Source: NFPA 70, National Electrical Code, Table 430.250 ; Induction-Type Squirrel Cage and Wound Rotor (Amperes) Synchronous-Type Unity Power Factor (Amperes) HP 115 Volts 200 Volts … Capacitor manufacturers recommend no more than 20, three-second starts per hour. Use this table as a guide only. In today’s tutorial, we are gonna have a look at Introduction to Three Phase Induction Motor. 0 Unbalanced voltage (three phase only) Check the voltage at all phases. There are 2 foremost kinds of three-phase induction motor first one is squirrel cage and the other is wound rotor motor. It should be approximately the same. �m�`��-�`�"�����=������M�ˈ��}��c- One single-phase wattmeter plus miscellaneous apparatus as needed . A three-phase motor must be wired based on the diagram on the faceplate. Full-Load Amps: Three-Phase Alternating-Current Motors. 323 0 obj<> endobj Before troubleshooting the 3 phase induction motor, we must have to know about the 3 phase induction motor, star delta starter and it’s connection diagram. due to inadequate foundations. Therefore, motor troubleshooting involves the entire system, not just the motor. Single phasing (three phase only) Check the current at all phases. Please explain to me if I must really put a contactor on my 3 phase motor. 1 Motor Ohm Values Chart. 0000002918 00000 n 3 PHASE INDUCTION MOTOR FAULT LIST AND SOLUTION Problems: Like Causes: What To Do: 1) Motors Fails To Start/Accelerate 1) Connection Of Motor Is Not Proper. 0000002134 00000 n (b) A massive concrete foundation is preferred in order to minimize vibration. These motors have fewer parts and are more sturdily built than their single-phase counterparts. Hello friends, I hope all of you are doing great. 2)Loose connection at starter. Three-phase motors are normally used in commercial-type operations. One 208 Volt, 0.75 HP, 3-phase induction motor . 78681 2) Supply Voltage Is Low (Less Than 415 Volt In Any Of 3 Phases). These motors run conveyor belts, pumps, fans, and many other applications. H��W˒[7���m�����2�k�J��X�Y��Ш�n���H���� ��m�7�rR�A� px@F}^�|�Ѩ��V�X�����v��¨�C4V]ӗ�f\�ou��6a�����r��QF-o�+��0�:�����r�x����\���y�Ѓv.�e�fSV˯��������Qm��j��ܨ��F�W�����=����z�۬/�����b�6�U����DGN�����y�~xw7���xP���x:+:fu��������.w�|����S�qX�7�;�SX�=|>c�n�N�p:>�g���=m6��xB��G��Y�΃x"G�!/,ޟk6���~uy8a�j��'¹�l�vM�m��.�%����:?�/�}��B�qQ7��_�k�Z�����Y������%��^-�6� hؼ`���������q�R%��˷�5c�P +-������z�.�S��kY�n���a�"D7���T����:/����R��>~(��˷^�b%��8=���+C�����p��+���~�/�R��K�����=ɡ�X���>����o>��Ç��_ߩw�����Y.~k��h?���y�Ե-��ޤ�e�>᝺!$z�����?^��o,Ȭl8��*'���5����Q��[Kj�x�Q���WX��|��|UF�_ԧ?����k����i���?�ڌ���W)��d�"�Ƕ��ix�̽k�����̹!Y7B��d�1MD)l��d|4ߌ��C�a�����B[��5X��h;%Jq�hM�j�nA�}U}ʈf�2>8�8(���Q9N�O�b?�6nF&�)�R攭 ��M��[�Zm�D9��^P��\S�KI�^�~�xع�� 5D�N�t&f&��� C�vZ�cr�d����C��vC�T6G����E�VH���,�z�d�t}d�A��� x�i��1'>3 ��R����F�mmX�sFՂ�l�j܏�c�!Χ�-n���O��{�Ä:L�� 2 0 obj << /Length 15061 /Filter /FlateDecode >> stream 0000005588 00000 n (Telecommunication Engineering), Southwest Jiaotong University, China, 2005 0000001864 00000 n 0000001288 00000 n For three-phase motors, a three-phase current sets up a rotating magnetic field that produces the starting torque without Contents. Improper ventilation. Caution: The actual motor amps may be higher or lower than the average values listed above. Squirrel cage and induction-type refer to the construction and operation of the rotor. ; 2 it’s a very easy way here to Know The Motor Ohm Values Chart & set up the coil size of the motor. startxref <<5cae4ba88f1cd74fa14ae8cbb3e34afd>]>> You should also make a DC measurement of stator winding line-to-line resistance using a DMM. Kx�����εa���[A7v숾���ȕ�t�hҏ$�Ն�4��N��F���>�UY�j�������Z8�׫ˊ}d���08�t�|N���$5o���7�ڕP������^�bƫ�7�ܡ�����0���4 ;T��zQ�^ ���w{E��狼ގ��WEoՏ5����� A three-phase induction motor is a type of machine which mostly used in industries. No responsible discussion of electrical equipment maintenance would be complete without first covering the need to maintain a safe working environment. Here we have classified these faults in three types, but these are further sub divided. a) Please correct voltage balance in all 3 phases and connected load. %PDF-1.4 %���� polyphase AC induction motors operated within the nameplate ratings will run trouble-free for many years. In this post, we have shown how to set up the coil size of a 1 hp 3 phase motor. Troubles with the induction motors are generally divided into two categories. The other is the mechanical problems, such as the problems of the bearing, fan blade, motor frame, coupling, end bell, bearing cover, spindle and so on. If the motor is delta-connected, determine (a) the power input, (b) the line current and (c) the phase current. The squirrel cage brand is the most popular and they perform various tasks wherever they are applied. Three phase induction motors are one of the most popular electric motors commonly found in processing plants or any manufacturing concern. Such high currents may pose serious problems for the motor and the electrical system when large motors are started. %PDF-1.2 %���� 6. Verify duty cycle. 325 0 obj<>stream In the United States, for low voltage motors (below 600v), you can expect either 230v or 460v. Otherwise the capacitors may fail. In this tutorial, we will show the Star-Delta (Y-Δ) 3-phase induction AC Motor Starting Method by Automatic star-delta starter with Timer with schematic, power, control and wiring diagram as well as how star-delta starter works and their applications with advantages and disadvantages. c)Check all 3 … If the motor starter leads are clear, move on to the motor. Initial Data . 4. • The basic idea of an electric motor is to generate two magnetic fields: rotor magnetic field and stator magnetic field and make the stator field rotating. The voltages listed below are standard rated motor voltages. 0000001155 00000 n (Telecommunication Engineering), Southwest Jiaotong University, China, 2005 Diagnostics of Rotor and Stator Problems in Industrial Induction Motors by Fang Duan B.E. That being said, there is a wide range of different motors and what you have on hand can be completely different. dezembro 11, 2020 . One Phase Sequence Indicator . A three phase induction motor is basically a constant speed motor so it’s somewhat difficult to control its speed. Be sure to take all necessary precautions to protect yourself or your employees from harm. Vibration testing of motor after it … 0000002211 00000 n due to inadequate foundations. a) Reduce load / overload protection to be given. larger motors. 2) Maintain Proper Supply Voltage By Using Autotransformer Or Transformer Tap Changer. 0000001900 00000 n x�b```f``�a�```]� �� ,�@���������@q ��C(&F /�������A�;�QQC*[e�B�Ls3K ��9���� �/��3E�^�c�f�P�|�%�E:M�轫O0���3nt�|9��̎��/:����4i��T��+a�yr���`�ʓ[�&=��EjR���W��l�e[��-��-��f�ŧ��k��� 6�խ�e���4(b��� ��`�`mA��6;V>W��W2�B�g�/��+_�� �y�*p��H@ �AQ���5�%;�/``h` �/�yG�����$�ظ�� a�4�,kH1����A��`=0~�$�� +��B� � �pA(��50��e4P#���B���?h('K��� 2)Check the unbalance voltage and inform to Electricity Board people. H��U�nA��W�)�Rh�{z=��$� Insulation – resistance tests on insulated bearings. A three phase induction motor is a type of AC induction motors which operates on three phase supply as compared to the single phase induction motor where single phase supply is needed to operate it. 0000000016 00000 n Rigidity and b)1) Check loose connection. Generally, two types of induction motors are used in our industry such as wound rotor and squirrel cage rotor, but their faults are almost same. Starting & Running current are the three important factors for the rating of AC induction motor. Any value greater 0.5 ohms indicate trouble with the motor. As a result these motors are less prone to malfunctions and tend to operate for many years. Every good electrician knows the lead numbering sequence of three phase motors, or he has diagrams available for ready reference. �"��:�>��ԞpA�i$� c ������&U�F[�t׆Wh�*vt_6q� �I$z�K)-����M5��I%^Ge-O&���FI+ƹ%շT�w��r}�#=4UՃ�P��ւ�[Lp���~�7FTkg��L@�����G0����ʤ�Me���U�{��=퓡�iQ�w,L;%6].~9X�'�SУ$&�+��8��qu������8�1��7<07 "3n�����X�� ;����~. 3.2.3 The foundation of vertical induction motors: (Also the foundation of pump) (a) Foundation of motor/pump must be rigid and secure to provide adequate support. Phase to phase stator resistance tests. 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