In this automatic changeover switch for generator circuit diagram the contactors of the generator are indicated kg and km. It is about two electrically controlled circuit breakers.

3 Phase Generator Wiring Diagram Phase Automatic Changeover
Automatic changeover switch circuit diagram. Automatic changeover switch circuit principle. It is also shows the working and operation for different changeover switches wiring connections like single phase manual changeover switch with generator three phase manual transfer switch connection with generator as well as single phase and three phase automatic transfer switches connections to the 1 and 3 phase generators and main fuse board. The circuit diagram shown here is of a automatic changeover switch using ic ltc4412 from linear technologies. The timer output is connected to a transistor which acts as a switch being on or off depending upon the timer. This contact being in series with the coil of the other contactor will not allow the other contactor to close. 2 simple automatic transfer switch ats circuits.
In the first diagram the ac changeover to the load is automatic but the generator will need to be started manually by pulling the chord whenever the mains fails. This circuit can be used for the automatic switchover of a load between a battery and a wall adapterltc4412 controls an external p channel mosfet to create a near ideal diode function for power switch over and load sharing. This circuit is based on the principle of bistable mode operation of 555 timer. If you need a fully automatic design you can try the following circuit. In this mode the timer output is either high or low depending upon the status of trigger and reset pin. A smart way to build an automatic changeover switch or automatic transfer switch ats is by using two contactors together with a good ats or amf controller.
These powerful relays are not allowed to close simultaneously but only one at a time. A contactor when closed opens its own auxiliary contact.