Known by its grey outer sheathing, this type of outdoor electrical wire (Underground Feeder Cable) is generally used to power outside equipment and fixtures such as post lamps, pumps, and other devices installed in wet or damp locations.
UF-B cable may be used underground, including direct earth burial (no conduit or raceway required).
Multiple conductor UF-B cable may be used for interior branch circuit wiring in residential or agricultural buildings at conductor temperatures not to exceed 90°C (with ampacity limited to that for 60°C conductors) as specified by the National Electrical Code.
Type UF-B Wire Manufacturer’s Specification Sheet.
Type UF-B Wire Composition and Sample Uses.