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Fred Carry MAIR 1449. 02 3-24-11 R. Q.
Unit being unfaithful (E. B. ) 1 . What is magnetism? When two pieces of flat iron are interested in each other simply by physical means or electric means. 2 . Torque is known as a. Strength that the motor makes by turning. 3. A magnetic field is M. All the above. 4. True or perhaps False: A permanent magnet is known as a piece of material that has been magnetized and can keep its magnet strength to get a reasonable period of time. True. your five. How is definitely an electromagnet produced? Through electricity. six. Which from the following produces the best electromagnet? B. very soft iron 7.
Unlike poles of a magnetic repel the other person and like poles catch the attention of each other. almost eight. What part does polarity play in the procedure of an electric powered motor? It allows the motor to operate continuously. being unfaithful. What a part of a electric motor produces an inductive permanent magnet field within itself to facilitate the rotating movement? Rotor and stator. 15. What portion does the regularity of alternating electric current play in the operation of an electric motor? Helps change polarity 120 times a second. eleven. What could be the speed of a two-pole motor operating over a 120 v 60 Hertz power supply? 3450rpm 12. What are the five types of single-phase motor used in the industry? 3. Which from the following correctly lists the motor’s beginning torque by lowest to highest? M. Shaded rod, three phase, permanent break up capacitor, capacitor start. 14. Which of the following is a common use of a shaded post motor? A. Furnace fan motor. 12-15. How does a shaded rod motor operate? The tinted poles produce a magnetic field that is out of period with the permanent magnet field in the main turning. 16. How can a shaded pole motor unit be reversed? The stator must be reversed to change the positions from the shaded poles, and this usually means that disassembling the motor. 18.
What decides the rotation of a shaded pole motor? B. Position of shaded pole. 18. Draw a diagram of your three speed, shaded pole motor. nineteen. What permits a break up phase motor to develop enough torque to begin rotation? The strategy of dividing the period of incoming power to produce a second stage of electrical power, giving the motor enough displacement to get started on. 20. What removes the starting winding from the electrical circuit associated with an open type split period motor when it actually reaches 75% of its operating speed? Centrifugal switch. 21 years old. What are the three probable parts of trouble within a split period motor?
The bearings, windings, and the centrifugal switch. twenty-two. What is the device of dimension for the effectiveness of a capacitor? C. microfarad. 23. Precisely what is the purpose of the capacitor? To increase the starting torque or running productivity of a single phase motor. 24. What is the difference between a working and a starting capacitor? Starting capacitors are usually manufactured from plastic and used to help a single period motor in starting. A running capacitor has an petrol filled circumstance and is mainly used to increase a motor’s operating efficiency. 25. List the five capacitor replacement rules. 1 .
The voltage of any capacitor used for replacement must be equivalent or greater than that of the one being substituted. 2 . The effectiveness of the starting capacitor substitute must be for least corresponding to but not more than 20% more than the one getting replaced. a few. The strength of the running capacitor replacement can vary by as well as or minus 10% in the strength from the one becoming replaced. 5. If capacitors are installed in parallel, the sum in the capacitors is definitely the total capacitance. 5. The total capacitance of capacitors in series may be found in this formula: twenty six. Explain the operation of the permanent divide capacitor motor.
It has two windings, working and starting. A running capacitor is usually put in series with the starting winding. The capacitor triggers the electron to flow through the starting winding to shift it of stage with the operating winding. Consequently , a spinning magnetic field is set up, triggering the disc to turn. twenty seven. How are a PSC motor and a capacitor commence capacitor work motor related? C. Both equally use beginning relays. twenty eight. What are the huge benefits and disadvantages of using the next types of motors? A. Shaded post motor- twenty nine. What are the similarities among an open type split stage motor and a capacitor start engine?
C. Both have a centrifugal switch. 30. Which with the following is definitely an advantage in using a three phase engine? B. More powerful. 31. Attract a wiring diagram of the capacitor start off capacitor manage motor: 32. True or false: All starting apparatuses are installed externally to the hermetic converter shell. Accurate. 33. What is the purpose in troubleshooting virtually any electric motor? 34. Which of the next is the capacitance of an 88 uf and a 108 uf starting capacitor linked in series? A. 196uf. 35. Which usually of the subsequent is the capacitance of two 20 uf running capacitors connected in parallel? N. 20uf. thirty-six.
If a capacitor produces 15 A over a 240 watt supply, which in turn of the pursuing is their microfarad ranking? A. 166 uf. thirty seven. Which with the following capacitors could be accustomed to replace a 35 uf, 370 volt running capacitor? B. 35uf, 390 watt. 38. Which will of the following capacitors could be used to replace a one-hundred and eighty-eight uf, 250 volt beginning capacitor? C. 200uf, two hundred and fifty volts. 39. Which from the following capacitors or combination of capacitors could possibly be used to substitute a 45 uf 370 watt running capacitor? A. 40uf, 440 volt. 40. Which usually of the following capacitors or perhaps combination of capacitors could be accustomed to replace a great 88uf two hundred and fifty volt starting capacitor?
M. 150uf, 250V. 41. Find the common, start, and operate terminals from the following hermetic compressor. 40. Briefly clarify the procedure for troubleshooting hermetic compressor motor. Electrically currently taking resistance readings of the windings with a good ohmmeter. 43. Exactly what the electric failures types for hermetic compressor motors? Open, shorted, or grounded. 44. What precautions should be taken once checking hermetic compressor power generators? Infinity. forty five. What could be the highest permitted resistance studying for a grounded compressor engine? Zero. 46.
What are the huge benefits of applying an in electronic format commutated electric motor over a PSC motor? 47. Explain the construction of an ECM. The household power converters convert the pulsating direct current that the electric company supplies to direct current, which could then become regulated to vary the speed in the motor. forty-eight. An ECM is a W. Three-phase POWER motor. forty-nine. True or perhaps False: The resistance blood pressure measurements of the windings of a properly operating ECM should be equivalent. False. 40. True or False: The queue voltage power of an ECM should never be turned off or linked to the power about. True.
