Stoelting U421/U444 User manual

Model U421/U444
(Serial #17978 and up)
OWNER'S MANUAL
Manual No. 513595-4 July, 2004 Rev. 1

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STOELTING, LLC Tele: 920-894-2293
502 Hwy 67
Kiel, WI 53042-1600 Fax: [phone]
STOELTING®OWNER'S MANUAL
FOR
MODEL U421/U444
CAB MODEL SOFT-SERVE PRESSURIZED FREEZER
This manual provides basic information about the freezer. Instructions and suggestions are given
covering its basic operation and care.
Theillustrationsandspecificationsarenotbindingindetail. Wereservetherighttomakechanges
at any time without notice, to the freezer and its components, without incurring any obligation to
modify or provide new parts for freezers built prior to date of change.
DO NOT ATTEMPT to operate the freezer until instructions and safety precautions in this manual
are read completely and are thoroughly understood. If problems develop or questions arise in
connection with installation, operation or servicing of the freezer, contact the company at the
location listed below.

Section 1 .............................................................................................................. 1
1.1 Description.............................................................................................. 1
1.2 Specifications.......................................................................................... 2
Section 2 .............................................................................................................. 3
2.1 SafetyPrecautions .................................................................................. 3
2.2 Shipment &Transit .................................................................................. 4
2.3 FreezerInstallation................................................................................... 4
2.4 Installing PermanentWiring...................................................................... 4
2.5 Mix Pump ................................................................................................ 5
Section 3 .............................................................................................................. 9
3.1 SafetyPrecautions .................................................................................. 9
3.2 OperatingControls andIndicators............................................................ 9
3.3 ImportantInformation RegardingCleaningandSanitizing......................... 11
3.4 Disassemblyof FreezerParts.................................................................. 12
3.5 Cleaning Disassembled Parts ................................................................. 13
3.6 SanitizeFreezerParts ............................................................................. 13
3.7 Cleaningthe Freezer ............................................................................... 14
3.8 AssemblingtheFreezer........................................................................... 14
3.9 Sanitizing ................................................................................................ 16
3.10 InitialFreeze downand Operation............................................................ 16
3.11 MixInformation ........................................................................................ 17
3.12 OperationofMixPump ............................................................................ 18
3.13 MixPumpCleaning ................................................................................. 18
3.14 Disassemblyand InspectionofRemovableParts..................................... 18
Section 4 .............................................................................................................. 21
4.1 Freezer Adjustment ................................................................................. 21
4.2 ProductTemperatureAdjustment ............................................................. 21
4.3 OverrunAdjustment ................................................................................. 21
4.4 Mix PumpHose Reposition ..................................................................... 22
4.5 MixPump HoseReplacement.................................................................. 22
4.6 CabTemp.Adjustment............................................................................. 22
4.7 DriveBeltTensionAdjustment.................................................................. 22
4.8 Condenser Cleaning(Air Cooled Freezers) ............................................. 23
4.9 PreventativeMaintenance........................................................................ 23
4.10 ExtendedStorage ................................................................................... 23
4.11 Troubleshooting ....................................................................................... 24
Section 5 .............................................................................................................. 29
5.1 How toOrder ReplacementParts ............................................................ 29
5.2 PartsLists andReferenceDrawings........................................................ 29
TABLE OF CONTENTS

ILLUSTRATIONS
Figure 1 Model U421/U444 Series Freezer .........................................1
Figure 2a Air-Cooled Specifications ......................................................2
Figure 2b Water-Cooled Specifications .................................................2
Figure 3 Decal Locations.....................................................................3
Figure 4 Water/ElectricalConnections .................................................4
Figure 5 AugerRotation.......................................................................5
Figure 6 MixHoseInstallation...............................................................5
Figure 7 MixPump...............................................................................6
Figure 8 3-wayTee..............................................................................7
Figure 9 MixInletTube &ProbeAssy.Clip...........................................7
Figure 10 HoseHolder...........................................................................7
Figure 11 OperatingControls.................................................................9
Figure 12 AugerFlight Wear&FrontAugerSupport BushingWear .......12
Figure 13 FrontDoor Disassembly ........................................................13
Figure 14 AugerFlightRemoval.............................................................13
Figure 15 RearSealRemoval................................................................13
Figure 16 RearSeal Lubrication ............................................................14
Figure 17 SpringInstallation...................................................................14
Figure 18 FrontDoorAssembly .............................................................15
Figure 19 Air Bleed Valves ....................................................................16
Figure 20 DrainingSanitizer ..................................................................16
Figure 21 RefrigeratedCabinet .............................................................17
Figure 22 MixPumps.............................................................................18
Figure 23 RemovableParts ...................................................................19
Figure 24 CleaningAirTube ..................................................................19
Figure 25 CleaningFeedTube ..............................................................19
Figure 26 MixPumpTubeRouting .........................................................19
Figure 27 Potentiometer ........................................................................21
Figure 28 OverrunAdjustment................................................................21
Figure 29 TemperatureControlCab ......................................................22
Figure 30 BeltAdjustment ......................................................................23

Safety Alert Symbol:
This symbol Indicatesdanger,warning orcaution.
Attentionis requiredin orderto avoidserious personal
injury. The message that follows the symbol contains
importantinformationaboutsafety.
Signal Word:
Signal words are distinctivewordsused throughout
this manual that alert the reader to the existence and
relativedegree ofa hazard.
CAUTION
Thesignal word “CAUTION” indicatesa potentially
hazardoussituation, which, if not avoided,may result
inminor or moderateinjury andequipment/property
damage.
A Few Words About Safety
SafetyInformation
Read and understand the entire manual before
operating or maintaining Stoelting equipment.
ThisOwner'sManual providestheoperator with
informationforthe safeoperation and maintenanceof
Stoelting equipment. As with any machine, there are
hazards associated with their operation. For this
reasonsafety isemphasized throughoutthe manual.
To highlightspecific safetyinformation, thefollowing
safetydefinitions areprovided toassist thereader.
The purpose of safety symbols is to attract your
attention to possible dangers. The safety symbols,
andtheir explanations, deserveyour carefulattention
andunderstanding. Thesafety warningsdo notby
themselveseliminate anydanger.Theinstructions or
warningsthey giveare notsubstitutes forproper
accidentpreventionmeasures.
If you need to replace a part, use genuine Stoelting
partswith thecorrect partnumber oran equivalent
part. We strongly recommend that you do not use
replacementpartsofinferior quality.
WARNING
Thesignal word“WARNING” indicates a potentially
hazardoussituation, which, if not avoided,may result
indeath orserious injuryand equipment/property
damage.
CAUTION
Thesignal word “CAUTION”not precededbythe safety
alert symbol indicates a potentially hazardous situa-
tion, which, if not avoided, may result in equipment/
propertydamage.
NOTICE
Thesignalword “NOTICE” indicatesinformationor
procedures that relate directly or indirectly to the
safetyor personnel orequipment/property.

1
SECTION 1
INTRODUCTION
1.1 DESCRIPTION
TheStoeltingU421andU444floormodelfreezersarepres-
sure fed. The freezers are equipped with fully automatic
controlsto provide auniform product.The U421 freezeris
designed to operate with almost any type of commercial
softserve or non-dairymixes available,including icemilk,
icecream, yogurt,and frozen dietary desserts. TheU444
freezer is designed to dispense soft serve product from
the right side and shake product from the left side.
Thismanual isdesigned toassist qualifiedpersonnel and
operators in the installation, operation and maintenance
ofthe StoeltingModel U421 and U444pressure freezer.
Figure 1. Model U421/U444 Series Freezer
1.2 SPECIFICATIONS
444U/124ULEDOM
SNOISNEMID
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THGIEW
)gk244(etarC/w.sbl579)gk5,914(.sbl529
LACIRTCELE
srotomevird.P.H2owT,hP3rohP1,tlov032/802
srosserpmoCHUTB06811owTdna
GNILOOC
pot)mc52("01dnaecnaraelcdnuoralla)mc6,7("3s'qer.deloocriaroretaW
.sgnittifniarddnaretawTPN)mc3,1("2/1s
'qerdeloocretaW.ecnaraelc

2
Figure 2a. Air-Cooled Specification
Figure 2b. Water Cooled Specification

3
SECTION 2
INSTALLATION INSTRUCTIONS
2.1SAFETYPRECAUTIONS
Do not attempt to operate the freezer until the safety
precautionsandoperatinginstructionsinthismanualare
readcompletelyandarethoroughlyunderstood.
Takenoticeofallwarninglabelsonthefreezer.Thelabels
have been put there to help maintain a safe working
environment.Thelabelshavebeendesignedtowithstand
washing and cleaning. All labels must remain legible for
the life of the freezer. Labels should be checked periodi-
callytobesuretheycanberecognizedaswarninglabels.
1 324722 Decal Mix Low
2 324798 Decal Clean-Off-Serve Switch
3 324141 Decal Caution - Rotating Blades
4 723526 Tag Read Manual & All Decals
6 324393 Decal Stoelting Swirl Logo
7 324800 Decal Cab ON/OFF
8 324799 Pump On/Off
9 324208 Decal Refrig. Leak Check
11 324103 Decal Caution - Rotating Shaft
12 324686 Decal Danger Automatic Start
13 324107 Decal Caution Moving Parts
14 324125 Decal Elect.Shock Hazard
15 324151 Decal Field Connections
16 324198 Decal Attention Installer
17 130000 Bag, Envelope Front Loading
18 324584 Decal Adequate Ventilation
19 324158 Decal Copper Conductors Only
20 324106 Decal Caution Wiring Mat'l
22 324566 Decal Wired According To
23 324015 Decal 2 x 1-1/4 Blk on White
24 723552 Tag, Caution - Supply Voltage
26 324803 Decal GM Header (Stoelting Logo)
26 324804 Decal GM Header (Stoelting Swirl)
26 324805 Decal DQ Header (DQ Logo)
27 324346 Decal Caution Hazard.Moving
28 324797 Decal Standby/Serve
29 324242 Decal Temperature Control
30 324200 Decal Manual Reset
32 324014 Decal Arrow
33 324496 Decal Freezing
Water Cooled Only
A 324065 Decal Water Inlet
B 723525 Tag Winterizing Disconnect Line
C 723517 Tag, W/C Tower Instructions
D 324107 Decal Caution Moving Parts
Air Cooled Only
E 324346 Decal Hazardous Moving Parts
F 324107 Decal Caution Moving Parts
Figure 3. Decal Locations
Ifdanger,warningorcautionlabelsareneeded,indicate
the part number, type of label, location of label, and
quantityrequired along withyour address and mail to:
STOELTING,LLC
ATTENTION: CustomerService
502 Hwy. 67
Kiel,Wisconsin 53042

4
2.2 SHIPMENT AND TRANSIT
The freezer has been assembled, operated, and in-
spected at the factory. Upon arrival at the final destina-
tion, the freezer must be checked for any damage which
may have occurred during final transit.
Withthemethodof packaging used,theequipmentshould
arriveinexcellent condition.THE CARRIER ISRESPON-
SIBLEFORALLDAMAGEINTRANSIT, WHETHERVIS-
IBLE OR CONCEALED. Do not pay the freight bill until
thefreezer has been checked for damage. Havethe car-
riernoteanyvisibledamage on thefreightbill.Ifconcealed
damage and/or shortage is found later advise the carrier
within ten days and request inspection. The customer
must place claim for damage and/or shortages in ship-
ment with the carrier. Stoelting, LLC. cannot make
any claims against the carrier.
2.3FREEZERINSTALLATION
WARNING
Installation must be performed by a qualified electri-
cian/refrigerationspecialist. Incorrect installationmay
causepersonalinjury,severedamage tothemachine
andwill void factorywarranties.
WARNING
Lifting hazard
Donot attemptto lift freezer manually. Use proper lift-
ing equipment such as a forklift, lift table, or pallet
jack,withliftingdevicepositionedbeneaththe freezer’s
base.Ensurethatpersonnelremainclearofsuspended
load. Failure to do so may result in personal injury
and/ordamage to thefreezer that willvoid anyfactory
warranties.
Installationofthefreezerinvolvesmovingthe freezer close
to its permanent location, removing all crating, setting in
place,assembling parts, and cleaning.
A. Uncrate thefreezer.
B. Install the four casters. Turn the threaded end into
the freezer until zero threads are showing.To level,
turn out casters no more than 1/4" maximum, then
tighten all jam nuts.
C. The freezer must be placed in a solid level position.
NOTE
Accurate leveling is necessary for correct drainage of
freezerbarrel andto insurecorrect overrun.
Figure 4. Water/Electrical Connections
D. Thefreezermust have a minimum of 3" (7,5cm)
-6" (15cm) high ambient conditions- of space on all
sides and 10" (25cm) at the top for proper circula-
tion.
CAUTION
Risk of product damage
Aircooledcondenser requires properventilation.Fail-
ure to provide adequate ventilation will void factory
warranties.
E. Water-cooled freezersneed anadequate water
supply. Install 1/2" (12,7mm) pipe or 1/2" (12,7mm)
inside diameter copper water line to the freezer.
Connect water outlet to a drain using a 1/2"
(12,7mm) inside diameter line. Automatic washer
hoses work well for final connections. All water
connections must comply with local codes. Fig. 4.
CAUTION
Flushall water lines before installation.In stores with
sedimentinwater,addsuitablefilterorstrainertowater
inlet.
F. Place theCLEAN-OFF-SERVE switches in the OFF
position before continuing. Figure 11.
2.4 INSTALLING PERMANENT WIRING
Permanentwiringisrequiredbylocalcodes,thefollowing
proceduremustbeperformed:
WARNING
Hazardous voltage
Highvoltage willshock, burnor causedeath. Turnoff
and lock out main power disconnect before installing
wiring. Do not operate machine with cabinet panels
removed.

5
2.5 MIX PUMP
A. Mix Pump Hose Installation
Follow the steps below to install the mix pump hose.
1. Turnpumpon.
2. Feed one end of mix pump hose into the entering or
pick-up hose side (left) of black cover.
3. Gently push the hose into the black cover until it
beginstofeed.
4. Allow the hose to feed itself thru the pump until 6"
(15cm)remainson theenteringside.
Figure 6. Mix Hose Installation
A. Refertothenameplateattherearofthefreezerfor
specific electrical requirements. Make sure the
powersourceinthebuildingmatchesthefreezer
nameplaterequirements.Bringthewiresintothe
junction boxes through the access holes in the
bottomrearofthefreezer.Figure 4.
NOTICE
Three phase freezers in areas of unbalanced
electrical loads require special attention when
connecting input electrical power. The unbal-
ancedlegof power(calledwild or high)mustbe
connected to L2 in the junction box.
NOTICE
Verifyactual voltage.Machineis equippedwith
a transformer to supply a control circuit. You
will need to check voltage on terminal C1 and
C2 on EACH control board. (Located behind
decorative header panel on front of machine.)
Transformersarelocatedbehindelectricalpanel
enclosing control boards. Access these by re-
movingtoppanelofmachine.Actualtransformer
voltageshouldread 20-28V.A.C.
B. Remove thelower back panel and thetwo junc-
tion box covers located at the bottom of the
freezer.
C. lnstall permanent wiring according to local
code.
D. Check the auger shaft rotation by placing the
MAIN DRIVE switch in the CLEAN position.
Auger shaft rotation is clockwise as viewed through the
clear plastic front door. If the rotation is not clockwise,
turnmain electrical powerOFF. Thenreverse L1 and L3
electrical power lines to the junction box (three phase
only).Re-check auger shaft rotation.Figure 5.
Figure 5. Auger Rotation
6" (15cm)

6
B. Connect1/2inch(12,7mm)I.D.plasticfoodgrade
tubing to check valve and then to the mix con-
tainer. Observe check valve flow arrow. Secure
withhoseclamps.Thenplaceassemblythruhole
in cover and install retainer clip. Figure 9.
C. Connect1/2inch(12,7mm)I.D.plasticfoodgrade
tubing between the large port of air/mix tee and
refrigerated mix transfer line. Secure with large
hoseclamporequivalent.Figure9.
CAUTION
Air/Mix tee must remain below the black cover/
clamp. If the tee is above the pump mix will
drain to the air compressor resulting in pump
damage.
D. Connect mix low cords.
Figure 7. Mix Pump
5.Turnpumpoff.
6.Connect mix pump hose to pickup hose
adapter using small hose clamp.
CAUTION
DO NOT TWIST MIX PUMP HOSE.
7.Turnpumpoff.
8.Allowremaining6"(15cm)of tubing tofeed hru
pumpuntilhoseadapterpreventsfurtherfeeding.
9.Turnpumpoff.
10.Connectfreeend of mixpumphose to3-wayTee

7
Figure 8. 3-way Tee
Figure 9. Mix Inlet Tube & Probe Assy. Clip
Refrigerated
Mix Transfer
Line
ÅÅ
ÅÅ
Å
Large Port
(Air/Mix) 3-way Tee
ÆÆ
ÆÆ
Æ
Low Mix Cord
Cover
Retainer
Clip
Mix
Container
ÌÌ
ÌÌ
Ì
ÉÉ
ÉÉ
É
ÇÇ
ÇÇ
Ç
Hose Holder
Figure 10. Hose Holder
ÅÅ
ÅÅ
Å
ÈÈ
ÈÈ
È

8

9
SECTION 3
INITIAL SET-UP AND OPERATION
3.1 SAFETY PRECAUTIONS
SAFE OPERATION IS NO ACCIDENT; observe these
rules:
A. Know the freezer. Read andunderstandtheoperat-
ing instructions.
B. Notice all warning labels on the freezer.
C. Wear proper clothing.Avoidloosefittinggarments,
and remove watches, rings or jewelry which could
cause a serious accident.
D. Maintain a clean work area. Avoid accidents by
cleaning the area and keeping it clean.
E. Stay alert at all times. Know which switch, push
button or control you are about to use and what
effect it is going to have.
F. Disconnect electrical power for maintenance.
Never attempt to repair or perform maintenance on
the freezer until the main electrical power has been
disconnected.
G. Do not operate under unsafe operating condi-
tions. Neveroperatethisfreezer ifunusualorexces-
sive noise or vibration occurs.
Figure 11. Operating Controls
3.2 OPERATING CONTROLS AND INDICATORS
Before operating the freezer, it is required that the op-
eratorknow the function ofeach operating control. Refer
to Fig.11 for the location of the operating controls on the
freezer.
WARNING
Hazardous voltage
TheCLEAN-OFF-ONswitchmustbeplacedintheOFF
positionwhendisassemblingforcleaningorservicing.
The freezer must be disconnected from electrical
supply before removing any access panel. Failure to
disconnect power before servicing could result in
death or serious injury.
A. Spigot Switch
When the spigot handle is opened the SPIGOT
switch will start the auger drive and refrigeration
systems.Whenthespigothandleisclosed,thedrive
motorandcompressorwillremainonuntiltheproduct
in the barrel reaches the proper temperature.
B. Clean-Off-ServeSwitch
TheCLEAN-OFF-SERVE switch is athree position
toggle switch used to control the operation of the
refrigeration system and auger. When the switch is
placedinthe CLEANposition,the refrigerationsys-
temwillbe off and auger will rotate for cleaning.

10
When the switch is placed in the OFF position, the
refrigeration system and auger will not operate.
When the switch is placed in the SERVE position,
therefrigerationsystemandaugerwilloperateauto-
matically.TheswitchshouldbeplacedintheSERVE
position for normal operation.
C. Cabinet-Off-OnSwitch
TheCABINET-OFF-ONswitch is atwoposition
toggleswitch.Whentheswitchisplaced in theOFF
position,the lower cabinetrefrigeration system will
not run. When the switch is placed in the ON
position,the lower cabinetrefrigeration systemwill
run until the preset temperature is reached; then
cycle ON and OFF to maintain that temperature.
D. Cab Indicator Light
A flashing light indicates the cab OFF-ON switch is
intheOFFposition,norefrigeration.PlacetheOFF-
ON switch in the ON position for cab refrigeration.
E. PumpSwitch
The pump motor switch is a two position toggle
switch. When the switch is placed in the OFF
position, the pump will not run. When the switch is
placedintheONposition,thepumpwillrununtilthe
presetpressureisreached,thencycleONandOFF
as product is drawn to maintain that pressure.
F. Standby/Serve Switch
Thestandby/serve switchis atwo positiontoggle
switch. When the switch is placed in the standby
positionthefreezerwillcycletomaintainatempera-
ture below 41°F (-15°C). When the switch is in the
Serve position the freezer will cycle to maintain a
servableproduct.
G. Freezing Switch
The freezing switch is a two position toggle
switch.When theswitch isplaced inthe MAXIMUM
positionthefreezer will beforcedto run30seconds
after the temperature control is satisfied.
H. High Head Pressure Cut Out
If the head pressure exceeds 445 psig (28 bar) air
cooled andwater cooled, the high head pressure
cutout will trip. The reset button can be accessed
from the side of the freezer.
I. Low Mix Light
Thelowmixlightwillilluminatewhentheliquidlevel
in the mix container drops below two gallons.
J. Front Door Safety Switch
Thefrontdoorsafetyswitchpreventstheaugerfrom
turning when the front door is removed. The switch
isopen when the door isremoved and closedwhen
the door is properly installed.