SU1464240A1 - Device for monitoring voltage drops in a.c. mains - Google Patents

Abstract

The invention relates to electrical engineering, in particular, can be used to monitor network voltage. The purpose of the invention is to increase reliability by eliminating a false signal of a decrease in voltage at the moment of switching on. This is achieved due to the fact that the additional relay 19 triggers only after the voltage control relay 12 triggers and the presence of a turn-on signal through the serially connected make contacts 18.2 and 21.1, while the relay 19 becomes its own contact 20.1 and contacts 18.2. on self-locking. After that, any reduction below the normal voltage of the AC mains or phase failure causes the release of the voltage control relay 12 and the formation of the Avtarya alarm signal. 2 Il. (L

Description

The invention relates to electrical engineering and can be used in automation and computer engineering, in particular, in air cooling devices of computer units for monitoring the AC voltage from decreasing or losing phase and signaling to the operator console.

The purpose of the invention is to increase reliability by eliminating the high voltage drop signal at the moment of switching on.

Fig. 1 is represented in principle: a circuit diagram of the proposed device; in FIG. 2, a temporary diagram i a of the operation of the device. I The device contains a starting relay | 1, the opening contacts of which | 2.1 and 2 „2 are connected to buses 3 and 4 of the AC network through fuses 5 and 6 and to the loads 7., n, IB of which may be windings of the fans. An alternating current network is provided with a series circuit from diode 8 and a light indicator 9 “In parallel with the loads, a series circuit from a ballast resistor is connected. 10, diode 11 ,, winding

Relay 12 control voltage winding jKOToporo 3 is connected by a capacitor | 13 "To buses 14 and 15 of a source of 1-JUNCH voltage through fuse 16 are connected except for starting relay 1, switching on intermediate relay 17 with contacts 18.1 and 18.2, additional relay 19 with contacts 20.1 n 20.2. Voltage control relay 12 contains contacts 21.1 and 21.2, In addition, there are pass-through capacitors 22-25, protective diodes 26-28, an indication display actuator; executed for example in the form of a light 29

to one of the VYUODOV of which the alarm output bus 30 is connected and the serially connected contacts 20.2 and 21.2, and the other output is connected to the bus 14 bus through a fuse 16, the Input control bus 31 is connected to the output winding terminal of the intermediate relay 17 on,

In the initial state, the turn-on signal on bus 31 is missing the relay coil 17 is de-energized, and its expanding contacts 18.1 close the power supply circuit of the winding of the starting relay 1, the open contacts 2.1 and 2.2 of which are open and the load circuit.

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5 Formulas

(windings of fans) open. The presence of the AC line voltage is indicated by a light indicator 9.

When a switch-on signal appears on the bus 31 from the control panel, the power supply resets the relay 17, contacts 18.1 of which break the power supply circuit of the winding of the starting relay 1, which breaks the IQ contact contacts which blink

power windings of fans (load, 7.1-7, p) and relay 12. voltage control. The ballast resistor 10, the rectifying diode 11 and the capacitor t5 13 allow, when a voltage of the alternating current network is applied to the loads, to create on the winding of the relay 12 of the control voltage a sufficient voltage to operate it. 20 Some delay in triggering

The voltage control relay 12, due to the need to charge the filter capacitor 13, does not allow a false signal about .25 reduction: (1-loss) voltage of the AC mains on the output signal bus 30, because the closing contacts of the additional voltage Relay 19 pa30MKfiyTbu 30 Only after the relay 12 has operated is turned on the counter voltage and the signal is input through the series-connected make contacts 18.2 and 21.1, an additional relay 19 is triggered, which through its contact contacts 20.I and is constantly closed s when the contact becomes 18.2 to samoblokirrvku. Thereafter, any fault below the norm of alternating current grid or phase loss causes the voltage control relay 12 to be released and the Ventilation alarm signal generated on the output bus 30 of the alarm and the light indicator 29 to come on.

The positive signal generated by the Avariari ventilation signal is output to the engineering console through the switch bus 30.

Thus, the proposed device is reliably monitored and protected from the AC mains against a drop in voltage loss.

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Formulas

The invention is a device for monitoring AC mains from undervoltage, containing an object switch, the intermediate relay contact of which is connected between the buses of the DC source and the winding of the starting relay, the contacts of which are connected to the load circuit of the alternating current to which The driver and the ballast resistor are connected to the winding of the voltage control relay, the disconnecting contacts of which are connected in a series with the actuating element of the display, which differs from In order to increase reliability by eliminating the issuance of a false voltage signal at the moment of switching on, additional

and,

a relay, the auxiliary relay winding is connected between the buses of the DC source through the series-connected closing contacts of the intermediate switch-on relay and the voltage control relay, the first closing contacts of the additional relay are connected in parallel to the short-circuiting contacts of the voltage monitor relay, relay control voltage and the executive body of the display are connected between the buses of the source of direct voltage through the second circuit ie the auxiliary relay contacts.

Claims (1)

Claim A device for monitoring an alternating current mains against undervoltage, comprising an object switch, contacts of an intermediate switching relay of which are connected between the buses of the constant voltage source and the winding of the starting relay, the contacts of which are included in the load circuit of the alternating current, to which the winding is connected through a rectifier and a ballast resistor voltage monitoring relay, the NC contacts of which are connected in series with the display actuator, which is characterized by the fact that, in order to increase reliability, by eliminating the generation of a false signal about a decrease in voltage at the time of the relay, and the winding of the auxiliary relay is connected between the buses of the DC voltage source through series-connected closing contacts of the intermediate relay and voltage monitoring relay, the first closing contacts of the additional relay are connected in parallel to the closing contacts of the relay voltage control, and the conclusions of the serial circuit from the NC contacts of the voltage control relay and the actuator The connections are connected between the buses of the DC voltage source through the second circuit. Order 830/55 Circulation 605 VNIIPY of the State ’Committee on Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Plant Patent, Uzhgorod, st. Gagarina, 10 ’