SU1141493A2 - Device for protection against current stroke - Google Patents

Abstract

DEVICE FOR PROTECTION AGAINST DAMAGE TO ELECTRIC CURRENT BY ANT, ST. No. 1010689, which is so that, in order to reduce the size of the device when used by the capacitive current compensation unit, the separation capacitor is made in the form of two series-connected capacitors, to the midpoint of which is connected the neutral wire capacitive leakage current compensation unit. (Ls

Description

The invention relates to protective devices and is intended to protect against dangerous leakage of current to earth, in particular to protect against electrical shock from a person in a network with an insulated neutral. According to the main auth. No. 1010689, there is a known device for protection against electric shock, which contains a short-circuit block and a damaged phase selector, a time relay, a leakage relay with a constant operational voltage source, the output of which is connected to a breaker release coil, the output of the damaged phase selection block time relays a. the last outputs are connected to the input of the leakage relay and to the control input of the short-circuit block; connected to ground through an isolating capacitor, in parallel with which a low-resistance resistor is connected, the circuit of which a time relay contact,. The known device can determine self-leakage, but when the device and the capacitance leakage compensation unit, consisting of a compensating throttle and separation capacitor, turn on, the size increases as it involves the use of two capacitors — an isolation capacitor of the compensation unit and capacitors current. The purpose of the invention is to reduce the size of the device when used with a capacitive leakage compensation unit. This goal is achieved by the fact that in the device the separation capacitor is made in the form of two successively connected capacitors to the midpoint of which the neutral wire of the capacitive leakage current compensation unit is connected. The drawing shows the functional scheme of the device. The device contains a block of 1 short-circuitors, the closing contacts of which are connected to the corresponding phases of the network and through a separation capacitor, made in the form of two capacitors 2, to the ground, a block. 3 for selecting the faulty phase of time relay 4, leakage relay 5, capacitive leakage current compensation unit 6, consisting of a three-phase connecting transformer and a compensating choke, disconnecting the coil 7 of the switch 8, the resistor 9, and the time relay 10 contact. At the time a person touches the live part of the electrical installation, a single-phase closure mode occurs, as a result, unit 3 operates, sends a signal to one of the three short-circuits and to the relay 4 times. After receiving the signal, the shorting terminal through the coupling capacitor 2 and the resistor 9 short-circuits the desired phase to ground. thereby reducing the phase-to-safe voltage at this phase to a safe value. After a certain time delay, the time relay opens contact 10 and sends a signal to the leakage relay 5, allowing it in the presence of a leak in the network to give a signal to disconnect the network. In the case of self-eliminating leakage, the disconnection will not occur, since the device is reset and returns to its initial state when the relay signal 4 is applied to the damaged phase selection unit 3, resulting in a time relay with a maximum time delay opening shortcut The device returns to its original state due to the presence of coupling capacitor 2, which is used to determine if there is a leak in the network by applying an operational direct current leakage relay to the AC circuit and artificially shorting the phase to ground, during opening 10 of the switch before turning off the switch V. it is not long. and allows to increase the current through the person to a short-term allowable (.100 ml). This allows the use of a capacitor capacitor that shunts a relatively small amount. Therefore, in this case, it was possible to use two capacitors connected in series, having a comparatively small operating voltage, which in sum would be sufficient when shorting the network. During normal network operation (when

 ; . 1141493.4

no leakage) these capacitor: So the separation

serve as an element for the unit-capacitor unit, intended for

capacitive currents. In this leakage bypass, performs a new

In addition, the capacitance of the separating con-function — the element of the compensator block is large enough, such that the 5 Qi of capacitive currents, which is important as a compensating choke, reduces the dimensions of the devices;

which current pulses pass, combining it with a "block

It is not connected to earth through the same capacitors, i the capacitance of the capacitance of the currents is eternally already connected in parallel.

Claims (1)

DEVICE FOR PROTECTION AGAINST ELECTRIC SHOCK according to ed. No. 1010689, characterized in that, in order to reduce the dimensions of the device when used with a capacitive current compensation unit, the isolation capacitor is made in the form of two series-connected capacitors, to the midpoint of which a neutral wire is connected to the capacitive leakage current compensation unit .