Blodgett 20120SB Service Manual

Installation, Operation &

Maintenance Manual

Refrigerated Base – Self-Contained

1100 Old Honeycutt Road, Fuquay-Varina, NC 27526

919-552-9161 • 800-348-2558 • 919-552-9798 (fax) • 800-238-8444 (after hours)

Printed in USA 12/02

MODELS

20036SB 20084SB

20048SB 20096SB

20060SB 20108SB

20072SB 20120SB

Printed in USA 12/02

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

Printed in USA 12/02

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"

4 6 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

Printed in USA 12/02

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 Timer

Contact Points Controls scheduled evaporator coil defrosting

Solenoid Valve Automatic Plunger Shuts off refrigerant flow

Freezers

OPERATION

Printed in USA 12/02

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.

Printed in USA 12/02

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

Printed in USA 12/02

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.

Printed in USA 12/02

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

Printed in USA 12/02

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

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

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