SU702449A1 - Device for protecting several three-phase users against damage - Google Patents

Description

(54) DEVICE FOR PROTECTING AGAINST DAMAGE TO MULTIPLE THREE-PHASE CONSUMERS

it is shunted by a closing congactum of an additionally mounted button.

The drawing shows a diagram of a device with three consumers.

Between the power source and the consumers, the power contacts 1 of the starter and the transformer 2 of the zero-sequence current are connected, the output of which is connected via the amplifier 3c to the coil 4 of the relay. The opening contacts 5 of this relay are installed in series with the coil 6 of the actuator. Between the zero points 7–9 of the consumer and the neutral wire 10 of the power supply, the threshold light indicators (neon lamps) 11–13 and the resistor 14–16 are connected in succession. to the disconnecting contacts 5. In the coil of the coil, the actuator includes control buttons 18.

When you turn on the contacts 1 starter receive power consumers. With supply voltage symmetry between zero 7-9 and neutral wire 10, the voltage is close to zero and no current flows through resistors 14-16. At the exit of trans. the formator 2, the voltage is also close to zero, the coil 4 of the relay does not receive power, and the contacts 5 of this relay do not open.

Damage to the insulation between the phase and the neutral wire Yu at any point of the consumer, as well as the phase failure, upsets the current balance. At the output of transformer 2, TOitc appears, which is amplified by amplifier 3, and a current flows through the coil 4 of the relay sufficient to operate the relay 4, which opens contact 5 in the coil circuit of the actuator 6. The coil loses power, pins 1 are opened, and consumers are de-energized.

If one of the consumers, for example, the upper phase, breaks between the zero point 7 and the neutral wire 10 of the source, a voltage appears, the neon lamp ignites, and the current through it is limited by the resistor 14. The current through the resistor 14 violates the equality of the phase currents, current transformer 2 output appears current. Relay 4 trips breaks contacts 5 in the coil 6 circuit of the starter. The coil loses power, pins 1 open,

consumers are de-energized. To expose a consumer with a disconnected phase, briefly press button 17 and turn on starter 6,

A consumer who has the phase interrupted will indicate that the lamp that has burnt from the neon lamp 11, the other lamps 12 and 13 do not light up the vehicle. After that, let go. button 17, and contacts 1 trigger

I will break the vehicle. |

When the middle phase at the source is broken, the coil 6 does not lose power, but there is a voltage between zero points 7-9 and zero wire 10. The neon lamps 11-13 light up and zero-sequence currents flow through the resistors 14, 15, 16. Relay 4 is triggered and contacts 5 and contacts 1 open, the dampers are de-energized. When the button 17 is briefly pressed and the starter is turned on, the neon lamps of all the drivers on each lamp turn on, indicating; em on the phase failure in the mains.

Thus, the introduction of the light indicator of the chain of current transformer of the zero sequence of each consumer makes it possible to quickly detect the consumer with dangling

° phase.,

Claims (1)

1. USSR author's certificate g 418932, кп. H 02 H 7/08, 1972. 2, Lukovnikov A.V. Labor Protection, M., Kolos, 1973, p. 188.