Scotsman EC 46, Service Manual

Page: 18 / 28

Page 18
Page 18
The thermostat sensing bulb is located into a
plastic tube (bulb holder) secured by two clips
directly to the evaporator serpentine.
This control determines the length of the freezing
cycle and correspondingly the size of the cubes.
A lower setting will produce a larger cube
(oversize) while a higher setting a smaller cuber
(shallow size).
When closed on contacts 3-2 it activates the
defrost or harvest cycle components.
The cube size control is set up in the factory
(knob in the black dot position) and doesn't
require any adjustment when the ambient
temperature remains between 15 and 30
°
C
(60 and 90
°
F).
F. FAN MOTOR (Air cooled version)
The fan motor is electrically connected in parallel
to the water pump and it operates continuously
only during the freezing cycle keeping the proper
head pressure by circulating air through the
condenser fins.
G. COMPRESSOR
The hermetic compressor is the heart of the
refrigerant system and it is used to circulate and
retrieve the refrigerant throughout the entire
system. It compresses the low pressure
refrigerant vapor causing its temperature to rise
and become high pressure hot vapor (hot gas)
which is then released through the discharge
valve.
H. WATER SPRAY SYSTEM
Through its nozzles it sprays the water in each
individual cup to be frozen into ice.
I. CLEANING SWITCH
Located on the bottom side of the control box is
used to energize the water inlet and the hot gas
valves so to charge the water into the sump of the
machine when neaded.
J. HI PRESSURE CONTROL (Water cooled
version)
Used only on the water cooled versions it operates
to keep between 8.5 and 10 bars (120
÷
140 psig)
the hi-side or discharge pressure of the refrigerant
system by energizing the coil of the water inlet
solenoid valve that control the cooling water flow
to the condenser.
K. GREEN MASTER SWITCH PUSH BUTTON
Located in the front of the machine it’s used to
switch ON and OFF the unit by pushing its green
push button. When ON, its green light is ON as well.
L. RED ALARM/RE-SET PUSH BUTTON
Located in the front of the machine (just beside
the Master Switch) it works in conjuction with
the Cleaning Remind Board and it’s activated
when:
• Consensing temperature is higher then 70
°
C
(air cooled version) - ON steady with machine
in OFF mode
• Condensing temperature is higher then 60
°
C
(water cooled version) - ON steady with
machine in OFF mode
• Condenser sensor out of order - Blinking
twice and repeat with machine in OFF mode
• Condenser air filter need to be cleaned - ON
steady with machine in ON mode
• Water system need to be cleaned - Slow
blinking with machine in ON mode.
On the first two cases it’s possible to Re-Set the
operation of the machine pushing and hold the
Red Alarm Re-Set Button by 5" till the Red Light
is OFF.
On the third case, it’s necessary first to replace
the condenser sensor then, push and hold for 5"
the Red Re-Set Button.
M. CLEANING REMIND AND PWD PC BOARD
Located on the front left side of the machine, it
works in conjuction with the condenser sensor
and the Red Alarm Re-Set Push Button.
It is used to energise the Water Drain Pump any
time the level of the water into the Sealed water
Reservoir reaches the upper metal pins (low
power electrical circuit closed through the water).
The water pump is kept energised by the PWD
PC Board for 8 seconds.
It consists of a Printed Circuit Board with a step
down transformer (230V - 12V), a relay, a Dip
Switch with two keys, a Jumper for the set up of
the Cut OFF/Alarm condensing temperature
(70
°
C - jumper OUT - for air cooled version and
60
°
C - jumper IN - for water cooled version), a
green four contacts connector for power IN and
OUT, a Red socket for the Water Level Sensor,
a Black socket for the Condenser Sensor and a
White socket for the Red Alarm Re-Set Push
Button.
The main function of this PC Board is to switch
OFF the machine when the condensing tempe-
rature is higher of its setting value or signal out
the need for the cleaning of the condenser air
filter (air cooled only) or of the water system.
WATER LEVEL
SENSOR
CONDENSER
SENSOR
RESET
BUTTON
CONNECTOR
DIP SWITCH FOR CLEANING
REMIND SETTING
POWER IN & OUT
CONNECTOR
TRANSFORMER
JUMPER FOR 70
°
C - OUT - OR 60
°
C
-IN - CONDENSING TEMPERATURE