Allen-Bradley 855T-B10FN3 Electromechanical Time Delay Relay

The Allen-Bradley 855T-B10FN3 is an electromechanical time delay relay from Rockwell Automation designed to introduce a controlled delay in control circuits by delaying the switching of its contacts after a trigger or power application. As a member of the 855T family, this model supports timing functions used for sequencing and timer-based control in industrial panels and legacy automation applications, offering a compact timing relay suitable for older equipment that still relies on discrete relays for sequencing tasks. Distributor notices and official product listings indicate this specific configuration is not currently available to order, highlighting its status as a legacy/limited-build device within the 855T lineup. Exact electrical specifications—such as input coil voltage, timing range, and contact arrangement—vary by configuration, so the precise numbers should be verified on the official Rockwell Automation product page or the corresponding 855T cut sheet for this model. In practical use, the 855T-B10FN3 provides a simple, reliable means to time a signal before energizing or de-energizing a downstream load, making it suitable for basic conveyor sequencing, machine interlocks, and other straightforward timing tasks in industrial control schemes that historically relied on electromechanical timing relays.