SU1483506A1 - Automatic circuit breaker - Google Patents

Abstract

The invention relates to electrical engineering and can be used in low-voltage switching devices. The purpose of the invention is to provide automatic reclosing (AR) at short-circuit currents exceeding the set current of the breaker node. At circuit currents exceeding the set point of the cut-off node, the speed of movement of the movable contact 2 is sufficient for charging the free tripping mechanism. Pin 2, the path δ, presses on the protrusion 15 of the lever 4 in the direction of engagement with the latch 6. If the energy level of the arc exceeds the specified level, which corresponds to the case of disconnection of the circuit with one switch, the switch mechanism is not activated and the AR does not occur. If the arc energy is less than a predetermined level, which is caused by participation in the disconnection of the circuit and the downstream circuit breaker, the lever 4 engages with the latch 6 and triggers the free tripping mechanism. Since the handle 10 of the switch is held by the remote actuator carriage 12 in the "on" position, the springs 11 of the mechanism automatically restart the circuit. 2 Il.

Description

The invention relates to electrical engineering and can be used in low-voltage electrical switching devices intended for selective (selective) protection of circuits.

The aim of the invention is to provide an automatic reclosing (ALV) at short-circuit currents (SC) exceeding the set value of the opening action of the cut-off circuit breaker.

FIG. 1 shows the circuit breaker in the Disabled position automatically; in fig. 2 - the same, with a modified implementation of the stop moving contact.

The switch contains, in each pole, a fixed contact 1 installed on the base with a device for compensating the electrodynamic forces of their rejection, made in the form of a double electrodynamic loop, a movable contact 2 and a free tripping mechanism, which includes breaking levers 3 connected to the moving contact 2, uncoupling the lever 4, which engages with the latch 5, which, in turn, engages with the disconnecting rail 6. The latch 5 is mounted on the axis 7, which can move upwards in an extended hole 8. On the axis 7 affects the adjustment unit with a screw and a spring 9, which provides the setpoint. - node cutoff. The handle 10 is connected by a spring 11 with breaking levers 3 mechanisms. A remote control carriage 12 (not shown) is worn on the switch 10 handle. The switch also contains the overcurrent release 13 and the arc energy release 14. The stop, on which the movable contact is supported in the open state, is made in the form of a protrusion 15 of the tripping lever 4 of the free tripping mechanism (Fig. 1). The function of the stop can also be performed by the clamp 16 fixed on the same axis with the release lever 4, the end 17 of which is held in the initial position by the spring 18

The switch works as follows.

When a short circuit in the circuit when the short-circuit current value is less than the current cut-off angle setting, the mechanism trips when the maximum current release 13 influences the tripping rail 6. When the latter is turned, the latch 5 disengages from the rail 6 and releases the tripping lever 4. Under by the action of the tension spring 1 of the mechanism, the common axis of the breaking arms 3

Q starts moving upwards, moving contact 2 is also carried along. At the same time, the moving contact 2 also acts on the moving contact 2 from the side of the compensating electrodynamic device of the fixed contact of tact 1 and the electrodynamic forces caused by the flow of short-circuit current. And although these forces act only in the path of failure selection, they increase

0 contact speed when moving them to the Disabled position, Since when switching the short-circuit current less than the cut-off current, the circuit is disconnected with a deliberate time delay,

5 the magnitude of the forces acting on the moving system from the side of the compensators will be significantly (several times) less than if this current were turned off without a time delay.

r. (during the first half period). Passing the path S, the moving contact 2 starts to press the protrusion 15 of the lever 4 towards the engagement with the latch 5. As the handle 10 is held by the carriage 12 of the remote drive,

the On position, when the release lever 4 moves towards the engagement with the catch 5, the spring 11 of the mechanism begins to stretch. Thereby, forces are created that prevent further movement of the movable contact 2 to the side of disconnection. In this case, the movable contact 2 occupies a position corresponding to the contact solution S in the initial position of the switch Disconnected automatically. This position is determined by a non-rigid (spring-loaded) stop of the movable contact 2 into the protrusion 15 of the tripping device.

0 lever 4 (fig. 1) or in bracket 16

(Fig. 2), the position of which, in turn, is determined mainly by the tension of the spring 11 (Fig. 1) or the springs 11 and 18 (Fig. 2) in the disengaged state of the free release mechanism.

When disconnecting short-circuit currents exceeding the cut-off current of the switch,

0

Moving contact 2, moving in the direction of opening, travels a path equal in magnitude to S + (20-40%) S (the corresponding position of moving contact 2 is shown in dashed lines) and is sufficient to provide an automatic charging of the free tripping mechanism. The latter is achieved by the action of the movable contact 2 through the protrusion 15 of the lever 4 (Fig. 1) or through the bracket 16 to the lever 4 (Fig. 2), which creates the necessary conditions for the subsequent automatic reclosing of the switch (engagement of the lever 4 with the latch 5 of the free tripping mechanism).

Since the handle 10 of the switch is held in the On position, after the kinetic energy of the movable contact 2 is used to energize the mechanism, forces directed to the contact side will affect the movable contact 2 on the spring side 11 of the mechanism. Thus, due to the use of electrodynamic forces, after switching off the short-circuit current, the device will automatically be switched on again. But such a re-start will occur only if the value of the arc energy released will be less than the trip threshold of the release, which reacts to the value of the arc energy, and this will be the case when the downstream switch in the power supply system participates in the shutdown. If, however, only this device participates in switching off the short-circuit current, then the arc energy exceeds the trigger threshold of the tripping arc energy 14, and by turning the disconnecting rail 6, it will exclude the possibility of the lever 4 hooking up for 0

five

0

five

0

five

0

five

click 5, which means the switch will not turn on again. This ensures the selectivity of the protection of circuits in the range of short-circuit currents exceeding the cut-off current of the switch.

Claims (1)

Invention Formula A circuit breaker that contains a remote drive, moving and fixed contacts, a device for compensating electrodynamic forces of discharge, an emphasis on which a moving contact rests with a complete solution of the contacts, a free disconnect mechanism with a tripping rail, an overcurrent release with time delay and a release that responds to energy arc, the latch cut-off assembly in the form of a latch of the free tripping mechanism, with which the end of the tripping lever of the free tripping mechanism engages mounted on an axis in the rack with the possibility of additional movement together with the axis in the direction of disengagement of the latch with the rack, while a spring is attached to the axis of the latch, creating a force in the opposite direction to the movement during disengagement. automatic reclosing at short-circuit currents exceeding the set current of the operation of the switch-off node, the emphasis is made as a protrusion on the tripping lever of the free tripping mechanism, located relative to the axis of the lever on the other side of its end, which enters into engagement with the latch mechanism of the free tripping. FIG. 2