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NEC National Electrical Code Directory
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Summary: The National Electrical Code Directory of visual code definitions and explanations. This article covers the Changes and Revisions of the 1999 and 2002 NEC. |
National Electrical Code Listing for Codes Used for Home Electrical Wiring
Review of Changes to the 1999 and 2002 NEC Code
This is a partial listing which includes some of the most enforced electrical wiring codes that are practiced when installing home electrical wiring.
The following are excerpts of the changes made to these portions of the elecetrical codes.
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Two Wires Under a Single Terminal, Section 110-14(a). Dedicated Equipment Space, Section 110-26(f)(1)(a). Replacing Non grounding-Type Receptacles, Section 210-7(d)(3)(c). Branch Circuit Tap Conductors, Section 210-19(d) Exception 1c. Number of Receptacles Per Circuit - Commercial, Section 220-3(b)(9). Line and Load Not Permitted, Section 230-7. Line and Load Permitted. Ground Rod Does Not Provide Any Protection From Electric Shock (1 of 2), Section 250-2(d) and 250-54. Ground Rod Does Not Provide Any Protection From Electric Shock (2 of 2), Section 250-2(d) and 250-54. Raceways not Required to be Supported With In 3 ft of Couplings, Section 348-13. Okay to Support Fixtures to Suspended Ceiling Grid, Section 410-16(c). CATV Wiring Methods, Article 820. |
90.2 Scope of the NEC |
This subsection was revised to group similar types of installations together and to make it easier to read. |
90.2 Scope of the NEC |
The rule that exempts electric utilities from complying with the requirements of the NEC was revised to read: (B) Not Covered. (5) E |
90.4 Enforcement (Inspection) |
The first paragraph of this section was revised to read: This Code is intended to be suitable for enforcement by governmental bodies. |
Grounding Electrode Conductor |
The definition for “Grounding Electrode Conductors” was revised to read:Grounding Electrode Conductor. |
Ground-Fault Circuit Interrupter |
The definition for “Ground-Fault Circuit Interrupter” was revised to read: Ground-Fault Circuit Interrupter. |
Luminaire |
A new definition was added to replace the NEC terms “fixtures” and “lighting fixtures.” |
Qualified Person |
The definition of “Qualified Person” was revised to read: Qualified Person. A person who has the skill and knowledge. |
110.12 Mechanical Execution of Work |
This rule was revised to read: (A) Unused Opening. Unused cable or raceway openings in boxes, auxiliary gutters, cabinets, cutouts... |
110.14 Electrical Connections |
New text was added to clarify conductor sizing for terminals and it reads: (C)Temperature Limitations (1) Equipment Provisions. |
110.15 High-Leg Marking |
New rule added to cover the identification of the high-leg. This rule reads: On a 4-wire, delta-connected system where the midpoint of one... |
110.16 Flash Protection |
A new Code section and two FPN’s were added to provide requirements for marking equipment where arc fault hazards may be present. |
110.22 Identification of Disconnecting Means |
The text was revised to read: All installed disconnecting means must be legibly marked to indicate their purpose unless they are... |
110.26 Spaces About Electrical Equipment |
A new sentence was added, which addresses exit door requirements (panic hardware) for rooms containing large electrical equipment. |
110.26 Spaces About Electrical Equipment |
The intent of the requirements for "dedicated equipment space" located indoors was completely revised and the rule reads: (F) Dedicated... |
200.6 Means of Identifying Grounded (neutral) Conductor |
The term "natural" was deleted and a FPN was added to this section. It reads: (A) Identifying Grounded (neutral) Conductors 6 AWG or Small... |
200.7 Use of Insulation of a White or Gray Color |
The term "natural" was deleted and a FPN added to this section to read: (C) Circuits Over 50V. The use of white or natural gray in... |
210.63 Heating, Air-Conditioning, and Refrigeration Equipment Outlet |
The words “on rooftops and in attics and crawl spaces” and the exception were deleted so that this rule would coordinate with the mechanical... |
210.7 Branch Circuit Receptacle Requirements |
New text clarifies the requirement for simultaneously disconnecting the ungrounded branch circuit conductors. (C) Multiple Branch Circuits.... |
210.8 Ground-Fault Circuit-Interrupter Protection for Personnel |
New subsection was added to include boathouses.(A) Dwelling Units. GFCI protection must be provided for all 15 and 20A, single-phase... |
210.8 Ground-Fault Circuit-Interrupter Protection for Personnel |
New subsection was added to include kitchens. (B) Other than Dwelling Units. All 15 and 20A, single-phase, 125V receptacles instal... |
210.12 Arc-Fault Circuit-Interrupter (AFCI) Protection |
The word "receptacle" was deleted and the words “listed device that protects the entire branch circuit” were added. This subsection... |
210.52 Dwelling Unit Receptacle Outlets |
The maximum distance the required receptacle for the counter surface can be above a dwelling unit kitchen counter surface was changed from 18 in. to 2... |
210.52 Dwelling Unit Receptacle Outlets |
This section was revised to read: (D) Bathrooms. In dwelling units, at least one 15 or 20A, single-phase, 125V receptacle outlet... |
210.52 Dwelling Unit Receptacle Outlets |
This section was revised to read: (G) Basements and Garages. For a one-family dwelling, at least one 15 or 20A, single-phase 125V... |
225.32 Disconnecting Means Location |
Exception No. 1 was revised to read: The disconnecting means for a building or structure must be installed either inside or outside of the... |
230.10 Vegetation as Support |
A new rule was added, which reads:Vegetation such as trees cannot be used for the support of overhead service conductors. Figure 230-1... |
230.50 Protection of Cables Against Damage – Above Ground |
Item (3) was revised from “rigid nonmetallic conduit” to Schedule 80 rigid nonmetallic conduit, so that this section reads... |
230.70 Service Disconnect - General |
New text was added and it reads: (A) Location of Service Disconnecting Means (3) Remote Control. Where a remote control... |
240.2 Definitions |
The following definitions were added for Article 240: Current-Limiting Over current Protective Device. A current-limiting over current... |
240.21 Location in Circuit |
A new subsection was added to read: (C) Transformer Secondary Conductors (6) Secondary Conductors Not Over 25 ft. Secondary conductor... |
240.33 Vertical Position |
This section was revised to read: Enclosures for over current devices must be mounted in a vertical position unless it is impracticable. |
240.83 Marking |
This subsection was revised and it reads: (D) Used as Switches. Circuit breakers used to switch 120V or 277V fluorescent lighting... |
240.85 Applications |
The second paragraph was revised and a FPN was added to read: A circuit breaker with a straight voltage rating (240V or 480V) can be used... |
240.85 Applications |
Author’s Comment: A 120/240V slash circuit breaker cannot be used on the high-leg of a solidly-grounded 120/240V delta system, because... |
250.2 Definitions |
Definitions were added to Article 250: Effective Ground-Fault Current Path. |
250.4 General Requirements for Grounding and Bonding |
Section 250-2 in the 1999 NEC was revised and relocated to 250.4. It now reads: (A) Grounded Systems. (2) Grounding of Electrical Equipment . |
250.4 General Requirements for Grounding and Bonding |
Section 250-2 in the 1999 NEC was revised and relocated to 250.4. It now reads: (A) Grounded Systems. (3) Bonding of Electrical Equipment . |
250.4 General Requirements for Grounding and Bonding |
Section 250-2 in the 1999 NEC was revised and relocated to 250.4. It now reads: (A) Grounded Systems. (4) Bonding of Electrically Conductive. |
250.4 General Requirements for Grounding and Bonding |
(A) Grounded Systems. (5) Effective Ground-Fault Current Path. Electrical equipment and other electrically conductive materials. |
250.30 Grounding Separately Derived Alternating-Current Systems |
This Subsection was reworded and additional requirements added to contain the requirements for grounding multiple separately derived systems. |
250.32 Buildings or Structures Supplied with Feeder |
This subsection added a new requirement and it reads: (B) Grounded Systems (2) Grounded (neutral) Conductor. Where (1) an equipment. |
250.32 Two or More Buildings or Structures Supplied with Feeder |
The rule now reads: (E) Grounding Electrode Conductor. The size of the grounding electrode conductor for a building. |
250.50 Grounding Electrode System |
This section was completely revised to read: If available on the premises at each building or structure, all of the electrodes identified. |
250.54 Supplementary Grounding Electrodes |
This section was revised to read: Supplementary grounding electrodes can be installed and they can be connected to the equipment grounding. |
250.102 Equipment Bonding Jumpers |
A new exception was added to this subsection and this subsection now reads: (E) Installation. The equipment bonding jumper can be installed. |
250.104 Bonding of Piping Systems and Exposed Structural Steel |
The word “interior” was deleted in this section. This section now reads: (A) Metal Water Piping (1) General Requirements. |
250.104 Bonding of Piping Systems and Exposed Structural Steel |
An exception was added to this section. This section now reads: (A) Metal Water Piping (4) Separately Derived Systems. To prevent. |
250.104 Bonding of Piping Systems and Exposed Structural Steel |
The word “interior” was deleted in this section. This section now reads: (B) Other Metal Piping Systems. |
250.104 Bonding of Piping Systems and Exposed Structural Steel |
The word “interior” was deleted and the sizing of the bonding jumper was changed from 250.122 to 250.66. |
250.118 Types of Equipment Grounding Conductors |
This subsection was completely revised to read: (11) MC Cable. The outer metal sheath of smooth or corrugated tube type MC cable can serve. |
250.146 Connecting Receptacle Grounding Terminal to Box |
The first sentence of this rule in the 1999 NEC was revised to delete the words “or at.” This section now reads: (A) Surface Mounted. |
250.148 Continuity and Attachment of Equipment Grounding Conductors to Metal Boxes |
This section was completely reworded to read: Where circuit conductors are spliced, or terminated on equipment within a box, any separate. |
285.1 Scope |
This Article covers the installation and connection requirements for TVSS that are permanently installed on premises wiring systems. Figure 285. |
285.21 Connection |
Where a TVSS is installed, it must be connected as follows: (A) Location. (1) Service Supplied Building or Structure. |
300.4 Protection Against Physical Damage |
The word “listed” was added so that this subsection now reads: (B) Through Metal Framing Members. (1) Nonmetallic-Sheathed Cable. |
300.5 Underground Installations |
Replace the word “service laterals” with “service conductors,” so that this section now reads: (D) Protection,. |
300.7 Raceways Exposed to Different Temperatures |
The requirement for sealing against the flow of warm air to a colder section was completely reworded to read: (A) Sealing. |
300.15 Boxes, Conduit Bodies, or Fittings – Where Required |
This subsection was completely revised to read: (I) Enclosures. A box or conduit body is not required where a splice is made. |
310.8 Locations |
The text was revised to read: (D) Locations Exposed to Direct Sunlight. Insulated conductors and cables used where exposed. |
310.15 Ampacities for Conductors |
A new exception was added and it reads: (B) Table 310.16 Ampacity (2) Adjustment Factors. (a) More than Three Current-Carrying Conductors. |
314.22 Exposed Surface Extensions |
The text was revised to read: Surface extensions from a flush-mounted box must be made by mounting and mechanically securing. |
314.27 Outlet Boxes |
The exception to the rule that required boxes used at luminaire or lamp holder outlets be designed for the purpose was revised. |
314.27 Outlet Boxes |
A new subsection was added and it reads: (B) Maximum Luminaire Weight. Outlet boxes that are properly supported in accordance. |
314.27 Outlet Boxes |
This subsection was revised to read: (D) Boxes for Ceiling Paddle Fan. Where a box is used as the sole support for a ceiling paddle. |
320.17 Through or Parallel to Framing Members |
The text was revised to read: AC cable installed through or parallel to framing members must be protected against physical damage. |
320.30 Securing and Supporting |
The text was revised to read: (B) Unsupported. AC cable can be unsupported where the cable is: (1) Fished between concealed access. |
334.10 Uses Permitted |
This subsection was completely revised to read: Type NM and NMC cables can be used in any of the following occupancies: (1) One and Two.. |
334.12 Uses Not Permitted |
The following text was added. (A) Types NM, NMC, and NMS. Types NM, NMC, and NMS cables shall not be used as open runs in dropped... |
334.17 Through or Parallel to Framing Members |
The text was revised to read: NM cable installed through or parallel to framing members must be protected against physical damage. |
338.10 Uses Permitted |
The text was revised to read: (B) Branch Circuits or Feeders (4) Installation Methods for Branch Circuits and Feeders. (a) Interior Installation. |
342.30 Securing and Supporting |
This subsection was revised to read: (B) Supports (3) Vertical Risers. Exposed vertical risers for industrial machinery. |
354.6 Listing Requirement |
This new section reads: NUCC and its associated fittings must be listed for the purpose. Figure 354–1 Intent. |
362.10 Uses Permitted |
A new exception was added and it reads: (2) In buildings exceeding three floors. ENT must be installed concealed in walls, floors,. |
362.10 Uses Permitted |
An exception was added and it reads: (5) Above Suspended Ceiling. ENT can be installed above a suspended ceiling if the suspended ceiling |
376.23 Wire way Sizing |
This section was revised to read: (A) Bending Radius. Where conductors are bent within a wire way, the wire way must be sized. |
376.23 Wire way Sizing |
This section was revised to read: (B) Wire way Used as Pull Box. Where insulated conductors 4 AWG or larger are pulled through. |
392.3 Uses Permitted |
This section was revised to read: Cable trays can be used as a support system for services, feeders, branch circuits, communication. |
392.6 Installation |
This section was revised to read: (J) Raceways, Cables, and Boxes Supported from Cable Trays. In industrial facilities. |
400.7 Uses Permitted |
The word “stationary” was replaced with “utilization.” The subsection was revised to read: (A) Uses Permitted. |
400.8 Uses Not Permitted |
This subsection was revised to read: Unless specifically permitted in 400.7, flexible cords and cables cannot be used for the following... |
404.8 Accessibility and Grouping |
The text to this section was revised to read: (B) Voltage Between Adjacent Devices. Snap switches shall not be grouped or ganged... |
404.9 Provisions for Grounding Switch Faceplates |
The text to this subsection was revised to read: (B) Grounding. Snap switches, including dimmer and similar control switches... |
404.14 Rating and Use of Switches (including Dimmers) |
This new subsection reads: (E) Dimmer. General use dimmer switches must only be used to control permanently installed incandescent... |
406.8 Receptacles in Damp or Wet Locations |
Parts of this section were revised to read: (B) Wet Locations (1) 15 and 20A Outdoor Receptacles. 15 and 20A, 125 and 250V receptacle... |
406.8 Receptacles in Damp or Wet Locations |
Parts of this section were revised to read: (B) Wet Locations (2) Other Receptacles. All other receptacles installed in a wet... |
408.21 Grounded Conductor Terminations |
Intent: This new section should ensure that grounded (neutral) conductors terminate within the panel board to an individual terminal. This has b... |
408.21 Grounded Conductor Terminations |
Author’s Cot:mmen If two grounded (neutral) conductors are connected to the same terminal, and someone removes one of the neutrals... |
430.52 Branch Circuit Short-Circuit Protection Device Rating |
Table 430-152, which contains the maximum rating or setting of motor branch-circuit short-circuit and ground-fault protective devices, was relocated... |
430.62 Feeder Protection Device Rating |
The first paragraph was revised to read: (A) Motors Only. A feeder supplying a specific fixed motor load(s) and consisting of conductors... |
430.102 Disconnect Means Location |
This subsection and its exception were revised, and two Fine Print Notes were added. This subsection now reads: (B) Motor Disconnect. |
440.14 Location |
A sentence was added to this section so that it now reads: Disconnecting means must be located within sight (within 50 ft) from and readily... |
445.13 Ampacity of Generator Conductors |
The first sentence of this section was revised: The ampacity of the conductors from the generator terminals to the first distribution device... |
500.2 Definitions |
A new definition for Electrical and Electronic Equipment was added and it reads: Electrical and Electronic Equipment. Materials,... |
500.8 Equipment |
Additional text was added to this subsection on the suitability of equipment and it reads: (A) Approval for Class and Properties. |
501.5 Sealing and Drainage |
A new exception No. 2 was added to read: (A) Conduit Seals, Class I, Division 1 (4) Boundary Seal. A sealing fitting must be installed... |
505.21 Multi wire Branch Circuits |
A new section covering the requirements for multi wire branch circuits located in Zone-classified systems reads: Multi wire Branch Circuits.... |
511.3 Classifications of Locations |
This exception was revised to read: (B) Classified Locations (1) Up to 18 inches Above the Floor. For each floor, the entire are... |
511.3 Classifications of Locations |
New subsection added for compressed natural gas and it reads: (B) Classified Locations (2) Within 18 in. of the Ceiling. |
514.13 Disconnect for Maintenance and Service of Dispensing Equipment |
This section was revised to read: Each dispensing device must be provided with a means to remove all external voltage sources, including... |
517.13 Grounding of Receptacles and Fixed Electric Equipment in Patient Care Areas |
The section was completely revised to read as follows: (B) Insulated Equipment Grounding Conductor. In areas used for patient care... |
517.30 Essential Electrical Systems for Hospitals |
A new subsection was added and it reads: (E) Receptacle Identification. The cover plates for receptacles, or receptacles supplied... |
525.32 Grounding Conductor Continuity Assurance |
A new requirement was added to require testing of the equipment grounding conductor. This new section reads: The continuity of the grounding... |
527.3 Time Constraints |
The word “Christmas” was replaced with “holiday” so this section now reads: (B) 90-Day Rule. |
527.4 General |
A new sentence was added to this subsection, which reads: (J) Supports. Vegetation cannot be used for support of overhead spans. . . |
547.2 Definitions |
The definition for an Equipotential Plane was revised to read: Equipotential Plane. An area where wire mesh or other conductive... |
547.5 Wiring Methods |
This section was revised to require equipment enclosures, boxes, conduit bodies, and fittings installed in agricultural buildings to comply with the... |
547.5 Wiring Methods |
The GFCI requirements for agricultural buildings were revised to read: (G) Receptacles. All 15 and 20A, single-phase 125V general-... |
550.25 Arc-Fault Circuit Interrupter Protection |
A new subsection was added and it reads: (B) Bedrooms of Mobile Homes and Manufactured Homes. All branch circuits that supply 15... |
555.2 Definitions |
A new definition for Electrical Datum Plane was added and it reads: Electrical Datum Plane. The electrical datum plane is defined as... |
555.17 Boat Receptacle Disconnecting Means |
The requirement for the boat disconnecting means was completely revised to read: (B) Location. The disconnecting means for a boat... |
555.19 Boat Receptacle |
New text was added and it reads: (A) Boat Receptacles (4) Ratings. Receptacles that provide shore power for boats must be rated... |
600.21 Ballasts, Transformers, and Electronic Power Supplies |
This subsection was revised to read: (F) Suspended Ceilings. Ballasts, transformers, and electronic power supplies are permitted... |
604.6 Construction |
This section was completely revised to read: (E) Support. Manufactured wiring systems must be supported in accordance... |
640.6 Mechanical Execution of Work/Cable Support |
There is a Mechanical Execution of Work and Cable Support... |
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