The Omron H3CAA 2 is an 8-function multifunction timer relay from the H3CA series, offering 7 selectable time ranges covering 0.1 s to 9990 h. It switches through a single-pole changeover (1CO) contact rated at 750 VA / 3 A at 250 V AC, making it suitable for controlling small contactors, signal lamps, or pilot devices in control panels.
Termination is via an 11-pin socket — the relay body unplugs from the base, so a failed timer swaps in seconds without disturbing panel wiring.
Eight selectable operating modes cover on-delay, off-delay, interval, one-shot, and star-delta timing, among others. The 7 time ranges are set via front-panel DIP switches and potentiometers, with the longest range reaching 9990 hours — over a year of continuous timing for long-cycle processes like HVAC defrost or filter backwash sequencing.