Scotsman MDT2 - Manual (Page 10)

After diagnosing and fixing the cause of the
temperature rise, push the RESET BUTTON on
the control board.
Before resuming operation the unit will go through
the usual 3 minute STAND-BY period.
E. Check for the correct CUT-OUT and CUT-IN of
the float reservoir water level sensors by shutting
off the valve on the water supply line. This will
cause a gradual decrease of the water level in the
float reservoir and as soon as the level gets below
the sensors, the flaker stops operating and the 5th
YELLOW WARNING LED will glow to signal the
shortage of water (Fig.5).
NOTE: The water level sensor detects the
presence of sufficient water in the float reservoir
and confirms it to the microprocessor by
maintaining a low voltage current flow between the
two sensors using the water as conductor.
CAUTION: The use of
de-mineralized water (water
with no salt content) having an
electrical conductivity lower than
30mS, will cause the water
sensors to stop working
properly which will CUT-OUT
the flaker operations and turn on
the YELLOW LED that indicates
a shortage of water, even though
water is indeed in the reservoir.
After this is done, open the water
supply line shutoff valve to refill
the float reservoir; the 5th
YELLOW LED goes off and the
2nd RED LED starts blinking.
The gear motor will start-up
immediately, 2 seconds later the
compressor will start and after
the 3 minutes the unit resumes
normal operation.
F. To check for the correct
operation of the electronic eye
that controls ice bin level, place
one hand between the sensing
“eye” (located in the ice spout) to
interrupt the light beam. This
interruption will cause the 1st
RED LED to go out. After about
6 seconds the unit shuts off and
the 6th YELLOW LED will light
signaling that there is a full storage bin (Fig.6).
Remove your hand to allow the electronic eye to
resume normal operation. After about 6 seconds
the flaker will resume the ice making process and
the YELLOW LED will turn off – after the 3 minute
STAND-BY period.
NOTE: The ICE LEVEL CONTROL (INFRARED
SYSTEM) is independent of the temperature.
However, the reliability of its detection can be
affected by dirt and scale sediment that may
deposit directly on the light source and on the
receiver.
To prevent ice machine malfunction due to
sediment build-up, be sure to follow the
instructions for the periodic cleaning of the light
sensor elements as detailed in the
MAINTENANCE AND CLEANING
INSTRUCTIONS section of this manual.
MDT2
May 2003
Page 10
Fig 5
Bin full
Bin empty
Reset button
No water
Power
Hi cond temp when Steady
3 minute wait when Blinking
Auger Motor when Steady
Hi evap temp when Blinking
Fig 6
Bin full
Bin empty
Reset button
No water
Power
Hi cond temp when Steady
3 minute wait when Blinking
Auger Motor when Steady
Hi evap temp when Blinking