It is used in three-phase motors to allow the engine to start with less power at start-up (to reduce the electric absorption), passing from star to delta link after a few moments. In high power engines, to avoid excessive current at the starting point, the "star-delta" starter is used; it consists in starting the star engine for a few seconds, then making it work normally in a triangle. There are special timers for this delicate maneuver, usually lasting half a second, just enough to make the contacts of the command remote control switches. Starting with a star, we have a starting current reduced by 1/3, when the motor is then stopped, it does not perform this exchange.