Bunn Ultra NX Service & Repair Manual page 23

A common problem occurs when the proper preventive maintenance procedures are not followed. Failure to
perform these procedures may result in damaged equipment and may not be covered by warranty.
Fault Message: "CHECK LEFT SIDE" "PRODUCT MIX" "OR DRIVE SYSTEM"
"CHECK RIGHT SIDE" "PRODUCT MIX" "OR DRIVE SYSTEM"
Probable Cause: Inconsistent product mix ratio (very low brix percentage), residue build-up or too much
Krytox grease on auger motor pin or defective position sensor (torque) board.
IMPORTANT: Please check the following items before assuming a refrigeration fault.
When the product does not freeze, there are several possibilities other than a failure in the refrigeration sys-
tem. The torque between the auger motor and the frozen product is controlled by the torque sensor board
measuring the distance between the pins on the coupler and shaft. When the distance between the pins
reaches the maximum allowable distance, the compressor shuts off. The machine thinks the product thick-
ness has reached the maximum and shuts off the compressor. The illustration below shows some of the other
possible causes for the Fault Message and/or false reading from the torque sensor board.
Proper inspection and preventive maintenance (including daily cleaning) will avoid expensive repairs and
costly down time.
A
B
C
D
E
A. MOTOR SHAFT TORQUE SENSOR PIN
B. AUGER SHAFT TORQUE SENSOR PIN
C. TORSION SPRINGS
D. AUGER SHAFT
E. AUGER MOTOR COUPLING
WEAK TORSION SPRINGS
DAMAGED/CORRODED AUGER SHAFT
DAMAGED/WORN BUSHINGS/SEALS
TROUBLESHOOTING
NORMAL OPERATION
CHILL MODE
POSSIBLE CAUSES FOR FALSE READINGS
ICE MODE
TOO MUCH KRYTOX GREASE
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