Hoshizaki DCM-750BAH-OS, DCM-750BWH-OS service manual Sequence of Operation

C. Sequence of Operation

The steps in the sequence are as outlined below. When power is supplied, the power switch is in the "ON" position, the door switch is engaged, and the control switch is in the "ICE" position, the "POWER" LED on the control board comes on.

1. Fill Cycle

WV opens and the reservoir fills with water until UF/S closes. Note: GM will not start unless UF/S is closed. For details, see "IV. Service Diagnosis".

2. Ice Purge Cycle (60 seconds)

"GM" LED is on. WCR energizes, closing the low water safety circuit and de-energizing the WV. GM, GMPR, HCR, and HTR energize. GM runs for 60 seconds to clear any ice from the evaporator.

3. Freeze Cycle

"COMP", "GM" LEDs are on. Comp and FMS energize. As the water in the evaporator cools, ice starts forming within 4 to 6 minutes. This time frame depends on the inlet water and ambient temperature conditions. UF/S and LF/S operate WCR and WV as needed to continue the icemaking process. This continues until BC shuts the icemaker down or power is turned off to the icemaker.

4. Drain Cycle

12 hour DT activates, "FLUSH" LED is on after 150 second shutdown sequence. Comp and FMS de-energize 90 seconds after the 12 hour DT activates, GM, GMPR, HCR, and HTR de‑energize 60 seconds later. DV then energizes and remains energized for

20minutes.

5.Shutdown

BC is activated and a 150 second shutdown sequence begins. After BC has been open for 90 seconds, Comp and FMS de-energize, AM energizes for 0.6 seconds, and 60 seconds later GM, GMPR, HCR, and HTR de-energize.

Legend: AM–agitating motors; BC–bin control; Comp–compressor; DT–drain timer; FMS–self‑contained fan motor; GM–gear motor; GMPR–gear motor protect relay; HCR–heater control relay; HTR–extruding head heater; LF/S–lower float switch; UF/S–upper float switch; WCR–water control relay; WV–inlet water valve

12