A weatherhead, also called a weathercap, service head, service entrance cap, or gooseneck (slang) is a
weatherproof service drop entry point where overhead power or telephone wires enter a building, or where wires transition between overhead and underground cables. At a building the wires enter a
conduit, a protective metal pipe, and the weatherhead is a waterproof cap on the end of the conduit that allows the wires to enter without letting in water. It is shaped like a
hood, with the surface where the wires enter facing down at an
angle
In Euclidean geometry, an angle can refer to a number of concepts relating to the intersection of two straight Line (geometry), lines at a Point (geometry), point. Formally, an angle is a figure lying in a Euclidean plane, plane formed by two R ...
of at least 45°, to shield it from precipitation. A
rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds.
Types of polyisoprene ...
ized
gasket makes for a tight
seal against the
wire
file:Sample cross-section of high tension power (pylon) line.jpg, Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample d ...
s. Before they enter the weatherhead, a ''drip loop'' is left in the
overhead wires, which permits
rain water that collects on the wires to drip off before reaching the weatherhead.
A weatherhead termination is only used at low voltages (up to 600 volts), since higher distribution voltages require more insulation between conductors and metal enclosures. Higher-voltage connections are made through a
pothead.
[Anthony J. Pansini. ''Guide to Electrical Power Distribution Systems'', The Fairmont Press, 2005. . page 138.]
Weatherheads are required by
electrical codes or
building codes. They are also used on
utility pole
A utility pole, commonly referred to as a transmission pole, telephone pole, telecommunication pole, power pole, hydro pole, telegraph pole, or telegraph post, is a column or post used to support overhead power lines and various other public util ...
s where
overhead power lines enter a conduit to pass underground.
References
Electric power systems components
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