Special Occupancies
Mobile Homes (550), Recreational Vehicle Parks (551) and Marinas/Docking Facilities (555)
NFPA 70 National Electrical Code, 2023 edition · Reviewed 2026-09-21
Three Chapter 5 articles the Florida blueprint groups under "special occupancies" that share one idea: the structure is a plug-in load — a mobile home feeder assembly, an RV site pedestal, a shore-power receptacle — so the Code fixes the receptacle configurations, the demand factors, the mounting heights and the ground-fault protection. In the 2023 edition the demand tables live inside the articles: mobile home parks use Table 550.31, RV parks use Table 551.73(A), and marina shore power uses the 220.120 demand factors referenced by 555.6. Written from the 2023 text (the Florida edition; 2023 section numbers throughout).
1. Mobile and manufactured homes — Article 550
- 550.10 power supply: not more than one listed 50 A mobile home power-supply cord (40 A permitted where the home is factory-equipped with gas or oil central heating and cooking), or a permanently installed feeder. The feeder assembly is permanently attached to the panelboard (or a junction box tied to it), has four conductors (one green or green/yellow EGC), a strain-relief clamp at the panel knockout, and terminates in a 3-pole, 4-wire grounding-type attachment plug cap rated 50 A, 125/250 V (Figure 550.10(C)); a right-angle cap is oriented with the grounding member farthest from the cord. No adapters, pigtails or extension cords ship with the home. Cord length: 21 ft to 36½ ft overall (bared leads to plug face), at least 20 ft from the plug face to the entry point; marked "FOR USE WITH MOBILE HOMES — 40 (or 50) AMPERES". Where the calculated load exceeds 50 A or a permanent feeder is used: a mast weatherhead with four insulated color-coded conductors, or RMC/IMC/PVC from the disconnect to the underside of the home.
- 550.11 disconnect/panelboard: a single disconnect near the point of entrance, main marked "Main", ≥ 24 in. from the bottom of the equipment to the floor, not in a bathroom or clothes closet, 30 in. × 30 in. working space; a 50 A cord needs a panelboard rated ≥ 50 A with a 2-pole 50 A main breaker (40 A for a 40 A cord).
- **550.18 load calculation (in lieu of Article 220)
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