11.7 Assembly, Theaters, Carnivals, Temporary Installations and Pools

Article 518 — Assembly Occupancies

518.1 Scope. Article 518 covers all buildings or portions of buildings or structures designed or intended for the assembly of 100 or more persons.

518.2(A) Examples. Assembly occupancies include armories, assembly halls, auditoriums, bowling lanes, club rooms, conference rooms, courtrooms, dance halls, dining and drinking facilities, exhibition halls, gymnasiums, mortuary chapels, multipurpose rooms, museums, places of awaiting transportation, places of religious worship, pool rooms, restaurants, skating rinks, and similar occupancies.

518.2(B) Multiple Occupancies. Where an assembly occupancy forms a portion of a building containing other occupancies, Article 518 applies only to that portion of the building considered an assembly occupancy.

518.2(C) Theatrical Areas. Where an assembly occupancy includes a theatrical area or an audience seating area with a stage, permanent stage equipment, or projection booth, it shall comply with Article 520.

518.4 Wiring Methods. (A) General. The fixed wiring methods shall be metal raceways, flexible metal raceways, nonmetallic raceways encased in not less than 50 mm (2 in.) of concrete, Type MI, MC, or AC cable. (B) Nonrated Construction. In addition to the wiring methods of 518.4(A), nonmetallic-sheathed cable, Type AC cable, electrical nonmetallic tubing, and rigid nonmetallic conduit shall be permitted to be installed in those buildings or portions thereof that are not required to be of fire-rated construction. (C) Spaces with Finish Rating. ENT and PVC shall be permitted where installed in club rooms, conference and meeting rooms in hotels or motels, dining rooms, restaurants, and similar spaces, where the raceways are installed above suspended ceilings having a 15-minute finish rating.

518.5 Supply. Portable switchboards and portable power distribution equipment shall be supplied only from listed power outlets of sufficient voltage and ampere rating.

Article 520 — Theaters, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations

520.5 Wiring Methods. The fixed wiring method shall be metal raceways, nonmetallic raceways encased in at least 50 mm (2 in.) of concrete, Type MI, MC, or AC cable, with the same nonrated-construction and finish-rating allowances as Article 518.

520.10 Portable Equipment Used Outdoors. Portable stage and studio lighting equipment and portable power distribution equipment shall be permitted for temporary use outdoors, provided the equipment is supervised by qualified personnel while energized and barriered from the general public.

520.44 governs borders, proscenium sidelights, drop boxes, and connector strips, and 520.53 governs portable switchboards on stage, including the requirement in 520.53(H)(1) that supply conductors be listed extra-hard usage cord.

520.62 covers portable strips, 520.65 covers festoons, and 520.68 governs conductors for portables, requiring flexible conductors used to supply portable stage equipment to be listed extra-hard usage cord or cable.

520.81 through 520.83 cover dressing rooms, requiring pendant lampholders to be prohibited in dressing rooms, luminaires in dressing rooms with exposed lamps to be provided with guards, and switches controlling receptacles adjacent to mirrors and above dressing table counters to be provided with pilot lights outside the dressing room.

Article 525 — Carnivals, Circuses, Fairs, and Similar Events

525.5(B) Clearances to Portable Structures. Portable structures shall be maintained not less than 4.5 m (15 ft) in any direction from overhead conductors operating at 600 volts or less, except for the conductors supplying the portable structure. Where the conductors operate at over 600 volts, the clearances in Table 525.5(B)(2) apply.

525.10 Services. Services shall be installed in accordance with Article 230 and the additional requirements in 525.10, including that service equipment shall not be accessible to unqualified persons and shall be mounted on a solid backing.

525.20 Wiring Methods. (A) Type. Where flexible cords or cables are used, they shall be listed for extra-hard usage. Where used outdoors, flexible cords and cables shall also be listed for wet locations and shall be sunlight resistant. (B) Single-Conductor. Single-conductor cable shall be permitted only in sizes 2 AWG or larger. (D) Support. Wiring for an amusement ride shall be supported. (E) Boxes and Fittings. A box or fitting shall be installed at each connection point, outlet, switch point, or junction point.

525.23 Ground-Fault Circuit-Interrupter Protection. (A) Where GFCI Protection Is Required. GFCI protection for personnel shall be provided for the following: all 125-volt, single-phase, 15- and 20-ampere non-locking-type receptacles used for disassembly and reassembly or readily accessible to the general public; and equipment that is readily accessible to the general public and supplied from a 125-volt, single-phase, 15- or 20-ampere branch circuit. (B) Where GFCI Protection Is Not Permitted. Egress lighting shall not be GFCI protected.

525.32 Equipment Bonding. Lists the metal parts that must be bonded, including metal raceways, metal-sheathed cable, metal enclosures, metal frames and parts of rides and concessions, and other metal parts likely to become energized.

Article 590 — Temporary Installations

590.2(A) Other Articles. Except as specifically modified in Article 590, all other requirements of the Code for permanent wiring shall apply to temporary wiring installations.

590.3 Time Constraints.

• (A) During the Period of Construction. Temporary electrical power and lighting installations shall be permitted during the period of construction, remodeling, maintenance, repair, or demolition of buildings, structures, equipment, or similar activities.
• (B) 90 Days. Temporary electrical power and lighting installations shall be permitted for a period not to exceed 90 days for holiday decorative lighting and similar purposes.
• (C) Emergencies and Tests. Temporary electrical power and lighting installations shall be permitted during emergencies and for tests, experiments, and developmental work.
• (D) Removal. Temporary wiring shall be removed immediately upon completion of construction or purpose for which the wiring was installed.

590.4 General. (B) Feeders shall originate in an approved distribution center and shall be permitted to be run as multiconductor cord or cable assemblies, or, where not subject to physical damage, as single insulated conductors in a raceway or as open conductors supported on insulators. (C) Branch Circuits shall originate in an approved power outlet or panelboard. (D) Receptacles shall be of the grounding type. (G) Splices — a box, conduit body, or terminal fitting shall not be required for a splice in nonmetallic-sheathed cable or multiconductor Type UF cable, provided the equipment grounding continuity is maintained and the splices are made with a listed device. (J) Support — cable assemblies and flexible cords and cables shall be supported in place at intervals that ensure protection from physical damage, and shall not be installed in a manner that creates a trip hazard.

590.6 Ground-Fault Protection for Personnel.

• (A) Receptacle Outlets. Temporary receptacle installations used to supply temporary power to equipment used by personnel during construction, remodeling, maintenance, repair, or demolition shall comply with (A)(1), (A)(2), or (A)(3) as applicable. (A)(1) All 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are not a part of the permanent wiring of the building or structure and that are in use by personnel shall have GFCI protection for personnel. (A)(2) For receptacles other than 125-volt, single-phase, 15-, 20-, and 30-ampere, GFCI protection or an assured equipment grounding conductor program in accordance with 590.6(B)(2) shall be permitted. (A)(3) Receptacles that are part of the permanent wiring and used for temporary electric power shall have GFCI protection.
• (B) Use of Other Outlets. Where flexible cords or cables are used to supply equipment from receptacles other than those covered by 590.6(A), (B)(1) GFCI protection or (B)(2) an assured equipment grounding conductor program shall be provided.

590.7 Guarding. For wiring over 1000 volts, nominal, suitable fencing, barriers, or other effective means shall be provided to prevent access of other than authorized and qualified personnel.

590.8 Overcurrent Protective Device Identification requires each temporary overcurrent device to be legibly marked to indicate its purpose.

Alaska construction sites operate in conditions that put unusual strain on temporary wiring: cords frozen to the ground, snow load on temporary feeders, and enclosures that fill with drifted snow. 590.4(J) requires support that ensures protection from physical damage, 400.12(7) prohibits cord use where subject to physical damage, and 590.4(D) and 590.6(A) ensure grounding-type, GFCI-protected receptacles regardless of conditions.

Article 680 — Swimming Pools, Fountains, and Similar Installations

680.22(A)(1) Receptacles — Circulation and Sanitation System, Location. Receptacles that provide power for water-pump motors or for other loads directly related to the circulation and sanitation system shall be permitted to be located between 1.83 m (6 ft) and 3.0 m (10 ft) from the inside walls of the pool, and shall be single and of the grounding type, and shall be protected by a ground-fault circuit interrupter.

680.22(A)(2) Other Receptacles, Location. Other receptacles shall be not less than 1.83 m (6 ft) from the inside walls of a pool.

680.22(A)(3) Dwelling Unit(s). Where a permanently installed pool is installed at a dwelling unit, at least one 125-volt, 15- or 20-ampere receptacle on a general-purpose branch circuit shall be located not less than 1.83 m (6 ft) from, and not more than 6.0 m (20 ft) from, the inside wall of the pool. This receptacle shall be located not more than 2.0 m (6 ft 6 in.) above the floor, platform, or grade level serving the pool.

680.22(A)(4) Restricted Space. Receptacles shall not be installed in a space where the dimension from the inside wall of the pool is less than the specified distances, unless the specific allowance applies.

680.22(A)(5) GFCI Protection. All 15- and 20-ampere, single-phase, 125-volt through 250-volt receptacles located within 6.0 m (20 ft) of the inside walls of a pool shall be protected by a ground-fault circuit interrupter.

680.22(B) Luminaires, Lighting Outlets, and Ceiling-Suspended (Paddle) Fans. New outdoor luminaires and ceiling fans shall not be installed over the pool or over the area extending 1.5 m (5 ft) horizontally from the inside walls of the pool unless mounted at least 3.7 m (12 ft) above the maximum water level.

680.26 Equipotential Bonding. This is the heart of Article 680 and the item most likely to appear on an exam.

• (A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in the pool area.
• (B) Bonded Parts. The parts specified in (B)(1) through (B)(7) shall be bonded together:
  1. Conductive pool shells — bonding to conductive pool shells shall be as specified for concrete and vinyl liner pools;
  2. Perimeter surfaces — the perimeter surface shall extend for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall include unpaved surfaces as well as poured concrete and other types of paving. Bonding to perimeter surfaces shall be provided and attached to the pool reinforcing steel or copper conductor grid at a minimum of four points uniformly spaced around the perimeter of the pool;
  3. Metallic components of the pool structure;
  4. Underwater lighting — all metal forming shells and mounting brackets of no-niche luminaires;
  5. Metal fittings — all metal fittings within or attached to the pool structure, with an exception for isolated parts not over 4 inches in any dimension and not penetrating into the pool structure more than 1 inch;
  6. Electrical equipment — metal parts of electrical equipment associated with the pool water circulating system;
  7. Fixed metal parts — all fixed metal parts, with exceptions for parts separated by a permanent barrier, parts more than 1.5 m (5 ft) horizontally from the inside walls of the pool, and parts more than 3.7 m (12 ft) measured vertically above the maximum water level.
• (C) Pool Water. An intentional bond of a minimum conductive surface area of 5800 mm squared (9 in. squared) shall be installed in contact with the pool water.

The bonding conductor shall be a solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG. Connections shall be made in accordance with 250.8.

Note what equipotential bonding is not: it is not a grounding connection and it is not required to be extended to any remote panelboard, service equipment, or electrode. Its whole purpose is local — to hold everything a swimmer can touch at the same potential so no gradient exists across their body.

680.42 Outdoor Installations (Spas and Hot Tubs). A spa or hot tub installed outdoors shall comply with the provisions of Parts I and II of Article 680, except as modified. 680.42(B) permits the equipotential bonding requirements of 680.26(B)(2) to be satisfied by an alternative for listed self-contained spas and hot tubs.

680.44 Protection. The outlet(s) that supplies a self-contained spa or hot tub, a packaged spa or hot tub equipment assembly, or a field-assembled spa or hot tub shall be protected by a ground-fault circuit interrupter, with listed exceptions.

680.71 Hydromassage Bathtubs. Hydromassage bathtubs and their associated electrical components shall be on an individual branch circuit and protected by a readily accessible ground-fault circuit interrupter. All 125-volt, single-phase receptacles not exceeding 30 amperes and located within 1.83 m (6 ft) measured horizontally of the inside walls of a hydromassage tub shall be protected by a GFCI.