Scotsman EC 46, Руководство по обслуживанию

Страница: 17 / 28

Page 17
Page 17
COMPONENTS DESCRIPTION
A. WATER PUMP
The water pump operates continually throughout
the freezing cycle.
The pump primes the water from the sump to the
spray system and through the spray nozzles
sprays it into the inverted cup molds to be frozen
into crystal clear ice cubes.
B. WATER INLET SOLENOID VALVE -
3/4 MALE FITTING
The water inlet solenoid valve is energized only
during the defrost cycle.
When energized it allows a metered amount of
incoming water to flow over the evaporator cavity
to assist the hot gas in defrosting the ice cubes.
The water running over the evaporator cavity
drops by gravity, through the dribbler holes of the
platen, into the sump.
On water cooled versions the water inlet solenoid
valve has one inlet and two outlets with two
separate solenoids energized the first (ice
productioon) by the contacts 3-2 of the evaporator
thermostat and the second (water cooled
condenser) by a specific hi pressure control.
C. HOT GAS SOLENOID VALVE
The hot gas solenoid valve consists basically in
two parts: the valve body and the valve coil.
Located on the hot gas line, this valve is energized
by the contacts 3-2 of the evaporator thermostat
during the defrost cycle.
During the defrost cycle the hot gas valve coil is
activated so to attract the hot gas valve piston in
order to give way to the hot gas discharged from
compressor to flow directly into the evaporator
serpentine to defrost the formed ice cubes.
D. BIN THERMOSTAT
The bin thermostat control body is located in the
front of control box behind the front louvered
panel.
The thermostat sensing tube is located into a
bulb holder on the side wall of the ice storage bin
where it automatically shuts the icemaker OFF
when in contact with the ice and re-starts the
icemaker when the ice is removed. Factory
settings are 1
°
C (35
°
F) OUT and 4
°
C (39
°
F) IN.
E. CUBE SIZE CONTROL (EVAPORATOR
THERMOSTAT)
The cube size control (evaporator thermostat)
body is located in the front of control box behind
the front louvered panel; it’s basically a reverse
acting temperature control which closes the
contacts 3-2 when its temperature decreases
and closes the opposite contacts 3-4 when the
temperature rises.
OPERATION - ELECTRICAL SEQUENCE
The following charts illustrate which switches
and components are ON or OFF during the two
phases of the icemaking cycle.
Refer to the wiring diagram for reference.
FREEZING CYCLE
Electrical components ON OFF
Compressor ............................................
•
Water Pump ...........................................
•
Fan Motor (Air cooled only) ....................
•
Hot Gas Valve ........................................
•
Inlet Water Valve ....................................
•
Electrical Controls CLOSE OPEN
Evaporator Thermostat (contacts 3-4) ...
•
Evaporator Thermostat (contacts 3-2) ...
•
Bin Thermostat .......................................
•
HARVEST CYCLE
Electrical components ON OFF
Compressor ............................................
•
Water Pump ...........................................
•
Fan Motor (Air cooled only) ....................
•
Hot Gas Valve ........................................
•
Inlet Water Valve ....................................
•
Electrical Controls CLOSE OPEN
Evaporator Thermostat (contacts 3-4) ...
•
Evaporator Thermostat (contacts 3-2) ...
•
Bin Thermostat .......................................
•
Freeze Cycle
Average Discharge Pressure
A/C:
7
÷
11 bars (100
÷
155 psig)
Average Discharge Pressure
W/C:
8.5
÷
10 bars (120
÷
140 psig)
Suction Pressure
End Freeze Cycle: 0
÷
0.1 bar (0
÷
1.5 psig)
REFRIGERANT METERING DEVICE:
capillary tube
REFRIGERANT CHARGE (R 134 A)
Model Air cooled Water cooled
EC 46 260 gr ( 9.5 oz.) 250 gr (9.0 oz.)
EC 56 260 gr ( 9.5 oz.) 250 gr (9.0 oz.)
EC 86 280 gr (10.0 oz.) 250 gr (9.0 oz.)