Southbend 20036SB Instruction manual

2Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
INTRODUCTION
GENERAL INFORMATION
This technical manual provides information for the installation,
operation, maintenance, and inspection of this unit
manufactured by Middleby. A complete parts breakdown
is also provided.
TECHNICAL SUPPORT
For any questions regarding the installation, operation or
maintenance of the unit, contact the factory at the following
address:
Technical Service Department
Middleby
1100 Honeycutt Road
Fuquay-Varina, NC 27526
SCOPE OF THE MANUAL
This manual provides sufficient information for maintenance
of the equipment.
EQUIPMENT DESCRIPTION
The unit consists of the following parts:
• Storage compartment - The insulated food storage
compartment is clear storage area. The cooling coil
(evaporator) is contained in this area.
• Drawers - Product is stored by means of food pans set in
drawers. The drawer face is made of an insulated panel.
The drawer face (panel) is fully “gasketed”
to provide a tight seal against the cabinet.
• Condensing Unit Compartment - This area contains
the condensing unit(s) along with the necessary controls
and other components.
• Evaporator Coil - The evaporator coil is located in the
storage compartment and is responsible for distributing
the cold air associated with the refrigeration system.
• Cabinet - The cabinet is the enclosure in which all
of the above mentioned items are housed.
EQUIPMENT SUPPLIED
The unit is shipped from the factory assembled. The
complete assembly is palletized and crated to minimize
the possibility of damage in shipping and storage.
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Scheduled Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Corrective Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Electrical and Mechanical . . . . . . . . . . . . . . . . . . . . . . . . .24
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
NOTICE! MIDDLEBY RESERVES THE RIGHT
TO CHANGE SPECIFICATIONS AND PRODUCT DESIGN
WITHOUT NOTICE. SUCH REVISIONS DO NOT ENTITLE
THE BUYER TO CORRESPONDING CHANGES,
IMPROVEMENTS, ADDITIONS OR REPLACEMENTS
FOR PREVIOUSLY PURCHASED EQUIPMENT.

Self-Contained, Refrigerated Bases
SAFETY
3
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
DANGER
EXPLOSION HAZARD
If gas odor is detected, shut down equipment at the main
shutoff valve. Immediately call the emergency phone
number of your gas supplier.
SPECIFICATIONS
SAFETY NOTICES
DANGER
This symbol warns of immediate hazards which WILL
result in severe injury or death.
WARNING
FIRE HAZARD
For your safety, do not store or use gasoline or other
flammable vapors and liquids in the vicinity of this or any
other appliance.
Keep area around appliances free and clear of
combustibles.
WARNING
Asphyxiation can result from improper ventilation. Do
not obstruct the flow of combustion and ventilation air to
/and from your cooking equipment.
WARNING
This symbol refers to a potential hazard or unsafe
practice which COULD result in injury or death.
CAUTION
This symbol refers to a potential hazard or unsafe
practice which COULD result in injury, product or
property damage.
NOTICE! This symbol refers to information that requires
special attention or must be fully understood, even
though not dangerous.
SAFETY PRECAUTIONS
NOTICE! Post the emergency telephone number of your
gas supplier and instructions to follow if gas odor is
detected.
NOTICE! Be sure this manual and important papers are
given to the proper authority to retain for future
reference.
Model W D H* Drawers No. of Ref. Elec. Compressor Evap. Amps Shipping
Number Pans Volume V/Ph/Hz HP BTU Weight
12"x20"x4" (cu.ft.) (lbs.)
18" 26" 31"
20036SB
20048SB
20060SB
20072SB
20084SB
20096SB
20108SB
20120SB
36"
48"
60"
72"
84"
96"
108"
120"
2
-
-
-
-
2
-
4
-
2
-
4
-
4
6
4
-
-
2
-
4
-
-
-
2
4
4
8
8
10
12
12
5.9
8.6
12
15.5
19.3
22.5
24
29.2
1/4
1/4
1/4
1/3
1/3
1/2
1/2
1/2
6
6
6
7
7
7
7
7
310
410
530
650
740
840
960
1050
1100
1100
1100
1600
1600
1600
1600
1600
115/1/60
115/1/60
115/1/60
115/1/60
115/1/60
115/1/60
115/1/60
115/1/60
32"
32"
32"
32"
32"
32"
32"
32"
26"
26"
26"
26"
26"
26"
26"
26"
*Includes 6" legs or casters
Figure 1.1 - General Arrangement Picture
Table 1.1 - Leading Particulars

4Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
OPERATION
INTRODUCTION
This model is a heavy-duty piece of equipment designed for
continuous use. It incorporates automatic controls to regulate
the cycling of the refrigeration system.
CONTROLS AND INDICATORS
Table 2.1 - Controls and Indicators
NAME TYPE FUNCTION
Low Pressure Switch Contact Points Cycles the refrigerator system (automatic)
Suction Valve Manual Plunger Valve Isolate suction at the compressor
Discharge Valve Manual Plunger Valve Isolate discharge line at receiver
Power Control Switch (On/Off) Contact Points Terminates all of the electrical into and past
the supply cord
Thermostat Contact Points Cycles the refrigerator system (automatic)
Defrost Timer1Contact Points Controls scheduled evaporator coil defrosting
Solenoid Valve Automatic Plunger Shuts off refrigerant flow
1Freezers

OPERATION
5
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
START-UP PROCEDURE
The refrigeration system is completely factory assembled,
pre-charged and ready for operation. To energize the system
it is only necessary to find the power supply cord and
connect it to a proper electrical source. Once the supply cord
SHUT-DOWN PROCEDURE
To shut down, disconnect the electrical supply cord and open
or remove the drawer(s) allowing the interior cabinet
temperature to equalize with the room temperature. A mild
detergent diluted in warm water should be used to wash
down the interior and exterior surfaces of the cabinet.
Table 2.2 - Start-up Procedure (Refrigerated Storage)
Operation Results
1. Activate system by inserting electrical service cord into
electrical supply source and flip power control switch.
2. Locate liquid refrigerant indication glass mounted on
the receiver.
3. Wait 15 minutes.
4. Wait 3 hours.
Compressor should immediately come on line along with the
condenser fan and the evaporator fan.
Once the system has been operating for two minutes, the
glass should appear clear and full of liquid refrigerant.
The temperature in the storage area should begin to
approach the “green zone” on the thermometer indicating
adequate operation.
Once the operating temperature has been reached, stocking
of the containment area can begin.
has been connected to a power source, the unit can be
started by flipping the power control switch to the “ON”
position.
WARNING
Prior to any cleaning of the system involving placing
hands in areas with moving parts, the system should
be deactivated by disconnecting the power supply cord.
Table 2.3 - Shut Down Procedures
Operation Results
1. De-energize the system by flipping the power control
switch to the “OFF” position and disconnecting the
electrical supply cord.
Once the system is de-energized, the condenser fan and the
evaporator fan will cease operation.

6Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
OPERATION
PREPARATION FOR AN EXTENDED PERIOD
OF INACTIVITY
This unit is designed for continued use at automatically
cycled intervals. However, in the event of an extended shut
down, both the mechanical refrigeration system and the food
storage compartment system must be serviced.
Table 2.4 - Shut Down Procedures for an Extended Period
Operation Results
1. Fully close discharge valve at the receiver.
2. Fully close suction valve at the compressor.
3. Disconnect power supply.
4. Clean and wipe dry the food storage compartment.
Compressor will pump liquid refrigerant from system
to receiver.
This will isolate the refrigerant between the two valves.
De-energizes the system.
This will reduce the odor buildup during shut down.

FUNCTIONAL DESCRIPTION
7
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
SYSTEM DESCRIPTION
This unit is a self contained, automatically controlled,
continuous duty, perishable food storage system. It is
designed with the intent and purpose of storing food items.
The operating temperature is automatically monitored by
controls that are factory set to maintain a predetermined
adequate condition.
The equipment is installed in two basic compartment
assemblies. They are:
• Condensing Unit Compartment - This area contains the
condensing unit along with the necessary controls.
• Storage Compartment - This insulated food storage area
is clear storage area.
SYSTEM OPERATION
The design of the refrigerated cabinet focuses primarily on
the safe storage of food products requiring refrigeration. In
engineering, considerable attention was placed on its
functionality and its serviceability.
The refrigeration system is a closed loop system. Barring a
leak in the system, the addition of refrigerant is not required.
However, a periodic check of its level is recommended to
insure that the system operates at the optimum level at which
it was designed.
The condensing unit is found within the regular equipment
compartment. Also in this compartment is the electrical
control panel that contains the power switch and a terminal
box. On all models that feature forced air evaporators, a
heated condensation evaporator pan or a heated condensing
unit base is provided. The evaporator pan is also located in
the equipment compartment.
Special care in the initial loading of the storage compartment
should be taken. It is suggested that the loading be
scheduled in three equal portions allowing three hours
between each loading.
The chilled food compartment is designed for the storage of
perishable food items that require a temperature range of 37
to 40 degrees Fahrenheit. It is a general rule that adequate
spacing is allowed between stored items to allow for proper
air circulation.
SCHEDULED MAINTENANCE
INTRODUCTION
To ensure the longest and most trouble free operation of the
unit, a thorough maintenance schedule is required to be
adhered to periodically. The maintenance system should
be designed to maximize the efficient use of maintenance
personnel, reduce down time, and provide the orderly
acquisition of spare parts support.
The Middleby refrigeration cabinet will generally be in
operation in a facility where scheduled maintenance is
performed according to Maintenance Index Plans. Your unit
is no exception to required maintenance. This section of the
manual is intended as an alternative to any standard
maintenance program that may pre-exist. The preventive
maintenance schedule is based upon similar maintenance
requirements for commercial refrigeration equipment.
PREVENTIVE MAINTENANCE ACTION INDEX
If you do not have a Maintenance Index Plan, one is included
for you in Table 4.1.
PREPARATION FOR MAINTENANCE
Since many areas affected by the maintenance schedule are
electrically supplied, it is recommended that the system be
de-energized prior to making the inspections.
MAINTENANCE
Weekly Inspection
1. The unit should first be de-energized by switching the
toggle switch to the “OFF” position. The switch is
found on the control panel in the condensing unit
compartment.
NOTE: It is necessary to first remove the front air grill. This
is done by lifting it straight up then pulling the bottom out and
down.
2. Using a vacuum or small hand broom, brush the
condenser in a vertical motion to remove any dust or
debris that may have accumulated.

8Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
SCHEDULED MAINTENANCE
Monthly Inspection
1. Check the evaporator drain line at both the inlet and
outlet ends to make certain that there are no
obstructions. It is not recommended to use any
chemicals in clearing a clogged drain. The preferred
method of unstopping an obstructed drain is to use
compressed air. Approximately 60 lbs. should be
sufficient. Simply remove the drain line at the
evaporator coil and attach an air-line to it.
2. With the unit in a cooling cycle, use a flashlight and
locate the refrigerant sight glass. If the compressor
has been running for three minutes there should be no
visible bubbles.
3. If bubbles are present:
a. Determine if there is a leak by using a halide or
electronic leak detector.
b. Repair leak(s).
6. To inspect the evaporator motor, first turn the unit off.
Then, remove the drain line from the evaporator pan.
Loosen the four screws that hold the shroud. Lower
the shroud and disconnect the polarized electrical
connection. With the shroud out of the cabinet,
proceed to inspect the motor mounting bolts and the
fan for cracks or excessive play.
7. Using a mild detergent and water, wipe the vinyl
gasket. Make certain to also clean under the gasket to
remove any mildew or residue.
8. Using a mild, non-abrasive detergent and warm water,
wipe the cabinet exterior. When cleaning always follow
the grain of the stainless steel to prevent scratching or
marring of the finish surface.
Annual Maintenance
1. Slide condensing unit out of the compartment and
check all refrigerant lines for leaks or fatigue. Make
certain that no exposed copper tubing is in contact with
any other metal surface. If there is contact, install an
insulating material between the tow metal components.
2. With the condensing unit out and the breaker at the
main panel “OFF”, inspect the system’s wiring. Look
for a tight fit of all connections and make certain the
that the wire restraining devices are tight. Inspect all
wires and cords, paying particular attention to nicks or
age cracks in the insulation.
3. Visually inspect the outer panel and components of the
cabinet. Check screws and bolts to make certain that
they are tight. Also, make sure that the bolts that
secure the base frame to the deck are tight.
Three Year Frequency
1. Replace the drawer gaskets. To accomplish this, it is
first necessary to remove all products from the
refrigerated compartment to avoid spoilage. Open the
drawers and remove the old gasket. The gaskets snap
in and out of a channel on the back side of the door.
Clean the track thoroughly. Replace the old gasket
with the new one by snapping it into place.
2. Inspect all motors and shafts for both noise and wear.
If they show age, replace them.
3. With the main power off, remove the condensing unit
from its compartment and inspect all wiring. Also,
remove the cover from the controls and check them to
make certain that they are operational and do not show
signs of wear.
4. Inspect the operation of the drawer slide assembly.
Make certain that the moving parts do not show any
signs of wear. Make sure that all screws are tight.
WARNING
The system should be de-energized when checking
for leaks.
i. If a leak is found on a flared fitting, it can often be
repaired by simply tightening the brass flare nut 1/4
of a turn. If tightening does not repair the leak, it
may be necessary to reflare the tubing.
ii. If a leak is found on a brazed joint, it will be
necessary to pump down the system’s refrigerant
charge to remedy the problem.
iii. To pump the refrigerant into the receiver, you must
first connect service gauges to the system at the
suction valve on the compressor and the liquid valve
on the receiver. Purge the gauges before opening
the system’s valves to avoid contamination. Run the
receiver (liquid or high pressure) valve all the way in
to stop the refrigerant from exiting the receiver.
Start the unit and allow it to run until the suction or
low-pressure gauge reads 5 lbs. When it reaches
5 lbs., de-energize the system.
iv. Once pumped down, the necessary repairs can be
made.
4 Using a mild non-abrasive detergent and soft cloth,
wipe the interior lining beginning with the top and
working down. Also, wipe the gasket and where it sits
on the cabinet exterior.
5. Remove the front air grill and unbolt and condensing
unit. Once unbolted, slide it out. The unit is capable of
being completely removed due to the extra tubing
coiled up behind the unit. With the unit de-energized,
check the condenser fan motor and make certain that it
is no loose. Inspect the fan for cracks and make sure
that it is tight on the motor.

SCHEDULED MAINTENANCE
9
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
5. To recalibrate the thermometer, remove it from the
cabinet. Using a small, flat screwdriver, remove the
lens. Prepare an ice water bath and immerse the
thermometer bulb at least two inches into the ice bath.
WIthin 30 seconds the indicator dial should read 32
degrees Fahrenheit. If it does not, it needs to be
recalibrated. Do this by placing your index finger on
the opposite side of the needle that needs to move.
Then, using a flat screwdriver, turn the screw at the
center of the dial 1/4 of a turn in the direction you want
to move the dial. Repeat the procedure until the
needle is on 32 degrees. See Figure 4.1.
Figure 4.1 - Thermometer Calibration
Table 4.1 - Preventative Maintenance Action Index
1.
2.
3.
4.
Weekly
Monthly
Annually
Three-year Frequency
a. Inspect condenser coil to make certain that air flow is not
hampered and that it is clear of dust and debris.
a. Inspect and clear drain line.
b. Check the liquid refrigerant sight glass to make certain that
the system is completely charged.
c. Clean the interior of the cabinet with a mild soap and warm
water solution. Be certain to dry thoroughly.
d. Check both the condenser fan motor and the evaporator
fan motor to make certain that they are operational and that
the fans are tight and secure.
e. Clean door gaskets and breaker strips with a damp cloth.
f. Clean exterior of cabinet with mild soap and warm water.
Dry thoroughly.
a. Slide condensing unit from the refrigeration compartment
and check all joints and fittings for any signs of leaks or
fatigue.
b. Inspect electrical connections to confirm that there is good
contact and that wires are neither weakened nor frayed.
c. Check the integrity of the cabinet.
a. Replace door gaskets.
b. Inspect motor shafts for noise or wear.
c. Inspect electrical controls and wiring.
d. Inspect drawer slides.
e. Recalibrate thermometer.
Lower Temperature
Higher Temperature

10 Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
TROUBLESHOOTING
INTRODUCTION
This chapter provides a systematic check of components in
determining a possible cause of failure in the event of various
symptoms.
It is necessary that the individual performing the
troubleshooting tasks be familiar with the function of the
equipment as described in the Functional Description section.
The following tables list the most common symptoms that
may be experienced and the recommended corrective action.
Table 5.1 - Mechanical and Electrical Troubleshooting Guide
SYMPTOM POSSIBLE FAILURE REMEDY
Unit does not operate
Unit runs continuously
Low head pressure
High head pressure
Short cycling
Unit does not cool
1. Control failure
2. Incorrect voltage
3. Failed compressor
1. Low on refrigerant
2. Control failure
3. Bad connection at TXV
4. Restricted air flow or dirty
5. Bad condenser fan motor
6. TXV stuck open
7. Compressor failure
8. Ineffective door seal
9. Restricted circulation in
storage compartment
1. Defective compressor
2. Low refrigerant
3. Ambient temperature too low
1. Blocked or dirty condenser
2. Ambient temperature too high
3. System contains air
4. Refrigerant overcharge
1. Maladjusted control
1. Blown fuse/circuit breaker
2. Bad connection at supply cord
3. Ill fitting gasket
1. Adjust or replace control
2. Correct
3. Replace
1. Leak check system and recharge
2. Adjust or replace control
3. Check and secure sensor bulb to suction line
4. Rectify air flow problem and clean condenser
5. Check and replace if necessary
6. Replace
7. Replace
8. Adjust door strike and hinges
9. Redistribute food for even air flow
1. Replace
2. Leak check system and recharge
3. Raise room temperature
1. Clean and remove any obstructions
2. Lower room temperatures
3. Evacuate, change filter dryer, recharge
4. Reduce amount of refrigeration in system
1. Adjust control
1. Replace fuse/reset circuit breaker
2. Check supply cord at outlet
3. Tighten strike on door latch

CORRECTIVE MAINTENANCE
11
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
INTRODUCTION
This chapter focuses on the instruction needed in the
removal and replacement of certain components. It also
addresses the repair of components not listed under the
scheduled maintenance index covered in the Scheduled
Maintenance section.
The level of skills required to perform the service or repair will
vary. Some may require specific training while others may be
performed by any type of mechanic. It is up to the individual
and his/her supervisor to determine the breadth of knowledge
required to perform the necessary service or to make the
necessary repairs.
It is also important to know that any procedure requiring the
handling of refrigerant requires proper certification.
The service or repair items are limited to those parts listed in
Table 7-3.
REPAIR PROCEDURES
7. Using wrenches, remove the suction and discharge
valve stem cover caps on each side of the compressor.
Also, remove the cap nut on the suction and discharge
side as well.
8. Disconnect the high-side line at the compressor. This
is done by heating the brazed connection using an
acetylene and oxygen torch set.
NOTE: Do not apply a flame to a line containing refrigerant.
9. To remove the low-pressure control capillary tube and
service fitting, loosen the 1/4" brass flare nut on the
suction valve.
10. The final step in removing the compressor is to
disconnect it from its mounting. To free the
compressor, remove the wire clips on each of the four
feet.
11. To install the compressor, place it in position on the
base and reinstall the four wire clips.
12. Reattach the suction and discharge valve blocks to the
appropriate sides of the compressor.
13. Reattach the low-pressure control capillary tube and
service fittings to the suction side of the compressor.
14. Reattach the suction line to the compressor.
15. In reconnecting the high-pressure line, it is necessary
to first prepare the line’s end. Using a fine sandpaper
or emery cloth, clean the residue off of the end. Also,
clean the connection on the compressor. Apply flux to
both ends and braze the connections into place.
16. Remove the valve stem cap from the suction valve
block on the side of the compressor. Run the valve
stem all of the way out and then in one turn clockwise.
17. Place the refrigeration service manifold gauge hoses
on the suction and high-side valves. Attach a bottle of
refrigerant to the charging hose and charge the system
with 150 psi of vapor. Using an electronic leak
detector, check the new connections for leaks. Should
a leak appear, evacuate the charge and repair the leak.
Repeat the leak check process again.
18. If the system checks out with no leaks, recover the test
charge using a vacuum recovery pump.
19. With the system pressure at zero, connect the vacuum
pump and evacuate the system. The pump should run
for one hour. The vacuum pump should pull the
system down to 30 inches of vacuum.
20. Reattach the electrical terminal box and secure all
wiring.
WARNING
Prior to performing any work on the refrigeration system,
it is required that the unit be de-energized.
Replacement of Compressor Motor
1. Evacuate the refrigerant from the system using a
refrigeration vacuum pump.
NOTE: Federal laws require the proper handling and
disposal of refrigerant. It is unlawful to release any
refrigerant into the atmosphere.
2. Disconnect the electrical power to the unit. This is
done by turning off the circuit in the main supply panel.
It should be noted on the panel that the refrigerator is
being serviced and that the breaker must remain off.
3. To reach the condensing unit, the front ventilation grill
on the front of the cabinet must be removed. This is
done by pulling the grill up vertically about one inch,
out over the retainer angles and then down.
4. With the grill removed, use a 3/8" wrench or socket
and ratchet to unscrew the mounting bolt that secures
the condensing unit to the cabinet base.
5. Once the mounting bolt is removed, carefully slide the
whole condensing unit forward - lifting it over the angle-
mounting clip at the front of the base. Due to extra
copper coil refrigeration lines, the unit can be
completely removed from the compartment and placed
on the deck.
6. Find the electrical terminal box on the side of the
compressor and remove the front cover. Disconnect
the wires from the compressor. Remove the screws
that attach the terminal box to the compressor. At this
point, the compressor will be electrically detached.

12 Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
CORRECTIVE MAINTENANCE
21. Check the refrigeration tag on the unit for the number
of ounces of refrigerant to place into the system for
start-up. Monitor the pressure on both the suction and
discharge sides of the manifold gauges. As the
temperature in the storage area begins to fall, check
the refrigerant flow through the sight glass. The unit is
fully charged when there are no bubbles in the sight
glass. If after five minutes of operation, bubbles are
still present, it may be necessary to add more
refrigerant (add refrigerant in small amount to keep
from overcharging).
WARNING
Overcharging a refrigeration system can be dangerous.
If the system overcharge is sufficient enough to immerse the
major parts of a hermetic compressor in liquid refrigerant, a
situation has been created that when followed by unusual but
possible circumstances, can lead to compressor housing
seam separation or rupture.
The sequence of circumstances that can lead to compressor
housing seam separation or rupture occurs in the following
manner:
1. The system overcharge immerses the compressor
motor, piston, connecting rods, cylinders, etc. in liquid
refrigerant, thereby effectively forming a hydraulic block
preventing the compressor from starting. This
condition is known as locked rotor.
2. Electrical current continues to flow through the
compressor motor windings that become, in effect,
electric resistance heaters. The heat produced begins
to vaporize the excessive liquid overcharge, causing a
rapid increase in system pressure.
3. If the system compressor protective devices fail for any
reason prior to or during this locked rotor heating cycle
or cycles, liquid refrigerant may be vaporized
sufficiently fast enough to raise the pressure within the
system to extremes far greater that the housing or weld
seam is designed to handle.
4. In some instances where the amount of refrigerant
overcharge is critical in proportion to the system
internal volume, the pressure reached can cause a
compressor housing seam separation or rupture that
can be hazardous.
The remedy to eliminate this exceedingly rare, but potential
hazard is to use correct refrigerant charge amounts and
techniques.
Middleby urges that all individuals responsible for training,
teaching, or advising installation mechanics and service
personnel emphasize proper charging techniques. In
addition, Middleby advises strict adherence to refrigerant
charge amounts specifically recommended by the
manufacturer of the refrigeration, air conditioning, or heat
pump system.
Replacement of Low Pressure Control
1. Disconnect the unit from electrical service.
2. Remove control cover and disconnect electrical
terminals.
3. Disconnect capillary tube.
4. Remove mounting fasteners on control base and install
new control by reversing the procedure.
5. To adjust the control, hook up the service gauges to
the suction and discharge valves and crack them to
allow the gauges to read.
6. Using a standard screwdriver, coarse adjust the control
by turning the adjustment screws on top of the control.
Preset the cut-in and cutout and 68 lbs. and 38 lbs.
respectively for a refrigerator and 25 lbs. and 10 lbs.
respectively for a freezer.
7. Start the system. Allow it to run for five minutes.
Monitor the low side pressure. Fine adjustments will
be required to achieve the prescribed cycling
pressures.
NOTE: Running the suction valve in or out as required to
effectively change the pressures can speed up the control
adjustment process.
Replacement of Thermal Expansion Valve (TXV)
1. Close liquid valve and run compressor until it pumps
refrigerant into the receiver (low side service gauge will
read 1 lbs.). Close the suction line valve.
2. Disconnect the sensor bulb on the suction line.
3. Disconnect the liquid line (1/4") and suction line (3/8")
then remove the TXV.
4. Install new TXV, reconnect lines, and re-fasten the
sensor bulb.
NOTE: It is not recommended to adjust the valve super heat
as this comes pre-set from the factory.
Replacement of Filter Dryer
1. Close liquid line valve and run compressor until the low
side refrigeration gauge indicates zero lbs., then close
suction.
2. Remove filter dryer from system and replace with new
dryer.
3. Purge system and add refrigerant if needed.
Replacement of Condenser Fan Motor
1. Disconnect all electrical power to the unit.
2. Remove the condensing unit from the condensing unit
compartment.

CORRECTIVE MAINTENANCE
13
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
3. Remove the protective wire shroud from around the
motor.
4. Disconnect the fan motor leads from the terminal box
on the compressor.
5. Remove the mounting screws at the motor base.
6. Using an allen wrench, remove the aluminum fan.
7. To install the new motor, reverse the process.
Replacement of the Condensing Fan
1. Disconnect all electrical power to the unit.
2. Remove the condensing unit from the condensing unit
compartment.
3. Remove the protective wire shroud from around the
motor.
4. Using an allen wrench, loosen the set screw on the
blade hub and slide the blade from the shaft.
5. Reverse the procedure to reassemble.
Replacement of the Anti-Condensate Heater
NOTE: The anti-condensate heater is located behind the
front edge of the vinyl breakers in the door opening.
1. Disconnect all electrical power to the cabinet.
2. Remove vinyl breakers by exerting pressure at the
front edge toward the center of the door.
3. Disconnect anti-condensate heater wiring connection.
4. Remove heater from recessed rail.
5. Replace new heater in rail and reconnect electrical.
Replacement of Drawer Gasket
1. Remove the gasket by pulling it out of the snap-in
track.
2. Clean the gasket track and the immediate area.
3. Snap new gasket into retainer.
Replacement of Power Switch
1. Shut off all electrical power going to the unit.
2. Remove the front air grill.
3. Using a flat blade screwdriver, remove the cover plate
with the switch attached.
4. Remove the wires connected to the switch.
5. Unscrew the lock washer and remove the switch.
6. Reverse the process when installing the new switch.
Replacement of the Drain Line
NOTE: To replace the vinyl drain line, it is necessary that
there be access to the rear of the cabinet.
1. On the cabinet exterior, remove the rear tubing cover
using a 1/4" nut driver.
2. On the interior of the cabinet, remove the drain line
cover.
3. From the inside of the cabinet, pull the drain from the
evaporator shroud fitting.
4. From the drain exit location, pull the drain through the
penetration of the cabinet.
5. At the bottom of the condensing unit compartment, cut
the drain line retaining strap. The drain line should
now be free.
6. To install the new drain line, reverse the process.
CHARGING THE REFRIGERATION SYSTEM
1. Connect service gauges to the suction and discharge
service valves then open valves one full turn.
2. If the system is pressurized slightly, open both manifold
gauge valves and purge the service line gauges.
3. With manifold gauge valves closed, start refrigeration
system.
4. Attach a drum of refrigerant to the suction service side
of the manifold gauges and add refrigerant until the
liquid sight glass is clear of bubbles.
RECALIBRATING THE THERMOMETER
1. To recalibrate the thermometer, remove it from the
cabinet. Using a small, flat screwdriver, remove the
lens. Prepare an ice water bath and immerse the
thermometer bulb at least two inches into the ice bath.
Within 30 seconds the indicator dial should read 32
degrees Fahrenheit. If it does not, it needs to be
recalibrated. Do this by placing your index finger on
the opposite side of the needle that needs to move.
Then, using a flat screwdriver, turn the screw at the
center of the dial 1/4 of a turn in the direction you want
to move the dial. Repeat the procedure until the
needle is on 32 degrees. See Figure 4.1.

14 Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
PARTS LIST
INTRODUCTION
This section of the manual contains lists of replaceable parts.
Each of the tables contains a list of removable parts
associated with an assembly of the cabinet or refrigeration
system. No parts identification has been provided for details
of permanently assembled items or those that are not
suitable for field repair.
Table 7.1 is a parts list of special tools required for routine
service.
Table 7.1 - Parts List - Special Tools List
Part Number Description Quantity
R1412 Refrigerant service gauges with hoses 1
VA70264 Service valve wrench 1
50992 Refrigerant 30 lbs.

PARTS LIST
15
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
Drawer Cartridge 18" DSB18C Middleby 1
Gasket GSB60MV 6449 Jeans 2
Recessed Pulls HXHL08 P73-2000 Component Hardware 2
Drawer Rollers HXDW02 7319000201 Kason 8
Heater Wire L1HR64 64" Refrigeration Hdwe. 1
Leg nut CNNP01MS 3/4" large hex nut Best Bolt 4
Parts List - Cabinet
20036SB
Item Middleby# Mfg# Vendor Qty
Table 7.2 - Parts List
Evaporator Coil Assy. RWE430 BBM11A Heatcraft 1
Evaporator Motor RWEM03 25300701 Heatcraft 1
Evaporator Fan RWE5101B 5101B Heatcraft 1
Expansion Valve RWEV39 EFS1/4C Sporlan 1
Thermostat RWTT08 A319ABC-24-01 Johnson Controls 1
Condensing Unit RUT220 AEA9422ZXAEC Tecumseh 1
Compressor RUT221 AEA590AT-946-A2 Tecumseh 1
Condenser RWCD17 50837 Tecumseh 1
Condenser Fan Blade RWFB20 51561 Tecumseh 1
Condenser Fan Motor RWCM05 810M006B45 Tecumseh 1
Receiver RWRT04 51080 Tecumseh 1
Start Capacitor RWCP42 858S165A47 Tecumseh 1
Run Capacitor - - - -
Relay RWRLY09 820RR12B79 Tecumseh 1
Overload RWOVL05 8300MRTE59 Tecumseh 1
Filter Dryer RWFD02 C-052-S Sporlan 1
Sight Glass RWSG01 SG-114 Watsco 1
Pressure Control RWPL02 010-1483 Ranco 1
Power Control Switch LWTS01 - Middleby 1
Power Cord MT-004 115V - 1
Wire Harness LH041 - - 1
Parts List - Refrigeration
20036SB
Item Middleby# Mfg# Vendor Qty

16 Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
PARTS LIST
Drawer Cartridge 26" DSB26C Middleby 1
Gasket GSB62MV 6449 Jeans 2
Recessed Pulls HXHL08 P73-2000 Component Hardware 2
Drawer Rollers HXDW02 7319000201 Kason 8
Heater Wire L1HR82 82" Refrigeration Hdwe. 1
Leg nut CNNP01MS 3/4" large hex nut Best Bolt 4
Parts List - Cabinet
20048SB
Item Middleby# Mfg# Vendor Qty
Evaporator Coil Assy. RWE430 BBM11A Heatcraft 1
Evaporator Motor RWEM03 25300701 Heatcraft 1
Evaporator Fan RWE5101B 5101B Heatcraft 1
Expansion Valve RWEV39 EFS1/4C Sporlan 1
Thermostat RWTT08 A319ABC-24-01 Johnson Controls 1
Condensing Unit RUT220 AEA9422ZXAEC Tecumseh 1
Compressor RUT221 AEA590AT-946-A2 Tecumseh 1
Condenser RWCD17 50837 Tecumseh 1
Condenser Fan Blade RWFB20 51561 Tecumseh 1
Condenser Fan Motor RWCM05 810M006B45 Tecumseh 1
Receiver RWRT04 51080 Tecumseh 1
Start Capacitor RWCP42 858S165A47 Tecumseh 1
Run Capacitor - - - -
Relay RWRLY09 820RR12B79 Tecumseh 1
Overload RWOVL05 8300MRTE59 Tecumseh 1
Filter Dryer RWFD02 C-052-S Sporlan 1
Sight Glass RWSG01 SG-114 Watsco 1
Pressure Control RWPL02 010-1483 Ranco 1
Power Control Switch LWTS01 - Middleby 1
Power Cord MT-004 115V - 1
Parts List - Refrigeration
20048SB
Item Middleby# Mfg# Vendor Qty

PARTS LIST
17
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
Drawer Cartridge 31" DSB31C Middleby 1
Gasket GSB64MV 6449 Jeans 2
Recessed Pulls HXHL08 P73-2000 Component Hardware 2
Drawer Rollers HXDW02 7319000201 Kason 8
Heater Wire L1HR90 90" Refrigeration Hdwe. 1
Leg nut CNNP01MS 3/4" large hex nut Best Bolt 4
Parts List - Cabinet
20060SB
Item Middleby# Mfg# Vendor Qty
Evaporator Coil Assy. RWE430 BBM11A Heatcraft 1
Evaporator Motor RWEM03 25300701 Heatcraft 1
Evaporator Fan RWE5101B 5101B Heatcraft 1
Expansion Valve RWEV39 EFS1/4C Sporlan 1
Thermostat RWTT08 A319ABC-24-01 Johnson Controls 1
Condensing Unit RUT220 AEA9422ZXAEC Tecumseh 1
Compressor RUT221 AEA590AT-946-A2 Tecumseh 1
Condenser RWCD17 50837 Tecumseh 1
Condenser Fan Blade RWFB20 51561 Tecumseh 1
Condenser Fan Motor RWCM05 810M006B45 Tecumseh 1
Receiver RWRT04 51080 Tecumseh 1
Start Capacitor RWCP42 858S165A47 Tecumseh 1
Run Capacitor - - - -
Relay RWRLY09 820RR12B79 Tecumseh 1
Overload RWOVL05 8300MRTE59 Tecumseh 1
Filter Dryer RWFD02 C-052-S Sporlan 1
Sight Glass RWSG01 SG-114 Watsco 1
Pressure Control RWPL02 010-1483 Ranco 1
Power Control Switch LWTS01 - Middleby 1
Power Cord MT-004 115V - 1
Wire Harness LH041 - - 1
Parts List - Refrigeration
20060SB
Item Middleby# Mfg# Vendor Qty

18 Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
PARTS LIST
Drawer Cartridge 26" DSB26C Middleby 2
Gasket GSB62MV 6449 Jeans 4
Recessed Pulls HXHL08 P73-2000 Component Hardware 4
Drawer Rollers HXDW02 7319000201 Kason 16
Heater Wire L1HR82 82" Refrigeration Hdwe. 2
Leg nut CNNP01MS 3/4" large hex nut Best Bolt 4
Parts List - Cabinet
20072SB
Item Middleby# Mfg# Vendor Qty
Evaporator Coil Assy. RWE450 BBM16A Heatcraft 1
Evaporator Motor RWEM03 25300701 Heatcraft 1
Evaporator Fan RWE5101B 5101B Heatcraft 1
Expansion Valve RWEV39 EFS1/4C Sporlan 1
Thermostat RWTT08 A319ABC-24-01 Johnson Controls 1
Condensing Unit RUT390 AKA9429ZXAEC Tecumseh 1
Compressor RUT391 AK174AT-0388-A9-8-952 Tecumseh 1
Condenser RWCD14 50840-1 Tecumseh 1
Condenser Fan Blade RWFB05 51551 Tecumseh 1
Condenser Fan Motor RWCM06 810M009B48 Tecumseh 1
Receiver RWRT03 81080-1 Tecumseh 1
Start Capacitor RWCP47 85PS165A53 Tecumseh 1
Run Capacitor - - - -
Relay RWRLY07 82498-1 Tecumseh 1
Overload RWOVL38 8300CRAN21 Tecumseh 1
Filter Dryer RWFD02 C-052-S Sporlan 1
Sight Glass RWSG01 SG-114 Watsco 1
Pressure Control RWPL02 010-1483 Ranco 1
Power Control Switch LWTS01 - Middleby 1
Power Cord MT-004 115V - 1
Wire Harness LH041 - - 1
Parts List - Refrigeration
20072SB
Item Middleby# Mfg# Vendor Qty

PARTS LIST
19
Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
Drawer Cartridge 31" DSB31C Middleby 2
Gasket GSB64MV 6449 Jeans 4
Recessed Pulls HXHL08 P73-2000 Component Hardware 4
Drawer Rollers HXDW02 7319000201 Kason 16
Heater Wire L1HR90 90" Refrigeration Hdwe. 2
Leg nut CNNP01MS 3/4" large hex nut Best Bolt 6
Parts List - Cabinet
20084SB
Item Middleby# Mfg# Vendor Qty
Evaporator Coil Assy. RWE450 BBM16A Heatcraft 1
Evaporator Motor RWEM03 25300701 Heatcraft 1
Evaporator Fan RWE5101B 5101B Heatcraft 1
Expansion Valve RWEV39 EFS1/4C Sporlan 1
Thermostat RWTT08 A319ABC-24-01 Johnson Controls 1
Condensing Unit RUT390 AKA9429ZXAEC Tecumseh 1
Compressor RUT391 AK174AT-0388-A9-8-952 Tecumseh 1
Condenser RWCD14 50840-1 Tecumseh 1
Condenser Fan Blade RWFB05 51551 Tecumseh 1
Condenser Fan Motor RWCM06 810M009B48 Tecumseh 1
Receiver RWRT03 81080-1 Tecumseh 1
Start Capacitor RWCP47 85PS165A53 Tecumseh 1
Run Capacitor - - - -
Relay RWRLY07 82498-1 Tecumseh 1
Overload RWOVL38 8300CRAN21 Tecumseh 1
Filter Dryer RWFD02 C-052-S Sporlan 1
Sight Glass RWSG01 SG-114 Watsco 1
Pressure Control RWPL02 010-1483 Ranco 1
Power Control Switch LWTS01 - Middleby 1
Power Cord MT-004 115V - 1
Wire Harness LH041 - - 1
Parts List - Refrigeration
20084SB
Item Middleby# Mfg# Vendor Qty

20 Printed in USA 12/02 Refrigerated Base-Self-Contained © 2002
PARTS LIST
Drawer Cartridge 18" DSB18C Middleby 2
Drawer Cartridge 26" DSB26C Middleby 2
Gasket GSB64MV 6449 Jeans 4
Gasket GSB62MV 6449 Jeans 4
Recessed Pulls HXHL08 P73-2000 Component Hardware 6
Drawer Rollers HXDW02 7319000201 Kason 24
Heater Wire L1HR90 64" Refrigeration Hdwe. 1
Heater Wire L1HR82 82" Refrigeration Hdwe. 2
Leg nut CNNP01MS 3/4" large hex nut Best Bolt 6
Parts List - Cabinet
20096SB
Item Middleby# Mfg# Vendor Qty
Evaporator Coil Assy. RWE450 BBM16A Heatcraft 1
Evaporator Motor RWEM03 25300701 Heatcraft 1
Evaporator Fan RWE5101B 5101B Heatcraft 1
Expansion Valve RWEV39 EFS1/4C Sporlan 1
Thermostat RWTT08 A319ABC-24-01 Johnson Controls 1
Condensing Unit RUT520 FJCF-A050-IAA-201 Copeland 1
Compressor RUT511 RS43C1E-IAA-100 Copeland 1
Condenser RWCD37 066-0303-00 Copeland 1
Condenser Fan Blade RWFB08 083-0130-00 Copeland 1
Condenser Fan Motor RWCM27 050-0259-12 Copeland 1
Receiver RWRT12 577-0346-02 Copeland 1
Start Capacitor RWCP03 014-0008-57 Copeland 1
Run Capacitor - - - -
Relay RWRLY02 040-0102-00 Copeland 1
Overload RWOVL02 071-0329-15 Copeland 1
Filter Dryer RWFD02 C-052-S Sporlan 1
Sight Glass RWSG01 SG-114 Watsco 1
Pressure Control RWPL02 010-1483 Ranco 1
Power Control Switch LWTS01 - Middleby 1
Power Cord MT-004 115V - 1
Wire Harness LH041 - - 1
Parts List - Refrigeration
20096SB
Item Middleby# Mfg# Vendor Qty