Energy-Efficient Electric Motors Vol. 78: Selection and Application Book

	Preface
1	Induction Motor Characteristics	1
1.1	Three-Phase Induction Motors	1
1.2	Single-Phase Induction Motors	15
2	Energy-Efficient Motors	33
2.1	Standard Motor Efficiency	33
2.2	Why More Efficient Motors?	36
2.3	What Is Efficiency?	36
2.4	What Is an Energy-Efficient Motor?	45
2.5	Efficiency Determination	52
2.6	Motor Efficiency Labeling	57
2.7	NEMA Energy-Efficient Motor Standards	61
3	Electric Power Costs	65
3.1	Industry Energy Trends	65
3.2	Electric Power Cost Trends	67
3.3	Electric Utility Rates	68
3.4	Summary	76
4	The Power Factor	79
4.1	What Is the Power Factor?	79
4.2	The Power Factor in Sinusoidal Systems	80
4.3	Why Raise the Power Factor?	82
4.4	How to Improve the Power Factor	84
4.5	The Power Factor with Nonlinear Loads	98
4.6	Harmonics and the Power Factor	102
4.7	Power Factor Motor Controllers	110
5	Application of Electric Motors	117
5.1	General Discussion	117
5.2	Varying Duty Applications	125
5.3	Voltage Variation	127
5.4	Voltage Unbalance	128
5.5	Overmotoring	139
5.6	Polyphase Induction Motors Supplied by Adjustable-Frequency Power Supplies	140
6	Induction Motors and Adjustable-Speed Drive Systems	157
6.1	Energy Conservation	157
6.2	Adjustable-Speed Systems	160
6.3	Application of Adjustable-Speed Systems to Fans	221
6.4	Application of Adjustable-Speed Systems to Pumps	230
6.5	Application of Adjustable-Speed Systems to Constant-Torque Loads	237
7	Economics of Energy-Efficient Motors and Systems	241
7.1	General Review	241
7.2	Life Cycle	243
7.3	Direct Savings and Payback Analysis	245
7.4	Efficiency Factor or Efficiency Evaluation Factor	250
7.5	Present Value or Present Worth Method with Constant Power Costs	254
7.6	Present Value or Present Worth Method with Increasing Power Costs	255
7.7	Net Present Worth Method	258
	Selected Readings	263
	Index	269