Abstract: An isolating circuit breaker (40) for pole mounting (12) in relation to a electrical distribution line, said isolating circuit breaker including: an isolating switch (50) with a pivoting link (52), said isolating switch having respective terminals (45, 44) for electrical coupling to load and supply conductors (54, 53) of the electrical distribution line; a circuit interrupter (55) disposed in series with the isolating switch (50), intermediate said load and supply conductors and preferably incorporated in the pivoting link of the isolating switch; an actuator (58) arranged for selectively opening and closing the circuit interrupter (55); an electronic controller (61) controlling operation of the isolating circuit breaker in response to electrical conditions in the distribution line; and said isolating switch, circuit interrupter, actuator and electronic controller arranged together on a mounting structure (41, 42, 43) adapted for pole mounting.