Electrical Sequence - Scotsman SLE400 User Manual

Initial Start Up
Note: If the first batch of cubes are not all uniform
discs, some ice machine cleaner should be added
to the reservoir.
1. After ice has been harvested, but before new
cubes begin to form, switch the ICE/OFF/WASH
switch to WASH.
2. Add 4 oz. of ice machine cleaner to the
reservoir. Allow unit to operate that way for 10
minutes.
3. Switch ICE/OFF/WASH switch to OFF
4. Shut the water supply off.
5. Remove the splash guard, and drain the
reservoir by removing the drain elbow.
7. Replace all parts, turn on the water and move
ICE/OFF/WASH switch to ICE. The next batch
of ice should be uniform.
13. Check harvest. The machine will have to
harvest all of the cubes before it goes back into the
freeze cycle.
14. Check operation of the bin control circuit by
holding ice on the bin control tube in the bin.
If the ice maker does not stop within 1 minute,
while keeping ice on the thermostat, rotate the bin
thermostat shaft counter clockwise until the ice
maker does stop. Remove the ice from the
capillary tube; the ice maker should restart within 2
minutes. If it does not, rotate the adjusting shaft
clockwise until the machine starts.
15. Replace all the panels. The ice machine is now
ready for automatic operation.
Siphon Tube Schematic
U-Tube Adjusted
Here = No Purge
Drain Outlet
Elbow
Siphon Breaker Hole
U-Tube Here =
Maximum Purge
Water Level
At Harvest
Water Level With
Pump ON
Water Inlet
1/8 - 1/4
Bottom of
Reservoir
January 1995
Page 13

Electrical Sequence:

Freeze Cycle:
During the first part of the freeze cycle, the ice
machine compressor, fan motor if air cooled, and
water pump are operating.
Assume the bin thermostat is open (low ice), relay
K1 will NOT have power thru its coil and K1
contacts 6-2 will be closed, connecting power to
the ice size thermostat.
The ice size thermostat contact 2-3 are closed,
connecting power to the fan and pump motors.
The Harvest Termination Thermostat is closed to
NC, but there is no power thru it.
The ice size thermostat heater is on, and the
compressor contactor coil is energized.
Harvest:
In the harvest cycle, the compressor is operating,
and the hot gas valve is energized. The water
pump is off, and air cooled models switch the fan
off.The bin thermostat is still open.
When the ice near the ice size thermostat sensing
tube grows large enough to force water over the
sensing tube, that tube looses heat, and at 38
contacts 2-3 open and 2-1 close.
This removes power from the water pump and fan
and connects power to the relay coil. When the
relay coil has power, it connects power to the:
Hot gas valve coil
The harvest termination switch is closed, and
power flows thru it to the relay coil. This keeps the
relay energized, even when the ice size thermostat
switches contact position as a result of ice falling
away from the sensing tube.
The unit stays in the harvest cycle until the
thermodisc on the suction line warms up to 55
at that time the defrost thermodisk switches to NO
and the harvest cycle is terminated. If the bin
thermostat is still open, relay K1 will still not have
power and the unit will go back into the freeze
cycle. If relay K1 has power, it shuts off the ice
machine by cutting power to the ice size
thermostat. The ice size thermostat heater is on.
Whenever there is ice on the bin thermostat, it
closes a circuit to the coil of relay K1 and stops the
ice making process at the end of a harvest cycle.
SLE400
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