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Page 1
Page 1
SERVICE MANUAL
MV 12
MV 21
MV 32
MV 50
R 404 A VERSION
Electronic modular cubers
MS 1000.24 REV. 03/00
Page 2
TABLE OF
CONTENTS
Table of contents
FOR THE INSTALLER
Important operating requirements
FOR THE PLUMBER
Conform to all applicable codes
START-UP
OPERATION
Refrigeration system during harvest
SERVICE SPECIFICATIONS
COMPONENT DESCRIPTION
REMOVAL AND REPLACEMENT PROCEDURES
WIRING DIAGRAM
MV 12-21-32-50 air/water cooled
SERVICE DIAGNOSIS
MAINTENANCE & CLEANING INSTRUCTION
Page 2
2
Page 3
SPECIFICATIONS
MODULAR CUBER MV12
Page 3 ice making capacity
K g .
130
AIR COOLED MODELS
°
C
10
21
110
90
32
38
70
50
32 27 21 15
WATER TEMPERATURE
10
°
C
K g .
130
WATER COOLED MODELS
110
°
C
10
21
32
38
90
70
50
32
27 21 15
WATER TEMPERATURE
10
°
C
NOTE. To keep your Modular cuber performing at its maximum capacity, it is necessary to perform periodic maintenance as outlined on page 29 of this manual.
Page 4
Page 4
SPECIFICATIONS (CONT'D)
④
3/4" GAS
③
3/4" GAS
①
Ø 20 mm
Ø 25/32"
3/4" GAS
①
20 mm - WATER OUTLET
20 mm - WATER OUTLET - WATER COOLED ONLY
③
3/4" GAS WATER INLET
④
CORD SET
Accessoires
KSC 12 - Cube stacking kit
Dimensions:
HEIGHT
WIDTH
DEPTH
WEIGHT
530 mm. (20" 6/7)
560 mm. (22")
600 mm. (23 5/8")
52 Kgs.
Model
MV 12 - AS
MV 12 - WS
MV 12 - MACHINE SPECIFICATIONS
Cond. unit
Air
Water
Finish Comp. HP
Stainless Steel 5/8
Water req.
lt/24 HR
190 *
1200*
Model
Basic electr.
MV 12 - AS
MV 12 - WS
220-240/50/1
Cubes per harvest: 132 Full
* With water at 15
°
C amps
4.0
3.8
Start amps
20
20 watts
750
650
Electric power cons.
Kwhx24 HR.
18 .
15.6
N. of wires
Amps
Fuse
3x1,5 mm
2
10
Page 5
SPECIFICATIONS
MODULAR CUBER MV 21
Page 5 ice making capacity
AIR COOLED MODELS
K g .
220
200
°
C
10
21
180
160
32
38 140
120
32 27 21 15
WATER TEMPERATURE
10
°
C
K g .
220
WATER COOLED MODELS
200
°
C
10
21
32
38
180
160
140
120
32 27 21 15
WATER TEMPERATURE
10
°
C
NOTE. To keep your Modular cuber performing at its maximum capacity, it is necessary to perform periodic maintenance as outlined on page 29 of this manual.
Page 6
SPECIFICATIONS (CONT'D)
Page 6
①
20 mm - WATER OUTLET
20 mm - WATER OUTLET - WATER COOLED ONLY
③
3/4" GAS WATER INLET
④
CORD SET
Accessoires
KSC 18 - Cube stacking kit
Dimensions:
HEIGHT
WIDTH
DEPTH
WEIGHT
530 mm. (20" 7/8)
800 mm. (31" 1/2)
600 mm. (25" 3/8)
77 Kgs.
Model
MV 21 - AS
MV 21 - WS
MV 21 - MACHINE SPECIFICATIONS
Cond. unit
Air
Water
Finish Comp. HP
Stainless Steel 1 1/4
Water req.
lt/24 HR
380 *
1800*
Model
Basic electr.
MV 21 - AS
MV 21 - WS
220-240/50/1
Cubes per harvest: 204 Full - 408 Half
* With water at 15
°
C amps
6
5.5
Start amps
30
30 watts
1100
1050
Electric power cons.
Kwhx24 HR.
26.4
25.2
N. of wires
Amps
Fuse
3x1,5 mm
2
16
Page 7
SPECIFICATIONS
MODULAR CUBER MV 32
Page 7 ice making capacity
AIR COOLED MODELS
K g .
330
300
270
240 32
210
38
180
32 27 21 15
WATER TEMPERATURE
10
°
C
°
C
10
21
300
270
240
210
K g .
330
WATER COOLED MODELS
°
C
10
21
32
38
180
32 27 21 15
WATER TEMPERATURE
10
°
C
NOTE. To keep your Modular cuber performing at its maximum capacity, it is necessary to perform periodic maintenance as outlined on page 29 of this manual.
Page 8
SPECIFICATIONS (CONT'D)
Page 8
①
20 mm - WATER OUTLET
20 mm - WATER OUTLET - WATER COOLED ONLY
③
3/4" GAS WATER INLET
④
CORD SET
Accessoires
KSC 25 - Cube stacking kit
Dimensions:
HEIGHT
WIDTH
DEPTH
WEIGHT
680 mm. (26" 3/4)
800 mm. (31" 1/2)
600 mm. (23" 5/8)
100 Kgs.
Model
MV 32 - AS
MV 32 - WS
MV 32 - MACHINE SPECIFICATIONS
Cond. unit
Air
Water
Finish Comp. HP
Stainless Steel 2
Water req.
lt/24 HR
470 *
3100*
Model
Basic electr.
MV 32 - AS
MV 32 - WS
220-240/50/1
Cubes per harvest: 289 Full - 578 Half
* With water at 15
°
C amps
9,0
8,0
Start amps
49
49 watts
1600
1500
Electric power cons.
Kwhx24 HR.
38,4
36,0
N. of wires
Amps
Fuse
3x1,5 mm
2
16
Page 9
SPECIFICATIONS
MODULAR CUBER MV 50
Page 1 ice making capacity
AIR COOLED MODELS
K g .
550
500
450
400
350
300
32
27 21 15
WATER TEMPERATURE
10
°
C
10
21
32
38
K g .
525
500
475
450
425
WATER COOLED MODELS
32
38
400
32 27 21
15
WATER TEMPERATURE
10
° °
C
°
C
10
21
NOTE. To keep your Modular cuber performing at its maximum capacity, it is necessary to perform periodic maintenance as outlined on page 29 of this manual.
Page 10
Page 10
SPECIFICATIONS (CONT'D)
④
①
③
①
20 mm - WATER OUTLET
20 mm - WATER OUTLET - WATER COOLED ONLY
③
3/4" GAS WATER INLET
④
CORD SET
WATER INLET - WATER COOLED ONLY
Accessoires
KSC 50 - Cube stacking kit
Dimensions:
HEIGHT
WIDTH
DEPTH
WEIGHT
745 mm. (29" 5/8)
1078 mm. (42" 1/2)
564 mm. (22" 1/4)
128 Kgs.
Model
MV 50 - AS
MV 50 - WS
MV 50 - MACHINE SPECIFICATIONS
Cond. unit
Air
Water
Finish Comp. HP
Stainless Steel 3
Model
Basic electr.
MV 50 - AS
MV 50 - WS
400/50/3 N
Cubes per harvest: 578 Full - 1156 Half
* With water at 15
°
C amps
6.5
6.0
watts
2500
2200
Water req.
lt/24 HR
720
4800*
3
Electric power cons.
Kwhx24 HR.
60
53
N. of wires
5x1,5 mm
2
Amps
Fuse
16
Page 11
Page 11
FOR THE INSTALLER
INSTALLATION NOTE: Allow 15 cm.
minimum space at sides and back for ventilation and utility connections.
INTRODUCTION
These instructions provide the specifications and the step-by-step procedures for the installation, start up and operation for the SCOTSMAN
Model MV 12-21-32-50 Modular Cubers.
The Models MV 12-21-32-50 Modular Cubers are quality designed, engineering and constructed, and are thoroughly tested icemaking systems, providing the utmost in flexibility to fit the needs of a particular user.
STORAGE BIN
The MV 12 stack on top of Scotsman bin model
B 190; the MV 21-32 stack onto SCOTSMAN bin model B.390 while the model MV 50 onto bin
B.550.
Refrigerant R 404 A
Charge per nameplate rating.
STANDARD LEGS: Furnished with storage bin.
Four legs screw into mounting sockets on cabinet base. Provide 16 cm. (6'’) minimum height including adjustable leveling foot.
Optional Kit Casters for B 190-390 (KRB 390) and for B 550 (KRB 550) are available on request.
IMPORTANT OPERATING REQUIREMENTS
MINIMUM MAXIMUM
Air Temperature
10
°
C (50
°
F)
40
°
C (100
°
F)
Water Temperature
5
°
C (40
°
F)
35
°
C (90
°
F) 0
Water Pressures 1 bar gauge 5 bar gauge
Electrical Voltage
Variations Voltage rating specified on nameplate -10% +10%
Extended periods of operation exceeding these limitations constitues misuse under the terms of
Manufacturer’s Limited Warranty, resulting in a loss of warranty coverage.
Page 12
Page 12
SELECT LOCATION
The first step in installing the equipment is to select the location. The purchaser of the unit will have a desired spot in mind, check out that spot to insure that it is:
- indoors, in an environment that does not exceed the air and water temperature limitations for the equipment.
- that the necessary utilities are available including the correct voltage electrical power.
- that there be space around the installed machine for service, 15 cm. minimum left, right, and rear for air-cooled models.
STORAGE BIN
The SCOTSMAN bins for these units are the
B 190, B 390 and B 550.
Other bins may be available with bin tops to vary the storage capacity. Lay the bin on its back, using cardboard from the carton to support it, screw in the legs.
Stand the bin upright, and correct any possible small tears in the machine mounting gasket with food grade silicone sealant.
ICE MACHINE
The use of a mechanical lift is recommended for lifting the uncrated icemaker onto the bin.
Remove front, top and sides panels.
Place the unit directly onto the bin, align it with the back of the bin. Locate the hardware package, take out two mounting screws, and use them to secure the Icemaker to the two sides of the bin.
See illustration below.
Remove first the ice deflector/evaporator cover then the masking tape from the ice thickness sensor.
MV 12 - AIR SEPARATOR
Install on the rear right side of the machine the air separator as per instruction provided with it.
Remove all shipping material as well as the masking tapes from the ice deflector/evaporator cover.
STACKING INSTALLATION
To stack a second MV onto the present one, first remove the top panel from the lower machine.
Add a bead of food grade silicone sealant to the top edges of the lower units freezing compartment. Lift the top machine onto the bottom
Page 13
Page 13 machine, (the use of a mechanical lift is recommended for this step). Align the two machines cabinets, and using the 2 screw from the top units, hardware package, fasten the two units together at the side cabinets.
Then make use of the Stacking Kit KSC 12,
KSC 21, KSC 32 or KSC 50 to be mounted as per fitting instructions included in their package, respectively on MV 12, MV 21, on MV 32 and
MV 50 located in the bottom for proper conveying, of the ice cubes made by the top unit, into the storage bin.
With food grade silicone perfectly seal the edge between the freezing compartment of the upper machine and of the bottom machine so to avoid any possible leak of water through the clearence in between.
FOR THE PLUMBER
CONFORM TO ALL APPLICABLE CODES
WATER INLET
AIR-COOLED MODELS: The recommended water supply is cold water, 3/8'’ O.D. copper tubing, connected a - 3/4'’ gas - male fitting at the back of the cabinet. Install a hand valve near the machine to control the water supply.
When choosing the water supply for the MV
Cuber, consideration should be given to:
A. Length of run.
B. Water clarity and purity.
C. Adequate water supply pressures.
Since water is the most important single ingredient in producing ice you cannot over emphasize the three items listed above. Low water pressure, below 1 bar may cause malfunction, of the icemaker unit. Water containing excessive minerals will tend to produce cloudy colored ice cubes, plus scale build-up on parts in the water system.
Heavily chlorinated water can be controlled using charcoal or carbon filters.
DRAINS
AIR-COOLED MODELS: There is one 20 mm.
dia sump drain fitting at the back of the cabinet.
Insulations in high humidity areas is recommended. The ideal drain receptacle would be a trapped and vented floor drain.
WATER-COOLED MODELS: Besides the above drain, a separate condenser drain must be run.
Connect it to the - 3/4'’ gas - condenser drain connection at the back of the cabinet.
STORAGE BIN: A separate gravity type drain needs to be run, similar to the air-cooled sump drain. Insulation of this drain line is recom-
mended.
1) Switch
2) Plug receptacle
3) Electrical plug
4) Water inlet
5) Shut-off valve
6) Water filter
7) Water outlet line
8) Bin water outlet line
9) Open vented water drain
10) Water outlet from the condenser:
water cooled version only.
FOR THE ELECTRICIAN
ELECTRICAL CONNECTIONS
The unit come equipped with an electrical cord for power supply. The lead wires must be connected to an electrical plug that corresponds to the local electrical codes and requirements or to a separate two poles disconnect box with opening to the contacts of about 3 millimeters.
The disconnect box shoulds be placed close to the selected ice maker location to be easily and prompt reached.
Undersized wiring or unproperly installed electrical circuit will result in major problems and malfunctions.
Voltage variations shoud not exceed ten percent.
IMPORTANT - All plumbing and electrical connections must be made by licensed plumbers and electricians, this one must follow the electrical specifications printed on the ice maker nameplate.
NOTE: All SCOTSMAN Cubers require a neutral wire and a solid earth ground wire to prevent possible severe Electrical Shock
Injury to individuals or extensive damage to equipments.
Page 14
Page 14
FINAL CHECK LIST
1. Is the cabinet/bin level?
2. Is the cuber in a location where ambient temperatures are a minimum of 10
°
C (50-degrees F.) all year around and to not exceed a maximum of 40
°
C. (100
°
F.).
3. Is there at least a 15 cm. clearance behind and around the cabinet for all connections and for proper air circulation?
4. Have all electrical and piping connections been made?
5. Has the electrical power supply wiring been properly connected and the voltage tested and checked against the nameplate rating? Has the unit properly grounded.
6. Is the water supply line shutoff valve installed and opened and has the inlet water supply pressure been checked to insure a minimum of
1 bar without exceeding a maximum of 5 bar.
TYPICAL STACKING INSTALLATION
7. Have the compressor holddown bolts been checked to be sure the compressor is snug on the mounting pads.
8. Check all refrigerant lines and conduit lines to gard against vibration and possible failure.
9. Has the cuber and the bin been wiped clean with clean damp cloths?
10. Has the owner/user been given the User
Manual and instructed on how to operate the icemaker and the importance of periodic maintenance?
11. Has the owner/user been given the name and telephone number of the Authorized
SCOTSMAN Distributor or Service Agency serving him?
12. Has the Manufacturer’s Registration Card been properly filled out?
Check for correct Model and Serial Numbers from nameplate, then mail the completed card to the Manufactured.
KIT STACKING KCS 12: TO STACK 2 MV 12's
KIT STACKING KCS 21: TO STACK ON THE MV 21
KIT STACKING KCS 32: TO STACK ON THE MV 32
KIT STACKING KCS 50: TO STACK 2 MV 50's
Page 15
Page 15
START-UP
1.
START-UP
1.
If not yet done remove screws and pull the
Front Panel out.
2.
Open the water supply line shut-off valve.
NOTE: Observe that the inlet water can be seen flowing into the Sump Assembly.
Allow water to fill the Sump about three minutes until the water is at level.
The float should cause the water flow to stop few mm. from reservoir overflow.
4.
First freezing time will range between 19 and 22 minutes.
Longer time for temperature above 25
°
C and shorter time required when temperature are below
25
°
C.
Average complete cycle time is about 22 min.
5.
Make sure of correct operation of float valve and water pump.
6.
Check for any irregular noise source and if any, eliminate it.
7.
Observe first ice cube harvest and check size of ice cubes; if an adjustment is required thread down or out screw N. 1 as shown on below illustration.
When the float has been risen from the water filling the Sump Assy, the water has forced all trapped air out of Water Pump and pump tube, thus preventing the pumping of water filled with air bubbles.
3.
Put unit under power by moving power line switch to ON position.
Immediately the fourth "LED" will glow and fourfive seconds later the third one too together with the compressor.
Check operation of the freezing cycle: a) Compressor is operating.
b) Fan motor (in air cooled version) controlled by the condensing temperature sensor located in contact with the condenser copper tube.
c) Water pump is operating as seen by water moving through the tygon tube up to the water distributor at the top of evaporator plate, where water is uniformly distributed and cascades down over the egg-crate evaporator back into the Sump for recirculation.
NOTE: The Water pump will start up after a minute delay time controlled by the PC Board so to avoid any possibility to such air
(cavitation).
NOTE: Do not remove the evaporator deflector cover as it will cause the switching off of the machine at "STORAGE BIN FULL".
This screw position determines the distance between the sensor reeds and the egg-crate evaporator thus keeping the ice cube at a proper thickness.
NOTE: This type of machine produce an
"ICE PLATE" that breaks when falls down into the storage bin. Setting the ice thickness sensor in order to have single ice cubes
may cause malfunction of the machine.
8. Observe second and third cube harvest.
Check if size and shape combination is correct.
In areas where extreme problem water conditions exist, filtering or purifyng equipment is recommended.
NOTE: If water used is too soft,
"demineralized" the ice thickness sensor might not be able to sense the water on its reeds, there by it will not switch the unit on harvest cycle.
A safety system built in the P.C. Board switches the unit on harvest cycle whenever the freezing period gets longer then 40'.
Page 16
Page 16
NOTE: To assure a correct operation of the machine the water must have a minimum
electrical conductivity of 20 us.
9.
Check operation of magnetic switch controlling it by keeping open the bottom end of plastic deflector for more than 30 seconds. The machine must switch off at storage bin full.
Release the plastic deflector. The machine should restart in the freezing cycle mode within few seconds going through a 3' delay time (green
LED blinking).
10. Place again all cabinet panels and screws previously removed.
11. Thoroughly explain to owner/user the significant specifications of the ice maker startup, reset and operation, going through the procedures in the operating instructions.
Answer all questions about the ice maker by the owner and inform the owner himseft of the name and telephone number of the authorized service agency serving him.
Page 17
OPERATION
FREEZE CYCLE
Page 17
REFRIGERATION SYSTEM SCHEMATIC
REFRIGERATION DURING FREEZE:
This ice machine employes either air or water as a condensing media, the refrigeration system for either one is a follows:
At the hermetic compressor, Refrigerant is compressed into a high temperature, high pressure gas.
The gas moves through the discharge line into the condenser, air or water-cooled. If air-cooled, the discharge pressure will change with the heat load and the ambient air temperature.
If water-cooled, the discharge pressure is controlled by the amount of water flowing through the condenser - which is determined by the water regulating valve.
After the gas is cooled in the condenser, giving up much of its heat, the gas condenses into a high pressure liquid. This liquid travels through the liquid line to the metering device, a
thermostatic expansion valve on models
MV 12-21-32 and two thermostatic expansion valves on model MV 50.
The thermostatic expansion valve meters how much liquid refrigerant is to be allowed into the evaporator section of the refrigeration system.
This is determined by the temperature of the TXV sensing bulb, located on the suction line manifold, at the outlet of the evaporator.
If the bulb senses a warm suction line, more refrigerant is allowed into the evaporator, (common at the beginning of the freeze cycle) and when the temperature begins to fall, less refrigerant is allowed through.
This is why the suction side gauge pressure will decline throughout the freeze cycle. At the evaporator, the liquid refrigerant released from high pressure, boils off in the low pressure environment and absorbs heat, thus cooling the evaporator surface and anything near it, such as water.
The low pressure refrigerant vapor then is forced through the heat exchanger where any excess liquid refrigerant boils-off, allowing only refrigerant vapor to enter the compressor suction tube, where it is recompressed into high pressure, high temperature gas again and the cycle repeats.
Page 18
Page 18
FREEZE CYCLE
WATER SYSTEM
A mechanical float valve is used to control the level of the water into the reservoir/sump.
A pump, running continuously, after the first minute of freezing cycle, forces the water to the top of the evaporators, where it is distributed through a water tube and then cascades down the evaporator surface by gravity. As it flows accross the refrigerated evaporator, some of the water will be chilled enough to change form, turn to ice, and stay frozen onto the evaporator cells.
Most of the water returns to the reservoir, to be sucked back into the pump, and repumped over the evaporator.
Page 19
HARVEST (DEFROST) CYCLE
Page 19
REFRIGERATION SYSTEM SCHEMATIC
REFRIGERATION SYSTEM DURING
HARVEST
The refrigeration system performs the harvest of ice by use of a hot gas bypass valve. When the time comes to de-ice the evaporators, the hot gas valve is energized, and the high temperature, high pressure gas bypasses the condenser, and is allowed directly into the evaporator. The high pressure gas is cooled by the cold evaporator so it condenses into a liquid, giving up its heat as it does so. This heat warms the evaporator and the ice frozen onto the evaporator surface melts, releasing the frozen cubes. Ice then falls by gravity into the storage bin.
The liquid refrigerant goes through the suction line into the heat exchanger where it boils-off so that only refrigerant vapor is drawn into the suction tube of the compressor.
WATER SYSTEM
During the harvest cycle, the electric water drain valve is energized thereby opening the drain line.
All water remained in the reservoir at the end of freezing cycle is pumped-out, to the waste, through the water solenoid and drain line during the first 20 seconds of the defrost cycle eliminating any possible build-up and accumulation of minerals concentration and impurities in the water reservoir.
As the pump stops, the incoming water, passing through the float valve, has still sufficient time, before the beginning of the next start up of the water pump, to properly fill up the sump/reservoir, so that there would not be any cavitation problem when the water pump will resume its operation.
This grants a better ice formation inside the cooling cells.
When the released ice cubes drop into the bin, they open-up for a fraction of a seconds the bottom end of plastic deflector.
This deflector swinging motion is enough to reset the contact of the magnetic switch which - via electronic control board - deenergizes the water drain valve allowing the unit to initiate a new freezing cycle.
Page 20
Page 20
On model MV 50 the release of the ice plate from the second evaporator will cause the restart of the machine in the freezing cycle.
NOTE: In case the P.C. Board does not receive the pulse from the second magnetic switch, after 40 second from the first pulse, it will switch the unit from defrost to freezing cycle.
The harvest cycle lasts about 1.5
÷
2 minutes.
CONTROL SEQUENCE
At the start of the freezing cycle, the contacts of the magnetic switch mechanically operated by the actuator plate of the deflector cover are closed, thereby - via electronic control board closing the circuit to the main contactor coil and consequently to the compressor and fan motors and to the water pump motors.
Then, as the ice thickness reaches the value that corresponds to the full cube size, the film of water that constantly cascades over the slab of ice formed on the evaporator, arrives to establish a contact between the two fingers (energised at low voltage) of the ice sensor control, located on the front upper right side of the evaporator. If the contact between the two fingers of the ice sensor remains established - by the film of water - for more than 10 seconds, a small relay of the electronic board, get energized, controlling simultaneously both the hot gas valve and the water drain valve.
NOTE: in case of failure of ice level sensor, the P.C. Board turns - on automatically the unit into the defrost cycle when the freezing cycle reaches 40 minutes.
At this point, the unit initiates the defrost cycle.
The hot gas circulating into the evaporator serpentine causes a slight melting of ice cubes which get released from their molds. Once entirely released the ice cubes drop simultaneously into the ice storage bin below; by doing so they move apart from the evaporator bottom end the plastic deflector. This plastic deflector has on its side a magnetic switch that on account of the deflector swinging motion, caused by the ice while dropping in the bin, opens and closes their contacts. This will, in turn, disactivate the relay contacts that controls the hot gas and water drain valve which get deenergized allowing the unit to start a new freezing cycle.
When the ice bin is full of ice, the last batch of ice cubes released from the evaporator accumulates to keep the bottom end of the plastic deflector in open position; with the magnetic switch contacts open for longer than 30'’ the entire unit stops.
On model MV 50 in case one or both the ice slabs, released from the evaporator, are maintaining in open position their corresponding deflector for longer than 30 seconds, with the consequent opening of the magnetic switch for the same extension of time, the P.C. Board cause the stopping of the unit operation. This normally occures in the full ice storage bin situation which are signalled by the simoultaneous glowing of the corresponding LED.
The machine will restart when the ice deflector will be back in its normal vertical position (both for model MV50) provided that 3' are elapsed from unit stop. If not the machine will delay its restart till
3' are elapsed with the blinking of the green LED.
Page 21
Page 21
SERVICE SPECIFICATION
In servicing a machine, it is often, useful to compare that individual units operating characteristics to those of a normally operating machine. The data that follows gives those characteristics; however, be aware that these values are for NEW, CLEAN machine operating at 21
°
C ambient and 15
°
C water. USE THESE
NUMBERS AS A GUIDELINE ONLY.
COMPONENT
Reservoir level .............................. 30
÷
35 mm
Cube Size Control Ice Sensor - distance from evaporator ......................................... 5
÷
7 mm
High Pressure Safety Switch.
C/IN 20 bar - C/OUT 28 bar
OPERATING CHARACTERISTICS
On air-cooled models during the freezing cycle, the discharge pressure is maintained between two preset values by means of fan control
(condenser sensor); and at the same time, the suction pressure will also decline reaching it’s lowest point just before harvest. Compressor amps experience a similar drop.
On water-cooled, the discharge pressure is constantly, maintained during the freeze cycle by the water regulating valve. However, suction pressure and compressor amps, will still decline as the machine freezes ice.
Model
Disch.
pressure freeze max
Disch.
pressure freeze min
MV 12 A
MV 12 W
16 bar
17 bar
14 bar
17 bar
MV 21 A
15.5 bar 13.5 bar
MV 21 W
17 bar 17 bar
MV 32 A
16.5 bar 14.5 bar
MV 32 W
17 bar 17 bar
MV 50 A
17.5 bar 15.5 bar
MV 50 W
17 bar 17 bar
Hi press.
Cut Out
Safety
28 bar
28 bar
28 bar
28 bar
28 bar
28 bar
28 bar
28 bar
Suction pressure
Beginning freeze
3.1 bar
3.3 bar
3.5 bar
3.0 bar
3.5 bar
2.8 bar
3.5 bar
28 bar
Suction pressure
End freeze
Freezing time
1.9 bar
2.2 bar
1.7 bar
1.7 bar
1.7 bar
1.5 bar
1.6 bar
1.4 bar
20'
22'
22'
22'
20'
20'
20'
20'
Amp.
compr.
Beginning freeze
Amp.
compr.
End freeze
5.0 A
5.0 A
8.0 A
7.0 A
6.5 A
6.0 A
4.0 A
4.0 A
5.5 A
5.5 A
5.5 A
5.0 A
Refrigerant charge R 404 A
Model
MV 12 MV 21 MV 32 MV 50
Air cooled 700 gr.
1200 gr.
1700 gr.
2000 gr.
Water cooled 650 gr.
650 gr.
700 gr.
1200 gr.
Refrigerant metering device
Thermostatic expansion valve (2 on MV 50).
NOTE: Always check nameplate on individual icemachine for special refrigerant charge before charging the refrigeration system. Such refrigerant charge is the average charge for the MV Modular Cubers. However it is important to check nameplate for each machine.
Page 22
COMPONENT DESCRIPTION
1.
Front Console Panel
Equipped with four LED plus a warning light that when glow or blink are monitoring:
LED N. 1 - RED
GLOW - Machine off. Too long defrost cycle.
BLINK - Too high condensing temperature.
To restart the machine press the reset button.
LED N. 2 - GREEN
GLOW - Bin is full of ice.
BLINK - Cleaning mode.
LED N. 3 - GREEN
GLOW - Compressor is under power.
BLINK - 3' delay/waiting time.
LED N. 4 - GREEN
Power ON.
RED LIGHT - Too high condensing pressure.
Page 22
2.
P.C. Board
Located in the control box, this board is the brain of the system as it governs the ice machine cyclematic through sensors, relays and switch.
It consists of two separated printed circuits one at high and the other at low voltage integrated with a fuse (4 A), of four connectors for the sensors/ switches (condenser sensor - BLACK -, two magnetic switches - BLUE - ice thickness sensor
- RED -), of two jumpers (one J1 for the selection between models MV 21-32 - one magnetic switch
- and the model MV 50 - two magnetic switches
- and the second J2 for the selection between manual or automatic reset mode), of one outlet connector (front LED display - black) and of five plug in terminals for input and output power.
With the two upper pins of the P.C. Board jumped the same is set up in automatic reset mode while when disconnected is in manual reset mode.
With the bottom ones jumped the P.C. Board is set up to operate with one magnetic switch
(MV 21 and MV 32); when disconnected is set up for two magnetic switches (MV 50).
The P.C. Board is equipped by an electronic safety timer that turns-on automatically the unit to defrost cycle when freezing cycle is longer then 40 minutes and trip-off complete unit when defrost cycle is longer then 3 minutes (Red LED
ON).
Page 23
Page 23
3.
Compressor Contactor
Located in the control box, the compressor contactor functions to carry the compressor line current. The contactor is wired to receive power from the P.C. Board.
4.
Ice Thickness Sensor
Located in the front upper right side off the evaporator, the sensor is made with two metal reeds in which passes power at low voltage. The two metal reeds, which are individually insulated, are set, through a setting screw, to maintain a minimum clearence from the evaporator
(5
÷
7 m/m). Once ice is formed into each mold and is thick enough to fill-up that minimum clearance existing between the two sensor reeds, and the evaporator, the water that cascades over the ice has gradually approached to make contact between the two sensor reeds.
It is enough that this contact remains there for about 10 seconds that the P.C. Board receives the signals to put the ice machine on defrost.
5.
Magnetic Switch
Located in the front of the evaporator front plastic deflector (one for each one on model MV 50), this switch sends a pulse to the P.C. Board which switches the machine back in the freezing cycle.
On model MV 50 after the pulse sent by the second magnetic switch, signalling the dropping into the bin of the second slab of ice, the P.C.
Board restarts a new freezing cycle.
NOTE: In case the P.C. Board does not receive the pulse from the second microswitch, after 40 second from the first pulse, it will switch in any case the unit from defrost to freezing cycle.
6.
Hot Gas Solenoid Valve
The Hot Gas Solenoid Valve functions only during the Harvest Cycle, to divert the hot discharge gas from the Compressor, bypassing the Condendenser and thermostatic expansion valve, for direct flow to the Evaporator Platen Assembly to release ice cubes from the ice cube molds.
The Hot Gas Solenoid Valve is comprised of two parts, the Body & Plunger and the Coil assembles.
Installed in the discharge line of the Compressor, the energized solenoid coil lifts the valve stem within the valve body to cause the hot discarge gas to be diverted when the ice Thickness sensor has signalled to the P.C. Board to start the
Harvest Cycle.
7.
Condenser temperature sensor
The condenser temperature sensor probe
(located in contact with the condenser tube coil) detects the condenser temperature variations and signals them by supplying current, at low voltage, to the P.C. BOARD.
In the air cooled versions, in relation to the different current received, the micro processor of the P.C. BOARD supplies, through a TRIAC, the power at high voltage to the fan motor so to cool the condenser and to reduce its temperature.
In case the condenser temperature rises and reaches 65
°
C (150
°
F) the current arriving to the micro processor is such to cause an immediate and total stop of the machine operation with the
blinking of the Red LED.
8.
High Pressure Control
The high Pressure Control, a safety control, is factory set to cut-out, at 28 bar and cut-in at 22 bar. The control, functions as a precautionary device to shut OFF electrical power to Icemaker, should a loss of water occur to the water cooled
Condenser or a burnt out of one of both the fan motors on air cooled versions. The high Pressure
Control is manual reset with reset button located on the rear side of the machine and a monitoring light on the Front Console Panel.
9.
Water Regulator Valve
(Water Cooled Models)
The Water Regulator Valve functions maintain a constant Compressor head pressure, by regulating the amount of incoming water flow through the Condenser, on water-cooled models.
The valve operate through the refrigerant system high side pressure. Rotating the adjusting screw located on top of the valve, can INCREASE or
DECREASE the water flow through the watercooled Condenser, which in turn, will DECREASE or INREASE the Compressor operating head pressure.
10. Water Distribution System
The Water Distribution System function to eventy supply water to all cells of the evaporator plate.
The water pump pumps water from the sump to the tee. From there water is channeled through the vertical tygon tube to the water distributors, above the evaporator plate, and from the holes in the distributor tube water flows to the cells on one side of the evaporator plate.
Gravity flow returns the unfrozen excess portion of water to the sump reservoir for recirculation.
11. Water Drain Solenoid Valve
The Water Outlet Solenoid Valve functions in conjunction with the water pump to flush-out the sump assembly at the beginning (first 20") of every harvest cycle. This action cleans-up and rinses the sump during each harvest cycle preventing dangerous water minerales concentration.
12. Thermostatic Expansion Valve
(TXV) (2 on model MV 50)
The Thermostatic Expansion Valve regulates the flow of refrigerant to the evaporator and reduces pressure of liquid refrigerant from condensing pressure to evaporating pressure.
13. Water pump
The water pump primes the water from the sump to the water distributor tube/s and through the distributing holes it cascades down onto the evaporator cells by gravity so to be frozen into clear ice cubes. The water pump remains off during the first minute of the freezing cycle (to avoid any cavitation problem) while it's kept running during the first 20" of defrost/harvest cycle to drain out (purge) the remaining water from the sump (reach in mineral salts).
Page 24
Page 24
REMOVAL AND REPLACEMENT PROCEDURES
WARNING - Disconnect electric power supply to icemaker whenever replacement procedure are performed.
WATER PUMP
1. Remove front panel.
2. Remove the control box cover.
3. Unplug pump from P.C. Board.
4. Remove screws holding pump bracket to the right side of freezing compartment.
5. Pull pump forward and lift up.
6. Remove discharge hose from pump outlet.
Reverse to replace.
RESERVOIR
1. Close water valve on water supply line.
2. Remove front panel.
3. Remove evaporator front cover.
4. Remove reservoir drain plug and flush reservoir out.
5. Remove screws securing reservoir.
6. Lift-up and pull forward to remove reservoir.
Reverse to replace.
DISTRIBUTOR/WATER TUBE
1. Remove front panel.
2. Remove evaporator front cover.
3. Locate water distributor at the top of the evaporator.
4. Pull distributor forward to unsnap it from its holdind clamps.
5. Remove hose clamp and water hose.
Reverse to replace.
OUTLET WATER VALVE
1. Remove front and right side panel.
2. Remove fan motor shroud.
3. Unplug water valve.
4. Remove clamp securing outlet tube to valve.
5. Remove hose clamp and hose from inlet fitting.
6. Remove two screws and nuts securing valve to its metal bracket and remove valve.
Reverse to replace.
COMPRESSOR
1. Remove top panel (if possible), front panel, left side service panel and left fan motor shroud.
2. Store refrigerant charge in liquid receiver.
3. Disconnect electrical lines from compressor.
4. Isolate parts to be opened from rest of the system.
5. Remove compressor mounting bolts.
Reverse to reassemble.
CONDENSER - AIR COOLED
1. Remove both side panels and remove screws of condenser bracket.
2. Store most of refrigerant charge in liquid receiver.
3. Isolate parts to be opened from the rest of the system.
4. Cut or unsweat liquid and discharge lines.
5. Unbolt and remove condenser from unit rear side.
Reverse to reassemble.
CONDENSER - WATER COOLED
1. Shut-off water.
2. Remove front and left side panels.
3. Store most of refrigerant charge in liquid receiver.
4. Isolate parts to be opened from the rest of the system.
5. Unsweat water and refrigerant lines.
6. Unbolt and remove condenser.
Reverse to reassemble.
HOT GAS VALVE
1. Remove front, right side panel and right fan motor shroud.
2. Unplug hot gas valve.
3. Purge system of refrigerant.
4. Cut or unsweat valve, remove from machine.
5. To replace, heat sinking the valve is CRITI-
CAL. Wrap the replacement valve in wet rags, and sweat into place. Leave rags on until joints cool.
Reverse steps 3-1 to reassemble.
WARNING - Be sure the electrical power supply circuit breaker and the inlet water supply are OFF, BEFORE starting any of the folloving REMOVAL AND REPLACE-
MENT procedures as a precaution to prevent possible personal injury or damage to equipment.
REMOVAL AND REPLACEMENT OF THE
DRIER
To remove the drier:
1. Remove front and left side panel.
2. Remove screws and remove left side fan motor shroud.
3. Store most of the refrigerant charge into liquid receiver.
4. Unsolder refrigeration lines at both ends of the drier and remove the drier.
To replace the drier.
Page 25
Page 25
CAUTION: If the factory seal is broken on the replacement drier, exposing it to the atmosphere more than a few minutes, the drier will absorb moisture from the atmosphere and lose substantial ability for moisture removal.
1. Remove the factory seals from the replacement drier and install the drier in the refrigerant lines with the arrow positioned in the direction of the refrigerant flow.
2. Solder the drier into the lines, two places, taking precautions to NOT OVERHEAT the drier body, during installation soldering.
3. Purge the system and check for leaks.
4. Throughly evacuate the system to remove moisture and non-condensables.
5. Charge the system with refrigerant, by weight.
SEE NAMEPLATE.
6. Replace and attach front and left side panel.
NOTE: Always install a replacement drier, anytime the sealed refrigeration system is opened. Do not replace the drier until all other repair or replacement has been completed.
REMOVAL AND REPLACEMENT OF THE
EVAPORATOR PLATE ASSEMBLY
1. Remove front and top panels.
2. Store refrigerant charge in liquid receiver and isolate parts to be opened from the rest of the systems.
3. Disconnect water distributor tube above the evaporator plate and remove it.
4. Unsnap and remove evaporator cover deflector.
5. Unloose and remove all screws securing the evaporator frame to the chassis.
6. Unsolder and remove the refrigerant lines at the top of the evaporator plate to be replaced.
7. Remove nuts at top and left and right side of the evaporator to remove top and side trimming that make the frame of the evaporator plate.
The evaporator plate is now free.
To replace the evaporator plate, reverse the removal procedures. See nameplate. Weight in proper charge of R 404 A in liquid phase.
WATER REGULATING VALVE
(WATER COOLED)
1. Shut off water.
2. Remove front and right side panel.
3. Unscrew water inlet fitting connection at the water regulator valve to condenser bracket.
4. Purge system of refrigerant.
5. Unscrew fitting connection at outlet of valve.
6. Unsweat valve connection from "T" joint on system liquid line.
7. Remove valve from machine.
Reverse to reassemble.
THERMOSTATIC EXPANSION VALVE
1. Remove front and top and right side panels.
2. Purge system of refrigerant.
3. Unsweat valve at inlet, equalizer, and outlet.
4. Remove insulation from valve bulb, remove mouting straps and valve from cabinet.
5. Place new valve bulb in same place as old valve, secure with straps, and reinsulate.
Reverse to reassemble.
NOTE: Always install a replacement drier, anytime the sealed refrigeration system is opened. Do not replace the drier until all other repair or replacement has been completed.
Throughly evacuate the system to remove moisture and non-condensables.
FAN MOTOR OR BLADE
(LEFT AND RIGHT SIDE)
1. Remove top and left or right side service panels.
2. Remove screws and fan motor shroud.
3. Unplug fan motor to be removed.
4. Remove fan motor bracket from upper tie rod of unit chassis.
5. Remove fan blade from motor. Note location on motor shaft, and hub position.
6. To replace fan motor also, remove it from bracket.
Reverse to reassemble.
NOTE: When replacing a refrigeration component, the exact refrigerant charge must be weighed or metered into a completely evacuated system, because the MV is a
critically charged system.
Page 26
MV 12-21-32-50 - WIRING DIAGRAM
220 V. 50 Hz. 1 ph.
m = brown bc = light blue gv = yellow green b = white n = black r = red
Page 26
A - Input terminal board
B - Compressor contactor
C - Compressor
D - Ice sensor
E - End defrosting switch (two on MV 50)
F - Led card
G - Electronic card
H - Fan motor (one on MV 12 and MV 50)
K - Water pump
L - Water dischargue electrovalve
M - Gas electrovalve
N - Max pressure switch
O - Max pressure switch signal
P - Condenser temperature probe
Q - Heating resistance of carter compr.
(where used)
Page 27
Page 27
SERVICE DIAGNOSIS
The table below is intended as a quick reference to aid the Service Agent in determining the cause of a particular type of malfunction, as well as the recommended repair. It is not intended to be can exclusive list.
Reference to other portions of this manual, inclusing wiring diagrams, installation, and operation are recommended to better determine the cause of a problem.
SYMPTOM
Machine does not run.
Warning Red LED ON
Warning Red LED BLINKS
Warning Red LIGHT ON
No warning LED/LIGHT ON
Bin full Yellow LED ON
Machine runs, compressor does not.
Machine runs, makes ice, does not try to harvest.
Machine runs, makes and harvests ice.
but very slowly.
POSSIBLE CAUSE CORRECTION
Defrost or harvest cycle too long Check for hot gas valve failure, for
(more then 3') malfunction of water pump, for shortage of water, for malfaction of magnetic switch, for proper operation of compressor contactor and for compressor operation.
Too high condensing temperature Check for correct operation of fan motor/s and condenser sensor.
Too high condensing pressure Check for correct operation of fan motor/s.
P.C. Board inoperative.
No power to unit.
Remove board and check.
Check electrical source.
Bin Full of ice.
Magnetic switch inoperative.
Nome.
Check and replace.
P.C. Board compressor relay open.
Compressor contactor open.
Compressor relay open.
Compressor winding open.
Test and replace.
Test and replace.
Test and replace.
Test and replace.
Ice thickness control open.
Too soft water.
Built-in relay on
PE.C. Board open.
Check sensor fingers if are not covered with scale sediment.
Water electrical conductivity must be higher then 20
µ
S.
Machine can't run with demineralized water.
Check and replace P.C. Board.
Low refrigerant charge.
Check system for correct refr. charge.
Check for leak weight in charge.
Page 28
Page 28
SERVICE DIAGNOSIS
SYMPTOM
Low ice capacity.
POSSIBLE CAUSE
High discharge pressure due to not-condensable or overcharge.
Inefficient compressor.
Condenser dirty.
Low water flow
(Water-cooled).
High air temperature
(air-cooled).
CORRECTION
Evacuate and weigh in charge.
Replace.
Clean.
Check and repair.
Check temperature of air entering condenser.
Machine makes irregular ice.
Low water supply.
Plugged water distributor.
TXV supertheat wrong.
Refrigerant charge low.
Check Float valve not mantaining proper water level in reservoir.
Clean water distributor.
Adjust or replace.
Adjust-check for leak.
recharge.
Page 29
Page 29
MAINTENANCE & CLEANING & SANITATION INSTRUCTIONS
A SCOTSMAN Ice System represent a sizable investment of time and money in any company’s business. In order to receive the best return for that investment, in MUST receive periodic maintenance.
It is the USER’S RESPONSIBILITY to see that preferable, and less costly in the long run, to avoid possible down time by keeping it clean, adjusting it as needed and by replacing worn parts before they can cause failure. The following is a list of recommended maintenance that will help keep your machine running with a minimum of problems.
Maintenance and Cleaning should be scheduled at a MINIMUM of twice per year while sanitation once per month.
9.
With unit out of operation, clean the condenser using vacuum, cleaner, wisk broom or brush.
Instruct customer to clean condenser frequently
DO NOT USE A WIRE BRUSH.
ICE STORAGE BIN
The interior liner of the bin is in contact with a food product, ice, and should be cleaned and sanitised regularly. Once a week sanitise it with a commercial food grade sanitiser compling with the manufacturer dilution.
ICEMAKER
THE FOLLOWING MAINTENANCE SHOULD
BE SCHEDULED AT LEAST TWO TIMES PER
YEAR ON THIS ICEMAKER. CALL YOUR
AUTHORIZED SCOTSMAN SERVICE
AGENCY.
1.
Check and clean or service any optional water treatment devices, if any installed.
2.
Clean water strainer.
3.
Check that the cabinet is level, in the sideto-side and front-to-back directions.
4.
Clean/Sanitise the water system, evaporator plate and sump assembly, using a solution ot Ice
Machine Cleaner/Sanitiser. Refer to CLEANING -
Icemaker.
5.
6.
NOTE: Cleaning/Sanitising requirements vary according to local water conditions and individual user operation.
Continuous check of the clarity of ice cubes and visual inspection of the water system parts, evaporator plates and the sump assembly before and after cleaning will indicate frequency and procedure to be followed in local areas.
Check and tighten all bolts and screws.
Check for water leaks and make corrections.
7.
Check the bin control to test shut-off.
Holding the evaporator deflector in open Position for more that 30", shold cause the ice maker to shut-off.
Once the evaporator deflector is released in its closed position, the ice maker will restart.
8.
Check cube size, adjust if required through setting screw of ice thickness control sensor.
CABINET EXTERIOR
Wipe clean unit and bin cabinet exterior with a clean cloth or disposable paper wipers, soaked in warm water with mild detergent solution.
CLEANING - Ice maker
WARNING - Ice Machine Cleaner contains
Phosphoric and Hydroxyacetic acids.
These compounds are corrosive and may cause burns. If swallowed, DO NOT induce vomiting. Give large amounts of water or milk. Call physician immediately. In case of sxternal contact, flush with water.
KEEP OUT OF THE REACH OF CHILDREN.
1.
Empty bin of ice.
2.
Remove front panel.
3.
Wait till the end of the defrost/harvest cycle then push the RESET BUTTON for 6-8 seconds.
The machine should stop with the blinking of the
Yellow LED (slow blink).
4.
Pour 100 cc on MV 12, 200 cc on MV 21-32 and 400 cc on MV 50 of Scotsman Ice Machine
Cleaner directly into the reservoir then push again the RESET BUTTON for a while. The water pump starts to operate with the fast blinking of the Yellow LED.
NOTE: The P.C. Board will keep the machine in Cleaning mode for 30 minutes. In case too long the cleaning mode can be stopped by pushing again the RESET BUTTON.
5.
After 20 minutes push the RESET BUTTON for a while. The P.C. Board put the machine in automatic rinsing mode with the special blinking
(blink twice and repeat) of the Yellow LED.
Page 30
Page 30
NOTE: RINSING mode consists of: a) energize the water drain valve and the water pump for 30 seconds to empty the reservoir b) deenergize the water drain valve and the water pump for 1 minute c) energize the water pump for 3 minutes.
The above sequence is repeted 7 times so to be sure to have removed any possible trace of Ice Machine Cleaner.
6.
At the end of the 7th Rinsing cycle the P.C.
Board stops the operation of the machine with the blinking (slow) of the Yellow LED.
7.
Pushing the RESET BUTTON for 6-8 seconds the machine restarts in the freezing cycle.
8.
Replace the evaporator cover deflector and front panel.
9.
Check the next batch of cubes to be sure all the cleaner is gone (no sour taste).
CAUTION - DO NOT use ice cubes produced from the cleaning solution. Be sure none remains in the bin.
10. Pour hot water into the storage bin melt the cubes, and to also clean the bin drain.
A
B190 - B390 - B550 - BIN
C
B
D
F
H
G
I
E
K
J L
B 190
B 390
B 550
A B C D E F G H
560 795 605 895 110 1005 430 65
I J K L
65 560 110 110
805 795 600 900 110 1010 600 100 100 620
1075 785 550 820 160 980 877 97 97 582
80
96
80
96
DIMENSIONS ARE IN MILLIMETERS
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