Mechanical System - Scotsman AF Series Service Manual

Page 23
The refrigerant suction or Lo-pressure sets - in
normal ambient conditions (21 °C) - on the value
÷ ÷
of 0.4 0.5 bar (6 7 psig) - 2.5 bar (36 psig) on
AF 30 only after few minutes from the unit start-
up.
This value can vary of 0.1 or 0.2 bar (1.5
in relation to the water temperture variations
influencing the freezer cylinder.
NOTE. If, after ten minutes from the unit start
up, no ice is made and the evaporating
temperature detected by the evaporator
sensor results to be higher than -1 ° C (30 ° F)
the ice maker stops (compressor first and 3'
later the gear reducer) and the 5TH
WARNING YELLOW LED blinks.
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.

MECHANICAL SYSTEM

The mechanical system of the SCOTSMAN
Flaker machines consists basically of a gear
motor assembly which drives, through a ratched
coupling, a worn shaft or auger placed on its
vertical axis within the freezing cylinder.
The gear motor is made of a single phase electric
motor with a permanent capacitor. This motor is
FIG. 7
WATER
LEVEL
GEAR MOTOR
CONDENSER TEMP.
EVAPORATOR TEMP.
ICE LEVEL CONTROL
÷
3 psig)
RESET
13
13
ROTATION
12 12
11
11
10 10
9
9
L 1
L 1
TRANSF.
2
N
N 2
directly fitted in the gear case through which it
drives - in counter clockwise rotation at a speed
of 9.5 r.p.m. - the freezer auger being linked to it
by the ratched coupling.
NOTE. In the event the gear motor will tend
to rotate in the wrong direction (counter-
clockwise) or not rotating at all or rotating at
lower speed the unit will stop immediately
with the glowing of the WARNING YELLOW
LED on account of the intervention of the
Electromagnetic Safety Device - based on
Hall Effect principle.
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
source of the failure, to restart the unit it is
necessary to switch OFF and ON the power
line main disconnnect switch (Fig. 7).
The RED LED will start blinking and after
3 minutes the ice maker will resume its total
operations by running first the gear motor
and then the compressor.
8 8
7
7
RELAYS
6 6
5
5
4
4
3
3
TRIAC
Page 23
CONTACTOR COIL
GEAR MOTOR
FAN MOTOR
ELECTRONIC
CARD