Hoshizaki MRH/3, MWH KM-515MAH, MRH KM-901MAH, MWH(-M) Control Board with Harvest Pump, Timer

"G" Control Board With Harvest Pump Timer Operation Sequence Flow Chart

Cycle

1. 1-Minute

2. Harvest Cycle

3. Freeze Cycle

4. Pump-Out Cycle

Steps

Fill Cycle

• Maximum inlet water valve time: 6 min. or the length of

• Minimum freeze time: 5 min.

• Factory set for every

harvest minus 50 sec. (S4 dip switch 7), whichever is shorter.

• Maximum freeze time: freeze timer

10th cycle

• Maximum harvest time: 20 min.

setting (S4 dip switch 9 & 10)

(except KM-515M_H)

Thermistor in

(S4 dip switch 5 & 6)

1 to 3-min. harvest timer in

• Pump motor stops for

control

control (S4 dip switch 1 & 2)

5-min. minimum

FS in control

2 sec., then reverses

for 10/20 sec.

Harvest Pump

freeze timer in

(S4 dip switch 3 & 4)

Timer

control

Startup

50 sec.

FS check

FS closed

FS check

FS closed

FS opens or

Comp continues

WV energized

Comp energized

PM energized

Comp continues

freeze timer

FMR continues

FMR energized

WV de-energized

FMR continues

terminates

HGV energized

HGV energized

Thermistor temperature reaches

FM energized

PM de-energizes for 2 sec.,

WV energized

LLV energized

FS open

48°F (9°C) (3.9 kΩ or less). Harvest

then reverses for 10/20 sec.

PM energized

timer starts (1 to 3 min.).

HGV de-energized

FM de-energized

FS open

LLV de-energized

If FS is open, Comp stops and cycle returns to 1-min. fill.

2. "G" Control Board with Harvest Pump

16

Shutdown and Restart

MBC Operation

1. Bin Full

Shutdown Delay:

•Fill Cycle–15 sec. after activation.

•Harvest Cycle–At the end of the harvest cycle, or up to 15 sec. into the

freeze cycle if activated at the end of the harvest cycle.

•Freeze Cycle–15 sec. after activation if activated at least 15 sec. before

the 5-min. short cycle protection timer terminates. Otherwise, at the end of the next harvest cycle.

2. Icemaker Off

All components de-energized.

3. Ice Level Lowered

Icemaker starts at

"1. 1-Minute Fill Cycle."

To 1 above

Timer Operation

MBC open (MBC actuator paddle engaged)	Yellow "BC OPEN" LED continues. All	MBC closed
Green "BC CLOSED" LED off	components de‑energized.	(MBC actuator paddle disengaged)
Yellow "BC OPEN" LED on		Green "BC CLOSED" LED on
		Yellow "BC OPEN" LED off
Legend:

Comp–compressor	Components Energized when the Control Switch is in the "WASH" Position
FM–fan motor	The "WASH" position on the control switch is used when cleaning and sanitizing the icemaker. When in the "WASH" position, power is
FMR–fan motor-remote
	supplied to the pump motor. With the cleaning valve closed, the cleaner and sanitizer flow over the outside of the evaporator plate assembly.
FS–float switch
	With the cleaning valve open, the cleaner and sanitizer flow over both the outside and the inside of the evaporator plate assembly.
HGV–hot gas valve
	Note: Close the cleaning valve after cleaning and sanitizing are complete, otherwise the icemaker will not restart when the control switch is
LLV–liquid line valve
	placed in the "ICE" position.
MBC–mechanical bin control
PM–pump motor
WV–inlet water valve