ATS Control Circuit Diagram
I’m going to explain the ATS Control Circuit Diagram. ATS stands for Automatic Transfer Switch. It is used for transfering electrical power from one source to another source automatically based on need. We all are familiar to electricity loadshedding. Load shedding means the discontinuation of the supply of electricity.
In some places it’s very important to keep electricity supply continuously like, hospital, market, mill and factory etc. So, they use generator as standby power plant and operate generator when it’s load shedding. Automatic Transfer Switch (ATS) operates external electrical source switching and internal (generator) source switching automatically. It in fact interlock two switching device (magnetic Contactor or ACB) mechanically and electrically.
The wiring diagram of ATS is explained below.
List of Components:
1. Two pieces Magnetic Contactor.
2. Two Pieces Timer.
3. One piece Relay.
4. Some wiring cable.
ATS Control Circuit Diagram Explaination
Get a phase from external electrical source (REB) and connect to the Relay coil and short the terminal with an NO (normally open) contact of the Relay. Connect the other end of the NO contact with Timer coil and short with timer’s NO contact.
Connect the other end of the NO contact of the Timer with an NC contact of the magnetic contact used for Generator and connect the other end of the NC contact with The coil of Magnetic Contactor used for REB .

Now connect neutral with relay coil, Timer coil and the magnetic Contactor’s coil.
Well, now get a phase from generator and connect to the relay NC (normally closed) contact one end. Connect other end of the contact with Timer (used for Generator) coil and short the terminal with an NO contact of the Timer.
The other end of the NO contact should be connected with an NC contact of the magnetic Contactor used for REB. Then connect the other end of the NC contact with the magnetic Contractor’s used for Generator coil.
Now connect neutral point with Timer and magnetic Contactor used for Generator coil.
Watch the video for best understanding