Electrical equipment in damp or wet locations must be placed in enclosures that prevent moisture entry and are listed for wet locations to ensure safe operation.

Portable substations must include grounding conductors that connect to the building’s disconnecting means and grounding electrodes, ensuring safe operation.

Portable structures supplied by multiple sources separated by less than 12 feet must have their equipment grounding conductors bonded together to ensure safety.

Pilot lights indicate the presence of power, ensuring operators are aware of live circuits before activating or deactivating switches.

Mobile home service equipment must be rated for at least 100
amperes at 120/240 volts, ensuring it can handle typical loads.

Conductors must be at least 8 AWG and have an ampacity that meets or exceeds the projector’s current rating to ensure safe operation.

Portable structures must maintain at least 15 feet of clearance from overhead conductors operating at 600 volts or less.

Stage lighting circuits must match the overcurrent device rating and are exempt from certain NEC requirements, like Table 210.21(B)(2).

Flexible cords used for portable equipment in projection rooms must be approved for hard usage per NEC Table 400.4 to ensure durability and safety.

Article 547 permits specific wiring methods such as Type UF, NMC, SE copper cables, jacketed MC cables, and appropriate raceways to address environmental challenges in agricultural buildings.

Demand factors reduce progressively, starting at 100% for the first 50,000 VA, 75% up to 100,000 VA, 60% up to 200,000 VA, and 50% for any load over 200,000 VA.

Illumination must be provided for outdoor service equipment, but additional lighting outlets are unnecessary if adjacent lighting is adequate.

Equipotential planes are required in confinement areas with concrete floors where livestock may contact metallic equipment that could become energized.

Ampacity adjustment factors depend on the number of current-carrying conductors in the multiconductor cord, per Table 520.44(C)(2).

Article 547 applies to agricultural buildings where environmental conditions like dust, moisture, and corrosive agents are present due to farming operations.

Mobile home service equipment must be rated for at least 100
amperes at 120/240 volts, ensuring it can handle typical loads.

For theaters requiring fire-rated construction, only metal raceways or concrete-encased nonmetallic raceways are permitted, along with listed metal cables.

Live parts must be enclosed, guarded, or positioned to prevent accidental contact or conductive material from touching energized parts.

Permanent installations in studios must use metal raceways, concrete-encased nonmetallic raceways, or listed metal cables with appropriate grounding conductors.

Temporary wiring in exhibition halls must meet Article 590 requirements, use approved cords, and may require specific markings.

The neutral terminal must have an ampacity twice that of the largest ungrounded terminal to safely accommodate potential current imbalances in 3-phase, 4-wire systems.

Lamps in backstage areas must be guarded and located to avoid physical damage or contact with combustibles, minimizing fire and safety risks.

In closed construction, cables must be secured at cabinets, boxes, or fittings when 10 AWG or smaller conductors are used to ensure safety and durability.

The overall length of a power-supply cord for a mobile home must be between 21 feet and 36.5 feet, providing adequate reach without excessive slack.

Neutral conductors must be marked white or gray at both ends for easy identification, enhancing safety during connections.

Manufactured homes are built on a chassis for transport and may not have a permanent foundation. Manufactured buildings are constructed offsite but installed on permanent foundations.

Article 540 applies to motion picture projection rooms and equipment, focusing on light sources that may produce hazardous gases, dust, or radiation.

Single-pole separable connectors with internal parallel connections must be prominently labeled to indicate the presence of such connections.

This article applies to the portable wiring and equipment used in temporary attractions, including carnivals, circuses, and fairs.

Temporary use of portable equipment outdoors is permitted if it is supervised by qualified personnel and kept away from public access.

Flexible cords used outdoors must be listed for wet locations and sunlight resistance to handle environmental exposure.

Mobile home service equipment must be rated for at least 100
amperes at 120/240 volts, ensuring it can handle typical loads.

Article 520 specifically addresses areas used for performances, such as theaters and studio audience areas.

Disappearing footlights must automatically disconnect from power when retracted into their storage recess to prevent heat buildup and potential fire hazards.

Article 550 applies to the electrical systems in mobile and manufactured homes, their connections to electrical supplies, and installations in mobile home parks.

Underground grounding conductors must be insulated to withstand the corrosive conditions common in agricultural settings and minimize leakage currents.

Electrical equipment in audience paths must be protected using secured nonconductive matting or other approved methods to prevent hazards.

Connectors must be designed to prevent mechanical tension from being transmitted to the connections, ensuring safe and reliable use.

Overcurrent devices for power-limited control circuits must not exceed 167% of the source’s volt-ampere rating divided by the rated voltage, ensuring proper system protection.

For phase-control dimming systems, the neutral conductor must have an ampacity of 130% of the ungrounded conductors due to harmonic currents.

Conductors must be rated at least 125°C to handle the heat generated by stage lighting equipment.

The overall length of a power-supply cord for a mobile home must be between 21 feet and 36.5 feet, providing adequate reach without excessive slack

Article 550 applies to the electrical systems in mobile and
manufactured homes, their connections to electrical supplies, and installations in mobile home parks.

Special-purpose multicircuit connectors must clearly display the voltage of the branch circuits they service to prevent misuse.

Single-conductor supply cables must be at least 2 AWG for phase conductors and 6 AWG for grounding conductors to meet NEC safety standards.

Single conductors used outside enclosures in control systems must be a minimum of 18 AWG, ensuring adequate strength and ampacity.

Article 530 applies to motion picture and television studios, as well as remote locations staffed by trained and qualified personnel.

Fire-rated construction must use robust methods such as metal raceways, flexible metal raceways, or metallic-sheathed cables to maintain safety.

The control voltage for systems in permanent amusement attractions is limited to 150 volts ac or 300 volts dc to ground to prevent hazards.

All receptacles accessible from outside a relocatable structure must have GFCI protection to ensure personnel safety, in addition to the general requirements of NEC 210.8(B).