Hoshizaki M029-897 II. Sequence of Operation and Service Diagnosis, IM Control Board

II. Sequence of Operation and Service Diagnosis

A. Sequence of Operation Flow Chart

"IM" Control Board

Cycle	1. 30-Sec.	2. Harvest Cycle	3. Freeze Cycle
Steps	Startup	• HGV: If CBT≤81°F (27°C) (CB Setting	• Max. freeze time: 45 min. (CB Setting 6)
	Cycle	74), HGV repeatedly energizes 40 sec./
		de-energizes 40 sec.

•FM: If CBT≥118°F (48°C) (CB Setting 34), FM operates continuously in harvest cycle

		• Max. harvest time: 30 min.						ET≤-1.3°F (-18.5°C)
	WV Delay		ET≥41°F (5°C)			PM Delay		(CB Setting 2)
			(CB Setting 1)							Time varies based on
	*1					*4
Startup										control board calculation
					Water Tank Closed
HGV energized		WV energized *2 (Actuator Motor PS)					PM energized		If CBT>81°F (27°C) (CB
		HGV continues		Comp continues		Comp continues			Setting 74) and CBT≤111°F
		AMD energized		AMU energized		FM continues			(44°C) (CB Setting 70), HGV
		Comp energized		FM energized		WV energized *4+*5			energizes 5 sec./de-energizes
				WV energized *3					25 sec./energizes 5 sec. (CB
				HGV de-energized					Setting 71, 72)

Shutdown and Restart Sequence Flow Chart

Shutdown	1. Bin Full	2. Icemaker Off 3. Ice Level Lowered
and Restart

BC Operation
	BC open 10 sec. or more	All components	BC closed 80 sec. or more
	(BC actuator paddle	de-energized.	(BC actuator paddle
	engaged). Shutdown		disengaged).
	occurs at end of harvest
	cycle.

Icemaker restarts at

1. 30-Sec. Startup Cycle.

		Initial Harvest and		Initial Harvest and Initial Freeze after
	CB	Initial Freeze after				Normal Harvest and Freeze
Note	Setting	Power On		Bin Control Initiated Restart
		All WT		WT>48°F (9°C)	WT≤48°F (9°C)	WT>48°F (9°C)	WT≤48°F (9°C)
*1	NA	20 sec.		0 sec.	0 sec.	20 sec.	20 sec.
*2	10, 11	95 sec.		10 sec. (CB Setting NA)	95 sec.	30 sec.	95 sec.
*3	NA	10 sec.		0 sec.	10 sec.	0 sec.	10 sec.
PD*4	12	30 sec. × 2		30 sec. × 2	30 sec. × 2	30 sec.	30 sec.
PD*5	15	22 sec. × 2		22 sec. × 2	22 sec. × 2	22 sec.	22 sec.
FD*4	12	60 sec.		60 sec.	60 sec.	60 sec.	60 sec.
FD*5	15	44 sec.		44 sec.	44 sec.	44 sec.	44 sec.
Legend:			FM–fan motor
AMD–actuator motor down
AMU–actuator motor up			HGV–hot gas valve
BC–bin control			PD–partial drain (CB Setting 14)
CBT–control board thermistor			PM–pump motor
Comp–compressor			PS–position sensor
ET–evaporator thermistor			WT–water temperature
FD–full drain (CB Setting 14)			WV–inlet water valve

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