Subzero IC-24CI Service Manual page 11

Controls and Operation
CLEAR FAULTS SCREEN (continued)
8 After 10 seconds, the Service Options screen appears.
SHOWROOM MODE SCREEN
1
Tap Settings .
2
Tap Service Options .
3 When the password screen appears, enter the password for
Showroom mode. Tap the arrow key to cancel and return to
the Service Options menu.
Enter Password
4 If the correct password is entered, the Showroom Mode
screen appears.
Showroom Mode
5 Tap Start to enter Showroom mode.
6 Tap Stop to exit Showroom mode.
DRAWER/DOOR SWITCH OPERATION
Opening the door or drawer closes the switch, completing a
circuit to the control board. If the unit is on and not in Sabbath
mode, the control board:
▪ Enables appropriate lights and internal dispenser operation.
▪ Disables the evaporator fan, ice maker, and air purification
fan.
▪ Monitors how long the door switch is closed to control the
door ajar alarm.
If the unit is in Sabbath mode, the control board:
▪ Reduces lights to 30% illumination regardless of the door
switch position.
▪ Does not disable the evaporator fan or air purification
system when the door or drawer opens.
7041389 REVA 06/2017
X
Start
EVAPORATOR FAN OPERATION
Evaporator fans are brushless direct current (BLDC) motors.
When the unit is on, the evaporator fan supply is 12 VDC at all
times. The control board monitors revolutions per minute (RPM).
On some models, the evaporator fan always runs at high speed.
On other models, the speed command drops to low speed after
30 seconds.
Operation of the refrigerator and freezer evaporator fans differ
during compartment defrost. See Freezer Adaptive Defrost for
freezer fan operation and Fan-Assisted Off-Cycle Defrost for
refrigerator fan operation.
EVAPORATOR FAN ACTIONS
Control Board Detects
High offset temperature
Compartment temperature
above high offset on models
where evaporator fan speed
lowers
Compartment low offset
temperature
Open door/drawer when
evaporator fan is running
Open door/drawer when unit
is in Sabbath mode
Max Ice feature on
12
IC-24C(I)
service.subzero.com
Action
Control board sends high
speed signal to evaporator
fan.
Evaporator fan continues to
run at high speed until
temperature drops below high
offset.
▪ Door/drawer switch
closes.
▪ Control board sends zero
speed command to
evaporator fan.
▪ Evaporator fan stops.
▪ Door/drawer switch
closes.
▪ Control board sends zero
speed command to
evaporator fan.
▪ Evaporator fan stops.
▪ Door/drawer switch
closes.
▪ Control board does not
change fan speed.
Freezer evaporator fan:
▪ Runs 100% of the time.
▪ Runs at high speed when
freezer compressor is on.
▪ Runs at low speed when
compressor is off.