The wild leg is the high leg of a 120/240 V four-wire delta service, where one transformer winding is center-tapped to create the neutral. Two phases read 120 V to neutral, but the third reads about 208 V and will burn up any 120 V load connected to it. Code requires it to be marked orange and placed on the B phase in panelboards, and anyone working in a panel fed by a delta service checks for it before landing a single-pole breaker.
B phase is the wild leg in this panel, orange tape on it, don't put a single-pole breaker anywhere on that bus.
Also heard as
- high leg
- red leg
- stinger leg
- power leg
Related terms
Hot
Ungrounded, voltage-carrying conductor of a circuit, and as an adjective anything that is live.
Tub
Empty panel enclosure, the steel back box that goes in at rough-in before the interior and cover arrive.
Guts
Interior of a panel: the bus bars, breaker mounting and neutral assembly that bolt into the enclosure.