Refrigeration Systems

Installation, Use & Care ManualThis manual is updated as new information and models are released.

Visit our website for the latest manual. www.manitowocfsg.com

Specified #1 Among Walk-insPart Number 11325 03/08

Safety NoticesAs you work on Manitowoc equipment, be sure to pay close attention to the safety notices in this manual. Disregarding the notices may lead to serious injury and/or damage to the equipment.

Throughout this manual, you will see the following types of safety notices:

Procedural NoticesAs you work on Manitowoc equipment, be sure to read the procedural notices in this manual. These notices supply helpful information which may assist you as you work.

Throughout this manual, you will see the following types of procedural notices:

NOTE: Text set off as a Note provides you with simple, but useful, extra information about the procedure you are performing.

Read These Before Proceeding:

NOTE: SAVE THESE INSTRUCTIONS.

! WarningText in a Warning box alerts you to a potential personal injury situation. Be sure to read the Warning statement before proceeding, and work carefully.

! CautionText in a Caution box alerts you to a situation in which you could damage the equipment. Be sure to read the Caution statement before proceeding, and work carefully.

ImportantText in an Important box provides you with information that may help you perform a procedure more efficiently. Disregarding this information will not cause damage or injury, but it may slow you down as you work.

! CautionProper installation, care and maintenance are essential for maximum performance and trouble-free operation of your Manitowoc equipment. Read and understand this manual. It contains valuable care and maintenance information. If you encounter problems not covered by this manual, do not proceed, contact Manitowoc Foodservice Group. We will be happy to provide assistance.

ImportantRoutine adjustments and maintenance procedures outlined in this manual are not covered by the warranty.

! WarningPERSONAL INJURY POTENTIAL

Do not operate equipment that has been misused, abused, neglected, damaged, or altered/modified from that of original manufactured specifications.

We reserve the right to make product improvements at any time. Specifications and design are subject to change without notice.

Table of Contents

Section 1 General Information

Model Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Serial Number Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Section 2 Installation Instructions

Pre-installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Location of Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Condensing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Multiple Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Walls or Obstructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Field Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Multiple Evaporator Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Refrigerant Piping Hanger Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Installing Model PR Field-charged Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Oil Traps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Installing Model PCL Pre-charged Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Evaporator Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Condenser Unit Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Drain Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Walk-in Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Walk-in Freezers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Panel Penetrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Charging Refrigeration System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Polyol Ester (POE) Lubricants (Used with HFC Refrigerants) . . . . . . . . . . 2-6Refrigerant Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6Leak Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Compressor Mounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7Mounting Defrost Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8Post Installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Part Number 11325 03/08 i

Table of Contents (continued)

Section 3 Operation

Component Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Start-up Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Defrost Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Operational Checks and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Compressor Superheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3Evaporator Superheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Defrost Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Refrigerant Evacuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Section 4 Maintenance

Cleaning Condensing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Maintenance Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Section 5 Before Calling for Service

Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Evaporator Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Compressor Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Equipment/Service Data Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4System Reference Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

ii Part Number 11325 03/08

Section 1General Information

Model NumbersThis manual covers the following models:

Serial Number LocationThis number is required when requesting information from your local distributor. The serial number is listed on the SERIAL NUMBER DECAL affixed to the condensing unit assembly.

Serial Number Location

Pre-charged Lines Field-charged LinesPCL PR

Serial NumberKS1005

Part Number 11325 03/08 1-1

General Information Section 1

THIS PAGE INTENTIONALLY LEFT BLANK

1-2 Part Number 11325 03/08

Section 2Installation Instructions

Pre-installation ChecklistFollow these guidelines during the installation process:

Location of EquipmentCONDENSING UNITFor optimum air-cooled equipment performance, these are the most critical clearance requirements:

• a sufficient supply of ambient air to the condenser

• adequate space for removal of the heated discharged air from the condensing unit area

Position the condensing unit:

• in a clean, dry, level area

• away from steam or hot air exhaust sources

• away from corrosive atmospheres

• away from noise-sensitive areas

• with adequate support to minimize undesirable vibration and noise transmission

Check the selected installation location to ensure that racks, braces, floor, foundations, etc., are adequate to support the weight of the unit.

Verify that system piping is in accordance with good refrigeration practices.

When brazing refrigerant lines, pass an inert gas through the line at low pressure to prevent scaling and oxidation of the tubing. Nitrogen is recommended.

! CautionDo not lift the condensing unit assembly by the refrigerant tubing. Damage may result.

! CautionIf either clearance requirement is ignored, higher system head pressure will result, causing poor system operation, shorter equipment life and an increased risk of equipment failure.

Part Number 11325 03/08 2-1

Installation Instructions Section 2

MULTIPLE UNITSSeparate side-by-side units with a minimum distance equal to the width of the largest unit.

Multiple Units with Horizontal Airflow

WALLS OR OBSTRUCTIONSTo avoid re-circulation of condenser air, and to allow for proper airflow and access, all sides of the unit should be positioned a distance equal to the total width of the condensing unit away from any wall or obstruction. Increase this distance where possible to increase airflow and access to the unit.

Space Requirements Near Walls and Obstructions

ElectricalFIELD WIRINGAll electrical connections and routing must conform to local and national codes. Do not modify the factory-installed wiring without written factory approval.

The field wiring must enter through the knockouts provided. All field wiring must be properly connected according to the wiring diagram.

NOTE: The wiring diagram for each unit is located on the inside of the electrical box within the unit.

Refer to the nameplate rating label on the unit to determine the correct electrical power supply. Consult the wiring diagram for proper electrical connections.

If a remote defrost timer is used, the timer must be located outside the refrigerated space.

The power supply to the unit must meet the following conditions:

• Single-phase must be within + 10% or – 5% of nameplate ratings.

• Three-phase voltages must be ± 10% of nameplate ratings.

• Phase imbalance cannot exceed 2%.

MULTIPLE EVAPORATOR SYSTEMSTo assure complete defrost with multiple evaporator systems, wire the defrost termination controls in series.

! CautionDo not position multiple units in a way that would permit discharge air from one unit to enter the air inlet of another unit. This could cause system overheating and equipment failure.

MINIMUM DISTANCE

MINIMUM DISTANCE

MINIMUM DISTANCE

AIR FLOW AIR FLOW

BUILDING WALL (VIEWED FROM ABOVE)

KS1002

AIR FLOW

MINIMUM DISTANCE

BUILDINGWALL

MOUNTING SURFACE KS1003

! CautionUse copper conductors only. The unit must be grounded.

ImportantConnections can become loose during shipment. Check all wiring connections before operation.

2-2 Part Number 11325 03/08

Section 2 Installation Instructions

Refrigerant Piping Hanger RequirementsFollow these hanger requirements:

• All tubing must be supported in at least two locations (near each end of the tubing run).

• Long runs will require additional support. As a guide, support 3/8" to 7/8" pipe every 5 feet; 1-1/8" to 1-3/8" every 7 feet; and 1-5/8" to 2-1/8" every 9 to 10 feet.

• Do not leave a corner unsupported when changing directions in a run of tubing. Place supports a maximum of 2 feet in each direction from the corner of the unit.

• Piping attached to a vibrating object (such as a compressor or compressor base) must be supported in a manner that will not restrict the movement of the vibrating object. Rigid mounting will fatigue the copper tubing.

• Do not use short radius elbows. Short radius elbows have points of excessive stress concentration and are subject to breakage at these points.

• Once the equipment is in operation, thoroughly inspect all piping. Add supports as needed.

Installing Model PR Field-charged LinesAlthough the condensing unit was thoroughly cleaned and dehydrated at the factory, take care to prevent contamination when installing the piping.

Install all refrigeration system components and piping in accordance with applicable local and national codes.

Follow industry refrigeration guidelines to maintain proper operation of the system.

NOTE: The interconnecting pipe size is not necessarily the same size as the stub-out on the condensing unit or the evaporator.

INSTALLATION GUIDELINESFollow these guidelines during the installation process:

• Purge the dry air charge from the unit by opening the liquid line service valve or by removing the liquid line outlet fitting (as applicable).

• The maximum air exposure for dehydrated condensing units or filter-driers is 15 minutes. (See page 2-6 for more information.)

• Use only refrigeration-grade copper tubing that is properly sealed against contamination.

• Suction lines must slope 1/4" per 10 feet toward the compressor.

• Install P-type oil traps at the base of each suction riser of four feet or more to ensure proper oil return to the compressor.

• When brazing refrigerant lines, pass an inert gas through the line at low pressure to prevent scaling and oxidation of the tubing. Nitrogen is recommended. Use only silver solder alloys when brazing.

• To prevent internal contamination, minimize the use of flux. Flux only the male portion of the connection. Remove excess flux after brazing.

OIL TRAPSInstall a suction line trap at the evaporator outlet if the suction line rises to a point higher than the connection on the evaporator.

To ensure proper oil return, position a suction trap at the base of all suction risers of four feet or more. The suction trap must be the same size as the suction line.

Additional traps are necessary for long vertical risers. Add a trap for each length of pipe (approximately 20 feet) to ensure proper oil return.

! CautionRefrigerant lines exposed to high ambient conditions must be insulated to reduce heat pick-up. This will prevent the formation of flash gas in the liquid lines.

Part Number 11325 03/08 2-3

Installation Instructions Section 2

Installing Model PCL Pre-charged LinesINSTALLATION GUIDELINESFollow these installation guidelines:

• Route the suction and liquid lines between the condensing unit and the evaporator. Install lines in accordance with industry refrigeration guidelines.

• Remove the dust caps from the quick connect fittings and verify that the O-rings are intact.

Quick Connect Fittings

• Wipe the coupling seals and threaded surfaces with a clean cloth to prevent contamination.

• Lubricate the threads and O-rings on the quick connect fitting with Polyol Ester oil.

• Thread the coupling halves together by hand to ensure proper thread mating.

• Tighten with a wrench until the coupling bodies “bottom” or until there is definite resistance. Tighten an additional 1/4 turn to ensure proper brass-to-brass seating.

• After connection, check the quick connect fittings for refrigerant leaks. If a leak is found, tighten the fitting until the leak is stopped.

Evaporator Mounting1. Use the evaporator for a template to locate and drill

evaporator mounting holes (1/2" diameter).

2. Place the four nylon bolts with washers through the 1/2" diameter holes as shown. Note the location of the 1-5/8" diameter washers.

3. Place the evaporator below the installation location and lift it straight upward toward the ceiling of the walk-in.

4. Continue lifting the evaporator toward the ceiling until the four nylon bolts extend through the mounting brackets.

5. Install washers and secure in place with nuts.

NOTE: For additional information, refer to the installation manual supplied with the evaporator.

Evaporator Mounting Detail

Condenser Unit Mounting1. Position the condensing unit assembly on the walk-

in ceiling.

2. Use a sharp punch to pierce four 1/8" diameter holes, using the condensing unit mounting holes as a template.

3. Perform operational start-up. See page 3-2.

! CautionRefrigerant quick connect fittings will not reseal. Remove all refrigerant before attempting to disconnect the fittings. Once disconnected, the coupling cannot be re-used.

DIAPHRAGMS CUTTER

KS1006

EVAPORATOR

CEILING PANEL

NOTE: FASTENERS ARE SUPPLIED IN THE MOUNTING KIT

EVAPORATOR MOUNTING BRACKET NUT

1” O.D. WASHER

1” O.D. WASHER

1-5/8” O.D. WASHER

NYLON BOLT

KS1008

2-4 Part Number 11325 03/08

Section 2 Installation Instructions

Drain LinesWALK-IN COOLERSFollow these guidelines:

• Provide a minimum 4" per one-foot pitch for proper drainage.

• A copper drain is recommended.

• Locate the drain line P-trap outside of the refrigerated space.

• Wrap any traps exposed to low ambient temperatures with a drain line heater.

• Provide a heater with 20 watts of heat per foot of drain line.

WALK-IN FREEZERSFollow these guidelines:

• Provide a minimum 4" per one-foot pitch for proper drainage.

• A copper drain is recommended.

• Insulate the drain line and seal where it passes through the wall.

• Locate the drain line P-trap outside the refrigerated space.

• Wrap any traps exposed to low ambient temperatures with a drain line heater.

• Provide a heater with 20 watts of heat per foot of drain line at 0°F, 30 watts per foot at –20°F.

Typical Drain Installation

Panel Penetrations

Sealing discs are supplied on PCL models to seal electrical and refrigerant line holes. PR models are not supplied with sealing discs. The sealing discs are approximately 3-1/2" in diameter and white in color. The discs are packaged in the evaporator carton with the evaporator mounting kit.

To apply a disc to the interior of the walk-in:

1. Slit the disc to the center.

2. Remove appropriate center sections to reach the correct hole size.

3. Remove the backing and place the disc in position around the conduit and copper tubing.

4. Seal the disc in place with sealant.

To apply a disc to the exterior of the walk-in:

1. Fill the hole with the fiberglass provided.

2. Remove the backing and place the disc in position.

3. Seal the disc in place with sealant.

KS1010Open Drain

! CautionAll walk-ins must have an air-tight seal. Check that all penetrations (refrigeration, electrical, etc.), through the walk-in panels are properly sealed.

Part Number 11325 03/08 2-5

Installation Instructions Section 2

Charging Refrigeration SystemPOLYOL ESTER (POE) LUBRICANTS (USED WITH HFC REFRIGERANTS)

Polyol Ester (POE) lubricants quickly absorb moisture from the ambient surroundings. POE lubricants absorb moisture more rapidly and in greater quantity than conventional mineral oils. Because moisture levels greater than 100 PPM will result in system corrosion and component failure, it is essential that system exposure to ambient conditions be kept to a minimum.

If a system is left open to the atmosphere for more than 15 minutes, the liquid line drier and compressor oil must be replaced. Drain at least 95% of the oil from the compressor suction port. Measure the amount of removed oil, and replace it with exactly the same amount of new POE oil.

Lubricants are packaged in specially designed, sealed containers. Once opened, use the lubricant immediately. Properly dispose of any unused lubricant.

Mobil EAL™ ARCTIC 22 CC is the preferred Polyol Ester lubricant because of its particular additives. ICI Emkarate RL 32S is an acceptable alternative when the Mobil is not available. These POE lubricants must be used with HFC refrigerants.

REFRIGERANT CHARGINGFollow these instructions:

1. Install a liquid line drier in the refrigerant supply line, between the service gauge and the liquid service port of the receiver. The liquid line drier will ensure that all refrigerant is clean and dry.

2. Add liquid refrigerant directly into the receiver tank when first charging a system that is in a vacuum.

3. Start the system and charge by weight and sight glass indication.

4. If refrigerant must be added to the system through the suction side of the compressor, charge in vapor form only. When charging with R-404A, the refrigerant must exit the charging cylinder in the liquid phase. Connect a sight glass between the charging hose and the compressor suction service valve to be sure the refrigerant entering the compressor is in the vapor state.

When charging the system to a clear sight glass (as an indication of proper charge):

• Verify the condensing temperature is above 105°F. If not, reduce the effective condenser face area to raise the discharge pressure above the equivalent 105°F. Proceed to charge to clear the sight glass.

• Adjust the evaporator superheat at this time. (See “Evaporator Superheat,” page 3-4.)

• Return to full condenser face area and allow the system to balance.

! CautionDo not leave a refrigeration system or compressor using POE oil open to the atmosphere for more than 15 minutes. System corrosion and component failure could result.

! CautionDo not leave the system or the compressor open or unattended.

! CautionCharge with liquid through the high side only. Introducing liquid refrigerant into the motor-compressor can damage the valves, rods, pistons, etc.

! CautionVerify that there is not an overcharge of refrigerant. An overcharge may permit liquid refrigerant to enter the motor-compressor and damage the valves, rods, pistons, etc.

2-6 Part Number 11325 03/08

Section 2 Installation Instructions

LEAK TESTINGAfter making all of the connections, perform a leak test on the entire system. This must include:

• the condensing unit

• the evaporator

• all connecting tubing

• all fittings

• all brazed joints

Leak check the entire system, by pressurizing to the low side test pressure marked on the unit rating label. Repair all leaks found.

Because HFCs have a smaller molecule size, they tend to leak more readily than CFCs. Consequently, it is important to employ proper system evacuation and leak detection procedures.

Compressor MountsOn most semi-hermetic compressors with external spring mounts, the grommets are factory-assembled and it is only necessary to loosen the nuts.

If field assembly is required:

1. Remove the hold-down nuts.

2. Place the rubber grommets provided on the studs.

3. Remove the spring steel clips from the mounting springs

4. Install the nuts. Allow approximately 1/16" between the nut and the rubber grommet for the compressor to float freely on the springs.

Properly Adjusted Compressor Mount

ImportantHermetic compressor springs are mounted internally in the compressor. Check the compressor mounting bolts to make certain the securing nuts have not loosened during shipment.

MOUNTING NUT(UPPER)

COMPRESSOR MOUNTING FOOT

MOUNTINGSTUD

RUBBERSPACER

MOUNTING SPRING

MOUNTING BASE

MOUNTING NUT (LOWER)

LOCKINGDEVICE

KS1013

Part Number 11325 03/08 2-7

Installation Instructions Section 2

Mounting Defrost Time ClockNOTE: Do not locate the timer in the refrigerated area.

Walk-in freezers are supplied with a timer for controlling the initiation and frequency of the defrost cycle.

The timer is shipped loose. Mount it in a convenient location outside of the refrigerated area.

Defrost Time Clock

Check the defrost controls for initiation and termination settings.

Set the fail safe at the length of defrost + 25%.

Example: 24 min. defrost + 25% (6 min.) = 30 min. fail safe

NOTE: If the defrost termination thermostat fails to close, the fail safe setting on the timer will terminate the defrost.

Post Installation ChecklistCheck the following before energizing the equipment:

Verify that the suction, discharge and receiver service valves are open.

Make sure all electrical and refrigerant connections are tight.

Check/adjust the room thermostat for desired temperature.

Check condenser fan motor(s) and evaporator fan motor(s) for proper operation.

Examine the fan motor mounts carefully for tightness and proper alignment.

Verify that all refrigerant tubing is properly insulated, routed and secured.

Verify that all wire routing is appropriate and properly secured.

2-8 Part Number 11325 03/08

Section 3Operation

Component Identification

Compressor

Evaporator

Condenser Coil

Condensing Unit

Ceiling Panel

Condenser Fan and Motor

Part Number 11325 03/08 3-1

Operation Section 3

Start-up Procedure

Operate the system for at least two hours at normal conditions. If there is no indication of malfunction, operate the system overnight on automatic controls.

Perform a thorough re-check of the entire system:

1. Check compressor discharge and suction pressures. If not within system design limits, determine the cause and take corrective action.

2. Check liquid line sight glass and expansion valve operation. If there are indications that more refrigerant is required, leak-test all connections and system components and repair any leaks before adding refrigerant.

3. For semi-hermetics, observe the oil level in the compressor crankcase sight glass. Add oil as necessary to bring the level to 3/4 of the sight glass while idle, or 1/2 of the sight glass when running.

4. Check the thermostatic expansion valve(s) for the proper superheat setting. Verify that the sensing bulb is insulated, properly located and in positive contact with the suction line.

NOTE: High superheat causes low refrigeration capacity. Low superheat promotes liquid slugging and compressor bearing washout.

5. Check the line voltage and amperage carefully at the compressor terminals. Use suitable instruments.

- Voltage must be within + 10% or – 5% of the voltage rating indicated on the condensing unit nameplate. If high or low voltage is indicated, notify the Power Company.

- If amperage draw is excessive, immediately determine the cause and take corrective action.

- On three-phase motor compressors verify there is a balanced load.

6. Check the defrost control initiation and termination settings, and set the length of defrost period. Set the fail safe at the length of the defrost + 25%.

Example: 24 min. defrost + 25% (6 min.) = 30 min. fail safe

7. Check crankcase heater operation (if applicable).

Sequence of OperationDEFROST TIME CLOCKThe timer starts the defrost cycle automatically at predetermined times. A setting of two to four defrost cycles per day is typical. For heavier frost loads, additional cycles may be required.

When the defrost cycle begins:

1. Switch 2 to 4 opens in the time clock, breaking the circuit to the room thermostat, liquid line solenoid, and evaporator fan motors. This allows the compressor to pump down and shut off. Simultaneously, switch 1 to 3 closes in the timer, energizing the defrost heaters.

2. The heaters increase the coil temperature above 32°F, melting the frost off the coil.

3. When the coil warms to 45-55°F, the defrost termination thermostat closes and energizes the switching solenoid in the timer. At this time, switch 1 to 3 in the timer opens, terminating the defrost heaters. Simultaneously, switch 2 to 4 closes in the time clock, energizing the temperature control circuit.

4. Suction pressure rises, the low pressure control closes, and the compressor starts.

5. The fan relay closes when the coil temperature reaches 23-30°F. This energizes the fan motors.

6. The system operates in the refrigeration cycle until another defrost cycle is initiated by the timer.

! CautionDo not start the compressor while it is in a vacuum.

! CautionDo not leave the unit unattended until the system has reached normal operating conditions.

3-2 Part Number 11325 03/08

Section 3 Operation

Operational Checks and AdjustmentsCOMPRESSOR SUPERHEAT

Suction superheat is the critical value that must be checked. Check the suction superheat at the compressor as follows:

1. Determine the suction pressure at the suction service valve of the compressor. Use an accurate gauge.

2. Determine the saturation temperature at the observed suction pressure using refrigeration pressure temperature tables.

3. Measure the temperature of the suction line (using an accurate thermometer) 6-10 inches away from the compressor.

4. Subtract the saturation temperature reading (Step 2) from the measured temperature (Step 3). The difference is the superheat of suction gas.

System capacity decreases as the suction superheat increases. For maximum system capacity, keep the suction superheat as low as practical. Copeland requires a minimum compressor superheat of 20°F. Kolpak recommends a compressor superheat between 25°F and 40°F.

Adjust the expansion valve at the evaporator when adjustments to the suction superheat are necessary. Refer to “Evaporator Superheat” on the next page for more information.

Determining Compressor Superheat

ImportantThe system must be balanced to obtain maximum capacity and ensure trouble-free operation.

! CautionA low suction superheat can cause liquid to return to the compressor. This will cause dilution of the oil and eventual failure of the bearings, rings and valves.

! CautionA high suction superheat will cause excessive discharge temperatures, which cause a breakdown of the oil. This causes piston ring wear, and piston and cylinder wall damage.

CHECK THE TEMPERATURE AND PRESSURE.

THEN, CONSULT A PRESSURE/TEMPERATURE CHART. P/T

CHART

Temperature

Pressure

TEMPERATURE, MINUSPRESSURE CONVERTED

TO TEMPERATURE, EQUALS SUPERHEAT

KS1011

Part Number 11325 03/08 3-3

Operation Section 3

EVAPORATOR SUPERHEATCheck the evaporator superheat once the box has reached the desired temperature. Generally, systems with a design TD of 10°F should have a superheat value of 6-10°F for maximum efficiency.

NOTE: A minimum compressor suction superheat of 20°F may override these recommendations on systems with short line runs.

To determine the evaporator superheat:

1. Determine the suction pressure at the evaporator outlet. Use an accurate gauge.

2. Determine the saturation temperature at the observed suction pressure using the refrigeration pressure temperature tables.

3. Measure the temperature of the suction line at the expansion valve bulb with an accurate thermometer.

4. Subtract the saturation temperature reading (Step 2) from the measured temperature (Step 3). The difference is the superheat of suction gas.

Determining Evaporator Superheat

TEMPERATURE CONTROLA temperature control thermostat, a solenoid valve and a low-pressure switch control all systems.

Set the temperature control to the desired temperature. Use a thermometer to verify accuracy at the set point.

When the temperature reaches the set point, the temperature control contacts will open. This de-energizes the solenoid valve and stops the flow of refrigerant.

The compressor continues to lower the pressure in the evaporator. When the pressure reaches the set point of the low pressure switch, the contacts will open, and the compressor and condenser fan motor(s) cycle off.

EVAPORATORFrost build-up on the evaporator depends on:

• the temperature of the room

• the type of product being stored

• how often a new product is brought into the room

• the percentage of time the door to the room is open

It may be necessary to periodically change the number of defrost cycles per day.

DEFROST TIME CLOCKInstructions for setting the timer are on the inside cover of the time clock.

REFRIGERANT EVACUATION1. Connect a reliable vacuum pump to both the low and

high side valves with copper tubing or a high vacuum hose (1/4" minimum inside diameter).

2. Evacuate the system to 250 microns or lower.

NOTE: Kolpak strongly recommends a vacuum decay test to assure the system is dry and free of leaks.

ImportantThe condensing unit must have the discharge pressure above the equivalent 105°F condensing pressure. See “Refrigerant Charging,” on page 2-6.

CHECK THE TEMPERATURE AND PRESSURE. THEN, CONSULT A PRESSURE/TEMPERATURE CHART.

P/T CHART

TEMPERATURE, MINUSPRESSURE CONVERTED TO

TEMPERATURE, EQUALS SUPERHEAT

Temperature

Pressure

KS1012

! CautionDo not use the refrigeration compressor to evacuate the system. This may cause damage to the equipment.

3-4 Part Number 11325 03/08

Section 4Maintenance

Cleaning Condensing Unit

Maintenance Chart

! CautionFailure to keep the condenser coil clean will result in reduced airflow through the condenser, resulting in poor system performance and premature compressor failure. This will not be covered under your compressor warranty.

Area Task FrequencyEvaporator Check for proper defrosting Monthly

Clean the coil and drain pan Every 6 monthsCheck for proper drainage

Condenser Inspect/clean the coil if the air supply is near polluting sources (such as cooking appliances) MonthlyClean the coil surface Every 3 months

General Check/tighten all electrical connections Every 6 monthsCheck all wiring and insulatorsCheck contactor for proper operation and contact point deteriorationCheck all fan motorsTighten fan set screws, and motor mount nuts and boltsFor semi-hermetics, check the oil level in the systemCheck the operation of the control systemMake certain all safety controls are operating properlyCheck operation of the drain line heater and examine for cuts and abrasionsCheck/tighten all mechanical/flare connections

Part Number 11325 03/08 4-1

Maintenance Section 4

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4-2 Part Number 11325 03/08

Section 5Before Calling for Service

ChecklistIf a problem arises during operation of your refrigeration system, follow the checklist below before calling service. Routine adjustments and maintenance procedures are not covered by the warranty.

EVAPORATOR CHECKLIST

Problem Possible Cause To CorrectFan(s) will not operate. Main switch open. Close switch.

Blown fuse(s). Replace fuse(s). Check for short circuits or overload conditions.

Defective motor. Replace motor.Defective timer or defrost thermostat. Replace defective component.Unit in defrost cycle. Wait for completion of cycle.

Walk-in temperature too high. Thermostat set too high. Adjust thermostat.Superheat too high. Adjust thermal expansion valve.System low on refrigerant. Locate and repair leak, recover, evacuate

and recharge.Coil iced up. Manually defrost coil. Check defrost

controls.Ice accumulating on ceiling around evaporator and/or on fan guards, venturi, or blades.

Defrost duration is too long. Adjust defrost termination thermostat (if adjustable).

Fan delay not delaying fans after defrost period.

Replace defective defrost thermostat.

Defective defrost thermostat or timer. Replace defective component.Too many defrost cycles per day. Reduce number of defrost cycles per

day.Frost on coil after defrost cycle. Coil temperature not getting above

freezing point during defrost.Check heater operation.

Not enough defrost cycles per day. Adjust timer for more defrost cycles per day.

Defrost cycle too short. Adjust timer for longer cycle, check defrost thermostat mounting.

Defective timer or defrost thermostat. Replace defective component.Ice accumulating in drain pan.

Defective heater. Replace heater.Unit not pitched properly. Check and adjust.Drain line plugged. Clean drain line.Defective drain line heater. Replace heater.Defective timer or thermostat. Replace defective component.

Part Number 11325 03/08 5-1

Before Calling for Service Section 5

COMPRESSOR CHECKLIST

Problem Possible Cause To CorrectCompressor will not run. Main switch open. Close switch.

Fuse blown. Check electrical circuits and motor winding for shorts or grounds. Investigate for possible overloading. Replace fuse after fault is corrected.

Thermal overloads tripped. Overloads are automatically reset. Check unit closely when unit comes back on line.

Defective contactor or coil. Repair or replace.System shut down by safety devices. Determine type and cause of shutdown

and correct.No cooling required. Wait until cooling is required.Liquid line solenoid will not open. Repair or replace coil.Low pressure switch will not close. Replace switch.Motor electrical trouble. Check motor for open windings or short

circuit.Loose wiring. Check all wire junctions. Tighten all

terminal screws.Compressor noisy or vibrating. Flooding of refrigerant into crankcase. Check superheat setting of expansion

valve.Improper pipe support. Relocate or add hangers.Worn compressor. Replace compressor.

High discharge pressure. Non-condensables in system. Recover, evacuate and charge.System overcharged with refrigerant. Remove excess charge.Discharge shutoff valve partially closed. Open valve.Fan not running. Check electrical circuit or replace

defective fan motor.Insufficient condenser air supply. Check for cause and correct.Dirty condenser coil. Clean coil.

Low discharge pressure. Faulty head pressure control. Check head pressure control operation.Suction shutoff valve partially closed. Open valve.Insufficient refrigerant in system. Locate and repair leak, recover, evacuate

and recharge.Low suction pressure. See “Low suction pressure” below.

High suction pressure. Excessive load. Reduce load or add additional equipment.

Expansion valve overfeeding. Secure and insulate TXV bulb or if required adjust superheat.

Low suction pressure. Lack of refrigerant. Locate and repair leak, recover, evacuate and charge.

Evaporator dirty or iced. Clean.Clogged liquid line or suction line filter-drier.

Replace filter-drier.

Expansion valve malfunctioning. Check and reset for proper superheat.Condensing temperature too low. Check head pressure control.Improper TXV. Check for proper sizing.

5-2 Part Number 11325 03/08

Section 5 Before Calling for Service

Compressor loses oil. Lack of refrigerant. Locate and repair leak, recover, evacuate and recharge.

Excessive compression ring blow-by. Replace compressor.Refrigerant floodback. Maintain proper superheat at

compressor.Improper piping or traps. Correct piping.

Compressor thermal protector switch open.

Operating beyond design. Add facilities so that operating conditions are within allowable limits.

Discharge valve partially shut. Open valve.Dirty condenser coil. Clean coil.Overcharged system. Correct charge.

COMPRESSOR CHECKLIST (Continued)

Problem Possible Cause To Correct

Part Number 11325 03/08 5-3

Before Calling for Service Section 5

Equipment/Service Data SheetA permanent data sheet must be prepared on each installation. The owner, the installing contractor and the intended service agency, will retain a copy.

System Reference DataThe following information should be filled out and signed by Refrigeration Installation Contractor.

Date System Installed: / / Installer and Address: ____________________________________________________________________

____________________________________________________________________Phone Number: ( ) - Service Agency: ____________________________________________________________________

____________________________________________________________________Phone Number: ( ) -

Condensing Unit: Model Number: _______________________________________________________Serial Number: _______________________________________________________

Compressor Model Number: _______________________ Compressor Model Number: __________________Compressor Serial Number: _______________________ Compressor Serial Number: ___________________

Electrical: ________________ Volts:___________ Phase:__________________ Voltage at Compressor: L1: ____________ L2: ____________ L3: ____________Amperage at Compressor: L1: ____________ L2: ____________ L3: ____________

Evaporator(s): Quantity: _______Evaporator Model Number: _____________________ Evaporator Model Number: ___________________Evaporator Serial Number: ______________________ Evaporator Serial Number: ____________________

Electrical: ________________ Volts:___________ Phase: ___________________________________Expansion Valve Manufacturer/Model Number: _____________________________________________________

Ambient at Start-Up: _______________ °FDesign Box Temperature: _______________ °F _______________ °FOperating Box Temperature: _______________ °F _______________ °FThermostat Setting: _______________ °F _______________ °FDefrost Settings: ______/day _______ minutes failsafe _______/day ________ minutes failsafe

Compressor Discharge Pressure: ______________ PSIG _______________ PSIGCompressor Suction Pressure: ______________ PSIG _______________ PSIGSuction Line Temperature at Compressor: _________ °F _______________ °FDischarge Line Temperature at Compressor: _______ °F _______________ °FSuperheat at Compressor: ______________ °F _______________ °F

Suction Line Temperature at Evaporator: __________ °F _______________ °FSuperheat at Evaporator: ______________ °F _______________ °FEvacuation: # Times ____ Final Micron ____ # Times _____ Final Micron ____

Evaporator Drain Line Trapped Outside of Box: Yes ❏ No ❏

5-4 Part Number 11325 03/08

© 2008 ManitowocContinuing product improvements may necessitate change of specifications without notice.Part Number 11325 03/08

Kolpak2915 Tennessee Avenue North

Parsons, TN 38363, USAPh: 731-847-5365 Fax: 731-847-5387

Visit us online at: www.manitowocfsg.com