Electrical Technology, Vol2: Machines and Measurements, 1/e

51

Watt Meters and Energy Meters

OBJECTIVES

In this chapter you will learn about:

• The difference between ampere meters, watt meters, ampere-hour meters and watt-hour meters
• Electrodynamic (dynamometer) and induction-type watt meters
• The construction and principle of operation of watt meters
• Energy meters—both commutator type and mercury type
• The essential parts of induction watt-hour meters
• The significance of the different parts
• Production of fluxes and driving torque
• Reading watt-hour meter
• Poly-phase induction watt-hour meters
• Errors in energy meters
• Different methods of measuring power in three-phase circuits
• Simple problems on the above

Watthour meter

51.1  INTRODUCTION

The measurement of electricity distributed for commercial purposes ...