HP56A60192 by Danaher

The HP56A60192 is a mechanical interval timer produced by Danaher within the Timers and Controllers series. The device provides fixed-cycle control for automated equipment that must start and stop auxiliary loads on a repeating schedule. Its reverse-start control action initiates timing when the hand dial is returned toward zero, providing fail-safe operation if an operator forgets to wind the mechanism. A sealed HN383 explosion-proof enclosure allows the timer to operate in areas where ignitable gases or dust may be present.

Powered by 120 VAC mains at 60 Hz, the internal synchronous motor advances the dial through ratios that allow selection of any period between the 1-minute minimum and the 30-minute maximum. The 7.85-inch dial circumference provides clear visibility, and each 0.5-minute division on the face allows fine adjustment. While the timer is running, a cam closes contacts rated at 10 A at 120 VAC, allowing the device to energize solenoids, heaters, or fractional-horsepower motors without an intermediate relay. The explosion-proof housing prevents internal arcs from reaching hazardous atmospheres. The reverse-start arrangement ensures that the circuit remains open unless the dial is deliberately set.

The magnetic clutch consumes only 10.5 VA, while the drive motor draws 2.45 VA, minimizing heat inside sealed panels. Coil pull-in occurs after 28 ms, and the armature drops out in 17 ms, permitting rapid cycling. A full mechanical reset requires only 0.5 seconds, and the mechanism maintains cycle repeatability within ±9 seconds across the entire timing range. Precise dial graduations make the desired interval easy to select without overshooting the intended setting. This timing control supports repeatable sequencing in applications such as mixers, conveyors, and purge valves.