Before we begin the basic operation, let's look at some of the features and benefits that make
Hoshizaki machines so dependable and serviceable. Regular maintenance checks and servicing are made
easier with the KM Cuber's removable panels. The component sections are divided into separate
compartments, free from the damaging effects of moisture. Separating the evaporator or wet
section from the dry electrical components of our machines helps eliminate many problem
areas. Dividing these compartments also helps insulate the heat generated by the compressor
from the cold section, making the KM Cuber more energy efficient. Unlike other ice makers on the
market, the KM Cuber's pump motor is housed in a separate insulated compartment, away from the
moisture of the evaporator, reducing corrosion, bearing, and winding failures. At the heart of
our pump assembly is a more efficient, permanent, split capacitor motor. This assembly can be easily
removed and rebuilt in the field. The sealed evaporator section has a smaller ice drop zone
than other ice makers. During operation, positive air pressure helps to reduce the airflow around
the evaporator, keeping airborne bacteria out and reducing algae growth. Many manufacturers build
evaporator plates and welded sections of copper, which are plated with nickel or tin. Plating the
copper is necessary for sanitation and to allow the ice to harvest properly, but it may flake and
peel from the copper with age, contaminating the ice. The unique plate design of Hoshizaki's
evaporator with its stainless steel freezing surface and oval-shaped serpentine tubing, produces
a crystal-clear crescent shaped hard cube of ice, which displaces more liquid than square or
diced cubes. Since pure water freezes first on the evaporator plate, minerals are left to run off into
the reservoir, reducing scale buildup and saving frequent and expensive cleaning. Removable panels;
Separate compartments; Insulated evaporator section; Efficient rebuildable pump assembly; Small ice drop
zone; And unique stainless-steel evaporator. Just some of the features and benefits of the KM Cuber
that help make your job easier. Now, let's look at the basic sequence of operation of the Hoshizaki
KM Cuber. When the power switch is turned to the ice position, the inlet water valve opens,
allowing water to enter and fill the reservoir. The one-minute fill cycle assures that the ice machine
will not start until there is sufficient water, eliminating overheated pumps and compressor problems. After
one minute, the controller board checks to see if the float switch is closed and if not repeats the
fill cycle until the water level is sufficient. The float switch check also occurs at the end of each
harvest cycle to ensure continuous automatic low water safety. When the switch is closed the
controller starts the initial harvest cycle, which runs approximately two to three minutes, depending
on ambient air and water temperature. First, hot gas from the compressor enters the serpentine
coils of the evaporator, while the inlet water valve remains open to assist in the harvest.
This causes any ice remaining from the previous cycle to be released from the plate, while water
continues to fill the reservoir. Starting the compressor in the harvest cycle with the hot
gas valve open provides a no load start, better efficiency, and longer life of the compressor and
components. When the thermistor senses that the evaporator temperature has reached 48 degrees,
the solid-state defrost completion timer on the circuit board takes control of the remainder of
the harvest cycle. During the harvest cycle, the inlet water valve brings water through the supply
tube and down the center of the evaporator plates. This water flow also helps transfer heat from the
serpentine coils to the stainless steel plates and pre-chills the water flowing into the reservoir.
During the freeze cycle, water is pumped to the outside of the plates through the distributor
tubes. In the freeze cycle, the hot gas and water valves are closed. As the self-contained condenser
fan and pump motor starts, water is circulated up and across the outside of the evaporator plate and
back down into the reservoir. The circuit board controls the freeze cycle for the first five
minutes, providing short-cycle protection. The float switch then assumes control to initiate the next
harvest. If power to the machine is interrupted, the unit will always restart in the one-minute
fill cycle. Before the second harvest, a ten-second pump out cycle occurs. As the hot gas valve opens
allowing gas to warm up the evaporator, the pump motor stops for two seconds then begins again
in reverse. This pumps out the water containing concentrated minerals from the bottom of the
reservoir, through the check valve and out the drain. At the same time water is used to power
flush the float switch. For improved cleaning, the pump out timer on the circuit board may be
adjusted to lengthen the cycle to 20 seconds. It can also be adjusted to occur every one, two, five,
or ten cycles. These adjustments provide the service technician with the flexibility to overcome some
problems associated with the high mineral content, present in some local water supplies. When the
pump out cycle is completed, the pump motor stops and the inlet water valve opens. Just as in the
initial harvest, the evaporator is warmed by the hot gas defrost and water assist, clearing any
ice left frozen on the plate as the reservoir then refills in preparation for the next freeze cycle.
The water level in the reservoir always overflows the stand pipe at the end of the harvest cycle.
On top of the stand pipe is a displacement cap, which pulls additional minerals from the bottom of the
reservoir and flushes them. This cleaning action can be extended by lengthening the
defrost completion timer setting. When the bin is filled with ice, the machine automatically
shuts off until more ice is needed. Let's review the basic sequence of operation. The ice maker
always starts with the one-minute fill cycle. The initial harvest cycle clears ice from the
plate, assures a full reservoir, and allows quick and easy compressor starting. After five minutes
in the freeze cycle, the float switch assumes control to initiate the next harvest. The 10 to 20 second
pump out cleans the reservoir every one, two, five, or ten cycles. The normal harvest is the same as
the initial harvest and allows the flush to clean the reservoir at the end of this cycle.