SU83453A1 - Device for automatic start of a multi-motor drive - Google Patents

Description

Devices are known for automatically starting an electric drive with several electric motors using a time relay and electrical interlocks in the magnetic starter circuits of each electric motor.

A distinctive feature of the proposed device is the use of a control device consisting of only two or three time relays, which significantly reduces the number of time relays installed according to known circuits.

The drawing shows the electrical circuit of the proposed device.

The diagram with dashed arrows shows the current passage when the even motors are turned on, and the flat arrows show the odd ones.

In the diagram, all start buttons for remotely switching on each electric motor are replaced by one command device.

The latter has three relays of direct current 1РВ, 2РВ and ЗРВ with time delay (such as relay РЭ-180) and a cuprope rectifier KB for powering these relays.

The order of operation of the 1PB, 2PB and ZRV relays corresponds to their numbering. The current pulses are transmitted to the switching circuit of electric motors by means of an ATP relay, which, through its contacts ZRV-} and ZRV-2, acts on two pulse channels D and one of which serves even and the other odd electric motors in order to turn them on.

Automatic start is as follows.

When power is applied to the rectifier K.B, a rectified voltage appears at points ab. In this case, a warning lamp lights up (not shown in the diagram) and the 1РВ relay is activated, the contacts 1РВ-1 and 1РВ-2 of which close the circuits of the relay coils 2РВ and ЗРВ. The 2РВ relay is activated and its contact 2РВ-1 opens the power supply circuit of the 1РВ relay.

After five seconds of exposure, the IPB relay will open the power supply circuit for the 2РВ and ЗРВ relays. . 83453-2 Relay 2PB returns to its original position, and the AIT relay will close in 5 seconds its contacts in the circuit of the corresponding pulse channel. Further the circuit will work automatically. Start the entire group of engines 1, 2, 3 ... will happen after turning on the first engine start / from pressing the start button I. The switching on of individual electrodes; the gates differ one from slightly. Each circuit contains a contactor starter (1K, 2K, 3K, etc., etc.), an interlock contact system (JK-1, 1K-2 ..., 2K, -1, 2K-2, respectively ... ZK-, ZK.-2 ..., etc.) and the contacts of the current relay TR. The circuits are connected to the phases C of the power supply line (/ 1, B, C) and to the automatic switching line consisting of three wires D, E and G. The presence of the indicated interlocking contacts in the motor starter circuits ensures an acceptable order of switching on the machines and their subsequent operation in blocking after automatic switching on. Each next electric motor, for example, 2 (or 3, 4 ...., etc.), is automatically switched on after the switching contacts 1K-2 (or, respectively, 2K-2, ..., etc.) ) previous start-up starter in the block of the block wire G. In this case, the current from the phase C of this motor through the blocking contact (or ZK-4 4K-4., etc., etc.) does not flow through the block wire G to the relay contacts ZRV, then through the currently closed contacts of this relay to the corresponding channel D or E and through the contact 2K-5 (or ZK-5, 4K-5 ..., etc.) and the 2K trigger starter (or ZK. 4K . .. etc.). After switching on the actuator, the interlock contacts are 2K-4 (or, respectively, ЗК-4, 4К-4 ..., etc.) and 2К-5 (or ЗК-5, 4К-5 ..., etc. ) disconnect the actuator circuit from the automatic enable circuit. The starter remains on due to the closure of the 2jK-} contacts (or, respectively, ЗК-1, 4К- ..., etc.). Thus, the command device will ensure the sequential start of all electric motors at different time intervals. Object of the Invention A device for automatically starting an electric drive with several electric motors using a time relay and electrical interlocks in the magnetic starter circuits of each electric motor, characterized in that, in order to significantly reduce the number of time relays, a command device consisting of two or three relays is used time, supplying at regular intervals electric pulses to the coil and starters via a block wire and two channels to which the starters are, respectively, even and odd (in order of starting) engines.