Uma verificação rápida da seção de definição da NEC 2008 pode fornecer uma resposta. A proteção do GFCI é necessária em todos os locais molhados e úmidos. Também é necessário em alguns locais secos, onde especificado no código.
Location, Damp. Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture. Examples of such locations include partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements, some barns, and some coldstorage warehouses.
Location, Dry. A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.
Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.
Vejamos também a seção 406.8 Receptáculos em locais úmidos ou úmidos.
(A) Damp Locations. A receptacle shall be considered to be in a location protected from the weather where located under roofed open porches, canopies, marquees, and the like, and will not be subjected to a beating rain or water runoff.
De acordo com esta seção, você também pode precisar de uma cobertura à prova de intempéries para os receptáculos.
A receptacle installed outdoors in a location protected from the weather or in other damp locations shall have an enclosure for the receptacle that is weatherproof when the receptacle is covered (attachment plug cap not inserted and receptacle covers closed).
Você pode ter um pouco de espaço de manobra se o espaço estiver completamente fechado, mas você ainda pode considerar a proteção do GFCI apenas para estar no lado seguro.
Seção 210.8 Proteção de Interruptor de Interruptor de Falha de Aterramento para Pessoal. especifica localizações que requerem proteção de GFCI.
(A) Dwelling Units. All 125-volt, single-phase, 15- and 20-ampere receptacles installed in the locations specified in (1) through (8) shall have ground-fault circuit-interrupter protection for personnel.
(1) Bathrooms
(2) Garages, and also accessory buildings that have a floor located at or below grade level not intended as habitable rooms and limited to storage areas, work areas, and areas of similar use
(3) Outdoors
Exception to (3): Receptacles that are not readily accessible and are supplied by a dedicated branch circuit for electric snow-melting or deicing equipment shall be permitted to be installed in accordance with 426.28.
(4) Crawl spaces — at or below grade level
(5) Unfinished basements — for purposes of this section, unfinished basements are defined as portions or areas of the basement not intended as habitable rooms and limited to storage areas, work areas, and the like
Exception to (5): A receptacle supplying only a permanently installed fire alarm or burglar alarm system shall not be required to have ground-fault circuit-interrupter protection.
FPN: See 760.41(B) and 760.121(B) for power supply requirements for fire alarm systems. Receptacles installed under the exception to 210.8(A)(5) shall not be considered as meeting the requirements of 210.52(G).
(6) Kitchens — where the receptacles are installed to serve the countertop surfaces
(7) Laundry, utility, and wet bar sinks — where the receptacles are installed within 1.8 m (6 ft) of the outside edge of the sink
(8) Boathouses
Dependendo da construção da varanda, esse espaço pode ou não ser considerado "ao ar livre". Como " outdoors " não é especificamente definido, eu colocaria o lado de precaução e instalaria proteções GFCI e à prova de intempéries. Use seu melhor julgamento e as definições de locais úmidos, secos e molhados para tomar uma decisão. No entanto, tenha em mente que o inspetor terá a palavra final sobre o que é e não é exigido.