SU1220043A1 - Device for protection of three-phase load against phase loss in supplying network - Google Patents

Abstract

The device relates to the protection of consumers against phase failure of the supply network. The purpose of the invention is to reduce power consumption. The device contains a three-phase rectifier 1 on diodes 2, 3 and 4, a power button (KB) 14, a thyristor switch with limiting resistors 10 and 12 and an actuator (IO) - relay 8, Introduction of a power button 5, photo thyristor optocouplers (FO) 6 and 7 and diode 9 protect consumers from abnormal conditions. If there is a three-phase voltage and the closing button 14 is turned on, a current passes through the LEDs and the FO 6 and 7 are unlocked, which allows the current to flow through the IO 8 winding, after which the button 14 opens. When a phase failure occurs, the PhD 6 and 7 are locked and the EO 8 is turned off. Forced shutdown of the device is possible by opening the shutdown button 5, which also contributes to locking the FE 6 and 7. If one of the phases breaks, the device cannot be turned on even when the button 14, 2 Il is turned on. i cl c: 4 od

Description

The invention relates to electrical engineering, in particular, to consumer protection schemes against abnormal operating conditions, in particular, to protection devices against phase failure of the supply network.

The purpose of the invention is to reduce power consumption.

FIG. 1 shows the electrical circuit of the device for monitoring the phases of a three-phase network; in fig. 2 - the schedule of the device.

The device (Fig. 1) contains a three-phase rectifier 1, made on diodes 2-4. The anodes of diodes 2 and 3 are connected to phases A and B of the three-phase network, and the anode of diode 3 is connected to phase C via the off button 5. The connection point of the cathodes of diodes 2-4 through the series-connected photothyristors of the optocouplers 6 and -7 is connected to the winding of the actuator 8 ( for example, a relay shunted by diode 9 and connected to the mains neutral N. The anode of the LED of the optocoupler 6 is connected via the limiting resistor 10 and the diode 11 to the anode of the first diode 2. The anode of the diode of the optocoupler 7 is connected via a limiting resistor 12 and diode 13 to the anode the second diode 3. The cathodes of the LEDs of the optocouplers 6 and 7 are connected and connected via the switch button 14 to the anode of the third diode 4. Actuator 8 has contacts 15 for connecting control circuits.

The device control phase break three-phase network works as follows.

If there is a three-phase voltage at the output, the rectifier 1 forms a constant voltage Uj (Fig.2, but since the photothyristors of the optocouplers 6 and 7 are locked, the voltage is not applied to the actuator 8. When the on button 14 is closed through the LEDs of the optocouplers 6 and 7 passes t

half-wave control currents 1 and 1

1 as a result of which the photothyristors of the optocouplers 6 and 7 are unlocked with the flow of current Ip of the complementary organ

and provides - on the winding is - after which

power button 14 is open. With

the occurrence of an incomplete-phase mode in the load circuit of the rectifier, a non-current pause T is formed, the photo thyristors of the optocouplers 6 and 7 are locked, and the actuator 8 is turned off. Forced shutdown of the phase failure monitoring device is possible by opening the off button 5, in this case an incomplete phase mode occurs, which helps to lock the photo thyristors of the optocouplers 6 and 7.

In the case of an incomplete power supply mode ABC, the device cannot be switched on 5 even if the power button is closed 14. In the absence of phase A, the voltage is not applied to the LED of the optocoupler 7, in the absence of phase C, the voltage is not supplied to the LED of the opto 6, in the absence of phase B Life is not supplied to the LEDs of the optocouplers 6 and 7.

Claims (1)

Invention Formula A device for protection of a three-phase load against a phase failure in the supply network, containing a three-phase rectifier on three diodes, whose input is connected to the phases of the supply network, a power button and a series-connected winding of the actuator and a thyristor switch with limiting resistors and diodes, characterized in that In order to reduce electricity consumption, an additional button is turned on, a diode shunting the winding of the actuator, the thyristor key is made on two series The anode of the first is connected to the output of a three-phase rectifier, the cathode of the second through the winding of the actuator is connected to the neutral of the mains supply, the anodes of the LEDs of each optocoupler through their limiting resistors and diodes are connected to the phases of the mains supply, and the connection point The cathodes of the LEDs of the optocouplers are connected via a switch-on button to the third phase of the power supply network, to the break of which the turn-off button is turned on.