Start of harvest: Evaporator thermostat senses its below-freezing cut-out setpoint, and triggers the hot-gas recirculation solenoid to begin harvest. Hot-gas recirculation heats the evaporator, thawing the bottom of the ice slab that has up to now been solidly frozen. Water solenoid energizes, sending fresh, room-temperature tap water into reservoir, with excess overflowing into drain tube which directs the overflow down the drain without rinsing and melting the existing ice in the bin. Suction-side pressure quickly rises from terminal 1 to 6 psig, up to 60 to 100 psig, due to the reversal.1:00Mid-harvest: Continued thawing loosens ice slab from evaporator plate, and the slab slides off onto the cutter grid. The slab makes a "thunk" sound when it hits the grid assembly and comes to rest on the top grid wires. The evaporator no longer has ice on it, so its temperature now rises above freezing due to the hot gas flowing through it from the reversed refrigeration unit.2:00End of harvest, start of liquid water chilling: Evaporator thermostat senses its above-freezing cut-in setpoint, de-energizes hot-gas solenoid to restore chilling. Water in reservoir is above freezing (now a mix of previous chilled water and fresh room-temperature water, proportion depending on how long the harvest took), but begins to chill as it recirculates over the evaporator plate. Suction-side pressure quickly falls to 10 to 15 psig range, and continues to fall as water chills.7:00Start of ice formation: Water fully chilled to freezing point, and ice begins to form on edges of evaporator plate. Suction-side pressure in the refrigeration unit declines to 6 to 10 psig.10:00Ice builds in thickness: Evaporator plate now fully covered with a thin layer of ice. Bottom of evaporator plate is well below freezing, but not enough to trigger the harvest thermostat. Suction-side pressure at about 6 psig.18:00 to 22:00Triggering of harvest: Ice has formed a full-thickness slab on evaporator plate. Top of slab is covered with recirculating water and is at freezing temp. Bottom of slab and underside of evaporator (with capillary sensing tube to thermostat) are well below freezing. As the ice grows thicker, the heat transfer slows, and the evaporator temperature progessively falls, eventually triggering the thermostat setpoint, and the cycle repeats. Suction-side pressure declines to minimum of 1 to 6 psig, depending on ambient conditions. Note: it's not unusual for thicker cubes or older machines to take about 30 minutes to cycle; but anything much longer than that is poor performance, indicating the need for repairs.