Electrical Power Systems Technology

Power Measurement Equipment 67

numerical readout of the kilowatt-hours used. Study Figure 3-7 to learn to

read a watt-hour meter.

The watt-hour meter is connected between the incoming power lines

and the branch circuits of an electrical power system. In this way, all

Figure 3-5. Measuring electrical power: (A) Basic dynamometer movement,

showing potential coil and current coil connections; (B) Wattmeter movement

using dynamometer movement, showing source and load connections; (C) Ther-

mal pens for a chart recorder (Courtesy Esterline Angus); (D) Programmable

thermal array recorder (Courtesy Soltec Corp.)