Article 550 Mobile Homes, Manufactured Homes, and Mobile Home Parks
Informational Note: For additional information on manufactured housing see NFPA 501-2017, Standard on Manufactured Housing, and Part 3280, Manufactured Home Construction and Safety Standards, of the Federal Department of Housing and Urban Development.
Appliance, Fixed. This definition shall apply only within this article.
Appliance, Portable. This definition shall apply only within this article.
An appliance that is actually moved or can easily be moved from one place to another in normal use.
Informational Note: For the purpose of this article, the following major appliances, other than built-in, are considered portable if cord connected: refrigerators, range equipment, clothes washers, dishwashers without booster heaters, or other similar appliances.
Feeder Assembly. This definition shall apply only within this article.
The overhead or under-chassis feeder conductors, including the equipment grounding conductor, together with the necessary fittings and equipment or a power-supply cord listed for mobile home use, identified for the delivery of energy from the source of electrical supply to the panelboard within the mobile home.
Manufactured Home. This definition shall apply within this article and throughout the Code.
A structure, transportable in one or more sections, which in the traveling mode is 2.4 m (8 ft) or more in width or 12.2 m (40 ft) or more in length, or when erected on site is 29.77 m2(320 ft2) or more is built on a permanent chassis and is designed to be used as a dwelling with or without a permanent foundation, whether or not connected to the utilities, and includes plumbing, heating, air conditioning, and electrical systems contained therein. The term manufactured home includes any structure that meets all the requirements of this paragraph except the size requirements and with respect to which the manufacturer voluntarily files a certification required by the regulatory agency. Calculations used to determine the number of square meters (square feet) in a structure are based on the structure's exterior dimensions and include all expandable rooms, cabinets, and other projections containing interior space, but do not include bay windows. [501:1.2.13] For the purpose of this Code and unless otherwise indicated, the term mobile home includes manufactured homes and excludes park trailers defined in 552.4.
Informational Note No. 1: See the applicable building code for definition of the term permanent foundation.
Informational Note No. 2: See 24 CFR Part 3280, Manufactured Home Construction and Safety Standards, of the Federal Department of Housing and Urban Development, for additional information on the definition.
Mobile Home. This definition shall apply within this article and throughout the Code.
A factory-assembled structure or structures transportable in one or more sections that are built on a permanent chassis and designed to be used as a dwelling without a permanent foundation where connected to the required utilities and that include the plumbing, heating, air-conditioning, and electrical systems contained therein.
Mobile Home Accessory Building or Structure. This definition shall apply only within this article.
Mobile Home Lot. This definition shall apply only within this article.
Mobile Home Park. This definition shall apply only within this article.
A contiguous parcel of land that is used for the accommodation of occupied mobile homes.
Mobile Home Service Equipment. This definition shall apply only within this article.
Park Electrical Wiring Systems. This definition shall apply only within this article.
Exception No. 1: A mobile home that is factory equipped with gas or oil-fired central heating equipment and cooking appliances shall be. permitted to be provided with a listed mobile home power-supply cord rated 40 amperes.
A suitable clamp or the equivalent shall be provided at the panelboard knockout to afford strain relief for the cord to prevent strain from being transmitted to the terminals when the power-supply cord is handled in its intended manner.
The cord shall be a listed type with four conductors, one of which shall be identified by a continuous green color or a continuous green color with one or more yellow stripes for use as the equipment grounding conductor.
- One mast weatherhead installation, installed in accordance with Article 230, containing four continuous, insulated, color-coded feeder conductors, one of which shall be an equipment grounding conductor
- A metal raceway or rigid nonmetallic conduit from the disconnecting means in the mobile home to the underside of the mobile home, with provisions for the attachment to a suitable junction box or fitting to the raceway on the underside of the mobile home [with or without conductors as in 550.10(1)(1)]. The manufacturer shall provide written installation instructions stating the proper feeder conductor sizes for the raceway and the size of the junction box to be used.
Where plug fuses and fuseholders are used, they shall be tamper-resistant Type S, enclosed in dead-front fuse panel-boards. Electrical panelboards containing circuit breakers shall also be dead-front type.
Informational Note: See 550.20(B) for information on disconnecting means for branch circuits designed to energize heating or air-conditioning equipment, or both, located outside the mobile home, other than room air conditioners.
A panelboard shall be rated not less than 50 amperes and employ a 2-pole circuit breaker rated 40 amperes for a 40-ampere supply cord, or 50 amperes for a 50-ampere supply cord. A panelboard employing a disconnect switch and fuses shall be rated 60 amperes and shall employ a single 2-pole, 60-ampere fuseholder with 40- or 50-ampere main fuses for 40- or 50-ampere supply cords, respectively. The outside of the panel-board shall be plainly marked with the fuse size.
The panelboard shall be located in an accessible location but shall not be located in a bathroom or a clothes closet. A clear working space at least 750 mm (30 in.) wide and 750 mm (30 in.) in front of the panelboard shall be provided. This space shall extend from the floor to the top of the panelboard.
- Not more than the circuit conductors; and
- Not more than 150 percent of the rating of a single appliance rated 13.3 amperes or more that is supplied by an individual branch circuit; but
- Not more than the overcurrent protection size and of the type marked on the air conditioner or other motor-operated appliance.