AMF panel is the short form of Auto Mains Failure panel. It is sometimes also called an Automatic Transfer Switch. It is normally connected to the generator set to control the generator set function, automatically detecting a power cut and causing the generator to start and support the load. It can call the generator set if it detects that the mains power is lost (power cut) or out of preset tolerances (e.g. brownout).
When the AMF panel detects that the mains has failed or is outside of tolerance, it will send a start signal to the generator to start up. Once the generator is ready to accept the load, the motorised switches or contactors in the AMF panel will switch the building load from mains supply to generator. When the main is restored, the opposite will happen. The AMF panel will put the building load back on to the mains supply and then stop the generator.