RU2364015C2 - Residual current circuit breaker - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to electrical engineering and can be used in electrical equipment of buildings. Under normal operating conditions, a load (13) is connected to the mains, since actuating mechanism (4) closes power contacts (1, 2). The same current flows through conductors and windings (8, 9). No current flows through coil (5) and winding (6). When a person (14), standing on ground, touches phase conductor (L) in the load (13), current in the winding (9) will be greater than in winding (9). Current appears in winding (6) and relay coil (5), which leads to actuation of relay (5) and, consequently, actuating mechanism (4). Contacts (1, 2, 3) open under the effect of this mechanism. The person will not be subjected to further effect of electric current. The new protective property of the proposed device manifests in the breakage mode on the side of protective earth wire network (PEN). In this mode potential of phase (L) of the network is applied across the ground terminal, although an extra winding (12) provides protection in such a mode.

EFFECT: more reliable protection of a person from electric shock.

1 dwg

Description

The invention relates to the field of electrical engineering and can be used in the electrical equipment of buildings.

The closest in technical essence and the achieved results is a residual current circuit breaker containing a contact group of three contacts, with an actuator mechanically connected to the relay, the coil of which is connected to a winding wound on an annular core, which also contains two power windings connected to power contacts, and the third contact connects the input and output terminals opposite to each other through the series-connected button and resistor. The disadvantage of this device is the lack of security.

The aim of the invention is to increase safety. This goal is achieved due to the fact that the device is equipped with an additional fourth winding, designed to connect to its conclusions of the input and output of the grounding conductor in the opposite direction to other power windings.

The drawing shows the structure of the residual current device.

Two power contacts 1 and 2 and an interlock contact 3 form a contact group driven by an actuator 4 mechanically connected to a relay, a coil 5 of which is connected to a winding 6. The latter is wound on a core 7, on which power windings 8 and 9 are also located (phase and zero). Contact 3 is included in the test circuit, consisting of a button 10 and a resistor 11. The fourth winding (protective earth) 12 is also located on the core 7, but counter to the previous one. In addition, the drawing shows two elements that illustrate the operation of the device and is not included in its composition. This is a load of 13 and a man of 14 standing on the ground. The drawing also indicates: N - neutral conductor, L - phase conductor, PE - grounding conductor, PEN - combined neutral and grounding conductor. Such a combination of PE conductors is carried out by the network (input).

The device operates as follows.

It is intended to protect a person from electric shock. Under normal conditions of use, the PEN conductor is not broken on the network side (an open circuit is shown in the drawing). The load 13 is connected to the network, as the actuator 4 closes the power contacts 1 and 2. The same current flows through the conductors and windings 8, 9. There is no current in coil 5 and winding 6. When a person 14 standing on the ground touches the phase (L) wire at load 13, the current in winding 9 will be greater than in winding 8. A current will appear in winding 6 and relay coil 5, which will trigger relay 5 and, therefore, actuator 4. Contacts 1, 2, 3 will open under the action of this mechanism. A person will not be subjected to further electric current.

The operation of the device can be tested in the on state by pressing the test button 10. This artificially creates an imbalance of currents in the windings 8 and 9, which leads to the shutdown of the device.

A new protective property of the proposed device is manifested in the open circuit on the network side of the integrated protective zero wire (PEN) wire. This mode is very possible, especially in rural and suburban areas, where the current supply is carried out by the air line. Such a break is shown in the drawing. In this mode, the potential of the phase (L) of the network with the load on is carried to the ground terminal. This conclusion is not closed at sockets. In addition, it connects to the body of electrical appliances. That is, a very high degree of touch, and therefore the likelihood of electric shock. Indeed, in this case, the electric shock current flows through the windings 8 and 9 in the opposite direction. And the device is not sensitive to this mode of electric shock. However, in the proposed device includes an additional winding 12, which provides protection in this mode. As a result of this, human security is improved.

Information sources

1. Recommendations for the design, installation and operation of buildings when using residual current circuit breakers. M., MPEI Publishing, 2001, p. 9, Fig. 3.2.

Claims (1)

A residual current device containing a contact group of three contacts, with an actuator mechanically connected to the relay, the coil of which is connected to a winding wound on an annular core, which also contains two power windings connected to the power contacts, and connects the third contact through series the included button and resistor are opposite input and output terminals, characterized in that it is equipped with a fourth winding designed to connect ground and input terminals to its terminals the measuring conductor in the opposite direction to other power windings.