Scotsman NU150 Service Manual page 22

NU Undercounter Ice Machine Service Manual
In order to enable the ice machine working
efficiently, had better clean the air filter monthly.
If the filter is damaged due to aging, call the
Scotsman service agent to replace it.
Power switches on front panel
There are two buttons on NU front panel: the
right green switch is the power switch, the red
switch is the cleaning switch.
PC Board (Data processor)
The PC board, fitted in its box located in the left
bottom of the front of the unit, consists of one
power-in high voltage transformer, one PC
board with both high and low voltage and a
display panel connected with the PC board.
The PC board is the brain of the ice machine; it
receives signals transmitted from the four
sensors through its micro processor to control
the operations of the different electrical
components of the ice machine (such as
compressor, Fan, defrosting valve, water inlet
valve, drain valve, water pump).
The lamps on the control box
BMLX： Ice full
ZBLX： Freezing
TBLX： Defrosting
SWLX： Water Supplying
R1LX： Water Shortage
R2LX： High Temperature Alarm
CLLX： Cleaning
MODE： Mode Button（Function is the same
with the main control board MODE)
CLEAN： Clean button（Function is the same
with the main control board CLEAN)
Mode Button Functions
Press the button one time in order, the machine
will enter the next step:
Power on - Water Supplying – Pre-Cooling –
Freezing - Defrosting - Ice Bin Full Detecting
Warning:
Only authorized maintenance people are
allowed to press the MODE button.
The function of the clean button
As power switching on, the clean button only
activates in the first minute. Press the clean
button and hold for 5 seconds, the ice machine
will enter into the clean procedure automatically.
Had better use Scotsman supplied cleaning
solution and sanitizer to clean and sanitize.
Alarm lamps failure description:
lamps State
BMLX + R1LX On
ZBLX + R1LX On
R1LX + R2LX On
BMLX + R2LX On
SWLX + R2LX On
R1LX On
R2LX On
R1LX + R2LX Blink
TBLX Blink
SWLX Slowly
Blink
21
Components Description
Failure Description
Ice trough failure
Making ice overtime
more than 5 times
Condenser sensor
failure
Ice thickness sensor
failure
Water level sensor
failure
Shortage of water
High temperature
alarm
High pressure alarm
Ice harvest overtime
more than 3 times
Water temperature
sensor failure