Single- or multi-pole power circuit-breaker and modular system

A single- or multi-pole power circuit-breaker, comprising, for each pole:

• main contacts;
• overload- and/or short-circuit current-actuated tripping means;
• an actuating mechanism configured to open and close the main contacts;
• an arc chute;
• and
• a pressure trip unit having a return element and an actuating element responsive to an overpressure in the arc chute,
• wherein tripping of the power circuit-breaker by a trip mechanism is executable both by the tripping means and by the pressure trip unit,
• wherein the pressure trip unit is arranged immediately adjacently to both the arc chute and to a main busbar which is routed to the main contacts, and is arranged within a closed pressure chamber which is connected to the arc chute,
• wherein at least one tripping lug which projects from the actuating element is configured to mechanically engage with the trip mechanism such that the overpressure in the arc chute associated with a generation of an arc between the main contacts is transmitted virtually instantaneously to the pressure chamber, where the overpressure acts on the actuating element of the pressure trip unit,
• wherein the actuating element is configured to switch over directly from a home position to a tripping position, against a force of the return element, in a case of overshoot of a pressure threshold value which is set by the return element,
• wherein the actuating element comprises a gate which is arranged to pivot about a pivoting axis, and
• wherein the gate includes laterally-projecting shielding elements which, with the pressure trip unit in a service position, at least partially cover the return element.

A single- or multi-pole power circuit-breaker, comprising, for each pole:

• main contacts;
• overload- and/or short-circuit current-actuated tripping means;
• an actuating mechanism configured to open and close the main contacts;
• an arc chute;
• and
• a pressure trip unit having a return element and an actuating element responsive to an overpressure in the arc chute,
• wherein tripping of the power circuit-breaker by a trip mechanism is executable both by the tripping means and by the pressure trip unit,
• wherein the pressure trip unit is arranged immediately adjacently to both the arc chute and to a main busbar which is routed to the main contacts, and is arranged within a closed pressure chamber which is connected to the arc chute,
• wherein at least one tripping lug which projects from the actuating element is configured to mechanically engage with the trip mechanism such that the overpressure in the arc chute associated with a generation of an arc between the main contacts is transmitted virtually instantaneously to the pressure chamber, where the overpressure acts on the actuating element of the pressure trip unit,
• wherein the actuating element is configured to switch over directly from a home position to a tripping position, against a force of the return element, in a case of overshoot of a pressure threshold value which is set by the return element, and
• wherein the actuating element comprises a gate which is arranged to pivot about a pivoting axis,
• further comprising at least one sealing element arranged in the pressure chamber, wherein the gate, in a case of transition from the home position to the tripping position, is permanently sealed with respect to the at least one sealing element.