Follett MCC400A/W - Manual (Page 22)

22
Electrical control system operation
The wiring diagrams which follow illustrate the circuitry of Follett icemakers used with ice dispensers. Both
normal operation of the icemaker (Stages 1 - 6) and non-normal diagnostic sequences showing torque-out
(Stages 7 - 10) for use in troubleshooting icemaker problems are shown.
Follett icemakers used on top of an ice storage bin have a slightly different circuitry. The operational and
diagnostic stages for these icemakers will be otherwise the same as Stages 1 - 10 that follow.
Circuitry notes
When the icemaker is used with a dispenser it receives power from two sources – the main power supply and
the bin control signal power from the dispenser. Disconnect both power sources 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 29 bar (425 PSI) and closes at 20 bar (287 PSI) (auto reset).
Compressor switch should read open in on position.
Compressor start relay is position sensitive. See label on start relay for proper orientation.
Flashing water LED at any time indicates that water signal to board had been lost for more than
one second.
Ten-second delay: There is a 10 second delay in reaction to loss of water (WTR) or bin (B-E) signals. If signals
are not lost for more than 10 seconds, no reaction will occur.
Normal operation – Stage 1
Power is supplied to L1 of the control board. The ice level control in the dispenser is closed and calling for ice,
completing the bin signal circuit to the control board. The control board will now go through the start-up sequence.
Less than 30 seconds will elapse as the water sensor located in the float reservoir checks for water in the
reservoir. The bin empty LED (B-E), and power LED (PWR) will be on.
WTR
B-E
B-T
2ND
60M
20M
C
POWER
DR
WHITE
BLACK
YELLOW
WHITE
4
3
2
T.O.L.
START
RUN
GEARMOTOR
COMPRESSOR
R
POTENTIAL
START RELAY
RUN
CAP.
CAPACITOR
START
C
S
2
1
5
T.O.L.
L1
L2
COMP
FAN
DRV
RED
WATER
SENSOR
G
GREEN/YELLOW
GRN IN
ELEC BOX
BROWN
BLUE
WHITE
WHITE
BLACK
BLACK
ORANGE
RED
BLACK
BLACK
BLACK BLACK
VIOLET VIOLET WHITE BLACK RED RED
BLUE
BLACK
FAN
M
ORANGE
BLACK
L
N
HIGH PRESSURE
SAFETY SWITCH
COMPRESSOR
SWITCH
BIN
T-STAT
BIN
SIGNAL
SWITCH
DISPENSER