SU634418A1 - Arrangement for interlocking switching apparatus in electric equipment power supply circuit - Google Patents

Description

The invention can be used in starters, feeder machines and in cells of high-voltage switchgear, used primarily in fire hazardous and extreme hazardous environments, for example, in underground mines of coal mines. The device for blocking is intended to automatically measure the leakage currents to the ground in the disabled lines or electrical installations and prohibit their switching on when the indicated currents increase beyond the permissible value. The known devices are designed to prevent the supply of voltage to an electrical installation with a leakage current to earth exceeding the permissible value. In them, the output of the interlock leakage relay (DCMS) is connected via a full-wave rectifier parallel to the primary winding of a ferroresonant stabilizer l}. However, in such a device, if the resistance of the resistors in the circuit is broken, they do not shunt the primary winding of the stabilizer and allow the starter with a zipper circuit in a disconnected electrical installation, Another known device of the same purpose is a contactless static protection relay and remote control of current collectors, binder a magnetic element and a transistor | 2. In this device, in the case of breakdown of transitions (short BEIMH) of the transistor, it is also possible to turn on the switching device during ground faults in a disconnected electrical installation. The closest to the technical essence of the invention is a device that contains a switchgear, a control unit and a control electromagnet of the switching device 3. However, this device allows to supply a voltage to an electrical installation with an increased leakage current of 3 times. The purpose of the invention is to increase the reliability of the prohibition to turn on the switching apparatus when the leakage current to earth in a controlled electrical installation exceeds the permissible value. This is achieved by the fact that in a device containing a control electromagnet of a modular apparatus, the circuit of which is connected to a short circuit, the unit контакт s контакт contact of the unit is jerked off and a block of electrical leakage from the relay, which is connected to the leaked relay. Litl: OjsOiva relay, g: EOg: ;; oh; The control unit (coegea-gomiom of the control unit on the district heater; 0The contact of the interlock leakage relay in the data circuit of which is connected to the junction of the control unit, has also been detected; s; one oh oo pen ощ key of the contact, contact to the dkom circuit of a blocking orifice leakage relay vyiolian eea contact of the relay time ™ ni fng.and n 2 give options for the principle of an electrical blocking device for co-operation of first-party hardware (accelerators) from electromechanical nichesk1: th prkv The direct mode of action in FIGS. 3 and 4 is the same for KOsiMyTation% of devices (switches) with electromechanical drives of indirect action; The device has a blocking relay 1 (BRU), a second circuit 2, a control unit 3, a transistor 4 VRU, executive relay 5 BRU, resistors of measuring organ w; -. Jc-rOBoro type, resistance 9 ISOLINES 3U.kgzymoy electrical wiring to the ground, switching device 10, relay AND control unit 12-stop button, button 13 start-up contact 14 BRU , resistor 15, magnet control Neither 1.6, breaker contact 17, switchboard relay, control unit 18 contact, control clock 19, control unit relay 19, control unit time relay 5 control unit relay 21, control unit intermediate relay contact 22 The blocking device for the switching device (see Fig. 1) contains a blocking leakage relay (DCU) 1, a control electromagnet 1b and a relay control unit 3. In the device of an electrical interlock, any DCU circuit can be used in which the executive relay Atates with satisfactory insulation resistance of a controlled electrical installation. The leakage blocking relay is in the form of an amplifier that is sensitive to field strength and has been made. for example, on the transistor 4, the executive relay 5 and the measuring body of the bridge type. The three arms of the latter form resistors 6–8, and on the fourth, the resistance 9 of the insulation of the controlled electrical installation with respect to ground is connected. llfiH OTKJisOieHHH installations from the network GlaiPa kogsakty switching appr kyuktsyu si zschchatsya and blocking relay / tech with the help of auxiliary KOHTf-iCrotj of the specified device podklyu- lushch-I to the resistance of the insulation resistance of the elec- The chain of which is connected in series with the stop 12 and start 13 buttons, the trigger contact 14 of the executive relay S "Sequential circuit of a kmupx start 13 and one circuit 12, terminal 14 is set up by a resistor 15. E Lfeub of the elektromggnit control 16 has a hole. contact 17 relay 5 n the closing contact 18 of the relay 1.1 and the relay control unit 3, The device operates as follows (see fig.). After each disconnection of the switching device 10, its main contacts are opened and the auxiliary KOHTaKTfii (isolation control), agitates. which power is supplied to the DCMS connected to the phases of the disconnected electrical installation. At a normal value of the monitored insulation resistance 9, the transistor 4 is open, since its emitter is under positive potential with respect to the base and the relay 5 is turned on, the closing contact 14 of relay 5 prepares the control relay 11 for switching on the relay. 19 opens the supply circuit on the input side of the switchgear unit. As a result, the transistor 4 closes and turns off the relay 5. The latter "etf; opens contact 14 in the relay circuit 11, which is held through a resistor 15. Other contacts TQf. T 17 relay 5 7 switches the switching device control electromagnet, 10 (contact 18 of relay 11 is closed, as relay 11 remains on). The device is turned off by pressing the stop button 12, which turns off the relay 11, and by its contact 18 it turns off the control electromagnet 16. When the measured resistance is reduced to a dangerous value, transistor 4 is closed, because its emitter 110 relative to the base is under negative potential . Due to the fact that the contact 14 of the relay 5 is open, it is impossible to turn on the switching device by the start button 13. If any transistor or relay circuit is interrupted, it is impossible to turn on the switching device for that reason. If the disconnected line has decreased the measured resistance 9 to a dangerous value and the transistor has failed (short), the relay 5 remains on regardless of the presence of

any signal at the input of the transistor. At the same time, contact 17 of the control electromagnet circuit remains open, therefore, it is impossible to turn on the switching device.

In the device circuit (see Fig. 1) in the case of non-switching of the contact 17 of the relay 5 (which is possible in some relay designs), the switching device will turn on when the insulation resistance decreases and the transistor breakdown. To prevent this, the opening contact 17 and the closing contact 14 of the relay 5 are replaced by one switching contact 14 of the same relay (see figure 2). In this case, in case of contact closure 14 in the upper or lower position, the permanently open circuit of the control electromagnet 16 or the relay 11 becomes permanently turned on and the switching device switching on becomes impossible.

If the relay of the control unit has a free closing contact, contact 19 can be connected to the fourth shoulder of the bridge (see figure 2). In this case, the difference between the work of VRU is as follows.

If the measured insulation resistance is satisfactory, (as in the case described), the transistor opens and relay 5 is triggered. After pressing button 13, relay 11 switches on, contact 19 closes the bridge arm, causing the bridge balance to break, and the emitter of the transistor in relation to its base, it acquires a negative potential and the transistor closes, disconnecting the relay 5. The contact 14 of the latter closes in the upper position and creates a circuit to turn on the control electromagnet 16. Otherwise, the operation of the device in the normal and in emergency modes it is not different from the one described above.

Thus, no matter by which contact (closing or opening), the input is prevented from entering the switchgear, the same effect is achieved: to prevent the activation of the restraint device and to prevent the supply of voltage to the faulty electrical installation.

FIG. Figure 3 shows a schematic diagram of the proposed device with reference to a switching device with an indirect-action drive, for example, a high-voltage switch having a shut-off electromagnet, operating on the basis of a minimum voltage relay, for example, an unpowered device. A switching (for example, bridge) contact 14 of the ACU in this case is connected to the tripping electromagnet 16 and to the relay control circuit (to relay 21). During the breakdown of the transistor 4, the relay 5 is turned on regardless of the magnitude of the monitored insulation 9. Contact 14 of relay 5 opens the tripping electromagnet 16, which, acting on the free tripping mechanism, separates the drive shaft with the shaft of the main contacts of the switch. When you press the start button

13 or contact closure 18 relay

21, triggered by one contact, turns on the motor of the switching unit of the switching apparatus, and the other contact 22, auxiliary relay 20, for example, a time relay used in a high-voltage explosion-proof cell of type YaV-6400 to protect the switch from repeated switching on (industrial catalog H1 Informielectro 02.12. 16-72 ). Relay 20, triggered by its contact 19, prohibits the input of the switchgear, but the faulty transistor (breakdown transition) does not close, relay 5 does not turn off, as a result of which the power supply of the opening electromagnet is open. After the drive preparation (charging) time has expired (usually a few seconds) under the action of mechanical energy stored in the drive battery, the latter works, but since the de-energized switching electromagnet 16 has disconnected the main contacts of the switch with the drive, the switch does not turn on. If any transistor circuit is interrupted, the relay 5 is turned off and its contact 14 3aivudKaay turns off the electromagnet 16, and the relay control unit circuit, bridged by resistor 15, is open. As a consequence, the inclusion of the relay 21, which gives the command to start the drive using either button 13 or contact 18, relay 11 does not occur. Thus, in case of various types of damage (interruption, short transition of transistors, non-switching of contact 14, interruption or short circuit of relay 5, 20, etc.), switching on the switching device and applying voltage to an electrical installation with an unacceptable leakage current to ground does not going on. Since the relay 20 is used to protect against repeated inclusions of the Spuleleth effect), by connecting its contact to the input switchgear circuit, control of the malfunction and its circuits is achieved.

If the switching device with the drive of indirect action is equipped with two executive bodies: a shut-off electromagnet 23, operating in the presence of a voltage on its coil, and a turn-on electromagnet (see Fig. 4), the switching contact

Claims (3)

An executive relay 5 is connected to the turn-on electromagnet 16 and relay 21. In case of various faults in the device circuit (described above), the pin 14 remains permanently closed in the upper or lower position, open or turn on the relay 21f circuit or turn on the electromagnet 16 o At In this case, switching on the switch is not possible one by one. At the CHIN Or there is no mechanical energy stored in the drive battery, since the relay 21 does not turn on, which starts the drive motor, or the switch-on electromagnet JI.6 does not operate, which It has a lock that prevents the switching device from switching on. Thus, the action of the proposed interlocking device does not depend on which actuators (control electromagnets) have a switching device: an electromagnet used both for switching off and for switching on a switching device, or for switching off and on are assigned to individual electromagnets. that the blocking action does not change when the control relay contacts 11 {see figl and 2), contact of control relay 21 (see figs 3 and 4) or contact of auxiliary relay 20 (see figs 3 and 4) if this relay is activated before switching on the switching device. Such an embodiment of the device makes it possible to increase the reliability of blocking and to exclude the supply of voltage to the electrical installation with the MfcJM not allowing the leakage current to ground without introducing additional units into the electrical circuits of the switching device. 8 claims 1. A device for blocking a switching device in an electrical power supply circuit comprising a control electromagnet of a switching apparatus whose supply circuit includes a closing contact of a control unit relay, and a blocking leakage relay, characterized in that, to increase reliability of operation, the closing contact interlock leakage relay included pi. The relay of the control unit and, in series with the closing contact of the relay of the control unit, the opening contact of the leakage blocking relay is connected, the input contact of the control unit is connected to the input circuit. 2. The device according to claim 1, characterized in that the opening and closing contacts of the leakage blocking relay are made in the form of one switching contact. 3. Device according to Claim 1, characterized in that the contact in the input circuit of the leakage blocking relay is designed as a time relay contact. Sources of information taken into account during the examination: 1. USSR author's certificate No. 284119, cl. H 02 H 3/16, 1966. 2. USSR author's certificate number 150933, cl. Q 01 R 31/08, 1961. 3. USSR author's certificate number 367504, cl. H 02 D 9/06, 1970. “, m mu 0 + w " 2