23
b) "G" Control Board
KM-320MAH-E and KM-650MAH-E Auxiliary Code U-1 and Later
KM-515MAH-E Auxiliary Code U-2 and Later
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 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. For details, see "II.B.1.b) "G" Control Board."
Sequence Step
LED
Energized
Components
Time LEDs are On
Min.
Max.
Avg.
1-Minute Fill Cycle
4
WV
1 minute
Harvest Cycle
1, 4, 2
Comp, FMR, HGV, WV
2 minutes
20 minutes 3 to 5 minutes
Harvest Pump Timer
(not used on these
models)
1, 3, 2
Comp, FMR, HGV, PM
0 seconds 50 seconds harvest pump timer
setting
Freeze Cycle
1
Comp, FM/FMR, PM,
LLV (KM-515MAH-E)
5 minutes
freeze timer
setting
30 to 35 minutes
Pump-Out Cycle
1, 4*, 3, 2 Comp, FMR, HGV, PM,
WV*
10 seconds 20 seconds *pump-out timer
setting
The built-in safeties shut down the icemaker and have alarms as listed below.
No. of Beeps
(every 3 sec.)
Type of Alarm
Notes
1
High Evaporator Temp.
(temperature > 127°F)
(53°C)
Check for harvest problem (stuck HGV or relay), hot
water entering icemaker, or shorted thermistor.
2
Harvest Backup Timer
(harvest > 20 min. for two cycles
in a row)
Check for open thermistor, HGV not opening, TXV or LLV
leaking by, low charge, or inefficient Comp.
3
Freeze Timer
(freeze > freeze timer setting for
two cycles in a row)
Check for F/S stuck closed (up), WV leaking by, HGV
leaking by, PM not pumping, TXV not feeding properly,
LLV not opening, low charge, or inefficient Comp.
To reset the above safeties, press the "ALARM RESET" button with the power supply on.
6
Low Voltage
(92Vac±5% or less)
Red LED turns off if voltage protection operates.
The control voltage safeties automatically reset when
voltage is corrected.
7
High Voltage
(147Vac±5% or more)
Legend:
Comp
–compressor;
FM
–fan motor;
FMR
–fan motor remote;
F/S
–float switch;
HGV
–hot gas valve;
LLV
–liquid line valve (KM-515MAH-E);
PM
–pump motor;
TXV
–thermostatic expansion valve;
WV
–inlet water valve