Automatic Transfer Switches (ATS) are produced according to IEC/EN 60947-2 and CE standards and fulfill transfering functions between network and Generator. ATS s are consisted of 2 pcs 4 poles MCCB and automatic control unit. When the Network Voltage is interrupted, ATS put the Generator MCCB into the service and provides the feeding of the system through Generator. When the Network Voltage comes back, ATS deactivates the Generator MCCB and put the Network MCCB into service. Also when the voltage decreases or increases below/above a certain value with the asisstance of control units, ATS fulfills the same fuction as well.