When power is applied (24 VDC and 120 VAC) the green LED will light, indicating normal supervision. A fault in the speaker loop will be directly supervised by the FACP bell circuit. An internal fault in the AU-360 Series amplifier module will cause the green LED to go out and the yellow LED to light as well as causing a fault on the FACP bell circuit. The yellow and green LEDs become modulation indicators when the microphone paging is utilized. They will flash on and off, indicating peaks in the voice paging source.
120 VAC Supervision circuitry places the module into the Battery Saver