About This Textbook... xvii About the National Electrical Code...xxi About the Author... xxv About the Illustrator... xxvi About the Team...

Transcription

1 About This Textbook... xvii About the National Electrical Code...xxi About the Author... xxv About the Illustrator... xxvi About the Team...xxvii Article 90 Introduction to the National Electrical Code Purpose of the NEC Scope of the NEC Code Arrangement Enforcement Mandatory Requirements and Explanatory Material Formal Interpretations Examination of Equipment for Product Safety Units of Measurement... 9 Article 90 Practice Questions Available Short-Circuit Current Circuit Impedance, Short-Circuit Current Rating, and Other Characteristics Deteriorating Agents Mechanical Execution of Work Mounting and Cooling of Equipment Conductor Termination and Splicing High-Leg Conductor Identification Arc-Flash Hazard Warning Markings Identification of Disconnecting Means Available Fault Current Lockable Disconnecting Means Part II. 600V, Nominal, or Less Spaces About Electrical Equipment Guarding Enclosure Types Chapter 1 Practice Questions Chapter 2 Wiring and Protection Chapter 1 General Article 100 Definitions Article 110 Requirements for Electrical Installations Part I. General Requirements Scope Approval of Conductors and Equipment Examination, Identification, Installation, and Use of Equipment Voltages Copper Conductors Conductor Sizes Wiring Integrity Suitable Wiring Methods Interrupting Protection Rating Article 200 Use and Identification of Grounded [Neutral] Conductors Part I. General Scope General Neutral Conductors Neutral Conductor Identification Use of White or Gray Color Terminal Identification Identification of Terminals Polarity Article 210 Branch Circuits Part I. General Provisions Scope Other Articles Mike Holt Enterprises, Inc NEC.CODE ( ) v

2 210.3 Branch-Circuit Rating Multiwire Branch Circuits Identification for Branch Circuits Branch-Circuit Voltage Limitations Multiple Branch Circuits GFCI Protection Branch Circuits Required Arc-Fault Circuit-Interrupter Protection Electric Vehicle Branch Circuit Guest Rooms and Guest Suites Part II. Branch-Circuit Ratings Conductor Sizing Overcurrent Protection Outlet Device Rating Permissible Loads, Individual Branch Circuits Permissible Loads, Multiple-Outlet Branch Circuits branch Circuits in Buildings with Multiple Occupancies Part III. Required Outlets General Dwelling Unit Receptacle Outlet Requirements Receptacles in Guest Rooms, Guest Suites, Dormitories, and Similar Occupancies Show Windows Heating, Air-Conditioning, and Refrigeration (HACR) Equipment Electrical Service Areas Lighting Outlet Requirements Article 215 Feeders Scope Minimum Rating Overcurrent Protection Sizing Feeders with Common Neutral Conductor Equipment Grounding Conductor Ground-Fault Protection of Equipment Conductor Identification Article 220 Branch-Circuit, Feeder, and Service Calculations Part I. General Scope Application of Other Articles Calculations Part II. Branch-Circuit Load Calculations General Lighting Other Loads All Occupancies Maximum Load on a Branch Circuit Part III. Feeder and Service Calculations General General Lighting Demand Factors Commercial Show Window and Track Lighting Load Other than Dwelling Unit Receptacle Load Motor Load Fixed Electric Space-Heating Load Dwelling Unit Small-Appliance and Laundry Load Dwelling Unit Appliance Load Dwelling Unit Electric Clothes Dryer Load Electric Ranges and Cooking Appliances in Dwelling Units and Household Cooking Appliances Used in Instructional Programs Commercial Kitchen Equipment Load Noncoincident Loads Feeder/Service Neutral Unbalanced Load Part IV. Optional Calculations for Computing Feeder and Service Loads Dwelling Unit Optional Load Calculation Existing Dwelling Unit Calculations Multifamily Optional Load Calculation Optional Calculation Two Dwelling Units Determining Existing Loads Article 225 Outside Branch Circuits and Feeders Part I. General Scope Other Articles Minimum Size of Conductors Luminaires Installed Outdoors Supports Over Buildings Attachment Masts as Supports Clearance for Overhead Conductors Clearances from Buildings Raceways on Exterior Surfaces of Buildings or Other Structures Trees for Conductor Support Raceway Seals vi Mike Holt s Illustrated Guide to Understanding the 2014 National Electrical Code, Volume 1

3 Part II. Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s) Number of Supplies Disconnecting Means Disconnect Location Maximum Number of Disconnects Grouping of Disconnects Access to Occupants Type Identification of Multiple Feeders Disconnect Construction Rating of Disconnecting Means Article 230 Services Part I. General Scope Number of Services Not to Pass Through a Building Conductors Considered Outside a Building Service Conductors Separate from Other Conductors Raceway Seals Clearance from Building Openings Vegetation as Support Part II. Overhead Service Conductors Overhead Service Conductor Size and Rating Vertical Clearance for Overhead Service Conductors Point of Attachment Means of Attachment Service Masts Used as Supports Part III. Underground Service Conductors Underground Service Conductor Size and Rating Protection Against Damage Part IV. Service-Entrance Conductors Number of Service-Entrance Conductor Sets Size and Rating Wiring Methods Spliced Conductors Protection Against Physical Damage Cable Supports Overhead Service Locations High-Leg Identification Part V. Service Equipment General Listed as Suitable for Service Equipment Part VI. Service Equipment Disconnecting Means Disconnect Requirements Number of Disconnects Grouping of Disconnects Manual or Power Operated Indicating Rating of Disconnect Connection to Terminals Connected on Supply Side of the Service Disconnect Part VII. Service Equipment Overcurrent Protection Overload Protection Required Article 240 Overcurrent Protection Part I. General Scope Definitions Protection of Equipment Protection of Conductors Protection of Flexible Cords and Fixture Wires Standard Ampere Ratings Supplementary Overcurrent Protection Ground-Fault Protection of Equipment Ungrounded Conductors Part II. Location Overcurrent Protection Location in Circuit Location of Overcurrent Devices Part III. Enclosures Damp or Wet Locations Vertical Position Part V. Plug Fuses, Fuseholders, and Adapters General Edison-Base Fuses Edison-Base Fuseholders Type S Fuses Type S Fuses, Adapters, and Fuseholders Part VI. Cartridge Fuses and Fuseholders General Classification Part VII. Circuit Breakers Method of Operation Indicating Nontamperable Markings Applications Mike Holt Enterprises, Inc NEC.CODE ( ) vii

4 Article 250 Grounding and Bonding Part I. General Scope Definition General Requirements for Grounding and Bonding Earth Shells Objectionable Current Objectionable Current Dangers of Objectionable Current Termination of Grounding and Bonding Conductors Protection of Fittings Clean Surfaces Part II. System Grounding and Bonding Systems Required to be Grounded Ungrounded Systems Service Equipment Grounding and Bonding Main Bonding Jumper and System Bonding Jumper Separately Derived Systems Grounding and Bonding Buildings Supplied by a Feeder Generators Portable and Vehicle-Mounted Permanently Installed Generators High-Impedance Grounded Systems Part III. Grounding Electrode System and Grounding Electrode Conductor Grounding Electrode System Grounding Electrode Types Grounding Electrode Installation Requirements Measuring the Ground Resistance Soil Resistivity Auxiliary Grounding Electrodes Lightning Protection Electrode Grounding Electrode Conductor Grounding Electrode Conductor Installation Sizing Grounding Electrode Conductor Termination to the Grounding Electrode Grounding Electrode Conductor Termination Fittings Part IV. Grounding Enclosure, Raceway, and Service Cable Connections Service Raceways and Enclosures Other Enclosures Part V. Bonding General Bonding Equipment for Services Intersystem Bonding Termination Bonding Other Enclosures Bonding Metal Parts Containing 277V and 480V Circuits Bonding Loosely Jointed Metal Raceways Bonding in Hazardous (Classified) Locations Bonding Conductors and Jumpers Bonding of Piping Systems and Exposed Structural Metal Lightning Protection System Part VI. Equipment Grounding and Equipment Grounding Conductors Fixed Equipment Connected by Permanent Wiring Methods General Specific Equipment Fastened in Place or Connected by Permanent Wiring Methods Cord-and-Plug-Connected Equipment Types of Equipment Grounding Conductors Identification of Equipment Grounding Conductors Equipment Grounding Conductor Installation Use of Equipment Grounding Conductors Sizing Equipment Grounding Conductor Part VII. Methods of Equipment Grounding Equipment Grounding Conductor Connections Equipment Connected by Permanent Wiring Methods Equipment Considered Grounded Cord-and-Plug-Connected Equipment Ranges, Ovens, and Clothes Dryers Use of Neutral Conductor for Equipment Grounding Connecting Receptacle Grounding Terminal to Metal Enclosure Continuity and Attachment of Equipment Grounding Conductors in Metal Boxes Part VIII. Direct-Current Systems Sizing Grounding Electrode Conductor Article 285 Surge Protective Devices (SPDs) Part I. General Scope Uses Not Permitted Number Required Listing Short-Circuit Current Rating viii Mike Holt s Illustrated Guide to Understanding the 2014 National Electrical Code, Volume 1

5 Part II. Installation Location Routing of Conductors Type 4 and Other Component Type SPDs Part III. Connecting Surge protective Devices Type 1 SPD Line Side of Service Equipment Type 2 SPD Feeder Circuits Type 3 SPDs Branch Circuits Chapter 2 Practice Questions Chapter 3 Wiring Methods and Materials Article 300 General Requirements for Wiring Methods and Materials Part I. General Scope Conductors Protection Against Physical Damage Underground Installations Protection Against Corrosion and Deterioration Raceways Exposed to Different Temperatures Not Permitted in Raceways Raceways in Wet Locations Above Grade Electrical Continuity Securing and Supporting Mechanical Continuity Splices and Pigtails Length of Free Conductors Boxes or Conduit Bodies Raceway or Cable to Open or Concealed Wiring Raceway Sizing Inserting Conductors in Raceways Supporting Conductors in Vertical Raceways Induced Currents in Ferrous Metal Enclosures and Raceways Spread of Fire or Products of Combustion Wiring in Ducts and Plenums Spaces Panels Designed to Allow Access Article 310 Conductors for General Wiring Part II. Installation Uses Permitted Conductor Ampacity Part III. Construction Specification Conductor Construction and Application Conductors Conductor Identification Article 312 Cabinet and Cutout Boxes Part I. Scope and Installation Scope Damp or Wet Locations Installed in Walls Repairing Gaps Enclosures Deflection of Conductors Cabinets and Cutout Boxes Containing Splices, Taps, and Feed-Through Conductors Article 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; and Handhole Enclosures Part I. Scope and General Scope Nonmetallic Boxes Metal Boxes Part II. Installation Damp or Wet Locations Number of 6 AWG and Smaller Conductors in Boxes and Conduit Bodies Conductors That Enter Boxes or Conduit Bodies Boxes Recessed in Walls or Ceilings Repairing Noncombustible Surfaces Surface Extensions Support of Boxes and Conduit Bodies Covers and Canopies Outlet Box Boxes and Conduit Bodies for Conductors 4 AWG and Larger Wiring to be Accessible Handhole Enclosures Part I. General Scope Mike Holt Enterprises, Inc NEC.CODE ( ) ix

6 Article 320 Armored Cable (Type AC) Part I. General Scope Definition Part II. Installation Uses Permitted Uses Not Permitted Exposed Work Through or Parallel to Framing Members In Accessible Attics or Roof Spaces Bends Securing and Supporting Boxes and Fittings Conductor Ampacity Part III. Construction Specifications Construction Equipment Grounding Conductor Article 330 Metal-Clad Cable (Type MC) Part I. General Scope Definition Part II. Installation Uses Permitted Uses Not Permitted Through or Parallel to Framing Members In Accessible Attics or Roof Spaces Bends Securing and Supporting Fittings Conductor Ampacities Part III. Construction Specifications Equipment Grounding Conductor Article 334 Nonmetallic-Sheathed Cable (Types NM and NMC) Part I. General Scope Definition Listed Part II. Installation Uses Permitted Uses Not Permitted Exposed Through or Parallel to Framing Members Attics and Roof Spaces Bends Securing and Supporting Boxes and Fittings Conductor Ampacity Part III. Construction Specifications Construction Conductors Equipment Grounding Conductor Insulation Article 338 Service-Entrance Cable (Types SE and USE) Part I. General Scope Definitions Part II. Installation Uses Permitted Uses Not Permitted Bends Article 340 Underground Feeder and Branch-Circuit Cable (Type UF) Part I. General Scope Definition Listing Requirements Part II. Installation Uses Permitted Uses Not Permitted Bends Ampacity Insulation Article 342 Intermediate Metal Conduit (Type IMC) Part I. General Scope Definition Listing Requirements x Mike Holt s Illustrated Guide to Understanding the 2014 National Electrical Code, Volume 1

7 Part II. Installation Uses Permitted Dissimilar Metals Trade Size Number of Conductors Bends Number of Bends (360 ) Reaming Securing and Supporting Couplings and Connectors Bushings Article 344 Rigid Metal Conduit (Type RMC) Part I. General Scope Definition Listing Requirements Part II. Installation Uses Permitted Dissimilar Metals Trade Size Number of Conductors Bends Number of Bends (360 ) Reaming Securing and Supporting Couplings and Connectors Bushings Part III. Construction Specifications Construction Standard Lengths Article 348 Flexible Metal Conduit (Type FMC) Part I. General Scope Definition Listing Requirements Part II. Installation Uses Permitted Uses Not Permitted Trade Size Number of Conductors Bends Number of Bends (360 ) Trimming Securing and Supporting Fittings Grounding and Bonding Article 350 Liquidtight Flexible Metal Conduit (Type LFMC) Part I. General Scope Definition Listing Requirements Part II. Installation Uses Permitted Uses Not Permitted Trade Size Number of Conductors Bends Number of Bends (360 ) Securing and Supporting Fittings Grounding and Bonding Article 352 Rigid Polyvinyl Chloride Conduit (Type PVC) Part I. General Scope Definition Part II. Installation Uses Permitted Uses Not Permitted Trade Size Number of Conductors Bends Number of Bends (360 ) Trimming Securing and Supporting Expansion Fittings Bushings Joints Equipment Grounding Conductor Mike Holt Enterprises, Inc NEC.CODE ( ) xi

8 Article 356 Liquidtight Flexible Nonmetallic Conduit (Type LFNC) Part I. General Scope Definition Listing Requirement Part II. Installation Uses Permitted Uses Not Permitted Trade Size Number of Conductors Bends Number of Bends (360 ) Securing and Supporting Fittings Equipment Grounding Conductor Article 358 Electrical Metallic Tubing (Type EMT) Part I. General Scope Definition Listing Requirement Part II. Installation Uses Permitted Uses Not Permitted Trade Size Number of Conductors Bends Number of Bends (360 ) Reaming and Threading Securing and Supporting Couplings and Connectors Grounding Article 362 Electrical Nonmetallic Tubing (Type ENT) Part I. General Scope Definition Part II. Installation Uses Permitted Uses Not Permitted Trade Sizes Number of Conductors Bends Number of Bends (360 ) Trimming Securing and Supporting Bushings Joints Equipment Grounding Conductor Article 376 Metal Wireways Part I. General Scope Definition Part II. Installation Uses Permitted Uses Not Permitted Conductors Maximum Size Number of Conductors and Ampacity Wireway Sizing Supports Splices, Taps, and Power Distribution Blocks Article 380 Multioutlet Assemblies Part I. General Scope Part II. Installation Uses Permitted Uses Not Permitted Through Partitions Article 386 Surface Metal Raceways Part I. General Scope Definition Listing Requirements Part II. Installation Uses Permitted Uses Not Permitted Size of Conductors Number of Conductors Securing and Supporting Splices and Taps Equipment Grounding Conductor Separate Compartments xii Mike Holt s Illustrated Guide to Understanding the 2014 National Electrical Code, Volume 1

9 Article 392 Cable Trays Part I. General Scope Definition Part II. Installation Uses Permitted Uses Not Permitted Cable Tray Installations Cable and Conductor Installation Number of Conductors or Cables Securing and Supporting Bushed Raceway Cable Splices Equipment Grounding Conductor Ampacity of Conductors Article 393 Low Voltage Suspended Ceiling Power Distribution Systems Chapter 3 Practice Questions Chapter 4 Equipment for General Use Article 400 Flexible Cords and Flexible Cables Scope Suitability Types of Flexible Cords and Flexible Cables Ampacity of Flexible Cords and Flexible Cables Uses Permitted Uses Not Permitted Pull at Joints and Terminals Protection from Damage Equipment Grounding Conductor Identification Article 402 Fixture Wires Scope Types Allowable Ampacity of Fixture Wires Minimum Size Raceway Size Neutral Conductor Uses Permitted Uses Not Permitted Overcurrent Protection Article 404 Switches Scope Switch Connections Switch Enclosures Damp or Wet Locations Position of Knife Switches Indicating Accessibility and Grouping Switch Faceplates Mounting Snap Switches Circuit Breakers Used as Switches Grounding of Enclosures Rating and Use of Snap Switches Switch Marking Article 406 Receptacles, Cord Connectors, and Attachment Plugs (Caps) Scope Definitions Receptacle Rating and Type General Installation Requirements Receptacle Mounting Receptacle Faceplates Attachment Plugs, Cord Connectors, and Flanged Surface Devices Receptacles in Damp or Wet Locations Connecting Receptacle Grounding Terminal to Equipment Grounding Conductor Tamper-Resistant Receptacles Dimmer-Controlled Receptacles Article 408 Switchboards, Switchgear, and Panelboards Part I. General Scope Arrangement of Busbars and Conductors Field Identification Clearance for Conductors Entering Bus Enclosures Unused Openings Part III. Panelboards Overcurrent Protection of Panelboards Panelboards in Damp or Wet Locations Equipment Grounding Conductor Neutral Conductor Terminations Mike Holt Enterprises, Inc NEC.CODE ( ) xiii

10 Part IV. Construction Specifications Maximum Number of Overcurrent Devices Article 410 Luminaires, Lampholders, and Lamps Part I. General Scope Definitions Listing Required Part II. Luminaire Locations Luminaires in Specific Locations Luminaires Near Combustible Material Luminaires in Clothes Closets Space for Cove Lighting Part III. Luminaire Outlet Boxes and Covers Outlet Boxes to be Covered Connection of Electric-Discharge and LED Luminaires Part IV. Luminaire Supports Supports Means of Support Part V. Grounding (Bonding) Methods of Grounding Part VI. Wiring of Luminaires Polarization of Luminaires Cord-Connected Luminaires Luminaires as Raceways Conductors and Ballasts Part VIII. Installation of Lampholders Screw-Shell Lampholders Lampholders in Wet or Damp Locations Lampholders Near Combustible Material Part X. Recessed Luminaires General Thermally Protected Recessed Luminaire Clearances Wiring Part XII. Electric-Discharge Lighting General Part XIV. Track Lighting Installation Fastening Article 411 Lighting Systems Operating at 30V or Less and Lighting Equipment Connected to Class 2 Power Sources Scope Low-Voltage Lighting Systems Listing Required Specific Location Requirements Secondary Circuits Branch Circuit Article 422 Appliances Part I. General Scope Definition Other Articles Ground-Fault Circuit-Interrupter (GFCI) Protection Part II. Branch-Circuit Requirements Branch-Circuit Rating Overcurrent Protection Central Heating Equipment (Furnaces) Storage Water Heaters Central Vacuums Flexible Cords Support of Ceiling Paddle Fans Space for Conductors Outlet Boxes to Be Covered Covering of Combustible Material at Outlet Boxes Tire Inflation and Automotive Vacuum Machines Part III. Disconnect General Permanently Connected Appliance Disconnects Cord-and-Plug-Connected Appliance Disconnects Unit Switches as Disconnects Vending Machines Electric Drinking Fountains Article 424 Fixed Electric Space-Heating Equipment Part I. General Scope Branch Circuits Permanently Installed Electric Baseboard Heaters with Receptacles xiv Mike Holt s Illustrated Guide to Understanding the 2014 National Electrical Code, Volume 1

11 Part III. Electric Space-Heating Equipment Disconnecting Means Part V. Electric Space-Heating Cables Clearances of Wiring in Ceilings Area Restrictions Clearance from Other Objects and Openings Installation of Cables in Concrete or Poured Masonry Floors Part VI. Duct Heaters Disconnect for Electric Duct Heater Controllers Installation Article 430 Motors, Motor Circuits, and Controllers Part I. General Scope Definitions Table FLC versus Motor Nameplate Current Rating Marking on Controllers Motor Controller Terminal Requirements Location of Motors The Highest Rated Motor Part II. Conductor Size Single Motor Conductor Size Several Motors Conductor Size Motor Feeder Taps Part III. Overload Protection Overload Overload Sizing for Continuous-Duty Motors Use of Fuses for Overload Protection Number of Overload Devices Part IV. Branch-Circuit Short-Circuit and Ground-Fault Protection General Branch-Circuit Short-Circuit and Ground-Fault Protection Single Overcurrent Device Part V. Feeder Short-Circuit and Ground-Fault Protection Feeder Protection Part VI. Motor Control Circuits Overcurrent Protection for Control Circuits Protection of Conductors from Physical Damage Disconnect for Control Circuits Part VII. Motor Controllers Controller Rating Need Not Open All Conductors of the Circuit Controller for Each Motor Part IX. Disconnecting Means Disconnect Requirement Operation of Disconnect Marking and Mounting Readily Accessible Disconnecting Means Rating Combination Controller and Disconnect Part XIV. Tables Table Full-Load Current, Single-Phase Motors Table Full-Load Current, Three-Phase Motors Table Locked-Rotor Currents Article 440 Air-Conditioning and Refrigeration Equipment Part I. General Scope Definitions Other Articles Marking on Hermetic Refrigerant Motor-Compressors and Equipment Ampacity and Rating Part II. Disconnecting Means Rating and Interrupting Capacity Cord-Connected Equipment Location Part III. Overcurrent Protection General Short-Circuit and Ground-Fault Overcurrent Device Size Part IV. Conductor Sizing Conductor Size for Single Motor-Compressors Part VII. Room Air Conditioners Branch-Circuit Requirements Disconnecting Means Supply Cords Leakage Current Detector-Interrupter and Arc-Fault Circuit Interrupter Mike Holt Enterprises, Inc NEC.CODE ( ) xv

12 Article 445 Generators Scope Marking Overcurrent Protection Ampacity of Conductors Disconnecting Means Ground-Fault Circuit Interrupter Protection for Receptacles on 15 kw or Smaller Portable Generators Article 480 Storage Batteries Scope Definitions Battery and Cell Terminations Wiring and Equipment Supplied from Batteries Racks and Trays Battery Locations Chapter 4 Practice Questions Article 450 Transformers Part I. General Scope Overcurrent Protection Ventilation Grounding and Bonding Marking Transformer Accessibility Disconnecting Means Index xvi Mike Holt s Illustrated Guide to Understanding the 2014 National Electrical Code, Volume 1