Automatic star-delta switch / star-delta time relay

Operating voltage of the relay for star-delta start modes (electric motor start relay) 24/220 V AC, indicator ON, STAR, TRIPLE, time setting for STAR mode. POWER SUPPLY, ERV-YU.

It is known that for a soft and smooth start of an electric motor, it must first be switched on according to the STAR scheme, and after a certain time, when the set speed is reached, switch the motor windings to the DELTA mode. This switching scheme ensures a lower starting current, which extends the service life of the electric motor and increases the stability of the entire electrical system.

The switching of STAR-DELTA modes can, of course, be done with a switch, but when using contactors (starters) and a starting relay, it is better to automate this process.

To control such contactors, TENSE offers star-delta relays or, as they are also called, star-delta switching relays - ERV - YU.

When the operating voltage is applied to contacts A1 - A2 of the ERV - YU relay, the STAR output is connected to the Faz contact, the STAR indicator lights up, and the acceleration interval t1 (0.1 ... 30 s) begins to count down. After the acceleration interval t1, the STAR and Faz outputs are disconnected, the STAR indicator goes out, and the pause interval t2 (15 ms) begins to count down. After the connection interval t2, the Faz and TRIANGLE contacts are connected, the TRIANGLE indicator lights up, and the trigger relay remains in this state until a disturbance is applied to contacts A1 - A2.