Square D 9050 BO-1E Pneumatic Timing Relay Delay

The Square D 9050-BO-1E is a single-contact pneumatic timing relay from Schneider Electric’s Class 9050 lineup, designed to introduce a timed delay in electrical control circuits. The BO series supports configurable timing that is convertible between on-delay and off-delay operation, with the standard-dial variant sold as 9050BO1Et and micrometer-dial variants available (for example 9050BO4Et) to adjust timing with greater precision. As a plug‑in timing relay, it provides one timing contact within the 9050 platform, enabling straightforward integration into control panels for sequencing, interlock, or delayed signaling in automation equipment. The Pneumatic Timers documentation for the 9050 family confirms the BO variants and their dial options, along with the convertible timing modes and single-contact configuration.