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REFRIGERATION SERVICE

General Information:
Work on the refrigeration system should only be
done when it is certain that the system needs
repair. 

••

Refrain from checking refrigeration
pressures without reason.
  Visual inspection
of the water system, observation of the ice
formation, amp draw, voltage, and other
techniques will lead to proper diagnosis.
Scotsman also recommends that, at the time of
initial start up, gauges not be used.

••

If gauges must be used, don’t always check the
high side pressure. If the condenser is clean
and seems to be operating correctly, it most
likely is. The low side pressure is more
important on an ice machine than the high side. 

••

If gauges must be used, use very short hoses to
minimize refrigerant discharged into the air. 

••

Refrigerant should not be added except as a
way to determine the proper operation of the
product. If the system was low on refrigerant,
there is a leak, and it must be found and
repaired.

••

This system has a critical charge, it must be
recharged with the correct amount of refrigerant
as listed on the nameplate of the ice machine,
or performance will suffer.

••

Anytime the refrigeration system has been
opened, the dryer should be replaced. Note:
Only a HFC type dryer should be used.

••

When brazing the tubing connections to
components such as the TXV, the component
must be protected by heat sink material.

Recover, reclaim or recycle refrigerant. The
method chosen is up to the service company. Any
refrigerant placed into a Scotsman ice machine
must meet ARI spec 700-88. Reclaim programs
are available through most refrigerant wholesalers. 
Access Valves: To use the access valves:
Remove the cap from the stem, use  a 3/16" allen
wrench to check that the valve is CLOSED. The
remove the core cap.
Close the valve and replace the caps when the
job is finished. The valve must be closed and
the caps must be on or the valve will leak.

Torque Stem Cap to

8-12 ft. lb.

Torque Stem to

6-8 ft. lb.

Torque

Core Cap to

7-12 ft. lb.

Access Valves

Note: There are no valve

cores in this valve.

Allen

Wrench

NDE750

December 1993

Page 30

Summary of Contents for NDE750

Page 1: ...HE INSTALLER Specifications 2 FOR THE INSTALLER 3 FOR THE PLUMBER 4 FOR THE ELECTRICIAN 5 FOR THE INSTALLER Final Check List 6 INITIAL START UP 7 COMPONENT DESCRIPTION 8 COMPONENT DESCRIPTION Control...

Page 2: ...facturing plant it takes in a raw material water and turns it into a food product ice The purity of the water is very important in obtaining pure ice and in maximizing product life General recommendat...

Page 3: ...rs so that the stand does not rock Counter Top or Machine Stand Installation The base of the icemaker dispenser must be sealed to the object it rests upon Food grade silastic sealant such as Scotsman...

Page 4: ...valve to control it It is connected to a 3 8 FPT condenser inlet at the back of the cabinet The water pressure to all lines must always be above 20 psig and below 120 psig Drains Air Cooled Models The...

Page 5: ...machine requires a solid chassis to earth ground wire The ice maker should be connected to its own electrical circuit so it would be individually fused Voltage variation must remain within design limi...

Page 6: ...checked and compared to nameplate requirements 3 Have all of the plumbing connections been made and checked for leaks 4 Has the machine been leveled 5 Is there a minimum of 6 inches of clearance at th...

Page 7: ...side pressure may be checked it should be 38 PSIG or 4 PSIG The air cooled discharge pressure will depend upon air and water temperatures but should be between 200 PSIG and 300 PSIG Water cooled disch...

Page 8: ...rator Condenser Air or water cooled where the heat removed in ice making is discharged Ice Storage Bin Assembly A plastic lined insulated cylinder that receives stores and dispenses the ice Fresh ice...

Page 9: ...of ice when the unit turns off and for the compressor On Off Switch Manual control for the machine Transformer Supplies low voltage to the circuit board Potential Relay The compressor start relay Por...

Page 10: ...two seal faces meet Ice Sweep A plastic cap with fingers It revolves with the auger to sweep the ice into the ice chute Breaker Where the ice is compressed and much of the extra water is squeezed out...

Page 11: ...otor relay opens and the auger motor stops If the ice level sensor is clear bin empty for more than 15 seconds the machine will start up again Another purpose of the circuit board is to turn the machi...

Page 12: ...ater regulating valve then to the water cooled condenser and down the drain The water dispensing station adds an additional water circuit When the water station glass filler lever is pushed a switch c...

Page 13: ...epending upon the temperature of the evaporator warmer evaporators get more refrigerant and colder evaporators get less At the evaporator the refrigerant enters an area of relatively low pressure wher...

Page 14: ...the agitator drive motor for a certain length of time depending upon the setting of the portion control knob The dispensing takes place when the agitator sweeps the ice through the ice dispensing chut...

Page 15: ...5 degrees F 8 Slowly pour the cleaning solution into the water reservoir until it is full Wait 15 minutes then switch the master switch to ON 9 As the ice maker begins to use water from the reservoir...

Page 16: ...l sensors from the ice chute and wipe them clean 3 The bearing in the breaker should also be checked at least two times per year A Check the bearing by removing the ice chute cover unscrewing the ice...

Page 17: ...ing drain hose 3 Remove bail clamp from over ice chute cover and remove cover 4 Unscrew and remove ice sweep 5 Remove ice chute from evaporator 6 Remove 4 allen screws holding breaker to evaporator 7...

Page 18: ...charge Check for a Thermostatic Expansion Valve that does not open if defective replace it Replace the drier evacuate and weigh in the nameplate charge E Check the high pressure cut out if closed go t...

Page 19: ...The bin full light on the tester should be ON if not replace the circuit board If the bin full light on the tester is ON move the tester switch to bin empty the light on the tester should go OFF and t...

Page 20: ...contactor 2 Check the contactor coil If the coil is open replace the contactor 3 Check the auger drive motor centrifugal switch If when the drive motor is running contact 4 black wire removed has no p...

Page 21: ...er leaks replace the water seal if found to be leaking 3 Check the low side pressure normal is about 38 psig If low assume a refrigerant leak locate repair and recharge If no leak the TXV may be restr...

Page 22: ...voltage and the agitator motor output shaft does not turn replace the agitator gear motor assembly C Check that the ice dispensing door opens when the glass filler lever is pushed If not check the ven...

Page 23: ...el sensor probe 8 Remove mounting screws from reservoir bracket and remove reservoir from icemaker 9 Reverse to reassemble BIN CONTROLS Ice Level Sensors 1 Disconnect electrical power 2 Remove front p...

Page 24: ...ring Check for rust rough spots and damage a The bearing is pressed into the breaker to remove the bearing and replace it an arbor press is needed b Replace lower seals before installing new bearing i...

Page 25: ...ews holding breaker to evaporator d Lift up remove breaker from evaporator e If the auger is stuck use a slide hammer type puller to pull on the auger at the threaded hole The size of that hole is 5 8...

Page 26: ...grove for the snap ring 2 Replace the snap ring and pull the water seal down against it 3 The part of the water seal that rotates with the auger must also be replaced Remove the old part from the aug...

Page 27: ...an new drier in the liquid line 7 Evacuate the system until dehydrated then weigh in the nameplate charge Check for leaks 8 Install auger breaker breaker bearing assembly and ice discharge chute in re...

Page 28: ...he oil is If there is evidence of water in the oil rusty bearings and gears the oil having a creamy white appearance oil level too high carefully inspect the bearings and gears If in doubt about the c...

Page 29: ...ction equipment is required to locate small refrigerant leaks Usually a leak detector capable of detecting a Halogenated refrigerant or HFC 134A will work Check with the leak detector manufacturer if...

Page 30: ...epaired This system has a critical charge it must be recharged with the correct amount of refrigerant as listed on the nameplate of the ice machine or performance will suffer Anytime the refrigeration...

Page 31: ...ug photo trans and LED connectors from the circuit board 2 Plug photo trans and LED connectors from the tester into the circuit board a Move the bin full switch on the tester to Full The light on the...

Page 32: ...ard should go ON If not replace the circuit board b Move the water switch on the tester to the Water position The No Water light on the board should go OFF If not replace the circuit board If the ligh...

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