Led Lights And Audible Alarm Safeties; E" Control Board - Hoshizaki KM-320MAH Service Manual

B. LED Lights and Audible Alarm Safeties

1. "E" Control Board

At startup, a 5-second delay occurs while the control board conducts an internal timer
check. A beep occurs when power is turned off. 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 4
Harvest Cycle
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 > specified 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
LED
Components
WV
1, 4, 2 Comp, FMR, HGV, WV
1 Comp, FM/FMR, PM,
LLV
1, 4*, 3, 2 Comp, FMR, HGV, PM,
WV*
Type of Alarm
Energized
2 minutes
5 minutes
10 seconds 20 seconds *pump-out timer
Check for harvest problem (stuck HGV or relay), hot
water entering icemaker, or shorted thermistor.
Orange "H TIMER" LED on.
Check for open thermistor, HGV not opening, TXV or
LLV leaking by, low charge, or inefficient Comp, or WRV
leaking by.
Yellow "F TIMER" LED on.
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.
44
Time LEDs are On
Min. Max.
1 minute
20 minutes 3 to 5 minutes
freeze timer 30 to 35 minutes
setting
Notes
Avg.
setting