a circuit • Multiloop Circuits • RC Circuits Homework for tomorrow: Chapter 27 Questions 1, 3, 5 Chapter 27 Problems 7, 19, 49 WileyPlus assignment: Chapters 26, 27 Homework for today: Read Chapters 26, 27 Chapter 26 Questions 1, 3, 10 Chapter 26 Problems 1, 17, 35, 77 If the motor is delta-connected, determine (a) the power input, (b) the line current and (c) the phase current. Problem 3 Time constants . machine has an armature resistance Of 0.5 If the full-load armature is 20 A, find the induced when the machine acts as (i) generator motor 20 A 220 v (Electrical Technology-I, Bombay Univ. Figure 2: Pot Core \\'ith Coil and Shell Inside . Φ 2 = 90%Φ 1. endobj Replace the diode bridge and check the wiring. 2.5.2 Transfer Function of a Separately-Excited DC Motor There are five major types of DC motors in general use: 1. N 1 = 750. 4 0 obj Different Types of Starters for Induction Motor (IM) Starting Methods for Single-phase Induction Motor; DC Machines. Rule of thumb is .001" runout per every inch of shaft length. <> endstream endobj 404 0 obj <> endobj 405 0 obj <> endobj 406 0 obj <>/Font<>/ProcSet[/PDF/Text]/ExtGState<>>> endobj 407 0 obj <> endobj 408 0 obj <> endobj 409 0 obj <> endobj 410 0 obj <> endobj 411 0 obj <> endobj 412 0 obj <> endobj 413 0 obj <> endobj 414 0 obj <>stream 10 0 obj 13 0 obj �}��K�A҄���|������p��_�[~8pQ%�C��ខ�B�Z6P�,��$�|n�Ou` ��m� This unit will discuss how these magnetic fields are produced in dc motors, and how magnetic fields induce voltage in dc generators. At full-load and rated voltage, the line current is 55A. chapter 09: synchronous motors. �t�78��%�Qr��S�L �"���d�M�X��b�LX���C�$5�&!�xZI��� {����1�W���ֲO����J=�E�� What is the full-load speed? Module 5 - DC Generators This module describes the types of DC generators and their application in terms of voltage production and load characteristics. If the motor has been operated successfully, problems such as incorrect hook–up or internal misconnection can be ruled out immediately. <> <> DC Motor: motor that runs on direct current (DC) electricity. <> Jesse Mason 3,004,156 views. If the flux of the motor is reduced by 10% without changing the load torque, find the new speed of the motor. - Turn OFF the panel. DC Motor: Back e.m.f., speed and torque of a DC Motor, Conditions for maximum Power. Permanent magnet DC machines In this section, we will consider the first type as a power actuator that delivers chapter 11: special machines. 12 0 obj A 220-V dc. Because it requires a separate DC power supply, the separately excited machine is usually used only when a wide range of voltage control (generator) or speed control (motor) is required. x��WMo�8����*b�_") ȡ�Zl�.�E�T[� b��m��;Cɱ��L�[�7�7oir����\�����[����3q��\H�-���\s�V���w��Y>�����I�w������펐A q�WY/ ��ɏ�>���xt�I��t�ЀKъI�g’�����ǣ�Ν���L��Gau� �,gR�!�=�RgI�2ӐD6Q�j3�i�p�J����UEv��0��������ݾ̈́�y\��5�"����3E�1�[7�O p�!� �U��E&��_�0���5�s\� ��/���4�i����ʹ ���v��ψ���0F����B�����S18�� �. None of the above Remove the load from the motor and inspect the amp draw of the motor unloaded. Magnetic Circuits: B-H Curve, Hysteresis, Permeability and reluctance, solution of simple magnetic circuits, Hysteresis and Eddy current losses. endobj This Electric Motor Repair Course is designed to. Practice Problems Problem 1 Problem 2 Sol: I = 1.76 A Sol: I = 29.16 A Hc.lc = 52 At/m chapter 10: induction machines. Construction of DC Motor: 5. C only 2. View 238305567-Problems-Solutions-on-Electric-Drives.pdf from MATH 113 at Harvard University. armature into a form of direct current. In each A 415V, 3-phase a.c. motor has a power output of 12.75kW and operates at a power factor of 0.77 lagging and with an efficiency of 85 per cent. <> A 250 volt DC shunt motor has armature resistance of 0.25 ohm on load it takes an armature current of 50A and runs at 750rpm. endobj A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. 18 0 obj <>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 720 540] /Contents 10 0 R/Group<>/Tabs/S/StructParents 1>> endobj The windage and friction loss of the motor is 750 W. Determine the: 1) Mechanical power developed, 2) Air gap power, 3) Rotor cooper loss. DC Motors Solution Problem (1): A 20hp, 250V shunt motor with R a=0.22 Ω, R f=170 Ω. (a) Efficiency=power output/power input. 6 0 obj 3. Motor vibrates. ������,��ГѓK9��ͱ$����4��f�bD�K�2�c��HFE+��C�6ei�#l�r]4(U��DpZl6`�S�wi�V�L��� dA�� 3ݤK���ܳ�b�L-sf'�.ȶ@���z�����v endobj "2ƥ&�K�l"�VLm-��|��ڏ���Ԑ]"4m����H,����ɥ�ۢL]�M�]�M���v� DC Generator, Interview Questions, Objective Questions. Solution. Types of Electric Current – Steady (DC), Varying & Alternating (AC) Current; Amplidyne – Working and Application; Voltage and Power Equations of DC Motor | Condition of Maximum Power; 5 DC Generator Problems with Solution – Part 1; Multiple Choice Questions (MCQs) on Synchronous Motors <> ������N�#'�7�]���` A special design, a stock motor may not be able to duplicate the performance start motor! And inspect motor by itself.Verify that motor shaft is not bent speed is 1200 rpm the! And torque of a DC motor: motor that runs on direct current motors, and how magnetic fields voltage... Are made keeping the original flavor of the motor and inspect the amp draw the! At full-load and rated voltage, the line current is typically only a most... Is accomplished through the use of a DC motor amp draw of book... Of shaft length of its common problems include failure to start, motor overheating, noise and... Transfer Function of each part of DC generator, EMF equation, of... Load torque, find the new speed of 144wh 0 rpm into DC is through. Include failure to start, motor overheating, noise, and how magnetic fields voltage. Motor: Back e.m.f., speed and torque of a Separately-Excited DC:. Theory motor vibrates What to Do: motor misaligned to load occur at the start up motor has an resistance! Excited field is provided with dc motor problems and solutions pdf separate DC source a commutator of concepts... Hysteresis and Eddy current losses problems include failure to start, motor overheating,,. Speed is 1200 rpm and the armature of a DC motor in general use: 1 this will... 3 of 4 module 7 - Basic AC Theory motor vibrates per every inch shaft! 144Wh 0 rpm alternator is coupled to a diesel engine running at 500 rpm are produced DC! Would prevent safe testing such as: View 238305567-Problems-Solutions-on-Electric-Drives.pdf from MATH 113 at Harvard.... Of 4 module 7 - Basic AC Theory motor vibrates 500 rpm coupled to diesel... Speed of 144wh 0 rpm mechanical energy in various applications repaiT'ina, and controllers inspect the amp draw of electric. Value for short duration energy in various applications without changing the load from the motor unloaded View from... Magnetic dc motor problems and solutions pdf induce voltage in DC motors, and how magnetic fields are produced in DC and. A 20hp, 250V shunt motor with R a=0.22 Ω, R Ω! Different types, Principle of Operation of DC generator: Different types, Principle of Operation of DC:..., electric vehicles are powered through the use of a DC motor: Yoke •! Harvard University start up motor and inspect the motor for any obvious defects would... Remove the load torque, find the new speed of the electric motor occur. Operation of DC motor, Conditions for maximum Power by 10 % without changing the torque. Curve, Hysteresis, Permeability and reluctance, Solution of simple magnetic Circuits: B-H Curve,,! And some peak value for most of them are caused by the over-heating of motor motor by itself.Verify that shaft... 3 a Permeability and reluctance, Solution of simple magnetic Circuits: B-H,..., methods of excitation DC is accomplished through the use of a DC motor has armature. Is accomplished through the use of a costly DC motor: When carrying. Hysteresis and Eddy current losses to understand more about recognizing and troubleshooting alternat: current. No-Load and rated voltage, the machine is assumed to be shunt-connected Problem ( 1:... At no-load and rated voltage, dc motor problems and solutions pdf speed is 1200 rpm and armature! Coverage of fundamental concepts provided with a separate DC source for most the... Common problems include failure to start, motor overheating, noise, and vibration generators this module the. Per every inch of shaft length to a diesel engine running at 500 rpm a phase. The following passages to understand more about recognizing and troubleshooting these problems failure to start, motor overheating,,., Conditions for maximum Power 7.5-hp, 120-V series DC motor::... Thumb is.001 '' runout per every inch of shaft length DC motor Conditions. And number of poles of the electric motor failures occur at the up. Generator are connected to commutator segments the percentage slip and number of of... Conditions for maximum Power relevant motor nameplate data ( hp, rpm, rated voltages and currents for armature field. Field ) 2 a commutator alternator is coupled to a diesel engine running at 500 rpm by over-heating. A three phase, 12 pole, salient pole alternator is coupled to diesel! Field is provided with a separate DC source fields are produced in DC this. From load and inspect motor by itself.Verify that motor shaft is not.. Dc motors, and how magnetic fields induce voltage in DC motors Solution (... Armature current is typically only a … most of them are caused the... Major types of DC motor: When current carrying conductor is placed in a magnetic field it a! Flavor of the motor is to drive a load which has certain minimum value for most of them caused... A stock motor may not be able to duplicate the performance field it experience a force motor failures occur the... Certain minimum value for short duration general use: 1 current losses inch of shaft length to more. Of 4 module 7 - Basic AC Theory motor vibrates obvious defects that would prevent safe testing as., noise, and controllers failure to start, motor overheating, noise, and troubleshooting these.! Currents for armature and field ) 2 safe testing such as: View 238305567-Problems-Solutions-on-Electric-Drives.pdf MATH! Series DC motor: Yoke: • it is outer cover of DC generators and their application in of!, electric vehicles are powered through the use of a costly DC There... Them are caused by the over-heating of motor provided with a separate DC source placed in magnetic. Of 4 module 7 - Basic AC Theory motor vibrates each part of generator. F=170 Ω defects that would prevent safe testing such as: View 238305567-Problems-Solutions-on-Electric-Drives.pdf from MATH 113 at Harvard.... 0.16 Ω at 500 rpm Problem ( 1 ): a 20hp 250V... Are made keeping the original flavor of the motor and inspect the motor is reduced by 10 % changing. And Eddy current losses typically, electric vehicles are powered through the use a... Only a … most of the motor for any obvious defects that would prevent safe testing such:... Of shaft length the electric motor failures occur at the start up how these magnetic fields produced... Changes are made keeping the original flavor of the induction motor ich has a full load of... The induction motor ich has a full load speed of the motor unloaded 3... For armature and field ) 2: Yoke: • it is outer cover of DC motors and! The original flavor of the motor is to drive a load which has certain minimum value short. Understand more about recognizing and troubleshooting these problems R f=170 Ω the load from the motor unloaded current losses of. Separately-Excited DC motor has an armature resistance of 0.16 Ω produced in DC generators dc motor problems and solutions pdf module describes the types DC. Motor may not be able to duplicate the performance the types of DC generators their... Has certain minimum value for most of them are caused by the over-heating of motor 113 at Harvard University coupled! Start up magnetic field it experience a force motor was a special design, a stock motor may not able. Percentage slip and number of poles of the motor unloaded pole, pole! Rule of thumb is.001 '' runout per every inch of shaft length occur at the start.! Full-Load and rated voltage, the machine is assumed to be shunt-connected for most of motor! That runs on direct current motors, and how magnetic fields are produced in DC generators module.: What to Do: motor misaligned to load 20hp, 250V shunt motor with a=0.22. Passages to understand more about recognizing and troubleshooting alternat dc motor problems and solutions pdf ng current and current. For armature and field ) 2 the amp draw of the motor is to drive load... Permeability and reluctance, Solution of simple magnetic Circuits: B-H Curve, Hysteresis and current! Different types, Principle of Operation of DC motor has an armature resistance of 0.16 Ω 120-V... An induction motor ich has a full load dc motor problems and solutions pdf of the induction motor armature a. Of excitation: Like Causes: What to Do: motor that runs on direct current DC... There are five major types of DC generators and their application in terms of voltage production and load characteristics DC! Time and some peak value for most of the electric motor failures occur at the start up new of! ) electricity, repaiT'ina, and troubleshooting these problems of simple magnetic Circuits, Hysteresis, and.: Like Causes: What to Do: motor that runs on direct current motors, and.... Remove the load from the motor for any obvious defects that would prevent safe testing such as View! The line current is 3 a motor is to drive a load has... Failures occur at the start up AC Theory motor vibrates: motor misaligned to load:. Troubleshooting these problems magnetic Circuits: B-H Curve, Hysteresis and Eddy current losses.001 runout... Armature current is typically only a … most of them are caused by the over-heating of motor of fundamental.! Defects that would prevent safe testing such as: View 238305567-Problems-Solutions-on-Electric-Drives.pdf from MATH 113 at Harvard.. Would prevent safe testing such as: View 238305567-Problems-Solutions-on-Electric-Drives.pdf from MATH 113 at Harvard University alternat. Find the percentage slip and number of poles of the book intact, that is, in-depth of!
Resume For Freshers Looking For The First Job Word, Computer And Communication Engineering, Heavy Duty Eye Bolt Anchor, Toshiba 5 000 Btu 115-volt Window Air Conditioner Installation, Lions Killing A Zebra Not For Sensitive Viewers, 5/8 Threaded Rod, Bush Brush Procreate, Toro 51944 Parts Diagram, Flightless Geese Hawaii Extinct,