Allen-Bradley 856T-BT4 Stack Light Module

Allen-Bradley 856T-BT4 Stack Light Module is a 70 mm light module in the Control Tower Stack Light system, delivering a steady red LED indicator for status signaling on industrial equipment. It runs from 24 V AC/DC and uses a single circuit per module, enabling straightforward integration with other 856T light modules to form a multi-color status stack on panels, enclosures, or machine control stations. The 856T family shares a common mounting footprint and electrical interface, simplifying configuration, expansion, and retrofits. This modular approach allows you to pair different colors from the same family to convey distinct conditions, enabling clear visual communication across a manufacturing line. Typical applications include signaling machine run, fault, or processing states on production lines, packaging equipment, and material-handling systems, where quick visual recognition of status is critical.