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The electrical components in operation during
the freezing cycle are:

COMPRESSOR

FAN MOTOR (in air cooled version)

WATER PUMP
and during the timed phase of freezing cycle
(Time mode) they are joined by the

ELECTRONIC TIMER

On the air cooled versions the refrigerant head
pressure is gradually reduced from a value of
approx. 10 bar (140 psig), generally recorded at
the beginning of the freezing cycle with the unit
at 21

°

C (70

°

F) ambient temperature, to a minimun

value of approx. 8 bar (110 psig) just at the end
of the freezing cycle few seconds before the
starting of the defrost cycle.
The declining of the pressure is subordinated to
the reduction of the evaporating pressure, caused
by the progressive growth of the ice thickness
into the inverted cup molds and to the flow of air
drown through the air cooled condenser by the
fan motor.
The above values are in relation as well to the
ambient temperature of the ice maker site and
they are subject to rise with the increase of this
temperature.
On the water cooled versions the refrigerant
head pressure is stable at 9 bar (125 psig) being
controlled by a water regulating valve.

With the unit installed in a normal location (21

°

C

ambient temperature) at the start of the freezing
cycle the refrigerant suction or lo-pressure lowers
rapidly to 1 bar (14psig) then it declines gradually
- in relation with the growing of the ice thickness
- to reach, at the end of the cycle, approx. 0

÷

0.1

bar (0

÷

2 psig) with the cubes fully formed in the

cup molds.
The total length of the freezing cycle ranges from
20 to 22 minutes.

DEFROST OR HARVEST CYCLE

As the electronic timer has carried the system
throughout the third phase of freezing cycle or as
soon as the second phase T2 is over (when its
length has been as long as 35 to 45 minutes) the
defrost cycle starts.

DIP SWITCH

1

 

2

 

3

4

5

 

6

 

7

8

9

10

Air Cooled

ON

OFF

OFF

OFF

ON

OFF

ON

ON

ON

OFF

Water cooled

ON

OFF

OFF

ON

OFF

OFF

ON

ON

ON

OFF

TAB. A

 DIP SWITCH KEYS FACTORY SETTING COMBINATIONS

NOTE. 

The length of the defrost cycle (not

adjustable)  is related to the length of the
second phase of freezing cycle T2 as detailed
in Table B.

The electrical components in operation during
this phase are:
COMPRESSOR
WATER INLET SOLENOID VALVE
HOT GAS SOLENOID VALVE
WATER DRAIN VALVE
and
WATER PUMP for the first 15 seconds.

The incoming water, passing through the water
inlet valve and its flow control (Fig. C) runs over
the evaporator platen and then flows by gravity
through the dribbler holes down into the sump/
reservoir.
The water filling the sump/reservoir forces part of
the surplus water from the previous freezing
cycle to go out to the waste through the overflow
pipe. This overflow limits the level of the sump
water which will be used to produce the next
batch of ice cubes.
Meanwhile, the refrigerant as hot gas, discharged
from the compressor (Fig. D) flows through the
hot gas valve directly into the evaporator
serpentine by-passing the condenser.
The hot gas circulating into the serpentine of the
evaporator warms up the copper molds causing
the defrost of the ice cubes. The ice cubes,
released from the cups, drop by gravity onto a
slanted cube chute, then through a curtained
opening they fall into the storage bin.
The water pump remains in operation, during the
first 15-20 seconds of the defrost cycle, to pump
out, trough the opened water drain valve, the
remaining water (reach of minerals and deposits)
of the previous freezing cycle.

NOTE. 

The length of the defrost cycle (not

adjustable) changes in accordance with the
duration of the second portion of the freezing
cycle  T2  .

At the end of the defrost cycle, both the hot gas
and the water inlet valves close and the machine
starts again a new freezing cycle.

Page 12

Summary of Contents for DX 40

Page 1: ...DX 40 Service Manual Cod 71503041...

Page 2: ...allation practice OPERATING INSTRUCTIONS Start up Operational checks OPERATING PRINCIPLES How it works Freezing cycle Harvest cycle Control sequence Component description ADJUSTMENT PROCEDURES Adjustm...

Page 3: ...MIN 10 C 5 C 1 bar 10 ice making capacity 40 35 30 25 20 15 10 Kg 38 32 5 27 21 15 10 32 38 10 21 40 35 30 25 20 15 10 Kg 38 32 5 27 21 15 10 AIR COOLED MODELS WATER TEMPERATURE AMBIENT TEMPERATURE I...

Page 4: ...hine specifications Cubes per harvest 24 medium A 15 C water temperature Electric power cons Kwh per 24 Hr Cond unit Finish Comp HP Stainless stell 3 8 15 Kg Dimensions HEIGHT 1720 mm WIDTH 380 mm DEP...

Page 5: ...es freely 7 Check that the compressor fits snugly onto all its mounting pads 8 Use clean damp cloth to wipe the surfaces inside the storage bin and the outside of the cabinet GENERAL INFORMATION AND I...

Page 6: ...e and the unit If water contains a high level of impurities it is advisable to consider the use of an appropriate water filter or conditioner WATER DRAIN The recommended drain tube is a plastic or fle...

Page 7: ...ency serving him G INSTALLATION PRACTICE 1 Hand shut off valve 2 Water filter 3 Water supply line flexible hose 4 3 4 male fitting 5 Vented drain 6 Open trapped vented drain 7 Drain fitting 8 Main swi...

Page 8: ...pressure below the Minimum value of 1 bar 14 psig 3 Any clogging situation in the water circuit like the inlet water strainer and or the flow control D At completion of the water filling phase 5minute...

Page 9: ...ontrolthetem perature of its probe progressively rises to reach 4 5 C 40 F and at this point the ice machine restarts to initiate a new freezing cycle with the simultaneous extinguishing of the 3rd RE...

Page 10: ...st to avoid to overfill the ice bucket when left in the dispensing compartment The yellow LED located beside the green one is lighted ON while the auger motor is energized NOTE The CUT IN RANGE OF THE...

Page 11: ...reezes into ice the rest of it cascades by gravity into the sump assembly below for recirculation FREEZING CYCLE The hot gas refrigerant discharged out from the compressor Fig B reaches the condenser...

Page 12: ...Page 11...

Page 13: ...5 to 45 minutes the defrost cycle starts DIP SWITCH 1 2 3 4 5 6 7 8 9 10 Air Cooled ON OFF OFF OFF ON OFF ON ON ON OFF Water cooled ON OFF OFF ON OFF OFF ON ON ON OFF TAB A DIP SWITCH KEYS FACTORY SET...

Page 14: ...s ON OFF Evaporator Sensor Ice Level Sensor HARVEST Water Filling Phase Electrical components Loads ON OFF Compressor Water Pump Fan Motor Air cooled only Hot Gas Valve Water Inlet Valve Water drain v...

Page 15: ...OMPONENTS DESCRIPTION A EVAPORATOR TEMPERATURE SENSOR The evaporator temperature sensor probe locatedincontactwiththeevaporatorserpentine detects the dropping of the evaporator tempera ture during the...

Page 16: ...S KEY MUST BE SET IN OFF POSITION ATTENTION The check up of the P C BOARD output must be performed in averyshorttimeinordertoavoidfrequent start and stop every few seconds of the electricalcomponentsw...

Page 17: ...il 8 9 DELTA T C ON ON 1 OFF ON 1 5 ON OFF 2 OFF OFF 2 5 TAB D ICE LEVEL SENSOR CONTROL TEMPERATURE RANGE ACCORDING TO THE DIP SWITCH SETTING COMBINATIONS Locatedonthehotgasline thisvalveisenergized t...

Page 18: ...on the front of the P C Board 2 Take note of the combination of the DIP SWITCH KEYS 3 4 5 6 and 7 and check the corrisponding length of freezing cycle 3rd phase as shown on Table C 3 Change the same D...

Page 19: ...OTOR C COMPRESSOR MOTOR D PUMP E WATER INPUT EL VALVE F DEFROST EL VALVE G AUGER GEAR MOTOR H BIN TEMP PROBE I EVAPORATOR PROBE L ICE PHOTOSWITCHES M ELECTRONIC CARD O FAN PRESSURE SWITCH P ANTI STRIP...

Page 20: ...MOTOR C COMPRESSOR MOTOR D PUMP E WATER INPUT EL VALVE F DEFROST EL VALVE G AUGER GEAR MOTOR H BIN TEMP PROBE I EVAPORATOR PROBE L ICE PHOTOSWITCHES M ELECTRONIC CARD O MAX PRESSURE SWITCH P ANTI STRI...

Page 21: ...Fan motor doesn t run during Replace fan motor freezing Check for correct operation of pressure control Cut in at 10 bar 140 psi Hot gas valve open during freezing Replace hot gas valve Water inlet va...

Page 22: ...more ventilation Overcharge of refrigerant Correct the charge Purge off slowly Capillary tube partially restricted Blow charge add new gas drier after evacuating system with vacuum pump Hot gas soleno...

Page 23: ...hine and fan motor OFF on aircooledmodels cleancondenserusingvacuum cleaner whisk broom or non metallic brush 5 Check for water leaks and tighten drain line connections Pour water down bin drain line...

Page 24: ...rage bin REMEMBER To prevent the accumulation of undesirable bacteria it is necessary to sanitize the interior of the storage bin with an anti algae disinfectant solution every week WARNING The Ice Ma...

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