Automatic mains failure (AMF) panels
Automatic mains failure (AMF) panels are an automated switching device that switches the load to main or stand by generator. During the event of main power failure, AMF automatically makes the power switch to emergency standby generators. Without AMF panels, stand by generators need to be operated manually and that can cause data loss, potential damage to electrical equipment, and huge amounts of disruption. When the mains power supply returns, the AMF panel switch back to the mains supply and shuts down the running generator after a suitable cooling run. Automatic mains failure panels are sometimes also called an Automatic Transfer Switch (ATS). The AMF panel includes a battery charger, electronic circuit boards, power relays, and terminal blocks.
Automatic Mains failure Panel includes a number of different sensors for sensing a loss and variation in the mains supply. The detection of these faults or variations is often achieved by voltage sensing relays, which will operate during the abnormal variations in the main supply. Simpler form the Mains Transfer panel consists of two contactors with control sensors. One of the contactor supply the mains to the site distribution board and the other contactor will supply power to the standby generator. During abnormal variations in main supply voltage sensors will detect it and the main contactor will de-energize Thus, prevent the load from severe damage. If the fault persists for over the programmed time, the standby generator will get a command to start. When the control sensors of standby generator have determined that the generator supply is at the correct frequency and voltage, the standby generator contactor will energize and generator fed the site distribution board. When the mains power supply returns, a timer will start to ensure that the supply is stable and after a preset time the mains contactor will energize and the standby generator contactor de-energize
Common components of an automatic transfer switch
Battery Charger (1): It helps to keeps the system charge at all time
Protection Fuses (2): For protections
Current transformer (3 and 4) :
Power contactors(5): A contactor is a control switch used for switching an electrical circuit. It used in amf panel to transfer the load immediately to the generator during the power failure
Power utility, generator & load terminal blocks(7)
Amf controller(9): Amf controller is designed to monitor voltage and frequency of incoming power supply from Mains and generator
Emergency switch (10): This will immediately shut down the entire system.
Mounted pilot lights: To indicate switch in normal or emergency position.