Carrier 26H - Manual (Page 19)

Carrier S E R V I C E 26H
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1. HOW THE AUTOMATIC ICE MAKER WORKS
The Ice Cube Maker is fully automatic and operates in two alternate cycles - first the freezing cycle, then the
harvesting cycle. The compressor operates continuously during both cycles
FREEZING CYCLE (SEE FIG. 1)
During the freezing cycle water is pumped from the
water pan (13) to a water header (16) at the top of
the unit. From, the water header it flows over individ­
ual spreader plates, down the four inside surfaces
of each of the square, stainless steel freezing col­
umns (18). Here water is frozen into individual
cubes. This is accomplished by unique evaporator
design. Copper sleeves are bonded to the outside
of each stainless steel column at eight points
spaced along its vertical dimension. Sections of
the evaporator coils are in turn soldered to these
copper bands. Because of the high rate of heat
transfer through the copper and the low conductiv­
ity of the stainless steel, individual cubes start
to form inside the columns opposite each copper
band and grow from this point. The hole in the cen­
ter is due to continuous water flow - necessary to
form clear cubes.
DEFROST CYCLE (SEE FIG. 2)
When the passage through any one of the columns
becomes restricted because of ice formation, water
backs into the overflow trough, (19), and drops into
the thermostat well,. (21). Here the cold water acti­
vates the cut-out side of the Ranco two-bulb con­
trol, (35A). This starts the harvest cycle by stop­
ping the water pump (14), and opening the hot gas
solenoid valve, (33). The solenoid valve allows hot
gas to pass directly from the condenser, (2), to the
evaporator coil, (6). The cubes are melted loose
and allowed to drop through the ice chute into the
storage compartment, or bin, (37). If the cubes fail
to drop, the water will continue to build up in the
overflow trough and will flow into the safety over­
flow well'(23). This actuates a safety switch (24)
and shuts the machine off.
The hot gas passing from the evaporator coil through
the suction line, warms the capillary bulb (35B)
attached to the vertical portion of the suction line
leading from the first accumulator. The warming of
this_ bulb activates the cut-in side of the Ranco
two-bulb control, which starts the machine on the
freezing cycle. As soon as the Ranco control moves
the machine into the freezing cycle, the water pump
is automatically started and the solenoid valve
closes.
19 26H-57PD