HZ170A601 by Danaher

The HZ170A601 is a preset electromechanical counter manufactured by Danaher for the Timers and Controllers series. In automated packaging, batching, or indexing stations, it registers incoming pulses and activates its relay contacts when the target total is reached, coordinating downstream devices without PLC programming. A reverse clutch arrangement disengages the drive shaft during reset, and the internal contact set includes two instantaneous SPDT contacts and two delayed SPDT contacts that route power to auxiliary motors, solenoids, or logic inputs after the counter reaches its target.

The unit accepts a supply of 120 VAC at 50/60 Hz and maintains 100% count accuracy throughout its range. Operators can select any value between a minimum of 2 counts and a maximum of 100 counts, while the mechanism reliably processes pulses at rates up to 500 counts/min. Its relay package carries up to 10 A at 120 VAC, permitting direct switching of moderate-duty loads. Each index step is driven by a coil that momentarily draws 26 VA of stepping inrush before dropping to its holding current. The fixed 80 ms interval between drive pulses allows the wheels to return to their detents before the next pulse is registered.

The counter resets to zero within 500 ms, after which the clutch re-engages. Clutch engagement requires only 50 ms, and the clutch requires 10.5 VA to remain latched. Initial energization produces a clutch inrush of 16 VA, which should be considered when several units share a control transformer. Each permitted drive pulse lasts no longer than 40 ms, matching the dwell needed to prevent duplicate counts at maximum speed. Because the clutch is reverse-acting, shaft rotation during reset moves the register backward rather than advancing it.