SU1517112A1 - Two-motor a.c. electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in electric drives of apparatuses with a mixing device, in particular, in a gearbox twin-engined electric drive of general industrial appliances with a mixing device. The aim of the invention is to increase reliability. The device contains electric motors 1 and 2, the shafts of which are interconnected, contactors 3.6 with contacts 4.5 and 7, current relay 8 with contact 9, intermediate relay 13 with contacts 14.15, time relay 16 with contacts 17.18. The device provides the start of both electric motors, after which, when the load on the shaft of the working element decreases, the second motor is disconnected and its connection with increasing load is carried out under the control of the current relay. 1 il.

Description

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The invention relates to electrical engineering and can be used in electric drives of apparatuses with a mixing device, in particular in a gearbox twin-engined electric drive of conventional devices with a stirrer.

The aim of the invention is to increase reliability

The drawing shows a circuit diagram of an electric drive.

The electric drive contains two three-phase asynchronous electric motors 1 and 2, the shafts of which are interconnected, the first contactor with the coil 3 to three power closing contacts

4 and a closing contact 5, a second contactor with a coil 6 and three power closing contacts 7, a current relay with a coil 8 and a closing contact 9, a current sensor 10 for switching on one of the phases of the power supply, one output connected to one coil terminal 8 current relay. The stator windings of each of the electric motors 1 and 2 through the corresponding power closing contacts 4 and 7 are integrated and provided with clamps for connection to the phases of the power source. The actuator contains a button 11 Stop, one button of which is equipped with a clip for connecting a power source to one phase, another button of Stop 11 is connected to one button of a button 12 Starting bypassing a closing contact

5 of the first contactor, one terminals of coils 3 and 6 of the first and second contactors are combined and provided with a clip for connecting to a different phase of the power source, an intermediate relay

with catutka 13 and opening contacts 14 and 15, time relay with coil 16 and locking; contacts 17 and 18, another output of current sensor 10 are connected to one of the first interrupting contact 14 of the intermediate relay and the first closing contact 17 against time, others Highways which are connected respectively to one and another highways of the coil 8 of the current relay, another pin of the button 12 Start is connected to another pin of the coil 3 of the first contactor, with one of the outputs of the second disconnecting contact 15 of the intermediate relay, the closing contact 9 of the current relay, ka carcass 16 rel

The time and the second closing contact 18 of the time relay, the other terminals of the second latching contact 15 of the intermediate relay and the closing circuit 9 of the current relay are connected to another output of the coil 6 of the second contactor, the other output of the second closing contact 18 of the time relay is connected to one output of the coil I3 of the intermediate relay, another the output of which is connected to another output of the coil 16 of the time relay and one of the terminals of the coils 3 and 6 of the first and second contactors.

The drive works as follows.

When you press the Start button 12, the coil 3 and 6 contactors and the time relay coil 16 are powered. Pin 5 of the first contactor shunts the Start button 12. At the end of the starting period, when the load current is less than the sum of the rated current of the first motor and the no-load current of the second motor, time relay contacts 17 and 18 are closed, which supply the current relay coil 8 and the intermediate relay coil 13, respectively. removes power from the coil 6 of the second contactor, disconnecting the electric motor 2 from the network, and its first opening contact I4 will dismount the coil 8 of the current relay, thereby turning it on. The current relay is set to operate at a current greater than the rated current of the first electric motor, i.e. when increasing the load on the shaft of the first electric motor above the nominal contact 9 of the current relay closes the power supply circuit of the coil 6 of the second contactor and switches on the second electric motor 2,

Thus, in the electric drive, the electric motors are started in the initial period, after which the second electric motor is disconnected while the load is reduced and connected when the load is increased, is controlled by the current relay.

Claims (1)

Invention Formula Two-way, electric alternating current motor containing two three-phase 1X asynchronous electric motors, whose shafts are connected between 51 a first contactor with a coil, three power closing contacts and a closing contact, a second contactor with a coil and three power closing contacts, a current relay with a coil, a current sensor designed to be included in one of the phases of the power supply, one output connected to one coil terminal the current relay, the stator windings of each electric motor through the respective power closing contacts of the contactors are integrated and provided with clamps for connection to the phases of the power source, the Stop button, one output of which is The terminal is connected to one phase of the power source, the other end of the button StN is connected to one end of the Start button, shunted by the closing contact of the first contactor, one end of the coils of the first and second contactors are combined and provided with a clip to connect the power source to the other phase and a normally open contact, characterized in that, in order to increase reliability, a time relay has been introduced from 2 " Coi and two make contacts, the intermediate relay is provided with a second disconnecting contact, the current relay has a closing contact, the other output of the current sensor is connected to one terminal of the first disconnecting contact of the intermediate relay and the first closing contact of the time relay, the other terminals of which are connected respectively to one and the other coil terminals current relay, another output of the Start button is connected to another output of the coil of the first contactor, with one of the outputs of the second disconnecting contact of the intermediate relay, closing contact and the current relay, the time relay coil and the second time relay contact, the other terminals of the second disconnecting contact of the intermediate relay and the current relay contact closure are connected to a different coil terminal of the second co-clock, the other pin of the second time relay contact is connected to one coil terminal intermediate relay, the other output of which is connected to another output of the coil a little time and some of the coils of the first and second contactors.