Understanding NEC Article 551: Recreational Vehicles and Recreational Vehicle Parks

NEC Article 551 establishes electrical safety standards for recreational vehicles (RVs) and RV parks, addressing wiring, grounding, and equipment connections. It ensures that electrical installations meet safety requirements for both temporary and permanent use in these unique environments.

Scope of Article 551

This article applies to:

• Recreational Vehicles: Portable vehicles designed for travel or camping, equipped with living accommodations and electrical systems.
• Recreational Vehicle Parks: Areas designed to accommodate multiple RVs with electrical hookups.

Referenced Standards:

• NFPA 1192: Standard on Recreational Vehicles.
• ANSI/RVIA LV: Standards for low-voltage systems in RVs.

Key Requirements for Recreational Vehicles

1. Combination Electrical Systems
   • RVs may use dual electrical systems, including low-voltage DC and 120/240-volt AC systems.
   • Voltage converters and dual-voltage fixtures must be listed and installed with proper separation between AC and DC wiring.
2. Generator Installations
   • Generators must be bonded to the RV chassis and ventilated per manufacturer specifications.
   • Automatic transfer switches are required to prevent simultaneous connection to multiple power sources.
3. Branch Circuits
   • RVs must include appropriate branch circuits based on their electrical load, with GFCI protection in wet locations like kitchens and bathrooms.
   • Panelboards must be listed, rated, and accessible.
4. Grounding and Bonding
   • Metal parts, such as the chassis and enclosures, must be bonded to the RV’s electrical system.
   • Grounding continuity must be maintained, even if components are removed.

Key Requirements for Recreational Vehicle Parks

1. Site Supply Equipment
   • Electrical hookups at each RV site must provide:
     • 20-amp, 30-amp, or 50-amp weather-resistant receptacles.
     • GFCI protection for 15- and 20-amp outlets.
   • Disconnecting means and overcurrent protection are required at each site.
2. Distribution Systems
   • Power distribution must accommodate RV loads, calculated per NEC demand factors.
   • Systems may include single-phase or three-phase feeders with balanced load distribution.
3. Overhead and Underground Conductors
   • Overhead conductors must maintain proper clearance from RVs and structures.
   • Underground conductors must be protected in raceways or conduits in areas prone to damage.
4. Load Calculations and Protection
   • Park distribution systems must meet demand factors for varying site capacities.
   • Overcurrent protection ensures equipment and conductors are not overloaded.

Applications

NEC Article 551 is essential for ensuring safe electrical installations in:

• Recreational Vehicles: For personal or commercial use.
• RV Parks: Providing temporary or permanent accommodations for travelers.
• Campgrounds: With electrical hookups for tents or trailers.

Conclusion

NEC Article 551 ensures the safety and reliability of electrical systems in RVs and parks by addressing dual-voltage systems, grounding, and site supply requirements. By adhering to these standards, users can ensure compliance and minimize risks in recreational environments.