HP56A616 by Danaher

The HP56A616 interval timer is produced by Danaher as part of the Timers and Controllers series. This electromechanical unit closes or opens a circuit after a user-defined delay, allowing conveyor sections, heaters, or fluid valves to actuate in a fixed sequence within automated lines. It mounts behind a control panel and is powered directly from standard plant mains, giving machine builders a simple stand-alone timing element that does not require a separate logic controller.

Line power is applied at 120 VAC and synchronized to a nominal line frequency of 60 Hz, so the motor inside the mechanism advances the dial at a predictable rate. The output contacts can switch up to 10 A at 120 VAC, which is suitable for small solenoids or motor starters. Users can select any delay between the dial minimum of 2 minutes and the upper limit of 60 minutes; divisions are marked at 1-minute intervals for straightforward setting. The device repeats a programmed cycle within ±18 seconds over its full range, providing adequate consistency for noncritical positioning or heating applications. The clutch burden is 10.5 VA, and the motor burden is 2.45 VA, minimizing the impact on auxiliary transformers.

Control relays engage after a pull-in interval of 28 ms and release after a dropout lag of 17 ms, limiting exposure to transient undervoltage. Mechanical endurance reaches 250,000 operations, and the reset lever returns the dial to zero in 0.5 seconds to start the next batch without waiting for the full cycle to expire. The circular housing fits a 3.187 in panel cutout and is secured with the provided bezel. Fifteen screw terminals along the rear simplify the wiring of power, clutch, and changeover contacts. The overall weight is 2 lb 14 oz, keeping strain on light-gauge panels low while still providing a rugged metal case for plant environments.