Allen-Bradley 855T-BPM40 Stack Light Base Assembly

Allen-Bradley 855T-BPM40 Stack Light Base Assembly is the Mounting Base for 70 mm Stack Lights, offering a 70 mm base interface and forming the foundational hardware for Allen-Bradley Control Tower signaling towers. This base is part of the Mounting Base 70 mm Stack Lights family, designed to accept standard 70 mm signaling heads in a vertical stack lighting configuration used to indicate machine state at a distance in industrial environments. The BPM40 designation in the part name identifies the 70 mm base in the 855T line and is associated with configurations that support pole-mounting options in the broader 855T signaling system. Rockwell Automation lists this item as discontinued as of October 1, 2019, with a Functional Replacement in the base/pole-mount ecosystem, guiding customers toward current 855T bases and compatible pole-mount components for ongoing installations. This base, when paired with appropriate light modules and mounting hardware, enables visible, multi-status signaling—typically used to convey conditions such as running, stopped, fault, or maintenance states—across factory floors, control rooms, and process lines.