INE 4080 - Generators Rotating Machines

1. State the function of a direct current (DC) generator.
2. List the major components of a generator.
3. Describe the difference between a separately excited and a self-excited generator.
4. Explain how the output voltage of a generator can be varied.
5. Explain the relationship of field current, field flux, and output voltage for a separately excited DC generator.
6. Describe the effects on the brush polarity of reversing the armature rotation and the field current.
7. Define residual flux and residual voltage.
8. Draw and explain the basic circuit.
9. Connect the generator.
10. Identify a self-excited shunt generator from a circuit diagram.
11. Describe how voltage buildup occurs for this type of generator.
12. List the causes for a failure of the voltage to build up.
13. Describe three methods that can be used to renew residual magnetism.
14. Define voltage control and voltage regulation.
15. Connect the generator.
16. State the difference between a shunt generator and a compound-wound generator.
17. Define what is meant by a cumulative compound-wound generator and a deferential compound-wound generator.
18. Describe how the voltage regulation of a generator is improved by compound windings.
19. List changes in output voltage at full load due to the effects of over compounding, flat compounding under compounding, and differential compounding.
20. Draw the basic generator circuit.
21. Connect the generator.
22. To provide the student with an opportunity to evaluate the information and understanding acquired in the study of the previous four units.
23. Explain how AC voltage is generated.
24. State the differences between a stationary armature and a stationary field generator.
25. Determine how to control the amount of output voltage.
26. Calculate the output frequency of an AC generator.
27. Explain what is meant by a single-phase sinewave.
28. Define what is meant by polyphase systems.
29. State the advantages in the generation and transmission of three-phase power.
30. Measure and calculate power in three-phase systems.
31. Calculate the power factor in three-phase systems.
32. Diagram the proper connections for a wye-connected generator and transformer.
33. State the application of the wye-connected generators and transformers in three-phase distribution systems.
34. Calculate the voltage and current values in various parts of the wye-connection circuit.
35. Diagram the proper way to make a delta connection.
36. State the applications of a delta-connected circuit in three-phase distribution systems.
37. Calculate the voltage and current values in various parts of the delta-connection circuit.
38. Make a delta connection.
39. To provide the student with an opportunity to evaluate the information and understanding acquired in the study of the previous four units.
40. Describe the purpose of an alternator.
41. Describe the ways in which the field of an alternator is established and how the alternator operates.
42. Explain the operation of the field discharge circuit.
43. State how the frequency of an alternator can be determined and give the formula for calculating the frequency.
44. Explain how voltage control for an alternator is accomplished.
45. Describe the structure and operation of a rotating-field alternator.
46. Diagram alternator connections.
47. Explain three-phrase voltages.
48. Describe the purposes of engine-driven generating sets.
49. List the advantages of using cogenerating sets.
50. Describe the operation of an automatic transfer switch.
51. Connect an automatic transfer switch.
52. State National Electrical Code requirements.
53. State the conditions that require two alternators to be paralleled.
54. Describe the use of synchronizing lamps in the three dark method and the two bright, one dark method of synchronizing alternators.
55. Demonstrate the procedure for paralleling two 3-phase alternators.
56. State the effect of changes in field excitation and speed on the division of load between paralleled alternators.
57. Describe “reverse power.”
58. Describe the connections for and the resulting operation of the direct-current field excitation circuit alternator.
59. Describe the connections for and the resulting operation of the instrument circuits for an alternator.
60. Describe various types of alternative local power sources.
61. Determine the type of power generation to best fit a particular need.
62. List the advantages and disadvantages of different systems.
63. Describe the connection method needed to connect power systems to a load.
64. List the NEC articles that pertain to special equipment.
65. Describe a separately derived system.
66. To provide the student with an opportunity to evaluate the information and understanding acquired in the study of the previous five units.
67. Explain how and why transformers are used for the transmission and distribution of electrical energy.
68. Describe the basic construction of a transformer.
69. Distinguish between the primary and secondary windings of a transformer.
70. List, in order of sequence the various steps in the operation of a step-up transformer.
71. Make use of appropriate information to calculate the voltage ratio, voltages, currents, and efficiency for step-up and step-down transformers.
72. Explain how the primary load changes with the secondary load.
73. Describe a single-phase, double-wound transformer, including its primary applications.
74. Diagram the series and parallel methods of a coil connection for a double-wound transformer and for primary and secondary dual-voltage connections.
75. Define additive polarity and diagram the connection and markings for this polarity.
76. List the steps in the AC polarity test for a single-phase transformer.
77. Demonstrate good electrical safety practices.
78. Describe an autotransformer, including its primary applications.
79. Identify primary taps.
80. Diagram the connections for a single-phase, three-wire secondary system.
81. List the advantages of a three wire service.
82. Describe what occurs when the neutral of a three-wire secondary system opens.
83. Explain why there is less copper loss for a three-wire system.
84. Explain, with the aid of diagrams, how single-phase transformers are connected in a three-phase, closed delta-delta arrangement.
85. Describe the relationships between the voltages across each coil and across the three-phase lines for both the input (primary) and output (secondary) of a delta-delta transformer bank.
86. List the steps in the procedure for checking the proper connection of the secondary coils in the closed-delta arrangement, including typical voltage readings.
87. Describe how delta-delta connected transformer bank can provide both a 240-volt, three-phase load and a 120/240-volt, single-phase, three-wire load.
88. Describe, using diagrams, the open-delta connection and its use.
89. Identify primary taps for the three-phase connection.
90. Diagram the simple wye connection of three transformers.
91. List the steps in the procedure for the proper connection and checking of the primary and secondary windings of three single-phase transformers connected in a wye arrangement.
92. State the voltage and current relationships for wye-connected, single-phase transformers.
93. Describe how the grounded neutral of a three-phase, four-wire, wye-connected transformer bank maintains a balanced voltage across the windings.
94. State how the kVA capacity of a wye-wye connected transformer bank is obtained.
95. Diagram the connection of three single-phase transformer coils to form a delta-wye transformer bank.
96. Describe how a delta-wye transformer bank is used to step down voltages.
97. Describe how a delta-wye transformer bank is used to step up voltages.
98. Diagram the connection of three single-phase transformers to form a wye-delta transformer bank.
99. Diagram the connections of two single-phase transformers connected open wye-open delta.
100. Describe how a wye-delta transformer bank is used to step down voltages.
101. List advantages and disadvantages of a three-phase transformer as compared to three single-phase transformers.
102. Explain the operation of an instrument potential transformer.
103. Explain the operation of an instrument current transformer.
104. Diagram the connections for a potential transformer and a current transformer in a single-phase circuit.
105. State how the following quantities are determined for a single-phase circuit containing instrument transformers: primary current , primary voltage, primary power, apparent power, and power factor.
106. Describe the connection of instrument transformers in a three-phase, three-wire circuit.
107. Describe the connection of instrument transformers to a three-phase, four-wire system.
108. Identify three-phase transformers.
109. Determine the lead identification of three-phase transformers.
110. Explain the efficiencies involved.
111. Determine the benefits and the detriments of three-phase transformers.
112. Use the National Electric Code (NEC) to determine the requirements and limitations of transformer installations.
113. To provide the student with an opportunity to evaluate the information and understanding acquired in the study of the previous nine units.