Siemens ABHW-4S — intelligent supervised audible detector base for sleeping areas, with a 520 Hz low frequency sounder.
The base pairs an addressable detector base with a sounder producing a 520 Hz square wave, the low frequency signal NFPA 72 requires in sleeping rooms. It detects the head type automatically, and bases on one loop stay in step.
- 520 Hz square wave; UL and ULC listed, meets UL464 and UL2075
- Two volume levels: 85 dB or more high, 75 dB or more low
- Six tones: Steady, Temporal 3 and 4, Temporal 4 low power, March time 120, Canadian March 30
- External supply 16 to 33 VDC; 90 mA at 24 VDC in alarm, high volume
- 32 to 120 °F (0 to 49 °C), 10 to 95 percent RH non-condensing
- Mounts to a 4 in. square gang box, 2.5 in. deep minimum; a 4 in. octagon does not fit
Alarm current must come from a regulated 24 VDC auxiliary supply or NAC; loop power runs control circuits. The ABHW-4B is the plain audible base, with no 520 Hz sounder. It takes FD-UL heads such as FDO421, FDOT421 and OP921, and H-Series heads such as HFP-11, where output is a fixed 85 dB with Steady and Temporal 3.
