Stephen L. Herman, Bennie Sparkman. Electricity and Controls for HVAC-R (6th edition)

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590 INDEX

Triac

AC switch, 513

AC voltage control, 513–514,

514f

general features, 512–513,

513f

key term, 251

phase shifting, 514f, 514–515

primary control component,

354

refrigeration control,

457–458, 458f

solid state relay, 249, 249f,

speed control, 271f,

271–272, 272f

testing, 515f, 515–516, 516f

thyristors, 500

Troubleshooting

ammeter, 369–371, 372f

basic questions, 360

commercial air conditioning

unit, 386–387

heat-pump controls, 398–399

hopscotch method, 365, 366f,

367f, 368f

measuring instruments, 361

ohmmeter, 365–369, 369f,

370f, 371f, 372f

packaged units, 411–412

room air conditioners,

381–382

shotgun method, 372–374

voltmeter, 363f, 363–365,

364f, 365f, 366f

True power, 18, 18f, 22

Turns ratio

clamp-on ammeter,

30–31, 31f

isolation transformers,

201, 201f

key term, 34

transformer calculations, 208f,

208–210, 209f, 210f

Two-conductor, 61

Two-conductor romex cable,

56–57

Two-phase power, 119,

119f, 130

Two-pole breaker, 56, 56f, 61

Two-speed compressors,

136, 145

Two-wire control circuits, 90–91,

91f, 105

Ultraviolet radiation (UV), 348

Unijunction transistor (UJT)

characteristics, 497

circuit operation, 497, 498f

construction, 496, 497f

general features, 496

key term, 500

testing, 498, 498f, 499f

Unity, 76, 77

Valence electrons

electron shell, 9, 10f

insulators, 12

key term, 14

Valence shell, 9, 14

Variable frequency, 145

Variable frequency drives

adjustment role, 143–144

induction motors, 138f,

138–141, 139f, 140f, 141f

SCRs/GTOs, 141–143, 142f,

143f, 144f

Variable resistor, 271, 271f, 273

Variable speed, 196

Variable speed air handlers, 194

Variable-speed motors

impedance, 272

key term, 273

use of, 270

voltage control, 271f,

271–272, 272f

VARs (Volt-Amps Reactive), 76, 77

Vector addition, 52, 52f

Volt-amps, 76, 76f, 77

Volt-Amps Reactive circuit. See

VARs (Volt-Amps Reactive)

Volt-omh-milliammeter (VOM),

32–33, 34

Voltage

human body impact, 4

key term, 22

inductive circuits, 73f,

73–74, 74f

pure-capacitive circuit, 81, 81f,

82–83, 83f

pure resistive circuit, 72, 73f

Voltage drop

combination circuits, 40

electrical circuits key term, 44

parallel circuits, 37

rating, 66, 70

series circuit, 35–36, 36f

speed control, 270

spikes, 202, 203f

term, 16, 361

tests, 69

transformer formulas, 201

Voltage follower, 521, 529

Voltmeter

key term, 34, 374

measurement instruments,

24–28, 25f, 26f, 27f

reading steps, 28f, 28–29

trouble shooting, 363f,

363–365, 364f, 365f, 366f

trouble shooting instrument,

361f, 361–362, 362f

Volts-per-turn method,

223, 226

Warning tag, 2, 2f

Watchdog timer, 554, 556

Water solenoid valve, 439,

439f, 450

Wattage,17–18, 18f, 22

Wattage rating, 466f, 466–467,

467f, 470

White tape, 56

White wires, 56

Wire(s)

area, 64, 64f

circuit conductors, 56

insulation, 66

material, 64

resistance factors, 63

size, 63

temperature, 64f, 65f, 66, 67f

termination temperature, 68

voltage rating, 66

Wire resistance formula, 64

Wire wound, 470

Wire wound resistors, 464, 465f

Wiring diagrams

compressor circuit, 113

fan control circuit, 108–110,

109f, 110f

INDEX 591

schematics/wiring design key

term, 105

start-stop push button, 100,

100f

term, 90, 96

Wood, 12

Wound rotor induction motor

key term, 184

motor operation, 180–181

schematic symbol, 180, 181f

step starting, 181–183, 182f

testing, 183

three-phase motors, 148,

179–180, 180f

Wye, 61

Wye connection

three phase, 51f, 51–53, 52f, 53f

three-phase motors, 153

wound rotor induction motor,

179–180, 180f

Wye-delta starting, 165,

168–170, 169f, 170f,

171f, 172f

Zero switching, 250, 251

Zinc selenide (ZnSe),

483–484, 484f