Industrial SC648AD Audible Alarm

The Mallory Sonalert SC648AD is an industrial panel‑mount audible alarm (piezoelectric) designed to provide a clear warning signal on control panels and equipment. It accepts 10–48 VAC/DC and emits a tone in the vicinity of 2 kHz (2000 ± 500 Hz), with loudness that scales with supply voltage—from about 60 dB(A) at 2 feet with 10 VAC/DC up to 75 dB(A) at 2 feet with 48 VAC/DC, and typical levels in the 65–80 dB(A) range depending on voltage. The device draws roughly 20 mA at rated voltage and is built in a black 6/6 nylon housing with a knurled nut for panel mounting; a 1.25 inch (31.75 mm) mounting hole is recommended, and the front thread is designed to fit standard 30 mm holes. Operating temperature ranges from -30 to +65°C, with storage tolerance from -40 to +85°C, and it carries environmental ratings of NEMA 3R, 4X, and 12. The SC648AD weighs about 1.6 oz (45 g) and is CUL approved, making it suitable for industrial warning applications, machine status indication, and general alert signaling on equipment and control panels.