Hoshizaki KM-260BWH Sequence of Operation, ONE Minute Fill Cycle, Initial Harvest Cycle

2. SEQUENCE OF OPERATION

The steps in the sequence are as outlined below. When power is supplied, a 5 second delay occurs at startup. Note that the order of the LEDs from the outer edge of the board is 5, 6, 8, 9, 4, 7.

[a] ONE MINUTE FILL CYCLE

LED 8 is on. WV opens and the fill period begins. After 1 minute, the board checks for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV will remain energized through additional 1 minute cycles until water enters the sump and F/S closes. This serves as a low water safety to protect the pump motor.

[b] INITIAL HARVEST CYCLE

LEDs 5, 6, and 8 are on. WV remains open, Comp energizes, HGV opens, and harvest begins. As the evaporator warms, the thermistor located on the suction line checks for a 48°F (9°C) temperature. When 48°F (9°C) is reached, a 3.9 kΩ signal turns the harvest over to the adjustable harvest timer which is factory set for normal conditions. The timer has settings of 60, 90, 120, and 180 seconds (S1 dip switch 1 & 2). When the harvest timer completes its count down, the harvest cycle is complete and the freeze cycle starts. The minimum total time allowed by the board for a complete harvest cycle is 2 minutes. WV is open during harvest for a maximum of 6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (adjustable by S1 dip switch 7 & 8), whichever is shorter. LED 8 goes off when WV closes. PM energizes and runs for the last 0, 10, 30, or 50 seconds of harvest depending on S1 dip switch 7 & 8 setting. LED 7 comes on when PM energizes. At the end of harvest, the control board checks the position of F/S and proceeds to the freeze cycle if it is closed or calls for a 1-minute fill if it is open.

[c] FREEZE CYCLE

LEDs 5 & 7 are on. Comp continues to run, PM and FMS energize, HGV closes and the freeze cycle starts. For the first 5 minutes after the thermistor temperature reaches 36°F (2°C), the control board will not accept a signal from F/S. This minimum freeze period acts as a short cycle protection. At the end of this period, F/S assumes control. As the evaporator cools, the thermistor located on the suction line checks the temperature and PM stops (see “III. 3. TIMING CHART” for details). This is to prevent slushing. As ice builds on the evaporator the water level in the sump lowers. The freeze continues until F/S opens and terminates ice production.

[d] PUMP-OUT CYCLE

LEDs 4, 5, 6, and 7 are on. Comp continues to run, HGV opens, FMS de-energizes. PM stops for 2 seconds, DV energizes, then restarts to take water from the sump and force it through DV and down the drain. When the drain timer stops counting, the drain is complete. The drain timer has settings of 10 and 20 seconds (S1 dip switch 3 & 4). Pump-out cycle always occurs on the 2nd harvest after startup. Then, depending on

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