Scotsman MAR 78 Service Manual page 22

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2. Provide power to the unit.
3. Observe the water filling operations.
a) Water flows into the float reservoir first.
b) Water is filling the freezing drum basin.
c) Float moves up as water level rises in water
reservoir.
d) Float stops water flow when water reaches
suitable operation level.
Now, water surrounds bottom half of freezing
drum.
4. Move the manual ON-OFF toggle of main
disconnect switch to ON position. The green
light on console panel will glow.
5. MAR uses an electrical "three phases
monitoring relay" which alerts installer in case
of wrong wiring by keeping green LED ON
only. In this case change phase connection
wiring.
6. Correct wiring is shown by both LEDs Green
and Orange steady ON together.
7. Observe immediately that evaporator drum
rotates in the right direction, namely toward
the scraping blade.
8. Meanwhile unit is under power KT1 relay
compressor device is energized as well in
order to delay compressor start up by 18'
(KT1 orange LED blinks during this delay). On
normal operation - compressor ON - KT1
LEDs (orange and green) are steady ON
together.
NOTE. In case on any temporally Ice maker
trip OFF (not alarm) due to NO/LOW water
pressure, bin full, ice spout switch activation
unit stops by only keeping drive motor operating
for 18' in order to clear evaporator by ice.
KT2 delay relay LEDs steady ON (orange
and green) during this delay.
WARNING - Drum drive motor is three
phases type. At unit start up, correct wiring
is assured by 3 phases monitoring relay
at power in. In addition proper drum
rotation speed is monitored by a Hall
Effect sensor. In case the drum is not
rotating at all or it rotates too slow (less
then 1/4 turn every 30 seconds) a special
Electronic Control trips the unit OFF so to
avoid that compressor can operate with
the drum OFF (in case of fiber keys, drive
motor or gear reducer breakage). In case
of any field drive motor replacement, care
must be taken to its wiring, checking the
correct evaporator drum rotation that must
be toward ice blade. In case of wrong
evaporator drum rotation, turn the unit
OFF and exchange two phases connection
at drive motor control box.
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