Allen-Bradley 855T-B20SA1 Stack Light With Siren

Allen-Bradley 855T-B20SA1 Stack Light with Siren is a transducer-style sound module (SA1) that sits on top of an 855T stack light to provide an audible alert in 240V AC systems. It supports 13 selectable tones for a single-tone output per stack, and uses one circuit in the stack; it must be placed on the top of the stack and can be paired with up to four light modules to form a signaling tower. The SA1 module draws about 65 mA at 240V, delivering its audible alert alongside the visual signal from the underlying light modules. This configuration is intended for industrial signaling such as machine faults, process alarms, or operator alerts on manufacturing lines, packaging equipment, or automated systems where rapid attention is required. Only one sound module per stack is allowed, ensuring straightforward signaling and avoiding cross-talk between modules.