Control Operation; Control Safeties; Restarts - Scotsman MVP456 Service Manual

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CONTROL OPERATION

Standard control:
• Electronic controller operating from a 12 AC volt
power supply. Will operate within a voltage
range between 10 and 15.5.
• User's Indicator lights, four front visible: Power,
Status, Water, De-scale/Sanitize.
• Accessible On switch.
• Accessible Off switch.
• Code Display: Displays letters and numbers to
indicate cycles and diagnostic codes.
• Manual Harvest switch: Use to trigger harvest at
any time.
• Clean switch: Use to initiate and finish the de-
scale or sanitizing cycles.
• Component Operation Indicator Lights: Indica-
te the status of certain components; water
level; ready for harvest; curtain switch position.
• Power Light: On when power is being supplied
to the controller.
• Status Light: Green when machine is in ice
making mode and is operating correctly. Blinks
red when a machine malfunction has been
detected.
• Water Light: Blinks red when reservoir does not
fill with allowed time period.
• De-scale / sanitize: Yellow when the controller
has determined it is time to de-scale and sanitize
the machine. Use clean process to reset light.
Time is determined by power up time and
controller's setting. Standard setting is 6
months. See adjustment process
Controller Connections:
• J1 - Ground and Power Supply
• J2 - High voltage power harness to loads
• J3 - Factory use
• J4 - Optional board connector
• J5 - Communications port
• J6 - Thermistor connection
• J7 - Curtain switch
• J8 - Curtain switch
• J9 - Water level sensor
• J10 - Ice thickness sensor
• J11 - Bin thermostat. Use with NO thermostat
(closes on temperature fall) & specified harness.

CONTROL SAFETIES

Max freeze time - 45 minutes
When exceeded, control shuts the unit off for 50
minutes and will attempt a restart. If the condition
is exceeded again the next cycle, the control will
shut the unit off for 50 minutes and attempt a
restart. If it fails a third consecutive time the
controller will shut the machine down and must
be manually reset.
Min freeze time - 6 minutes
If the controller switches the machine into harvest
within 20 seconds of the minimum freeze time,
the controller will harvest for a preset time and
does not stop if the curtain switch opens.
If this occurs again in the next three cycles, the
machine will shut down and must be manually
reset.
Max harvest time - 3 minutes
If the harvest cycle has continued for 3 minutes
without the curtain opening, the controller will
shut the machine off for 50 minutes and then
restart. If there is another the machine will shut
the machine off for another 50 minutes and then
restart. If it fails a third consecutive time the
controller will shut the machine down and must
be manually reset.
• Time between resets - 50 minutes
• Number of automatic resets - 2
• Max water fill time - 5 minutes. Machine will
attempt a restart every 20 minutes.
• Max discharge temp - 120°C (250 degrees F).
• Time interval between cleanings - 6 months
power on time - adjustable in one month
increments, can be set at 6, 5, 4 or 3 months of
power up time.
• Manual harvest time - 3 minutes
• Minimum compressor off time - 4 minutes
• Continuous Run Time Maximum Cycles - 25

RESTARTS

Power Interruption
The controller will automatically restart the ice
machine after adequate voltage has been
restored.
• H blinks on code display
• Status indicator light blinks
• Reservoir is drained and refilled
• Default harvest is initiated. The curtain switch
does not have to open to terminate harvest,
harvest will continue until either the curtain's
switch opens or the default harvest time expires.
Default harvest time is 2 and half minutes. The
machine will then return to a normal freeze
cycle.
Water Interruption
• The controller will attempt to fill the reservoir
every twenty minutes until it is successful.
On-Off Switch Access
All models ship with the On and Off switches front
accessible.
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