HA43B6 by Danaher

The HA43B6 is an electromechanical timer produced by Danaher for the Timers and Controllers series. Installed in control panels, it sequences equipment by opening or closing its internal cam-driven contacts after predetermined delays, making it suitable for conveyor indexing, heat-soak cycles, or batch processing in industrial automation. A geared mechanism linked to a front dial converts motor rotation into precise time intervals so that downstream devices receive consistent on-off commands.

Power is taken from a single-phase supply of 240 VAC, and the drive is synchronized to the mains at 60 Hz. Operating directly from these common line conditions keeps timing accuracy tied to the utility frequency. A synchronous motor maintains a constant speed regardless of load, so dial graduations stay proportional over the entire range. The front dial uses a 20:1 turn ratio, meaning that twenty full turns represent the entire scale and allow small timing adjustments without fine-pitch knobs. With a maximum timing span of 20 minutes, the unit can manage short dwell periods and timed production cycles. Three output poles share a contact current capacity of 15 A, allowing the timer to switch heaters, motor starters, or relays without auxiliary interface modules.

Mechanical engagement of the cam stack is handled by a solenoid clutch that moves the timing train in or out of service when an external enable signal is present. Each pole uses silver contact faces to keep resistance low and minimize pitting during repeated make-and-break operations. The assembly provides three independent contact sets for multichannel control. The dial is easy to read on the factory floor because its bezel measures 4 inches across, providing a clear scale while fitting into standard quarter-DIN-style panel cutouts. Its front-mounted format also keeps the timing adjustment accessible while the timer remains installed in a control enclosure.