SU367504A1 - DEVICE FOR PROTECTION OF ELECTRICAL INSTALLATION - Google Patents

Description

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Devices of protection of electrical installations with remote and automatic control are known, containing a switching device, a source of operating current from which the electromechanical drive is powered, a remote control unit, an automatic restart unit, an interlock leakage relay, an emergency blocking interlock unit and operation indicators activated by interlocking relay contacts. and blocking contacts of the switching apparatus.

In order to prevent the re-supply of voltage to a faulty electrical installation, the proposed device is equipped with a time relay, the coil of which is connected to the operating current source through the serially connected contacts of the remote control unit relay, the executive block of the emergency block and the leakage blocking relay. The time relay contacts are included in the disconnection circuit of the remote control unit, the emergency blocking execution unit and the switching circuit of the switching device actuator.

The drawing shows the proposed device. If there is a supply voltage, the contacts / and 2 voltage relays (not shown in the drawing) are closed, respectively, in the circuits of the automatic reclosing unit 3 and the emergency blocking execution unit 4. The disconnecting position indicator 6 of the switching device is turned on through the disconnecting block 5. If the insulation resistance of the switch-on electrical installation is satisfactory, the base of the transistor is under negative potential and it opens, causing the leakage blocking relay 7. The relay 8 trips its contacts 9, 10 in the time relay 11 and the indicator 12 of satisfactory insulation resistance. .

The initial start of the executive blocking block 4 is carried out by button 13. At that, the relay 14 of this block is activated and through its contact 15 is held in the on position, and the other contact 16 prepares to turn on the time relay 11 and the shut-off electromagnet 17.

The operative switching on of the switching device is carried out by the start button 18, which turns on the relay 19 of the switchboard control unit 20. The relay 19, by its contact 21, switches on the switching device drive. After switching on the switching device, its block contacts 5, 22-26, respectively, switch off the drive, locking relay, block

automatic reclosing and switching on the automatic reclosing and indicator of the key position of the switch. Relay 8 by pin 9 turns off the relay //, which by pin 27 supplies power to the automatic reclosing unit 3 and opens the day of the drive 28.

The quick disconnection is performed by button 29 OR 30, blur | Kayup1; she can rectify the rectified current of relay 19. When online disconnection the automatic reclosing does not occur, because with closed contacts 1, 31, 32 of relay 14, 19, the capacitor 33 is discharged to low. ohm resistor 34.

If in the process of switching on the switching device, it is disconnected (for example, during the free tripping mechanism), the relay does not have time to switch off, as its return time is slightly longer than the switching device switching on time and it does not turn on the HOBTOipHO due to the fact that the relay) / contacts 35, 36, closure, with a set time delay, short-circuits the relay 14, 19, which, by contacts 16, 21, open the power supply circuit of the relay 11, the opening electromagnet 17, and the drive 28.

If the serviceable switching device remained turned on for a time sufficient to charge the capacitor 33, when it is disconnected by relay protection, the capacitor 33 is discharged to the winding of the relay 37 through the contacts /, 38 and the block contact 26, causing the relay 57 to trip. 39 turns on the relay 19. In the future, the process of switching on is similar to the process of quick switching on the switching apparatus. If, according to safety conditions, it is necessary to prohibit the automatic reclosure of an electrical installation that is turned off, for example, by protection against short circuits (its contact 40), then contact 41 of relay 14 must be disconnected by removing jumper 42. In case of failure of the interlock leakage relay, for example, when the transistor breaks down Relay 8 remains on even if the insulation resistance of the electrical installation is not satisfactory and allows switching on the switching device, but after a predetermined time has elapsed (slightly longer than

the drive time of the relay 11, contacts 35, 36, short-circuit the windings of the relays 14, 19, which disconnect the switching device and block it in this position. The blocking of multiple inclusions is also carried out in case of a failure of the switching mechanism of the auxiliary contacts (for example, the auxiliary contact 23 does not open). In all cases of emergency shutdown, the indicator 43 is turned on. After eliminating the cause of the accident, before switching on the switching device, it is necessary by button 13 to turn on the relay, which by its contact 44 turns off the indicator.

Thus, in case of various types of failure modes, blocking contacts of the switching device, interlock leakage relay, a time relay is prevented by means of a time relay.

electrical installation with reduced isolation or disconnected relay protection.

Subject invention

A device for protecting electrical installations with remote and automatic control, containing a switching device, a source of operating current from which the electromechanical drive is powered, a remote control unit, an automatic reclosing unit, a blocking leakage relay, an emergency blocking control unit, and operation indicators activated by interlocking relay contacts and block contacts of the switching apparatus, characterized in that, in order to prevent re-supply, the voltage and on a faulty electrical installation, it

equipped with a time relay, the coil of which through the series-connected contacts of the relay of the remote control unit, the relay of the executive unit of the emergency lockout and the leakage blocking relay

connected to a source of operative current, and time relay contacts are included in the disconnecting circuit of the remote control unit, the executive block of the emergency interlock and in the switching on circuit of the switching device actuator.

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