F.
The ice making process takes place thereby,
with the water sprayed into the molds that gets
gradually refrigerated by the heat exchange with
the refrigerant flowing into the evaporator
serpentine. During the freezing process, when
the evaporator temperature falls below an
established value, the evaporator temperature
sensor supplies a low voltage power signal to the
electronic control device (P.C.BOARD) in order
to activate an electronic timer. This one takes
over the control of the freezing cycle up to the
complete formation of the ice cubes (Fig.4).
NOTE. The lenght of the entire freezing cycle
is governed by the evaporator temperature
sensor which has its probe placed in contact
with the evaporator serpentine (Non
adjustable) in combination with the electronic
timer (Adjustable) incorporated in the
P.C.BOARD. The timer adjustment is factory
set in consideration of the ice maker type,
cooling version and ice cube size (Small,
Medium, Large). It is possible, however, to
modify the timed lenght of the freezing cycle,
by changing the DIP SWITCH keys setting.
In Table B of PRINCIPLE OF OPERATION
are shown the various time extensions of the
freezing cycle second phase, in relation with
the different DIP SWITCH keys setting.
G.
After about 17
÷
20 minutes from the begin-
ning of the freezing cycle, in an hypothetic
ambient temperature of 21
°
C, the defrost cycle
takes place with the hot gas, the water inlet
and the water drain valves simoultaneously
activated (Fig. 5).
The electrical components in operation on models
are:
COMPRESSOR
WATER INLET VALVE
HOT GAS VALVE
WATER DRAIN VALVE
and the
WATER PUMP
on the first 15 seconds on model ACM 85 &
AC 125-175 and on the first 30 seconds on
model AC 225.
NOTE. The lenght of the defrost cycle is
determinated by the DIP SWITCH keys
setting in conjunction with the ambient tem-
perature sensor located just in front of the
condenser. The lenght of defrost cycle can
be adjusted by changing the combination
setting of keys 5, 6 and 7 of DIP SWITCH as
illustrated on Table C of PRINCIPLE OF
OPERATION.
As shown, per each individual keys
combination, it is possible to have a different
lenght of the defrost cycle in relation to the
different ambient temperature situations;
shorter when the ambient temperature is
high and longer in colder ambients to partially
compensate the lenght of the freezing cycle,
which is longer in high ambient temperatures
and shorter in low ones.
Page 16
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERA
TURE SENSORS
BIN
COMPRESSOR
TRANSF.
D
ATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
FIG. 5
