Operational Checks - Scotsman AF Series Service Manual

Page 18
NOTE. If, after ten minutes from the
compressor start-up, the evaporating tem-
perature has not dropped down to a value
° °
lower than -1 C (30 F) due to an insufficient
quantity of refrigerant in the system, the
evaporating temperature sensor detects such
an abnormal situation and stops consequently
the unit operation (drive motor keeps on
working for 3' delay then stops).
In this circustance, the 5th warning YELLOW
LED will blink.
The machine will remain in OFF mode for
one hour then it will restart automatically.
In case the unit trips OFF again in alarm for
3 times in 3 hours, the machine SHUTS OFF
DEFINITIVELY. After having diagnosed and
eliminated the cause of the poor evaporating
temperature (insufficient refrigerant in the
system, etc.) it is necessary to unplug and
plug in again to restart the machine.
The unit, before resuming the total operation,
will go through the usual 3 minutes STAND-
BY period.
OPERATION CHECKS UPON THE UNIT
START UP
D. Remove front service panel and if necessary
install the refrigerant service gauges on the
corresponding Service valves to check both the
HI and LO refrigerant pressures.
FIG. 4
WATER
LEVEL
GEAR MOTOR
CONDENSER TEMP.
EVAPORATOR TEMP.
ICE LEVEL CONTROL
RESET
13
13
ROTATION
12 12
11 11
10 10
9
9
1
L
L 1
TRANSF.
2
N
N 2
NOTE. On air cooled models, the condenser
temperature sensor, which is located within
the condenser fins, keep the head (conden-
sing) pressure between 8.5 and 9.5 bar
(120 ÷ 135 psig) - (17 and 18 bar on AF 30 only).
In case of condenser clogging such to prevent
the proper flow of the cooling air or, in case
the fan motor is out of operation or shortage
of water in the water cooled condenser, the
condenser temperature rises and when it
° °
reaches 70 C (160 F) - for air cooled version
° °
- and 60 C (140 F) - for water cooled version
- the condenser temperature sensor shuts-
off the ice maker (drive motor keeps on
working for 3' delay then stops) with the
consequent light-up of the RED WARNING
LIGHT (Fig.3).
The machine will remain in OFF mode for
one hour then it will restart automatically.
In case the unit trips OFF again in alarm for
3 times in 3 hours, the machine SHUTS OFF
DEFINITIVELY.
After having diagnosed the reason of the
temperature rise and removed its cause, it is
necessary to proceed as per the previous
"NOTE" to start up again the operation of the
ice maker.
E. Check for the correct CUT-OUT and
CUT-IN of the float reservoir water level
sensors by first shutting closed the water shutoff
valve on the water supply line.
8 8
7 7
RELAYS
6
6
5
5
4
4
3
3
TRIAC
Page 18
CONTACTOR COIL
GEAR MOTOR
FAN MOTOR
ELECTRONIC
CARD