Sub-Zero UC-24 series Service Manual page 15

Under Counter (UC-24) Series
Minimize Condensation on Refrigerator Door Glass (UC-24B Only)
To help minimize the formation of condensation, or fog, on the door glass of the model UC-24B, the microprocessor
detects when the refrigerator door is opened, via the light switch, then when the door closes, the evaporator fan is
energized for five (5) minutes, regardless of compressor operational state. This draws any warmer moist air away
from the door glass. (See Figure 3-21)
NOTE: The evaporator fan also cycles with the compressor.
HIGH VOLTAGE SCHEMATIC
ORANGE
J2
PIN 1
MAIN BOARD
PIN 1
J6
J4
PIN 1
PIN 1
J5
Figure 3-21. UC-24B Signal Trace Schematic - Evaporator Fan Operation in Glass Door Unit
115 VOLTS
60 CYCLES
L1
NEUTRAL
P4 WHITE
P3 BLACK
PURPLE
P1
P2
PIN 1
J3
ORANGE
REF LIGHT
ORANGE
Electronic Control System
REF LIGHT SWITCH
LIGHT TUBE SWITCH
(UC-24B ONLY)
WHITE
OVERLOAD
PROTECTOR
CONDENSER FAN
RED
2. Evap fan energized
for 5 minutes.
REF (TOP)
SWITCH
LIGHT
1. Door is opened, then closed. This is
monitored via the orange wire.
3-15
WHITE
PINK
LIGHTS
RUNNING
CAPACITOR
COMPRESSOR
COMPRESSOR
STARTING
M
RELAY
M
M
REF FAN MOTOR
#7003933 - Revision B - November, 2007
WHITE
(WHEN
USED)