The AU-502 can be powered from either a continuous or a switchable 24 VDC power source. By powering the AU-502 from a switchable 24 VDC source minimum power consumption during quiescent periods can be maintained. In addition, the AU-502 24 VDC power input is polarity sensitive allowing connection to be supervised by a polarity reversing source (i.e. NAC).
The AU-503 and AU-504 are normally wired to a continuous source of AC, with selection wired into the unit to select the desired tone.
Tone selection to the AU-500 Series can be permanently wired (via jumper) inside the unit to produce a single tone upon activation, or can be remotely controlled using dry relay contacts, allowing multiple tones to be selected based on alarm./emergency conditions.