Electrical Wiring Commercial

Cover......Page 1
Title Page......Page 5
Copyright......Page 6
Contents......Page 7
Preface......Page 15
Acknowledgments......Page 21
Objectives......Page 23
Safety in the Workplace......Page 24
Arc Flash and Arc Blast......Page 26
Electrical Power Tools on the Job......Page 28
General Clauses and Conditions......Page 29
Supplementary General Conditions......Page 31
Submitting Plans......Page 32
National Electrical Code......Page 37
NEC Arrangement......Page 38
Citing Code References......Page 39
Defined Terms......Page 40
Nationally Recognized Testing Laboratories (NRTL)......Page 41
Underwriters Laboratories, Inc.......Page 42
Intertek Testing Services (ITS)......Page 43
National Electrical Manufacturers Association (NEMA)......Page 44
Illuminating Engineering Societyof North America (IESNA)......Page 45
National Electrical Installation Standards (NEIS)......Page 46
Abandoned Cables......Page 47
Metrics (SI) and the NEC......Page 48
Trade Sizes......Page 49
Guide to Metric Usage......Page 50
Review......Page 52
Objectives......Page 55
Electrical Symbols......Page 56
The Drugstore......Page 65
Review......Page 66
Objectives......Page 69
What about Future Growth?......Page 70
The Electrical Load......Page 71
Lighting Loading Calculations......Page 72
Storage Area Lighting......Page 73
Receptacle for Servicing AC Equipment......Page 74
Motors and Appliances......Page 75
Hermetic Motor-Compressor......Page 76
Other Loads......Page 77
HVAC Equipment......Page 78
Review......Page 79
Objectives......Page 81
What’s the Big Deal with Ampacity?......Page 82
Conductor Type Selection......Page 83
Conductor Insulations with Multiple Ratings......Page 85
Correction Factors for Ambient Temperature......Page 86
Conduits on Roofs Exposedto Direct Sunlight......Page 89
Adjustment Factors for More Than Three Current-Carrying Conductors......Page 90
Heat and More Than Three Current-Carrying Conductors......Page 91
How Equipment Affects Conductor Selection......Page 92
Continuous Loads......Page 97
Overcurrent Protection......Page 99
Selection Criteria......Page 100
Actual Number of Branch Circuits......Page 101
Example 1......Page 102
Load Type (Column E)......Page 103
Review......Page 106
Objectives......Page 108
Receptacles......Page 109
Isolated Ground Receptacles......Page 113
Electronic Equipment Grounding......Page 115
Ground-Fault Circuit-Interrupter Protection......Page 119
Snap Switches......Page 120
Grounded Conductor......Page 122
Equipment Grounding Conductor......Page 123
Conductor Insulation Colors for Connecting Switches......Page 124
Snap Switch Types and Connections......Page 126
Switch and Receptacle Covers......Page 130
Review......Page 132
Objectives......Page 137
Raceway Sizing in the NEC......Page 138
Rigid Metal Conduit (RMC)......Page 139
Intermediate Metal Conduit (IMC)......Page 140
Installation of EMT......Page 141
Installation of Metallic Raceway......Page 142
Flexible Connections......Page 143
Flexible Metal Conduit (FMC)......Page 144
Liquidtight Flexible Metal Conduit (LFMC)......Page 145
Armored (Type AC) and Metal-Clad (Type MC) Cables......Page 147
Rigid Polyvinyl Chloride Conduit (PVC): (NEC Article 352)......Page 150
Electrical Nonmetallic Tubing (ENT): (NEC Article 362)......Page 151
ENT Boxes and Accessories......Page 152
Wireways and Auxiliary Gutters......Page 153
Conductors in Raceways—There Could Be Problems......Page 158
Special Considerations......Page 160
Surface Raceways......Page 161
Device Boxes......Page 162
Securing Boxes with Screws......Page 163
Trade Size 411⁄16 Square Boxes......Page 164
Box Sizing......Page 165
Box Fill When the Conductors Are Different Sizes......Page 167
Width of Box—Watch Out!......Page 168
Box Fill When There Isa Plaster Ring......Page 169
Pull and Junction Boxesand Conduit Bodies......Page 170
Power Distribution Blocks......Page 172
Review......Page 173
Objectives......Page 177
Appliance Branch-Circuit Overcurrent Protection......Page 178
Appliance Grounding......Page 179
The Basics of Motor Circuits......Page 180
Disconnecting Means......Page 181
Motor Branch-Circuit Conductors......Page 183
Color Coding for Motor Branch-Circuit Conductors......Page 184
Motor Overload Protection......Page 185
Insulation......Page 186
How Does Current Flow in the Windings of a Motor?......Page 187
Single Phasing......Page 188
Strange Things Happen......Page 190
Unbalanced Voltage......Page 192
Calculating Unbalanced Voltage......Page 193
Motor Branch-Circuit, Short-Circuit, and Ground-Fault Protection......Page 198
Motor Design Designations......Page 199
Type 1 and Type 2 Coordination......Page 200
Industrial Control Panels......Page 201
Supplying a Specified Load......Page 202
Several Motors and Other Loadson One Branch Circuit......Page 203
Several Motors on One Feeder......Page 204
The Bakery Equipment......Page 205
The Mixers and Dough Dividers (Three Appliances Connectedto One Circuit)......Page 206
The Doughnut Machine......Page 207
The Bake Oven......Page 208
Review......Page 209
Objectives......Page 213
Overcurrent Protection......Page 214
Conductor Selection......Page 215
Step 2: Minimum Ungrounded Conductor Size Determination......Page 217
Step 5: Neutral Conductor Size Determination......Page 218
Voltage Drop......Page 222
Parallel Conductors......Page 224
Problem......Page 225
Feeder Ampacity Determination, Drugstore......Page 226
Phase Conductor Selection......Page 228
Calculations for the Other Occupancies in the Commercial Building......Page 229
Review......Page 230
Objectives......Page 233
Multioutlet Assemblies......Page 234
Receptacle Wiring......Page 236
The Communications System......Page 237
Underfloor Raceway......Page 239
Floor Boxes......Page 240
Fire Alarm System......Page 241
Review......Page 244
Objectives......Page 245
Material Take-off......Page 246
Washer-Dryer Combination......Page 247
Review......Page 250
Objectives......Page 253
Timed Control......Page 254
Sump Pump Control......Page 255
Water Heater and Space Heating......Page 256
Elevator Wiring......Page 257
Optional Electric Boiler......Page 258
Review......Page 262
Objectives......Page 264
Panelboards......Page 265
Numbering of Circuits......Page 266
Panelboard Overcurrent Protection......Page 267
Circuit Directory or Circuit Identification......Page 270
Identification of Branch Circuits and Feeders......Page 271
Close Unused Openings!......Page 272
Working Space Considerations......Page 273
Working Space “Depth” [NEC 110.26(A)(1)]......Page 274
Working Space “Height” [NEC 110.26(A)(3)]......Page 275
Entrance to and Egress from Working Space......Page 276
Dedicated Electrical Space [NEC 110.26(E)]......Page 277
Review......Page 278
Objectives......Page 280
Dry-Type Transformers......Page 281
Single-Phase System......Page 282
Four-Wire Delta System......Page 285
Pad-Mounted Transformers......Page 286
Underground Vault......Page 288
Low-Voltage Metering......Page 290
Important Definitions......Page 291
Service Point......Page 292
Rating of Underground Service Conductors and Termination Box......Page 293
Termination Box at Service......Page 296
Installation of Wireways......Page 298
Service Disconnect Location......Page 300
Ampere Rating of Service Disconnects......Page 301
Optional Service for Electric Boiler......Page 302
Grounding/Bonding......Page 304
Grounding......Page 305
Where Does Fault Current Travel?......Page 306
Bonding......Page 308
Grounding Electrode System......Page 310
Grounding Systems and Electrodes......Page 311
Grounding Requirements......Page 312
Sizing the Grounding Electrode Conductors......Page 314
Sizing the Grounded Service Conductors......Page 315
Sizing Bonding Jumper on the Supply Side of the Service for More Than One Conduit......Page 316
Sizing Equipment Grounding Conductors......Page 317
Ground Fault Protection for Equipment......Page 318
Safety in the Workplace......Page 322
Review......Page 324
Objectives......Page 327
Lumen (lm)......Page 328
Color Rendering Index (CRI)......Page 329
Incandescent Lamps......Page 330
Construction......Page 332
Characteristics......Page 333
Low-Voltage Incandescent Lamps......Page 334
Characteristics......Page 336
Catalog Designation and Color......Page 337
Toxicity Characteristic Leaching Procedure (TCLP)......Page 338
Ballasts and Ballast Circuits......Page 339
Compact Fluorescent Lamps (CFL)......Page 344
High-Intensity Discharge (HID) Lamps......Page 345
Mercury Vapor Lamps......Page 346
High-Pressure Sodium (HPS) Lamps......Page 347
Energy Savings......Page 348
Energy-Saving Lamps......Page 349
Light-Emitting Diodes (LEDs)......Page 350
Fluorescent Lamps......Page 352
What to Do If You Have a Mercury Spill......Page 353
Review......Page 354
Objectives......Page 358
IESNA......Page 359
The Bottom Line......Page 360
Supports......Page 362
Surface-Mounted Luminaires......Page 363
Recessed Luminaires......Page 364
Labeling......Page 365
Installing Recessed Luminaires......Page 366
Thermal Protection......Page 368
Conductors Supplying Luminaires......Page 369
Multiwire Branch Circuits......Page 370
Loading Allowance Calculations......Page 371
Commercial Building Luminaires......Page 372
Luminaires in Clothes Closets......Page 379
Watts Per Unit Area Calculations......Page 380
Review......Page 383
Objectives......Page 385
Sources of Power......Page 387
Special Wiring Arrangements......Page 388
Engine Types and Fuels......Page 389
Capacity......Page 391
Derangement Signals......Page 393
Automatic Transfer Switches......Page 394
Wiring......Page 397
Sizing Generators When UPS Systems Are Involved......Page 398
Review......Page 399
Objectives......Page 401
Disconnect Switches......Page 402
Accessibility of Overcurrent Devices......Page 403
Protection of Conductors......Page 404
Short-Circuit Current Rating......Page 405
Using Fuses for Motor Overload Protection......Page 407
Using Fuses for Motor Branch-Circuit, Short-Circuit, and Ground-Fault Protection......Page 408
Types of Cartridge Fuses......Page 409
Plug Fuses......Page 415
Cable Limiters......Page 416
Delta, 3-Phase, Corner-Grounded “B” Phase System......Page 419
Solid Neutrals......Page 420
Time-Current Characteristic Curves and Peak Let-Through Charts......Page 421
The Use of Peak Let-Through Charts......Page 422
Circuit Breakers......Page 427
Thermal-Magnetic Circuit Breakers......Page 429
Ambient-Compensated Circuit Breakers......Page 430
Series-Rated Applications......Page 432
Series-Rated Systems Where Electric Motors are Connected......Page 434
Motor Circuits......Page 435
Heating, Air-Conditioning, and Refrigeration Overcurrent Protection......Page 436
Review......Page 438
Objectives......Page 441
Short-Circuit Calculations......Page 442
Determining Short-Circuit Currents at Various Distances from Transformers, Switchboards, Panelboards, and Load Centers Using the Point-to-Point Method......Page 444
Phase-to-Phase-to-PhaseFault (L–L–L)......Page 447
Arcing Fault Multipliers (Approximate)......Page 449
Fault Current at Main Service......Page 450
Review of Short-Circuit Requirements......Page 452
What Is Coordination?......Page 453
What Causes Nonselectivity?......Page 454
Selective System Using Fuses......Page 455
Single Phasing......Page 456
Review......Page 458
Objectives......Page 461
Conductor Withstand Rating......Page 464
Conductor Heating......Page 467
Calculating an Insulated 75°C Thermoplastic Conductor’s Short-Time Withstand Rating......Page 468
Calculating the Melting Point of a Copper Conductor......Page 470
Using Charts to Determine a Conductor’s Short-Time Withstand Rating......Page 471
Magnetic Forces......Page 472
Arc-Flash and Arc-Blast Hazards......Page 473
You Are Not Permitted to Tap a Tap......Page 474
When Is a Tap Not a Tap?......Page 475
Review......Page 476
Objectives......Page 478
Relays......Page 479
Single Switch......Page 480
Wiring Methods......Page 481
Low-Voltage Panelboard......Page 484
Review......Page 485
Objectives......Page 487
Refrigeration......Page 488
Compressor......Page 489
Condenser......Page 490
Hermetic Compressors......Page 491
Cooling System Control......Page 492
Electrical Requirements for Air-Conditioning and Refrigeration Equipment......Page 494
Special Terminology......Page 496
Air-Conditioning and Refrigeration Equipment Disconnecting Means......Page 498
Air-Conditioning and Refrigeration Equipment Motor-Compressor and Branch-Circuit Overload Protection......Page 500
Tons versus Amperes......Page 501
Review......Page 502
Objectives......Page 503
The Basic Utility Interactive Photovoltaic System......Page 504
Modules......Page 505
Disconnects......Page 506
Inverters......Page 507
Site or Plot Plan......Page 508
Calculations......Page 509
Mounting of Array......Page 512
Installation of Combiner Boxes......Page 513
Grounding Electrode System......Page 514
Utility Point of Connection......Page 515
System Checkout and Commissioning......Page 516
Review......Page 517
Appendix A: Electrical Specifications......Page 519
Appendix B: Useful Formulas......Page 547
Appendix C: NEMA Enclosures Types......Page 553
Appendix D: Outside Air Temperatures for Selected U.S. Cities......Page 555
Appendix E: Metric System of Measurement......Page 557
Appendix F: Glossary......Page 565
Appendix G: Web Sites......Page 577
Appendix H: Electrical Symbols......Page 589
Appendix I: Bender Guide......Page 601
Index (Code and Subject)......Page 607