A modular low voltage multipole circuit breaker, including a plurality of identical single-pole breaking units each including a parallelipipedic insulating box having two opposite parallel large side faces and two opposite parallel small side faces, two terminals located at respective opposite parallel small side faces, a stationary contact electrically connected to one of the terminals, a movable contact cooperable between a first position contacting the stationary contact and a second position separated from the stationary contact and a molded case for housing the single-pole breaking units. The molded case has two opposite parallel side walls having the same thickness, the single-pole breaking units being sequentially arranged and parallel to each other and parallel to the side walls such that adjacent single-pole breaking units are spaced apart a distance equal to twice the thickness of the side walls, the single-pole breaking units being spaced apart at a constant pitch. An operating mechanism is provided to be common to all single-pole breaking units for simultaneously operating all single-pole breaking units.

Range of molded case low voltage circuit breakers

A circuit breaker rotary contact arm is used within a plurality of single pole circuit breakers ganged together to form a single multi-pole circuit breaker. To provide uniform contact wear among the associated circuit breaker contacts, the rotor carrying the rotary contact arm pivot is slotted to automatically position the rotary contact arm to allow for changes in the contact geometry while maintaining constant contact compressive forces. The individual circuit breakers connect with the central operation mechanism by means of a single pin.

Rotary contact assembly for high ampere-rated circuit breakers

A circuit breaker rotary contact assembly employs a common pivot between the rotor assembly and the rotary contact arm. A pair of off-center expansion springs directly engage the rotor at one end and engage the rotary contact arm via a linkage arrangement at an opposite end thereof.

A thermal-magnetic trip unit, suitable for use in a circuit breaker, for eliminating the requirement for latching surfaces while still providing the additional force and motion required to trip the breaker during a short circuit or an overcurrent trip event. The trip unit comprises a link that is biased based on the position of a trip bar. A spring biases the link in a first direction when the trip unit is in a reset condition and biases the link in a second direction when the trip bar is rotated about a pivot point. A trip unit further including an improved indication-of-trip system comprising a two-piece trip bar mechanism and flag system is described to discriminate between overcurrent and short circuit faults. In this embodiment of the invention, visual confirmation of the cause of the trip is provided. The case of the circuit breaker includes a window disposed therein in a location conducive to a user viewing an identification flag thus enabling the rapid determination of the type of trip which has occurred. To identify a trip caused by an overcurrent condition, a first flag is employed. To identify a trip caused by a short circuit condition, a second flag is employed. If an overcurrent event occurs then the first slide of the two piece trip bar mechanism moves to expose the first flag. If a short circuit event occurs, only the second slide of the two-piece trip bar system moves to expose the second flag.

Circuit breaker thermal magnetic trip unit

A pressure sensitive trip mechanism for actuating a circuit breaker operating mechanism to trip a circuit breaker includes a trip lever and a trip bar The trip lever is rotatable about a first pivot The trip bar is positioned proximate the trip lever The trip bar is arranged to rotate about a second pivot in response to a predetermined level of pressurized gas created by separation of the pair of electrical contacts, thereby urging the trip lever to unlatch the circuit breaker operating mechanism The pressure sensitive trip mechanism provides for very fast tripping of the circuit breaker in the event of a short circuit condition or an overcurrent fault condition within any one on the circuit breaker poles In a multi-pole circuit breaker, the present invention provides for protection against single-phasing

Pressure sensitive trip mechanism for a rotary breaker

A limiting circuit breaker with a molded case comprises an overpressure actuator which, when an overpressure occurs in the arc extinguishing chamber due to the action of an arc drawn by the electrodynamic repulsion of the contacts, brings about actuation by a piston, subjected to this overpressure, of the circuit breaker trip bar. The overpressure actuator forms an almost leaktight assembly.

Instantaneous trip device of a circuit breaker

A circuit-breaker with moulded casing (10) of the limiter type includes an overpressure actuator (26, 27) bringing about, when an overpressure appears in the disconnection chamber (13) under the action of an arc drawn by the electrodynamic repulsion of the contacts (11, 12), actuation by a piston (26), subjected to this overpressure, of the tripping bar (23) of the circuit-breaker. The overpressure actuator constitutes a quasi-sealed unit.

Instantaneous tripping unit for a circuit breaker

Momentauslöser für einen Schalter.

Un disjoncteur a boitier moule (10) du type limiteur comporte un actionneur a surpression (26,27) provoquant lors de l'apparition d'une surpression dans la chambre de coupure (13) sous l'action d'un arc tire par la repulsion electrodynamique des contacts (11,12), un actionnement par un piston (26), soumis a cette surpression, de la barre de declenchement (23) du disjoncteur. L'actionneur a surpression constitue un ensemble quasi-etanche.

Hubert Merlin Gerin Garcia

Papers

Instantaneous trip device of a circuit breaker

Instantaneous tripping unit for a circuit breaker

Momentauslöser für einen Schalter.

Déclencheur instantané d'un disjoncteur