Electrical control system operation
The P425A/W, MCD425A/W_S and R425A/W wiring diagrams which follow illustrate the circuitry of Follett ice
machines used with ice dispensers . Both normal operation of the ice machine (Stages 1–6) and non-normal
diagnostic sequences showing torque-out (Stages 7–10) for use in troubleshooting ice machine problems are
shown .
Circuitry notes
When the ice machine is used with a dispenser it receives power from the main power supply . Disconnect the
power source before performing service . When performing electrical service, always use a meter to determine
whether or not the components being serviced are energized .
§
High pressure cutout opens at 425 PSI and closes at 287 PSI (auto reset) .
§
The bin signal input to the control board in the 425A/W ice machine must only be initiated by contact closure . Do
not supply power . To run the ice machine in the workshop, use the bin signal jumper (P/N 01069095)
.
Note: The operation stage descriptions that follow are based on the unit containing the split-phase gear
motor.
Normal operation – Stage 1
Power is supplied to L1 of the control board, the
POWER LED light begins flashing . The ice level bin thermostat in
the dispenser is closed and calling for ice, supplying contact closure to the control board . The
LOW BIN LED will
be on . The control board will now go through the start-up sequence . The board checks the water sensors (located
in the reservoir) for continuity between the common probe (B) and the high probe (C) . If continuity is not sensed,
the water fill valve (P21) is energized .
5
2
1
Start
Run
Compressor
T.O.L.
MAINTENANCE
LOW WATER
TIME DELAY
SLEEP CYCLE
MAKING ICE
LOW BIN
POWER
SERVICE
HI AMPS
HI PRESSURE
DRAIN CLOG
CLEANER FULL
High
Pressure
Switch
R S
C
Gearmotor
Start
Relay
Start
Relay
N
L1
Fan
A B C D
Water Sensors
RESET
Fill
Valve
Drain
Valve
3
4
2
Bin T-Stat
Clean Switch
Drain Clog Sensor
P6
P21
P20
P19
P3
P22
P4
AUGER
WATER LEVELS
BIN P11
HI PRS
L1
R
S
C
RED
WHITE
WHITE
BLACK
BROWN
BLUE
RED
BLACK
YELLOW
Compressor
Electrical Box
COMPRESSOR
1 2 3 4 5 6 7 8
BLACK
N
P15
Ice Dispense Input
Capacitor
BLACK
YELLOW
OR
NO CONNECT
MCD425A/W, R425A/W, MFD425A/W, P425A/W Ice Machines 15
