Sub-Zero UC-24 series Service Manual page 24

Electronic Control System
Under Counter (UC-24) Series
Temperature Log Recall Mode
The electronic control system is equipped with a temperature history data storage system. This system logs/stores
the average temperature of each individual thermistor every two hours, along with any event indicators (explained
later in this section), that may have occurred. These two-hour periods are referred to as "indexes". Up to 168
indexes can be stored for each compartment, making it possible to observe the preceding fourteen days of the unit's
temperature history (each index equals 2 hour temperature average; 2 hours X 168 indexes = 14 days). After 168
indexes are stored, each new index will bump the oldest index. Index number "1" being the most recent two-hour
temperature average and index number "168" being the oldest. Accessing this temperature history data so it can be
viewed on the LCD is accomplished by initiating Temperature Log Recall Mode.
There are two ways to initiate Temperature Log Recall Mode. One allows viewing of compartment temperature his-
tory only (see below), the other allows viewing of compartment temperature history and/or evaporator temperature
history (see following page).
Initiate Temperature Log Recall Mode To View Compartment Temperature History Only: Begin with the unit
ON. Now, press and hold the desired compartment WARMER key, then press the POWER key, then release both
keys (See Figure 3-43). The left display area on the LCD will show average compartment temperature and in the
right display area will be the index number. The first index number will be "1", indicating the most recent two-hour
temperature average. The right display area will also flash the thermistor location code at 3 second intervals (See
Figure 3-44).
Figure 3-43. Initiate Temperature Log Recall Mode To View Compartment Temperature History Only -
Press and Hold Desired WARMER Key, Then Press POWER Key
Figure 3-44. Thermistor Location Code Flashes Every 3 Seconds
To toggle up (increment) through the indexes (from 1 to 168), press the same WARMER key in multiple key strokes
(See Figure 3-45). To toggle down (decrement) through the indexes (from 168 to 1), press the corresponding
COLDER key in multiple key strokes (See Figure 3-46).
Figure 3-45. Toggle Up (Increment) Through Indexes - Press WARMER Key in Consecutive Key Strokes
Figure 3-46. Toggle Down (Decrement) Through Indexes - Press COLDER Key in Consecutive Key Strokes
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#7003933 - Revision B - November, 2007