Barriers are required in switchboards to protect persons and maintenance equipment from contact with energized uninsulated busbars and terminals during service work.

A new type of cable , Type G-GC, has been added to Table 400-4. This type of cable has an additional insulated ground check conductor that can be used on low voltage systems to monitor continuity of the equipment ground and provide a signal for controls.

Flexible cords and cables are allowed to be used for connection to portable and mobile signs. Although this has been a common practice and allowed by Section 600-10 there were no provisions in Article 400 in the 1996 Code for this.

This section has been revised to define the type of fans that cannot be installed in restricted areas near bathtubs and shower areas. Shower areas were added. Paddle fans, cord-connected fixtures, hanging fixtures, lighting track, and pendants are not allowed in a zone measured 3 feet horizontally and 8 feet vertically from the top of the bathtub rim or shower stall threshold. Recessed exhaust fans, as well as recessed fixtures, and surface mounted fixtures marked suitable for damp or wet locations are allowed in the restricted zone.

A revision now makes it clear that lighting fixtures are allowed in commercial cooking hoods provided a list of conditions are met. Note: one of those conditions is that the wiring methods supplying the fixtures cannot be located in the hood.

A revision now permits 2-wire or multiwire branch-circuits to pass through an integral fixture outlet box and supply power to fixtures connected together. The fixture does not have to be identified for through-wiring.

Listed boxes are required for supporting fixtures weighing over 50 pounds.

Clips used to attach fixtures to suspended ceiling grids shall be listed.

Where isolated grounded receptacles are installed in nonmetallic boxes, metal faceplates shall be permitted if there is means for grounding the faceplate.

Receptacles mounted on covers shall be mounted using two screws or the shall be mounted using a listed assembly if only one screw is used.

Plugs shall be installed so that the prongs and blades are not energized until they are inserted into a receptacle. Receptacles shall not be installed where they require an energized plug as a source of supply.

Minimum length of tap conductors has been reduced to 18 inches. Such tap conductors are required to be in a suitable raceway or Type MC or AC cable of at least 18 inches but not more than 6 feet in length. (Note: NM cable fixture whips are now allowed, but not as taps.)

This entire article has been reorganized and renumbered.

New requirements have been added for installing central vacuum cleaner outlets. Listed assemblies are required for connection to general purpose branch circuits.

Electrical Systems, including cables, used for heating floors in bathrooms, hot tub, spa and hydromassage bathtub locations shall be protected by ground-fault circuit-interrupter protection for personnel.

Ground-Fault protection of Equipment(GFPE) used for fixed electric deicing and snow-melting is required. There is an exception for equipment that uses mineral-insulated metal sheathed cable. This requirement does not require that the circuit be protected by GFPE, but that only the equipment be protected.

Ground-Fault Protection of Equipment(GFPE) used for heat tracing and heating panels, used in other than industrial establishments, is required. The industrial facility exception requires (1) qualified persons to service the installation, (2) a ground-fault alarm, and (3) that the circuit be kept on to provide safe operation of processes and equipment.

For all installations the ampere rating on the nameplate of an appliance is required to be used in place of the horsepower rating for sizing conductors, branch circuit ground-fault and short circuit protective devices, overload protection, and disconnecting means. This exception has been added to compensate for manufacturers' labeling appliances with the peak horsepower rating that does not correlate with the full load current tables in the Code. Peak horsepower ratings are usually much higher than the actual horsepower of an appliance and if used in sizing a motor circuit would require over-sized components.

A new requirement has been added to this section requiring work space about battery systems that complies with Section 110-26. This work space shall be measured from the edge of the battery rack.

This is a new Article that covers the general requirements for equipment operating over 600 volts. A new definition has been introduced that defines high voltage as more than 600 volts nominal. This new Article includes the material from Article 710 that was not placed in other Articles. Article 710 was deleted from the 1996 Code. Note this Article covers equipment that operates over 600 volts, while Article 710 in the 1996 Code covered equipment, wiring methods, and overcurrent protection. Since Chapter 4 covers equipment for general use Article 490 is appropriate for this Chapter. Other parts of Article 710 from the 1996 Code were placed in other appropriate Chapters.

A new requirement has been added requiring that all areas classified as hazardous be properly documented, and that this documentation be made available to authorized designers, inspectors, operators, and maintenance persons.

Rigid nonmetallic Conduit complying with Article 547 is permitted to be buried in a Class I, Division I location if encased in a 2 inch envelope of concrete (all around) and if buried so the top of the conduit is 24 inches below grade. The concrete envelope can be omitted at locations that are commercial garages (511-4), gasoline dispensing and service stations (514-8), and bulk storage plants (515-5.) The last 2 feet of the underground rigid nonmetallic conduit run to where it emerges above ground is required to be threaded rigid metal or intermediate metal conduit.

A new rule permits Instrument Tray Cable in Class I, Division I industrial locations with restricted public access, and where only qualified persons will service the installation. The cable must be listed for the application and must be terminated using listed fittings. It shall have an overall jacket of suitable polymeric material and a gas/vaportight continuous corrugated aluminum sheath.

This entire article has been reorganized and expanded. When this European method of classifying hazardous locations is used a qualified registered professional engineer shall supervise the classification of areas and the selection of equipment and wiring methods.

Dual classification of areas is not allowed. Either the Class I, Division 1 and 2 method shall be used or the Class 1, Zone 0, 1 and 2 method shall be used. There shall be no overlapping of areas. The two areas can abut.

The description of the type of building that is classified as an aircraft hangar has been revised. A hangar is a building where aircraft containing flammable liquids or combustible liquids whose temperature is above their flashpoint are stored, serviced or housed. If an aircraft that contains Jet A fuel that has a flashpoint above 100 degrees F. is stored in a building where the temperature is above its flashpoint, then the building would be classified as a hangar. Flammable liquids have flashpoints below 100 degrees F.

A new rule requires that a means for removing all external voltage sources including control circuits from each dispensing unit be provided so that maintenance and service personnel can service an individual dispensing unit without risking the hazard of feedback from parallel sources of power. The control circuits to some dispensers have been known to feedback into units that were supposedly turned off causing injury to service personnel. This new requirement should eliminate this hazard.

A provision in this section that required that the rules for gasoline dispensing stations be complied to when gasoline is dispensed at bulk storage plants has been modified to include gasoline and other volatile flammable liquids or liquefied flammable gases.
Flammable liquids include those that have a flashpoint below 100 degrees F.
Note, No. 1 and No. 2 Diesel does not have a flashpoint below 100 degrees F. Additionally, outdoor areas where drums of flammable fuel are stored is not a classified area according to Table 515-2, although this area may be classified by the authority having jurisdiction according to the FPN to Table 515-2.

Type AC cable containing an insulated equipment grounding conductor sized in accordance with Table 250-122 is now permitted as a wiring method in Places of Assembly.

A new Fine Print Note has been added to define a finish rating in contrast to a fire resistant rating. This note was added to clarify the areas where electrical nonmetallic tubing and rigid nonmetallic conduit wiring methods can be used in places of assembly since they can be used behind a thermal barrier with at least a 15 minute finish rating.
A finish rating is defined as the time at which the wood stud or stud joists reaches an average temperature rise of 250 degrees F. or an individual temperature rise of 325 degrees F as measured on the plane of wood nearest the fire. A fire resistance rating , on the other hand, limits the time and temperature for the side of an assembly opposite the fire. Fire resistance ratings apply to assemblies such as walls and floors, while finish ratings only apply to the finish material such as gypsum board.

The vertical clearance requirements for overhead conductors shall not apply to the inside of tents. All temporary lamps used in tents for lighting shall have a guard or be protected from accidental breakage by a suitable fixture. Wiring inside of tents and concessions shall be protected from physical damage and securely installed.

All general purpose 15- and 20 ampere, 125-volt single-phase receptacles used by personnel at carnivals, circuses, Fairs, and similar events shall have listed ground-fault circuit-interrupter protection. Receptacles for appliances are not required to have ground-fault protection unless the appliances can be used on 15- and 20-ampere receptacles. Other receptacles shall have GFCI protection or an assured equipment grounding program for all cord sets and receptacles. One or more designated persons shall ensure the safety of the equipment grounding conductors.

There is an extensive revision for disconnecting and grounding at agriculture buildings. There is a new definition of equipotential plane which includes an area accessible to livestock.

Permission is given to use single-phase power derived from a three-phase grounded system to supply 20- and 30-ampere receptacles. Power to 50-ampere receptacles shall be supplied from a single-phase, 120/240-volt, 3-wire system.

Permission is given to utilize field installed cord caps on supply cords for park trailers.

A new rule does not permit a cord-and-plug to be a disconnecting means for individual boats. Each boat is required to have an individual circuit breaker or switch or both that will cutoff the supply to the boat. This disconnect shall be located within site of the shore power connection and be readily accessible. Cord-and-plug disconnects caused a hazard in wet environments.

There is a new requirement requiring emergency switches for spas and hot tubs. A clearly labeled disconnect is required for stopping the motor(s) used for the jet stream and recirculation system . It shall be installed at a readily accessible location within 5 feet, adjacent to, and within sight of the spa or hot tub. This requirement does not apply to Single-Family dwellings. This new requirement is to prevent drowning when persons hair is sucked into the water intake.

A new rule has been adopted that requires GFCI protection for electric signs installed in fountains. Additionally, the sign installed in the fountain shall be 5 feet from the outside edges.

A new rule requires that fire pump equipment be listed. This equipment includes the controllers, motors, and transfer switches.

Electrical held automatic transfer switches are no longer allowed, they shall be mechanically held. A failure of an electrically held transfer switch was the reason for this change.

Class 1 circuits supplied from electronic power supplies can be protected from overcurrent using the power supply input overcurrent device. The power supply shall be listed and a number of conditions delineated in this new exception shall be followed.

A new Fine Print Note has been added that explains that a power limited circuit that has been reclassified and installed as a nonpower limited circuit can continue to be connected to a power limited power supply. This allows for circuits connected to a power limited power supply to be wired as nonpower limited circuits. This permits reclassified nonpower limited wiring methods on the load side and eliminates many of the separation requirements.

The Conduit fill requirements of Chapter 3 and Chapter 9 shall not apply to raceways that contain optical fiber cables unless these raceways also contain current-carrying electric conductors. The rationale for this change is that overfilling a fiber optical raceway and damaging cables does not cause a safety hazard.

The point of entry for underground communication services shall be within 20 feet of the electrical service entry point. Where this rule cannot be met, a separate grounding electrode shall be installed in the vicinity of the communications service and shall be bonded to the electrical service grounding electrode system.

Where raceways are installed for communication circuits the rules in Chapter 3 shall apply. Listed communications raceways are also allowed. This new rule settles a long standing controversy about communications raceways because Chapter 8, according to Section 90-3, is a stand alone chapter and other chapters and parts of the Code only apply when specifically referenced in Chapter 8.