Operational Checks - Scotsman AF 80 Service Manual

Page 14
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.
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
L 1
1
L
TRANSF.
N 2
2
N
NOTE. On air cooled models, the condenser
temperature sensor, which is located within
the condenser fins, keep the head
(condensing) pressure between 8.5 and 9.5
bar (120 ÷ 135 psig).
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 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 14
CONTACTOR COIL
GEAR MOTOR
FAN MOTOR
ELECTRONIC
CARD