RU2273935C1 - Device for active protection from influx of phase voltage onto body of device and damage from electric current - Google Patents

Abstract

FIELD: electric engineering, in particular, means for protecting from current damage when phase voltage hits body of device, for example, home appliance heating device.

SUBSTANCE: to body of device indicator for showing influx of phase voltage onto body is connected. Light signal coming from indicator is transformed in photo-transformer to electric current enough for activation of executive relay, disabling device from electric network. Device allows to avoid reassembling power grid in form of additional grounding wire connected to device, makes it possible to utilize two-contact sockets and plugs, also makes it possible to avoid recognition of zero wire in grid.

EFFECT: lower costs of protective means, expanded consumer capabilities of devices equipped with offered device, improved safety and comfort of device operation.

1 dwg

Description

The invention relates to electrical engineering, in particular to means of protection against electric shock when phase voltage gets onto the device body, for example, a household heating device.

Known devices for active protection against phase voltage entering the device case use various options for electrical connection of the device case to ground through specially grounded wire or connections to the neutral wire of the supply network, followed by a complete disconnection of voltage using fuses or other fuses operating from currents short circuit [1], [2], [3].

The disadvantages of the known protection devices are:

1. The need for rewiring the power supply network of the device, in case of grounding of the case, from two-wire to three-wire, as well as the need to switch to three-wire connectors [1]. This is the currently widely used protection device for the exploitation of domestic stoves. If the device is transferred for use to places equipped with a conventional two-wire electrical network, for example, to a summer residence, then it becomes dangerous to the life and health of the user.

2. The need to identify when connecting the device to the mains, which of the two wires is zero and which phase [2], which also does not guarantee against electric shock in case of accidental connection errors and during network repair.

3. Various touch devices [3], which allow to automatically determine the correct connection of the device to the zero wire of the network, are complex in design and roads.

4. In all known protection devices, when phase voltage enters the device case, not only the protected device, but the entire electrical network is disconnected to the first fuse.

The objectives of the invention are:

1. Cheaper cost of the protection device, which is achieved by the absence of the need to install an additional grounding electrical network and the localization of protective operation on one device protected by the device, and all other devices and the network as a whole remain in working condition.

2. The universalization of the protection device and the expansion of its consumer capabilities, i.e. providing protection against electric shock when the device is designed to operate in a network with a third grounding wire in a conventional two-wire network and vice versa, as well as providing protection against phase voltage entering the device from any extraneous AC voltage sources of a given magnitude.

3. Improving the safety of operation of devices, because device operation does not depend on errors in connecting the device to the network.

The invention is shown in the figure, it consists in the fact that an indicator I of the phase voltage incident on the housing is connected to the housing of the device 1, operating on the principle of using a bias current and thereby avoiding the use of a short circuit current for protective operation and grounding wires, consisting of in series interconnected: matching resistance 2, discharge lamp 3, isolated from the housing of the capacitor 4. The indicator I is connected to the housing at one end of the resistance 2. When enii phase voltage on the device in the circuit capacity indicator lamp appears bias current, the lamp glows. The light beam acts on the photoconverter II, in which the conversion of light energy into electrical energy and amplification of the electric signal to a value sufficient to operate the relay actuator 6, disconnecting the phase and neutral wires from the mains, only those devices that are protected by this device without affecting operability other serviceable devices powered from the same network, the signal lamp 7 is designed to alert the user of the device about the emergency condition and Proof of troubleshooting. Elements of circuit 2-6 are selected depending on the switched power and, in general, when using a modern element base, the protection device can be an inexpensive miniature device mounted on the body of electrical devices, which protects the device or series of devices for which it is installed in an accident, and not affecting other devices and the operability of the electrical network as a whole during an emergency shutdown of the protected device. The drawing conventionally shows the position when the protection tripped and the device is disconnected from the network.

Information sources

1. US patent 12.870.380, cl. 317-17, 1959.

2. Copyright certificate No. 762080, cl. H 02 H 3/14, 1980.

3. Copyright certificate No. 56534, cl. H 02 H 3/14.

Claims (1)

A protection device against phase voltage entering the device case and electric shock, consisting of an indicator of the phase voltage entering the device case, operating on the principle of using bias currents and thereby eliminating the use of a network of grounding wires and short circuit currents from the protection system for protective operation, consisting of matching resistance in series, a gas discharge lamp and a capacitor isolated from the housing, connected alone m the end of the matching resistance to the body of the device, issuing a signal in the form of a light flux, a photovoltaic converter that converts the light flux into an electric signal and amplifies this signal to a value sufficient to trigger a relay actuator that turns off only the device that is protected by this device without affecting the health of other serviceable appliances powered by the same electrical network.