HZ172A607 by Danaher

The HZ172A607 is an electromechanical preset counter manufactured by Danaher and supplied under the Timers and Controllers series. It integrates a step-driven register with cam-operated contacts to manage sequential operations such as indexing, cutting, or fill cycles in automated machinery. Each electrical pulse advances the internal wheel by one count, and when the preset value is reached, the device changes its output state to start or stop downstream equipment.

Power is taken from a 120 VAC, 50/60 Hz line. When the clutch first engages, it draws 16 VA and then settles to a holding demand of 10.5 VA. The armature seats within 50 ms, which establishes the minimum width of an acceptable command pulse. The programmable capacity ranges from 1 to 40 counts, and a dial-lock mechanism secures the setting against accidental movement. The register can follow shafts or sensors that issue up to 500 counts/min without losing position. A delayed differential cam releases one count early, giving a lead time for pneumatic or mechanical actuators, while the input circuit requires at least 40 ms of on-time for reliable stepping.

The output section provides two SPDT instantaneous contacts and two SPDT delayed contacts, each rated at 10 A at 120 VAC. System resets are handled by a solenoid that clears the register in 500 ms at the maximum count, preparing the counter for the next production cycle. After every step, the coil must remain de-energized for 80 ms so the escapement can return to its home position. The internal step motor imposes a transient load of 26 VA during each inrush, which must be considered when sizing the power source. The device has a minimum preset of one count and a differential cam that releases one count before the selected value. Its four independent contacts support separate switching functions for connected equipment.