HA42A6A211J by Danaher

The HA42A6A211J is an electromechanical interval timer manufactured by Danaher in the Timers and Controllers series. The device inserts a repeatable delay into machinery so sequential actions such as pump changeover, heater dwell, or conveyor indexing occur at controlled intervals. It integrates a motor-driven gear train with a clutch and contact stack to provide timing without relying on an external controller. Where PLC slots are limited or a reset after power loss is undesirable, its self-contained mechanism provides deterministic operation independent of controller scan cycles.

The timing motor accepts a single-phase supply of 120 VAC at 60 Hz, so it can be wired directly to standard control transformers without secondary regulation. The output section uses silver contacts rated at 15 A, allowing it to switch moderate inductive or resistive loads such as contactor coils, solenoid valves, or pilot lamps. The timer provides three separate poles, allowing make-or-break functions to be assigned to independent circuits within the same timing cycle. A solenoid-actuated clutch engages the drive train and couples the drive motor to the cam stack only when a timing command is issued. This arrangement reduces wear while the unit remains on standby.

For longer delays, the geared mechanism provides a maximum timing span of 120 s. The dial face uses a 20:1 turn ratio, so one full revolution equals six seconds and provides fine adjustment for short processes. The primary drive is a synchronous motor, and its speed remains locked to the line frequency for repeatable timing under modest supply fluctuations. An outer bezel measuring 4 in in diameter provides a clear scale that can be adjusted while wearing gloves. The cam follower resets automatically when the pointer returns to zero.