NOVELTY - The arrangement has device for disconnecting current of power distribution line, when current of distribution line exceeds first tripping condition. A current sensor (41) measures current of power distribution line. The device sets second tripping condition. A control unit compares the value of measured current with second tripping condition. A actuator unit mechanically turns lever of circuit breaker (11). The control unit drives actuator to turn lever into OFF position, when second tripping condition is met, so that the current of distribution line is disconnected.    USE - Circuit breaker arrangement for power distribution line such as switching power supplies, used for providing direct current (DC) supply for various electronic devices, such as base stations in cellular communications system and used in DC and AC power distribution lines such as telecommunication systems, electric car applications, and solar panels for circuit protection.    ADVANTAGE - Since the control unit drives actuator to turn lever into OFF position, when second tripping condition is met, so that the current of distribution line is disconnected, the electromechanical circuit breaker can provide backup overload protection as it trips according to its nominal tripping condition independently on the overload protection circuit. This enables energy savings, because the feeding supply is shut down with remotely controlled on/off interfaces and more energy is conserved so the manual mechanically turning off devices is needed. Hence, the operation of power distribution unit is monitored and controlled remotely, without a need to travel to the location of installation. The difference between the time values of the graph and the trip threshold values of the overload protection device depend on the current measurement accuracy, timing resolution of the overload protection arrangement.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a power distribution unit for supplying electrical power from at least one power supply to at least one load.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of circuit breaker arrangement and power distribution unit.    Electromechanical circuit breaker (11)    Core (24)    Current sensor (41)    Signal amplifier (47)    Manual current selector (58)