Automatic Circuit Re closer is an intellectual protective device capable of measuring interrupting fault current and which purpose is to increase distribution system reliability. Their function is to automatically disconnect a section of feeder in the event of fault, such as a short circuit.
- The ACR (Automatic Circuit Recloser) system is used to automatically switch on the device after a specified time, only if it was open during protection operation during temporary or non-permanent network disturbances. ACR system is used in HV (High Voltage) and MV (Medium Voltage) networks with ring systems, in which there are no problems of system stability. About 80% of short circuits in overhead lines are transient, so using the ACR system to eliminate interference is beneficial. The system allows the maintenance-free operation of a particular substation. Thanks to the function ACR in circuits with protection with grading of time, it is possible to quickly switch off first by implementing instantaneous protection. A quick shutdown reduces the arc duration to a minimum, which reduces the risk of line damage. Protection with a short time delay protects the system against damage fuses and eliminates the pre-arc appearing on the switch.
