Subzero WOLF ICB WS Series Service Manual page 23

International W
International W
Control Compressor, Condenser Fan, Dual Refrigerant Valve and Evaporator Fan Motors
The control senses evaporator and compartment temperatures via thermistors; one on each evaporator, and one in
each compartment. High Offset (Cut-in) is governed by the evaporator temperatures; Low Offset (Cut-out) is gov-
erned by the compartment/zone temperatures. High Offset and Low Offset are based on the set-point.
If either evaporator temperature is at high offset (calling for cooling), power is supplied to the compressor and con-
denser fan motor, cycling them ON
Two relays on the control board, which are in series with one another, are used to control the dual refrigerant valve.
The first "pulse" relay controls the length of time the solenoid is energized (500ms / 30 pulses per 1/2 second). The
second "sine" relay controls the negative polarity, or positive polarity of the pulse supplied to the valve's solenoid
(determined by which evaporator is calling for cooling, ( + ) = Upper Evaporator, ( - ) = Lower Evaporator). When an
evaporator calls for cooling, the bead inside the T-connection of the refrigerant valve is forced to one side or the
other, depending on the polarity of the pulse, supplying refrigerant to the appropriate evaporator
When the door is closed, the door switch is open, interrupting power to the relay coil, so the relay's P1 to P5 con-
nection remains closed, keeping the neutral side of the evaporator fan motors circuits intact; depending on which
evaporator is calling for cooling, the corresponding evaporator fan relay on the control board closes, completing the
circuit and delivering power to the appropriate fan motor
NOTES:
HIGH VOLTAGE
• When in
Sabbath
Mode, the
evaporator
thermistors
still control
cut-in,
except
there is a
random fif-
teen (15) to
WINE
CONTROL
twenty-five
BOARD
(25) second
delay
before
power is
BLACK
supplied to
cooling
compo-
LOW VOLTAGE
nents.
DISPLAY
Figure 3-17. Cooling Signal Trace (Upper Evaporator at High-Offset Temperature, Calling for Cooling)
ine Storage
ine Storage
(See Figure 3-17).
L1 220-240 VOLTS NEUT
50/60 CYCLES
EVAPORATOR FAN MOTORS
BLUE
J1 1
J8 J2
BROWN
8
1
J3
14
E2
E1
E3
GRAY
MEMBRANE SWITCH
J1
J8 J2
WINE
J3
CONTROL
BOARD
14
Series
Series
(ICBWS)
(ICBWS)
(See Figure 3-17).
5. Door closed; Switch open = Fan Energized
WHITE
FAN CONTROL
UPPER
PINK M WHITE/BLACK
WHITE/BLACK
LOWER
WHITE/BLACK
M
BROWN
LIGHT SWITCH
ORANGE/RED
TAN
CONDENSER FAN MOTOR
GRAY
OVERLOAD PROTECTOR
M
COMPRESSOR
WHITE
3. Energized
1
BLUE W/ WHITE
BLUE W/ WHITE
BLUE W/ BLACK
BLUE W/ BLACK
BLUE W/ RED
ORANGE W/ RED
BLUE W/ YELLOW
ORANGE W/ YELLOW
8
1
WHITE W/ RED
WHITE W/ BLUE
GRAY W/ WHITE
E2
E1
FOR OPTIONAL HOME ALARM HOOK-UP
E3
3-11
Electronic Control System
(See Figure 3-17).
RELAY
WHITE
1
5
3
4
LIGHTS
ORANGE
2 6
LIGHTS
WHITE
7
8
AWECO REF VALVE
WHITE
295 Ω
M WHITE
RUNNING CAPACITOR
(WHEN USED)
COMPRESSOR
STARTING RELAY
THERMISTER 1
LOWER CABINET
THERMISTER 2
UPPER CABINET
THERMISTER 3
LOWER EVAPORATOR
THERMISTER 4
UPPER EVAPORATOR
1. High offset tem-
perature detected,
calling for cooling
#7013455 - Revision A - April, 2009
4. AC pulse,
(+ polarity)
supplied to
solenoid,
valve
opens sup-
plying
refrigerant
to upper
evaporator
2. Temperature
above low off-
set detected