'Chapter 9 Review Questions\r'

'Fred Bear MAIR 1449. 02 3-24-11 R. Q. Unit 9 (E. B. ) 1. What is attractivenessics? When two pieces of iron ar attracted to to each unrivaled other(a) by physical means or galvanic means. 2. Torque is A. Strength that a labour take ons by turning. 3. A magnetized demesne is D. All the above. 4. veritable or False: A permanent magnet is a piece of material that has been magnetized and tidy sum hold its magnetic strength for a well-founded length of time. original. 5. How is an electromagnet produced? Through electricity. 6. Which of the adjacent produces the best electromagnet? B. cushioned iron 7.Unlike gats of a magnet repel each other and like poles attract each other. 8. What transfer does polarity play in the ope military rank theater of an electric force back? It allows the repulse to run continuously. 9. What part of a ram produces an inductive magnetic field deep down itself to facilitate the rotating motion? Rotor and stator. 10. What part does th e frequency of alternating current play in the operation of an electric ram? Helps change polarity great hundred times a second. 11. What would be the stronghold of a two-pole ride operating on a great hundred vanadiums 60 Hertz power total? 3450rpm 12. What are the five types of single- variety labours apply in the industry? 3. Which of the undermentioned correctly lists the motor’s outset tortuosity from lowest to highest? B. Shaded pole, three phase, permanent split electrical condenser, optical condenser start. 14. Which of the following(a) is a common use of a shaded pole motor? A. Furnace fan motor. 15. How does a shaded pole motor operate? The shaded poles produce a magnetic field that is out of phase with the magnetic field of the main tip. 16. How can a shaded pole motor be reversed? The stator essential be reversed to change the positions of the shaded poles, and this usually means disassembling the motor. 17.What determines the revolution of a shaded pole motor? B. Location of shaded pole. 18. fuck off a diagram of a three speed, shaded pole motor. 19. What enables a split phase motor to go against enough torque to begin rotation? The order of splitting the phase of incoming power to produce a second phase of power, giving the motor enough displacement to start. 20. What removes the showtime winding from the electrical circuit of an undefendable type split phase motor once it reaches 75% of its operating speed? Centrifugal switch. 21. What are the three probable areas of bother in a split phase motor?The bearings, windings, and the centrifugal switch. 22. What is the unit of measurement for the strength of a electrical capacity? C. microfarad. 23. What is the map of the capacitor? To boost the starting torque or running efficiency of a single phase motor. 24. What is the difference between a running and a starting capacitor? get-go capacitors are usually made of plastic and used to assist a single phase motor in sta rting. A running capacitor has an crude oil filled case and is mainly used to amplification a motor’s running efficiency. 25. angle of dip the five capacitor renewal rules. 1.The pentadage of whatever capacitor used for replacement must be equal or greater than that of the one macrocosm replaced. 2. The strength of the starting capacitor replacement must be at least equal to only when not more than 20% greater than the one macrocosm replaced. 3. The strength of the running capacitor replacement may vary by plus or minus 10% of the strength of the one being replaced. 4. If capacitors are installed in parallel, the sum of the capacitors is the kernel condenser. 5. The total capacitance of capacitors in series may be found in the following formula: 26. relieve the operation of a permanent split capacitor motor.It has two windings, running and starting. A running capacitor is put in series with the starting winding. The capacitor causes the electron to flow through th e starting winding to shift it out of phase with the running winding. Therefore, a rotating magnetic field is set up, ca victimisation the rotor coil to turn. 27. How are a PSC motor and a capacitor start capacitor run motor resembling? C. Both use starting relays. 28. What are the advantages and disadvantages of victimisation the following types of motors? A. Shaded pole motor- 29. What are the similarities between an open type split phase motor and a capacitor start motor?C. Both have a centrifugal switch. 30. Which of the following is an advantage in using a three phase motor? B. Stronger. 31. Draw a wiring diagram of a capacitor start capacitor run motor: 32. True or false: All starting apparatuses are mounted externally to the hermetic compressor shell. True. 33. What is the purpose in troubleshooting any electric motor? 34. Which of the following is the capacitance of an 88 uf and a 108 uf starting capacitor connected in series? A. 196uf. 35. Which of the following is the ca pacitance of two 20 uf running capacitors connected in parallel? B. 20uf. 36.If a capacitor produces 15 A on a 240 volt supply, which of the following is its microfarad rating? A. 166 uf. 37. Which of the following capacitors could be used to replace a 35 uf, 370 volt running capacitor? B. 35uf, 390 volt. 38. Which of the following capacitors could be used to replace a 188 uf, 250 volt starting capacitor? C. 200uf, 250 volts. 39. Which of the following capacitors or conspiracy of capacitors could be used to replace a 45 uf 370 volt running capacitor? A. 40uf, 440 volt. 40. Which of the following capacitors or combination of capacitors could be used to replace an 88uf 250 volt starting capacitor?D. 150uf, 250V. 41. Find the common, start, and run terminals of the following hermetic compressor. 42. Briefly explain the procedure for troubleshooting hermetic compressor motors. Electrically taking ohmic resistance readings of the windings with a practised ohmmeter. 43. What are the el ectrical failures categories for hermetic compressor motors? Open, shorted, or grounded. 44. What precautions should be taken when checking hermetic compressor motors? Infinity. 45. What would be the highest allowable resistance reading for a grounded compressor motor? Zero. 46.What are the advantages of using an electronically commutated motor over a PSC motor? 47. Explain the construction of an ECM. The civilise current transformers convert the alternating current that the power company supplies to direct current, which can then be regulated to vary the speed of the motor. 48. An ECM is a B. Three-phase DC motor. 49. True or False: The resistance readings of the windings of a justly operating ECM should be equal. False. 50. True or False: The line voltage power supply of an ECM should never be disconnected or connected with the power on. True.\r\n'