Allen-Bradley · 855T Series

855T-B24GL3

Active
UL CSA CE

855T Control Tower Light Green/Red/Yellow

Allen-Bradley 855T Series Introduced circa 2005

Allen-Bradley 855T modular stack light — green, red, yellow segments.

Common Applications

Stack light (tower light / andon light) that mounts on top of a machine or panel. Green/red/yellow segments visible from across the factory floor. More visible than panel-mount indicators. Used for machine status, production rate, and quality alerts in lean manufacturing. The segments are modular — add/remove colors as needed.

Specifications

Certifications
UL, CSA, CE
Color
Green/Red/Yellow (modular)
Mounting Type
1/2 NPT pipe mount or direct panel
Voltage
24V AC/DC

Installation Quick Reference

Panel cutout: 22mm. Insert from the front, secure with mounting nut.

LED module: Check the voltage rating matches your supply (typically 24V DC or 230V AC). Connect to PLC digital output or relay contact for status indication.

Color meaning (IEC 60204-1): Green = normal/running. Red = fault/danger. Yellow = warning/caution. Blue = mandatory action. White = neutral/general.

Dimensions

Troubleshooting

Light is dim or flickering

Check supply voltage matches the LED module rating. Low voltage causes dimming. If voltage is correct, the LED module is failing — replace it. LED modules have finite life (typically 50K-100K hours).

Light doesn't turn on

Verify voltage at the terminals with a multimeter. Check the PLC output or relay driving the light. LED modules are polarity-sensitive on DC circuits — try reversing the leads.

Where to Buy

Price range

$4.71 — $125.87

across 2 distributors

Quick Specs

Certifications
UL, CSA, CE
Color
Green/Red/Yellow (modular)
Mounting Type
1/2 NPT pipe mount or direct panel
Voltage
24V AC/DC

What People Are Saying

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