Stoelting U431-109I2 Service Manual

Model U421 & U431
(Ser. #6374 Plus)
Operator’s Manual
513725 Rev.0

Section 1: Introduction

INTRODUCTION

This manual provides basic information about the machine. Instructions and suggestions are given covering its operation
and care.

The illustrations and specifi cations are not binding in detail. We reserve the right to make changes to the machine without
notice, and without incurring any obligation to modify or provide new parts for machines built prior to date of change.

DO NOT ATTEMPT to operate the machine 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 machine, contact Stoelting.

MAINTENANCEPARTS TROUBLESHOOTING OPERATION

Stoelting Foodservice Equipment
502 Highway 67
Kiel, WI 53042-1600
U.S.A.

stoeltingfoodservice.com

Main Tel: [phone]
Fax: [phone]

Customer Service: 888.319.9549
Fax: [phone]
Email: [e-mail]

© 2017 Stoelting

2 U421-I2 & U431-I2 OPERATOR’S MANUAL 513725 REV.0

This manual is divided into the following fi ve sections:

Section 1: Introduction

INTRODUCTION

INTRODUCTION

OPERATION

MAINTENANCE

A. Parts of the Machine

B. Specifi cations

A. Empty the Freezing Cylinders - Start here if cleaning a machine with mix in it

B. Disassemble Parts - Start here if cleaning an empty machine

C. Cleaning Disassembled Parts

D. Cleaning the Machine

E. Assembling the Machine

F. Sanitizing

G. Freeze Down

H. Brushes for Cleaning

I. Lubrication Points

J. Pump Hose Routing

A. Mix Pump Hose Replacement

B. Mix Pump Hose Cleaning

C. Fine Consistency Adjustment

D. Daily Procedures - Night

E. Daily Procedures Morning

MAINTENANCE PARTSTROUBLESHOOTINGOPERATION

TROUBLESHOOTING

PART S

513725 REV.0 U421-I2 & U431-I2 OPERATOR’S MANUAL 3

A. Troubleshooting Flow Charts

A. Auger Shaft & Front Door Parts

B. Cab Tubing

Section 1: Introduction

A. Parts of the U421-I2 Machine

INTRODUCTION

MAINTENANCEPARTS TROUBLESHOOTING OPERATION

IntelliTec2™

Spigot Handle

Front Door

Gate Handles

Freezing Cylinder

Cabinet

IntelliTec2™ Touchpad

The U421 has two types of spigot handles, gate and pull-down. The gate style is opened by moving the handle to the
left. The pull-down style is opened by pulling downwards.

This manual shows the pull-down handles which are self-closing. The gate style handles need to be closed when fi nished
dispensing.

4 U421-I2 & U431-I2 OPERATOR’S MANUAL 513725 REV.0

Section 1: Introduction

B. U421-I2 Specifi cations

U421-I2 A/C U421-I2 A/C Remote U421-I2 W/C

Dimensions

width

height

depth

Weight

Electrical

circuit ampacity

(per barrel)

overcurrent protection

device (per barrel)

Compressor

Drive Motor Two - 2 hp

Cooling

Cabinet Volume Two - 8 gallon (30,28 liters)

Freezing Cylinder

Volume

Machine with crate Machine with crate Machine with crate

26-3/4’’

(67,9 cm)

68-3/4’’

(174,6 cm)

39-1/2’’

(100,3 cm)

785 lbs

(356,0 kg)

1 PH 3 PH 1 PH 3 PH 1 PH 3 PH

32A 20A

50A 30A

34’’

(86,4 cm)

78’’

(198,1 cm)

48’’

(121,9 cm)

930 lbs

(421,8 kg)

26-3/4’’

(67,9 cm)

67-3/4’’

(172,1 cm)

39-3/4’’

(101,0 cm)

760 lbs

(344,7 kg)

36A Left /
31A Right

50A Left /
45A Right

(86,4 cm)

(198,1 cm)

(121,9 cm)

930 lbs

(421,8 kg)

The machine requires one dedicated electrical circuit per barrel.

Two - 19,000 Btu/hr

Cabinet - 1,300 Btu/hr Compressor (R-134a)

Air cooled units require 6” (15,2 cm) air
space on all sides and open at the top.

Remote air cooled requires two remote

condensers and two precharged line

sets.

Two - 1.33 gallon (5,03 liters)

34’’

78’’

48’’

26-3/4’’

(67,9 cm)

67-1/2’’

(171,5 cm)

39-1/2’’

(100,3 cm)

760 lbs

(344,7 kg)

34’’

(86,4 cm)

78’’

(198,1 cm)

48’’

(121,9 cm)

930 lbs

(421,8 kg)

20A 32A 20A

30A 50A 30A

Water cooled units require 1/2” N.P.T.
water and drain fi ttings. Maximum water
pressure of 130 psi. Minimum water fl ow

rate of 3 GPM per barrel. Ideal EWT of

50°-70°F. The machine requires 6” (15,2

cm) air space on all sides for the cabinet

refrigeration system.

INTRODUCTION

MAINTENANCE PARTSTROUBLESHOOTINGOPERATION

513725 REV.0 U421-I2 & U431-I2 OPERATOR’S MANUAL 5

Section 1: Introduction

C. Parts of the U431-I2 Machine

INTRODUCTION

MAINTENANCEPARTS TROUBLESHOOTING OPERATION

Spigot Handle

IntelliTec2™

Front Door

Gate Handles

Freezing Cylinder

Cabinet

IntelliTec2™ Touchpad

The U431 has two types of spigot handles, gate and pull-down. The gate style is opened by moving the handle to the
left. The pull-down style is opened by pulling downwards.

This manual shows the pull-down handles which are self-closing. The gate style handles need to be closed when fi nished
dispensing.

6 U421-I2 & U431-I2 OPERATOR’S MANUAL 513725 REV.0

Section 1: Introduction

D. U431-I2 Specifi cations

U431-I2 A/C U431-I2 A/C Remote U431-I2 W/C

Dimensions

width

height

depth

Weight

Electrical

circuit ampacity

(per barrel)

overcurrent protection

device (per barrel)

Compressor

Drive Motor Two - 2 hp

Cooling

Cabinet Volume Two - 8 gallon (30,28 liters)

Freezing Cylinder

Volume

Machine with crate Machine with crate Machine with crate

26-3/4''

(67,9 cm)

68-3/4''

(174,6 cm)

39-1/2''

(100,3 cm)

785 lbs

(356,0 kg)

1 PH 3 PH 1 PH 3 PH 1 PH 3 PH

32A 20A

50A 30A

34''

(86,4 cm)

78''

(198,1 cm)

48''

(121,9 cm)

935 lbs

(424,1 kg)

26-3/4''

(67,9 cm)

67-3/4''

(172,1 cm)

39-3/4''

(101,0 cm)

760 lbs

(344,7 kg)

36A Left /

31A Right

50A Left /
45A Right

The machine requires one dedicated electrical circuit per barrel.

Two - 19,000 Btu/hr

Cabinet - 1,300 Btu/hr Compressor (R-134a)

Air cooled units require 6" (15,2 cm) air

space on all sides and open at the top.

Remote air cooled requires two remote

condensers and two precharged line

sets.

Two - 1.33 gallon (5,03 liters)

34''

(86,4 cm)

78''

(198,1 cm)

48''

(121,9 cm)

930 lbs

(421,8 kg)

26-3/4''

(67,9 cm)

67-1/2''

(171,5 cm)

39-1/2''

(100,3 cm)

760 lbs

(344,7 kg)

20A 32A 20A

30A 50A 30A

Water cooled units require 1/2" N.P.T.
water and drain fi ttings. Maximum water
pressure of 130 psi. Minimum water fl ow

rate of 3 GPM per barrel. Ideal EWT of

50°-70°F. The machine requires 6" (15,2

cm) air space on all sides for the cabinet

refrigeration system.

34''

(86,4 cm)

78''

(198,1 cm)

48''

(121,9 cm)

930 lbs

(421,8 kg)

INTRODUCTION

MAINTENANCE PARTSTROUBLESHOOTINGOPERATION

513725 REV.0 U421-I2 & U431-I2 OPERATOR’S MANUAL 7

Section 2: Operation

A. Empty the Freezing Cylinders

A.1

Turn off freezing cylinders.

A.2

OPERATION INTRODUCTION

MAINTENANCEPARTS TROUBLESHOOTING

In the cab, remove the mix
pickup assemblies and place
them in a bucket fi lled with cool
tap water.

Remove the mix containers
and covers.

Optional: Fill the bucket with Stera Sheen
solution to make cleaning parts easier
after disassembly.

Clean mix containers on a regular basis.
Refer to State and local health codes for
frequency.

NOTE

NOTE

A.4

Open spigots to drain product
into a container until the
container is full. Empty the
container and repeat until
product has been drained from
the freezing cylinders.

A.5

Refi ll the bucket in the cab with cool tap water (or
Stera Sheen). Allow the freezing cylinders to fi ll then
drain the water into a container. Repeat until the water
draining from the freezing cylinders is clear.

NOTE

If the “Clean Time Exceeded” warning
is displayed on the IntelliTec2™, turn
the freezing cylinder on and off again
and press the Clean button to clear the
warning.

A.7

A.3

Press the Clean buttons.

8 U421-I2 & U431-I2 OPERATOR’S MANUAL 513725 REV.0

Remove any remaining
water from the bucket in the
cabinet.

Drain the water and press
the Clean buttons to stop
the augers.

A.8

Remove the buckets in the cab
and turn on the pumps to clear
any remaining liquid in the hoses.

Open the spigots to drain the
freezing cylinders.

A.9

Press and hold the Main
Freezer Power button for
three seconds to turn off
the power.

Section 2: Operation

Auger Flight Wear

1. Front Door Disassembly

B.1

Remove the spigot
extensions or rosette
caps if installed.

OPERATIONINTRODUCTION

MAINTENANCE PARTSTROUBLESHOOTING

B. Disassemble Parts

Before using the machine for the fi rst time, complete
machine disassembly, cleaning and sanitizing
procedures need to be followed. Routine cleaning
intervals and procedures must comply with the local
and state health regulations. Inspection for worn or
broken parts should be made at every disassembly
of the machine. All worn or broken parts should be
replaced to ensure safety to both the operator and the
customer and to maintain good machine performance
and a quality product. Check the wear line on the auger
fl ights on a regular basis and replace as needed.

Unscrew the knobs
on the front door and
remove the door.

B.2

Remove the front
door o-rings and
remove the spigots
from the front door.

B.3

Remove the air bleed
valve from the front
door.

513725 REV.0 U421-I2 & U431-I2 OPERATOR’S MANUAL 9

Section 2: Operation

B.4

Remove all o-rings from
parts by fi rst wiping off the
lubrication using a clean
towel. Then squeeze the
o-ring upward to form a
loop. Roll the o-ring out of
the groove.

2. Removing Auger

B.5

OPERATION INTRODUCTION

Remove front auger
supports and bushings
and remove the augers
from the freezing cylinders.
As the augers are being
pulled out, remove the
plastic fl ights with springs.

3. Disassemble Pump Hose

B.8

Disconnect the sensor
connectors from the
pickup assemblies
and unscrew the hose
clamps nearest the
assemblies.

Remove the mix pickup
assemblies.

B.9

Remove the lock
clips from the check
valves and remove
the check valves and
springs.

MAINTENANCEPARTS TROUBLESHOOTING

B.6

Wipe any remaining
lubricant off the hex end
of the auger and remove
the rear seal assembly
and o-ring. Wipe any
remaining lubricant off
the o-ring and auger.

Remove the rear seal
adapter from the rear seal.

B.7

Unscrew springs
from the auger
fl ights.

Detach the check
valve from the spring.

B.10

Remove the o-rings from the
assemblies.

B.11

If the pump hoses require cleaning and inspection,
follow the steps in Section 3.

10 U421-I2 & U431-I2 OPERATOR’S MANUAL 513725 REV.0

Section 2: Operation

C. Cleaning Disassembled Parts

Disassembled parts require complete cleaning,
sanitizing and air drying before assembling. Local
and state health codes will dictate the procedure
required. Some state health codes require a four sink
process (pre-wash, wash, rinse, sanitize, air dry), while
others require a three sink process (without the pre­wash step). The following procedures are a general
guideline only. Consult your local and state health
codes for the procedures required in your location.

C.1

Place all parts in 90° to 110°F
(32°C to 43°C) mild detergent
water and wash thoroughly. Use

the brushes that shipped with
the machine to clean all holes in

the front door, fl ights, mix pickup
assembly, etc.

D. Cleaning the Machine

D.1

Using a detergent solution
and the large barrel
brush provided, clean
the freezing cylinders by
dipping the brush in the
solution and brushing
the inside of the freezing
cylinders.

Make sure to thoroughly clean the rear seal surfaces
on the inside of the freezing cylinders.

D.2

Wrap the brush in a clean cloth and thoroughly dry
the freezing cylinder.

D.3

OPERATIONINTRODUCTION

MAINTENANCE PARTSTROUBLESHOOTING

NOTE

Be sure to use the brushes that shipped
with the machine to properly clean the
parts.

C.2

Rinse all parts with clean 90° to 110°F (32°C to 43°C)
water. Then place all parts in a sanitizing solution for at
least 1 minute, then remove and let air dry completely
before assembling in machine.

Remove the drain tray from the
side of the machine. Remove the
drip tray from the front panel.
Clean and replace the trays.

D.4

The exterior of the machine should be kept clean at
all times to preserve the luster of the stainless steel.
A high grade of stainless steel has been used on the
machine to ease cleanup. To remove spilled or dried
mix, wash the exterior with 90° to 110°F (32°C to 43°C)
mild detergent water and wipe dry.

Do not use highly abrasive materials, as they will mar
the fi nish. A mild alkaline cleaner is recommended.
Use a soft cloth or sponge to apply the cleaner. For
best results, wipe with the grain of the steel.

513725 REV.0 U421-I2 & U431-I2 OPERATOR’S MANUAL 11

Section 2: Operation

E. Assembling Machine

NOTE

Total Blend or equivalent must be used
when lubrication of machine parts is
specifi ed.

The USDA and FDA require that lubricants
used on food processing equipment must
be certifi ed for this use. Use lubricants
only in accordance with the manufacturer’s
instructions.

OPERATION INTRODUCTION

NOTE

Stoelting recommends allowing the parts
to air dry before assembling.

E.1

Install the rear seal o-rings onto the augers. Lubricate
the outside of the o-rings with a generous amount of

MAINTENANCEPARTS TROUBLESHOOTING

sanitary lubricant.

E.2

Install the stainless steel adapter into the rear seal
WITHOUT LUBRICANT. Then lubricate the inside of
the adapter and install it onto the auger.

DO NOT lubricate the outside of the rear seal.

E.3

Lubricate the hex end of the auger with Total Blend.

12 U421-I2 & U431-I2 OPERATOR’S MANUAL 513725 REV.0