Q. What are the Code rules for installing receptacles in damp or wet locations?
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A. Receptacles installed in a damp location must be installed in an enclosure that’s weatherproof when an attachment plug cap isn’t inserted, and the receptacle cover is closed, or an enclosure that’s weatherproof when an attachment plug is inserted. All nonlocking 15A and 20A, 125V and 250V receptacles in a damp location must be listed as weather resistant [406.9(A)] (see Figure).
Damp locations include locations protected from weather and not subject to saturation with water or other liquids, as well as locations partially protected under canopies, marquees, roofed open porches, and interior locations that are subject to moderate degrees of moisture, such as some basements, barns, and cold-storage warehouses [Art. 100].
All 15A and 20A receptacles installed in a wet location must be within an enclosure that’s weatherproof when an attachment plug is inserted [406.9(B)(1)]. Outlet box hoods must be listed and must be identified for “extra-duty” use. All nonlocking type 15A and 20A, 125V and 250V receptacles in a wet location must be listed as weather resistant. Note: Exposed plastic surface material of weather-resistant receptacles must have UV resistance to ensure that deterioration from sunlight doesn’t take place, or that it’s minimal. In testing, receptacles are subjected to temperature cycling from very cold to very warm conditions, and then subjected to additional dielectric testing. The rapid transition from the cold to warm temperatures will change the relative humidity and moisture content on the device, and the dielectric test ensures that this won’t create a breakdown of the insulation properties.
Exception: Receptacles rated 15A and 20A that are subjected to routine high-pressure washing spray may have an enclosure that’s weatherproof when the attachment plug is removed.
A wet location is an area subject to saturation with water, as well as unprotected locations that are exposed to weather [Art. 100].
Receptacles rated 30A or more installed in a wet location must comply with (a) or (b) [406.9(B)(2)].
a) Wet Location Covers. A receptacle that’s in a wet location, where the load isn’t attended while in use, must be installed in an enclosure that’s weatherproof when an attachment plug is inserted.
b) Damp Location Covers. A receptacle installed in a wet location that will only be used while someone is in close proximity to it, such as one used with portable tools, can have an enclosure that’s weatherproof when the attachment plug is removed and the cover is closed.
Receptacles must not be installed within or directly over a bathtub or shower stall [406.9(C)].
The enclosure for a receptacle installed in an outlet box that’s flush-mounted on a finished surface must be made weatherproof by a weatherproof faceplate that provides a watertight connection between the plate and the finished surface [406.9(E)].
