G" Control Board - Hoshizaki KM-1301SAH/3 Service Manual

2. "G" Control Board

At startup, a 5-second delay occurs while the control board conducts an internal timer
check. A beep occurs when the control switch is moved to the "ICE" position. The red
"POWER OK" LED indicates proper control voltage and remains on unless a control
voltage problem occurs. The green LEDs 1 through 4 energize and sequence from
initial startup as listed in the table below. Note that the order of the LEDs from the
outer edge of the control board is 1, 4, 3, 2.
Sequence Step
1-Minute Fill Cycle
Harvest Cycle
Harvest Pump Timer
Freeze Cycle
Pump-Out Cycle
The built-in safeties shut down the icemaker and have alarms as listed below.
No. of Beeps
(every 3 sec.)
1 High Evaporator Temp.
(temperature > 127°F) (53°C)
2 Harvest Backup Timer
(harvest > 20 min. for two
cycles in a row)
3 Freeze Timer
(freeze > freeze timer setting
for two cycles in a row)
To reset the above safeties, press the "ALARM RESET" button with the power supply on.
6 Low Voltage
(92Vac±5% or less)
7 High Voltage
(147Vac±5% or more)
Legend: Comp–compressor; FM–fan motor; FMR–fan motor remote; FS–float switch;
HGV–hot gas valve; HM–headmaster (C.P.R.); LLV–liquid line valve; PM–pump
motor; TXV–thermostatic expansion valve; WRV–water regulating valve;
WV–inlet water valve
Energized
LED
Components
4 WV
1, 4, 2 Comp, FMR, HGV, WV
1, 3, 2 Comp, FMR, HGV, PM
1 Comp, FM/FMR, PM,
LLV
1, 4*, 3, 2 Comp, FMR, HGV, PM,
WV*
Type of Alarm
Min.
2 minutes
0 seconds 50 seconds harvest pump timer
5 minutes
10 seconds 20 seconds *pump-out timer
Check for harvest problem (stuck HGV or relay), hot
water entering icemaker, or shorted thermistor.
Check for open thermistor, HGV not opening, TXV or
LLV leaking by, low charge, or inefficient Comp, or WRV
leaking by.
Check for FS stuck closed (up), WV leaking by, HGV
leaking by, PM not pumping, TXV not feeding properly,
LLV not opening, low charge, HM not bypassing, or
inefficient Comp.
Red LED turns off if voltage protection operates.
The control voltage safeties automatically reset when
voltage is corrected.
50
Time LEDs are On
Max.
1 minute
20 minutes 3 to 5 minutes
setting
freeze timer 30 to 35 minutes
setting
setting
Notes
Avg.