Electrical Control System Operation - Follett MCD425A/W Operation And Service Manual

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 .
Start
Relay
Capacitor
OR
YELLOW
Water Sensors
T.O.L.
R
S
C
Compressor
2
1
RED
Start
Relay
5
Compressor
Electrical Box
WHITE
Drain Fill
4 Valve Valve
3 2
BLACK
R
S
C
Gearmotor
A B C D
Drain Clog Sensor
MCD425A/W, R425A/W, MFD425A/W, P425A/W Ice Machines
Fan
WHITE
N
N
L1
BLACK
L1
RED
P6
P21
P20
BROWN
P19
BLACK
P3
P22
BLUE
P4
AUGER
Bin T-Stat
High
Pressure
Switch
POWER
P15
LOW BIN
MAKING ICE
SLEEP CYCLE
HI PRS
TIME DELAY
LOW WATER
1 2 3 4 5 6 7 8
MAINTENANCE
RESET
SERVICE
HI AMPS
WATER LEVELS
HI PRESSURE
DRAIN CLOG
P11
BIN
CLEANER FULL
Clean Switch
15