Manitowoc MD0420A, MY0500A, MY0420A, MD0700A, MD0500A Technician's Manual

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M series

Manitowoc

Ice Machines

Technician’s

Handbook

This manual is updated as new information and models are

released. Visit our website for the latest manual. www.welbilt.cn

Part Number 040005626 5/17

Safety Notices

Warning

Caution

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

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

Text in a Warning box alerts you to a potential personal injury situation. Be sure to read the Warning statement before proceedi ng, and work carefully.

Text 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.

Procedural Notices

Important

As you work on M anitowoc e quipment, be s ure to read the procedu ral notices in t his handbook . These noti ces supply helpful information which may assist you as you work.

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

Text in an Important box provides you with information that may help you perform a procedure more efficiently. Disregarding this informat io n wi ll no t caus e dam age or in jury, but it may slow you down as you work.

NOTE: Text set of f as a Note prov ides you with simple, but useful, extra information about the procedure you are performing.

Read These Before Proceeding:

Caution

Important

Warning

Proper installation, care and maintenance are essential for maximum performance and troublefree operation of your equipment. Visit our website www.kool-aire.com for manual updates, translations, or contact information for service agents in you r area.

Routine adjustments and maintenance procedures outlined in this handbook are not covered by the warranty.

Read this manual thoroughly before operating, installing or performing maintenance on the equipment. Failure to follow instructions in this manual can cause property damage, injury or death.

Do not use electrical appliances or accessories other than those supplied by Manitowoc for your ice machine model.

Two or more people or a lifting device are required to lift this appliance.

Warning

This equipment contains high voltage electricity

Warning

and refrigerant charge. Inst allatio n and rep airs are to be performed by properly trained technicians aware of the dangers of dealing with high voltage electricity and refrigerant under pressure.The technician must also be certified in proper refrigerant handling and servicing procedures. All lockout and tag out procedures must be followed when working on this equipment.

Do not damage the refrigeration circuit when installing, maintaining or servicing the unit.

Do not operate equipment that has been misused, abused, neglected, damaged, or altered/modified from that of original manufactured specifications. This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision concerning use of the appliance by a person responsible for their safety. Do not allow children to play with this appliance.

All covers and access panels must be in place and properly secured, before operating this equipment.

Warning

Do not obstruct machine vents or openings.

Warning

Do not store gasoline or other flammable vapors or liquids in the vicinity of this or any other appliance.

Do not clean with water jet.

It is the responsibility of the equipment owner to perform a Personal Protective Equipment Hazard Assessment to ensure adequate protection during maintenance procedures.

Two or more people are required to move this equipment to prevent tipping.

Warning

When using electric appliances, basic

We reserve the right to make product

improvements at any time. Specifications and

design are subject to change without notice.

precautions must always be followed, including the following:

a. Read all the instructions before using

the appliance.

b. To reduce the risk of injury, close

supervision is neces sa ry when an appliance is used near children.

c. Do not contact moving parts.

d. Only use attachments recommended or

sold by the manufacturer.

e. Do not use outdoors.

f. For a cord-connected applia nc e, the

following must be included:

• Do not unplug by pulling on cord. To unplug, grasp the plu g, not the co rd.

• Unplug from outlet when not in use and before servicing or cleaning.

• Do not operate any appliance with a damaged cord or plug, or after the appliance m al fun cti ons o r is dro pp ed or damaged in any manner. Contact the nearest authorized service facility for examination, rep a ir, or electrical or mechanical adjustment.

g. Follow applicable lock out tag out

procedures before working on equipment.

h. Connect to a properly grounded outlet

only.

Table of Contents

GENERAL INFORMATION

Model Numbers . . . . . . . . . . . . . . . . . . . . .13

How to Read a Model Number . . . . . . . . .14

Ice Machine Warranty Information . . . . . 15

Commercial Warranty Coverage . . . . .15

Residential Warranty Coverage . . . . .18

INSTALLATION

Location of Ice Machine . . . . . . . . . . . . . .21

Ice Machine Clearance Requirements . .22

Clearance Requirements . . . . . . . . . . . . .22

Ice Machine Heat of Rejection . . . . . . . . .23

Leveling the Ice Machine . . . . . . . . . . . . .23

Electrical Requirements . . . . . . . . . . . . . . 24

Water Service/Drains . . . . . . . . . . . . . . . .25

Water Supply . . . . . . . . . . . . . . . . . . . . 25

Water Inlet Lines . . . . . . . . . . . . . . . . . 25

Drain Connections . . . . . . . . . . . . . . . .26

Cooling Tower Applications . . . . . . . . .26

MAINTENANCE

Interior Cleaning and Sanitizing . . . . . . .29

General . . . . . . . . . . . . . . . . . . . . . . . .29

Cleaning and Sanitizing Procedure . . .29

Toggle switch Operation . . . . . . . . . . .30

Remove Parts for Cleaning . . . . . . . . .34

Preventative Maintenance Cleaning . . . .36

Ice Machine Inspection . . . . . . . . . . . . . .37

Cleaning the Condenser . . . . . . . . . . . . .38

Removal from Service/Winterization . . .39

Air-cooled Models . . . . . . . . . . . . . . . .39

Water-cooled Models . . . . . . . . . . . . . 39

Part Number 040005626 5/17 9

OPERATION

Ice Making Sequence of Operation . . . . 41

Control Board Timers . . . . . . . . . . . . 42

Safety Limits . . . . . . . . . . . . . . . . . . . . 43

Energized Parts Chart . . . . . . . . . . . . 45

Operational Ch ecks . . . . . . . . . . . . . . . . . 47

Ice Thickness Check . . . . . . . . . . . . . 47

TROUBLESHOOTING

Control Board Test Mode . . . . . . . . . . . . 49

Diagnosing an Ice Machine that Will Not Run

Ice Machine Does Not Cycle Into Harvest when Water Loses Contact with the Harvest

Float Switch . . . . . . . . . . . . . . . . . . . . . . . 51

Ice Machine Cycles Into Harvest Before Water loses Contact with the Harvest Float Switch

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Ice Production Check . . . . . . . . . . . . . . . 54

Installation/Vis ual Insp ecti on Che ckl ist 55

Water System Checklist . . . . . . . . . . . . . 56

Ice Formation Pattern . . . . . . . . . . . . . . . 57

Safety Limits . . . . . . . . . . . . . . . . . . . . 60

Analyzing Dischar ge Pressur e . . . . . . . . 67

Analyzing Suction Pressure . . . . . . . . . . 69

Harvest Valve . . . . . . . . . . . . . . . . . . . . . . 73

Comparing Evaporator Inlet/Outlet

Temperatures . . . . . . . . . . . . . . . . . . . . . . 77

Discharge Line Temperature Analysis . 78 Refrigeration Component Diagnostics . 80

Final Analysis . . . . . . . . . . . . . . . . . . . 82

Refrigeration Component Diagnostic Chart

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

10 Part Number 040005626 5/17

COMPONENT CHECK PROCEDURES

Main Fuse . . . . . . . . . . . . . . . . . . . . . . . . .87

Bin Switch . . . . . . . . . . . . . . . . . . . . . . . . .88

Float Switch . . . . . . . . . . . . . . . . . . . . . . .90

Compressor Electrical Diagnostics . . . .92

Fan Cycle Control . . . . . . . . . . . . . . . . . . .94

High Pressure Cutout (HPCO) Control . . 95

Refrigeration Components . . . . . . . . . . .96

Head Pressure Control Valve . . . . . . .96

Harvest Cycle Operation . . . . . . . . . . .97

Harvest Pressure Regula ting (HPR) System

Remote Condenser Only . . . . . . . . . . .100

Water Regulating Valve . . . . . . . . . . .103

Refrigerant Recovery/Evacuation . . . . . .104

Definitions . . . . . . . . . . . . . . . . . . . . . .104

Refrigerant Re-use Policy . . . . . . . . . . 105

Recovery and Recharging Procedures 107

System Contamination Cleanup . . . . . . .110

Refrigerant Amount . . . . . . . . . . . . . . . . . 116

CHARTS

Cycle Times, 24 Hr. Ice Production and

Refrigerant Pressure Charts . . . . . . . . . . 117

Determining Severity of Contamination 110 Mild System Contamination Cleanup

Procedure . . . . . . . . . . . . . . . . . . . . . .112

Severe System Contamination Cleanup

Procedure . . . . . . . . . . . . . . . . . . . . . .113

Replacing Pressure Controls without

Removing Refrigerant Charge . . . . . . .114

M0420A Self-contained Air-cooled . . .118 M0500A Self-contained Air-cooled . . .119 M0500W Self-contained Water-cooled 120 M0700A Self-contained Air-cooled . . .121 M0700W Self-contained Water-cooled 122 M1000A Self-contained Air-cooled . . .123 M1000W Self-contained Water-cooled 124 M1400A Self-contained Air-cooled . . .125

Part Number 040005626 5/17 11

DIAGRAMS

Wiring Diagrams . . . . . . . . . . . . . . . . . . . 127

Wiring Diagram Legend . . . . . . . . . . . 127

M0420,M0500, M0700, M1000 1 PH Self-

contained Air/Water-cooled . . . . . . . . 128

Electronic Control Board . . . . . . . . . . . 129

Refrigeration Tubing Schematics . . . . . 130

Self-contained Air or Water-cooled . . . 130

12 Part Number 040005626 5/17

General Information

Model Numbers

This manual covers the following models:

Self-Contained

Air-Cooled

Self-Contained

Water-Cooled

MD0420A MY0420A MD0500A

MD0500W MY0500A MD0700A

MD0600W MY0700A MD1000A MY1000A

MD1000W

MY1000W MD1400A ----

----

Remote

----

Part Number 040005626 5/17 13

How to Read a Model Number

Warning

A - Air-cooled W - Water-cooled

Series

Condenser

Type

Model

M D 0500 A E

R - Regular D - Dice Y - Half-dice

Cube Size

E - WRAS 50Hz

An ice machine contains high voltage electricity and refrigerant charge. Repairs are to be performed by properly trained refrigeration technicians aware of the dangers of dealing with high voltage electricity and refrigerant under pressure.

14 Part Number 040005626 5/17

Ice Machine Warranty Information

Important

Owner Warranty Registration Card General

Warranty coverage begins the day the ice machine is installed.

Complete and mail the OWNER WARRANTYREGISTRATION CARD as soon as possible to validate the installation date.

If the OWNER WARRANTY REGISTRA TION CARD is not returned, we will use the date of sale to the Distributor as the first day of warranty coverage for your new ice machine.

COMMERCIAL WARRANTY COVERAGE

Welbilt, (hereinafter referred to as the “COMPANY”) warrants for a period of thirty-six months from the installati on d ate (exc ep t as l im ited bel ow) tha t new ic e machines manufactured by the COMPANY shall be free of defects in material or workmanship under normal and proper use and maintenance as specified by the COMPANY and upon proper installation and start-up in accord anc e wi th the instruc ti on man ual supplied with the ice machine. The COMPANY’s warranty hereunder with respect to the compressor and evaporator shall apply for an additional twentyfour months, excluding all labor charges.

The obligat ion of the CO MPANY under this warranty is limited to the repair or replacement of parts, components, or assemblies that in the opinion of the COMPANY are defective. This warranty is further limited to the cost of parts, components or assemblies and standard straight time labor charges at the servicing location.

Part Number 040005626 5/17 15

Time and hourly rate schedules, as published from time to time by the COMPANY, apply to all service procedures. Additional expenses including without limita tion, travel time, overt ime premium , material cost, accessing or removal of the ice machine, or shipping are the responsibility of the owner, along with all maintenance, adjustments, cleaning, and ice purchases. La bor cover ed under this warranty must b e performed by a COMPANY Contracted Service Representative or a refrigeration service agency as qualified and authorized by the COMPANY’s local Distributor. The COMPANY’s liability under this warranty shall in no event be greater than the actual purchase price paid by customer for the ice machine.

The foregoing warranty shall not apply to (1) any part or assembly that has been altered, modified, or changed; (2) any part or assembly that has been subjected to misuse, abuse, neglect, or accidents; (3) any ice machine that has been installed and/or maintained inconsistent with the technical instructions provided by the COMPANY; or (4) any ice machine initially installed more than five years from the serial number produc tio n date . This warran ty shall not apply if the Ice Machine’s refrigeration system is modified with a condenser, heat reclaim device, or parts and assemblies other than those manufactured by the COMPANY, unless the COMPANY approves these modifications for specific locations in writing.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES OR GUARANTEES OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

COMPANY be liable for any special, indirect, incidental or consequential damages. Upon the expiration of the warranty period, the COMPANY’s liability under this warranty shall terminate. The foregoing warranty shall constitute the sole liability of the COMPANY and the exclusive remedy of the customer or user.

16 Part Number 040005626 5/17

In no event shall the

To secure prompt and continuing warranty service, the warranty registration card must be completed and sent to the COMPANY within five (5) days from the installation date.

Warranty Service

To comply with the provisions of the warranty, a refrigeration service comp any qual ified and authorize d by your M series distributor, or a Factory Authorized Servicer must perform the warranty repair.

Service Calls

Normal maintenance, adjustments and cleaning as outlined in this manual are not covered by the warranty.

Authorized

Part Number 040005626 5/17 17

RESIDENTIAL WARRANTY COVERAGE WHAT DOES THIS LIMITED WARRANTY COVER?

Subject to the exclus ions and limit ations b elow, Welbilt warrants to the original consumer that any new ice machine manu fac ture d by Welbilt (the “Product”) s ha ll be free of defects in material or workmanship for the warranty period outlined below under normal use and maintenance, and upon proper installation and startup in accordance with the instruction manual supplied with the Product.

HOW LONG DOES THIS LIMITED WARRANTY LAST?

Product CoveredWarranty Period Ice MachineTwelve (12) months from the sale date

WHO IS COVERED BY THIS LIMITED WARRANTY? This limited warranty only applies to the original

consumer of the Product and is not transferable.

WHA T ARE WELBILT’S OBLIGA TIONS UNDER THIS LIMITED WARRANTY?

If a defect arise s an d W e lbi lt rec ei ves a va li d w arran ty claim prior to the expiration of the warranty period, Welbilt shall, at its option: (1) repair the Product at Welbilt’s cost, including standard straight time labor charges, (2) replace the Product with one that is new or at least as functionally equivalent as the original, or (3) refund the purchase price for the Product. Replacement parts are warranted for 90 days or the balance of the original warranty period, whichever is longer. The foregoing constitutes Welbilt’s sole obligation and the consumer’s exclusive remedy for any breach of this limited warranty. Welbilt’s liability under this limited warranty is limited to the purchase price of Product. Additional expenses including, without limitation, service travel time, overtime or premium labor charges, accessing or removing the Product, or shipping are the responsibility of the consumer.

18 Part Number 040005626 5/17

HOW TO OBTA IN WARRANTY SERVICE To obtain warranty service or inform at ion regardi ng

your M series product, please contact: WELBIL T 2110 So. 26th St. P.O. Box 1720, Manitowoc, WI 5422 1-1 720 Telephone: 920-682-0161 Fax: 920-683-7585 WHAT IS NOT COVERED? This limited warranty does not cover, and you are

solely responsible for the costs of: (1) periodic or routine maintenance, (2) repair or replacement of the Product or parts due to normal wear and tear, (3) defects or damage to the Product or parts resulting from misuse, abuse, neglect, or accidents, (4) defects or damage to the Product or parts resulting from improper or un authori zed altera tions , modif icatio ns, or changes; and (5) defects or damage to any Product that has not been installed and/or maintained in accordance with the instruction manual or technical instructions provided by Welbilt. To the extent that warranty exclusions are not permitted under some state laws, these exclusions may not apply to you.

Except As Stated In The Following Sentence, This Limited Warranty Is The Sole And Exclusive Warranty Of Welbilt With Regard To The Product. All Implied Wa rranties Are Strictly Limited To The Duration Of The Limited Warranty Applicable To The Products As Stated Above, Including But Not Limited To, Any Warranty Of Merchantability Or Of Fitness For A Particular Purpose.

Some states do not allow limitations on how long an implied wa rranty la st s, so the ab ove limit atio n may not apply to you.

Continued on next page …

Part Number 040005626 5/17 19

In No Event Shall Welbilt Or Any Of Its Affiliates Be Liable To The Consumer Or Any Other Person For Any Inciden tal, Co nsequential Or S pe cial Damag es Of Any Kind (Including, Without Limitation, Loss Profits, Revenue Or Business) Arising From Or In Any Manner Connected With The Product, Any Breach Of This Limited Warranty, Or Any Other Cause Whatsoever, Whether Based On Contract, Tort Or Any Other Theory Of Liability.

Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.

HOW STATE LAW APPLIES This limited warranty gives you specific legal rights,

and you may also have rights that vary from state to state or from one jurisdiction to another.

REGISTRATION CARD To secure prompt and continuing warran ty service, this

warranty regist ration card must be completed and sent to Welbilt within thirty (30) days from the sale date. Complete the foll ow in g reg is trat ion card and se nd i t to Welbilt.

20 Part Number 040005626 5/17

Installation

Location of Ice Machine

The location selected for the ice machine must meet the following criteria. If any of these criteria are not met, select another location.

• The location must be indoors.

• The location must be free of airborne and other contaminants.

• Air temperature: Must be at least 40°F (4°C) but must not exceed 110°F (43.4°C).

• The location must not be near heat-generating equipment or in direct sunlight.

• The location must be capable of supporting the weight of the ice machine and a full bin of ice.

• The location must allow enough clearance for water, drain, and electr ica l co nne cti on s in the rear

of the ice machine.

• The location must not obstruct airflow through or around the ice mac hine co ndenser a ir flow is in the back and out the sides. Refer to the chart for clearance requirements.

• The ice machine must be protected if it will be subjected to temperatures below 32°F (0°C). Failure caused by exposure to freezing temperatures is not covered by the warranty.

Part Number 040005626 5/17 21

Ice Machine Clearance Requirements

Warning

Caution

Clearance Requirements

Do not obstruct ice machine vents or openings

M0420

M0500 -M0

M1000 -

M1400

Top/Sides 8" (20.3 cm) 8" (20.3 cm)

Back 5" (12.7 cm) 5" (12.7 cm)

*There is no minimum clearance required for water-cooled or remote ice machines. This value is recommended for efficient operation and servicing only.

700

Self-Contained

Air-Cooled

Water-Cooled

Remote*

and

The ice machine must be protected if it will be subjected to temperatures below 32°F (0°C). Failure caused by exposure to freezing temperatures is not covered by the warranty.

22 Part Number 040005626 5/17

Ice Machine Heat of Rejection

Caution

Heat of Rejection

Series

Ice Machine

Conditioning

Air

Peak

M0420 5400 6300 M0500 5300 6100 M0700 9000 13900 M1000 16250 18600 M1400 28300 34300

1 B.T.U./Hour 2 B ecause the heat of rejection varies during the ice making

cycle, the figure shown is an average.

Ice machines , like other re frigeration equip ment, reject heat through the condenser. It is helpful to know the amount of heat rejected by the ice machine when sizing air cond itioning eq uipment whe re self-con tained air-cooled ice machines are installed.

Leveling the Ice Machine

1. The leveling legs must be s crewed into the bottom of the bin as far as possible.

The legs must be screwed in tightly to prevent them from bending.

2. Move the bin into its final position.

3. Use a level on top of the bin. Adjust each foot as necessary and leve l from front to back and side to side.

Part Number 040005626 5/17 23

Electrical Requiremen ts

Warning

Voltage

The maximum allowable voltage variation is ±10% of the rated voltage on the ice machine model/serial number plate at start-up (when the electrical load is highest).

Fuse/Circuit Breake r

A separate fuse/circuit breaker must be provided for each ice machine.

Total Circuit Ampacity

The total circuit ampacity is used to help select the wire size of the electrical supply.

The wire size (or gauge) is also dependent upon location, materials used, length of run, etc., so it must be determined by a qualified electrician

Refer to ice machine data plate, for electrical requirements. The ice machine data plate information overrides all other published data.

All wiring must conform to local, state and national codes.

The ice mach ine mu st be grou nded in accord ance with national and local electrical code.

24 Part Number 040005626 5/17

Water Service/Drains

Important

Warning

WATE R SUPPLY

Local water conditions may require treatment of the water to inhibit scale formation, filter sediment, and remove chlorine odor and taste.

If you are installing a water filter system, refer to the Installation Instructions supplied with the filter system for ice making water inlet connections.

For ice making, connect to a potable water supply only.

WATER INLET LINES

Follow these guidelines to install water inlet lines:

• Do not connect the ice machine to a hot water supply . Be sure all hot w ater restrictors installed for other equipment are working. (Check valves on sink faucets, dishwashers, etc.)

• If water pres sure exc eeds the maximum recommend ed pre ssure, 80 psig (5.5 ba r) o bt a in a water pressure regulator from your Manitowoc distributor.

• Install a water shut-off valve for ice making potable water.

• Insulate water inlet lines to prevent condensation.

Part Number 040005626 5/17 25

DRAIN CONNECTIONS

Caution

Follow these guidelines when installing drain lines to prevent drain water from flowing back into the ice machine and storage bin:

• Drain lines m ust have a 1.5-inch drop p er 5 fe et of run (2.5 cm per meter), and must not create traps.

• The floor drain must be large enough to accommodate drainage from all drains.

• Install a tee to vent the ice machine drain to the atmosphere.

• Insulate drain lines to prevent condensation.

COOLING TOWER APPLICATIONS Water Cooled Models Only

A water-cooling tower installation does not require modification of the ice mac hin e. The water regu lat or valve for the condenser continues to control the refrigeration discharge pressure.

It is necessary to know the amount of heat rejected, and the pressure drop through the condenser and water valves (inlet to outlet) when using a cooling tower on an ice machine.

• Water entering the condenser must not exceed 90°F (32.2°C).

• Water flow through the condenser must not exceed 5 gallons (19 liters) per minute.

• Allow for a pressure drop of 7 psig (.48 bar) between the condenser water inlet and the outlet of the ice machine.

• Water exiting the condenser must not exceed 110°F (43.3° C).

Plumbing must conform to state and local codes

26 Part Number 040005626 5/17

WATER SUPPLY AND DRAIN LINE SIZING/ CONNECTIONS

Fitting

Ice Machine

T ubing Siz e Up to

Fitting

Ice Machine

3/8" (9.5 mm) min.

3/8" Female

inside diameter

Pipe Thread

3/8" (9.5 mm) min.

3/8" Female

inside diameter

Pipe Thread

3/8" (9.5 mm) min.

3/8" Female

inside diameter

Pipe Thread

—

Water

Pressure

80 psi (5.5 bar) max.

20 psi (1.38 bar) min.

150 psi (10.3 bar) max.

—

Water

Temperature

33°F (0.6°C) min.

90°F (32.2°C) max.

33°F (0.6°C) min.

90°F (32.2°C) max.

Part Number 040005626 5/17 27

Location

Water Inlet

Ice Making

Water Inlet

Condenser

Water Dra in

28 Part Number 040005626 5/17

This Page Intentionally Left Blank

Maintenance

Caution

Interior Cleaning and Sanitizing

GENERAL

Clean and sanitize the ice machine every six months for effici ent operation. If the ic e machine requires more frequent cleaning and sanitizing, consult a qualified service company to test the water quality and recommend appropriate water treatment.

The ice mach ine mus t be t a ke n ap art for cleaning and sanitizing.

Use only Manitowoc approved Ice Machine Cleaner (part number 94-0546-3) and Sanitizer (part number 94-0565-3). It is a violation of Federal law to use these solutions in a manner inconsistent with their labeling. Read and understand all labels printed on bottles before use.

CLEANING AND SANITIZING PROCEDURE

Ice machine cleaner is used to remove lime scale and mineral deposits. Ice machine sanitizer disinfects and removes algae and slime.

Part Number 040005626 5/17 29

TOGGLE SWITCH OPERATION

Caution

Warning

Moving the toggle switch to clean will start a Clean cycle.

• Setting the ice machine to stop after the clean cycle: Place the toggle switch in the clean position. The ice machine will stop after the clean cycle.

• Pausing the cleaning cycle: Move the toggle switch to Of f. Movi ng the toggle switch to clean will restart the clean cycle.

• Setting the ice machine to start ice making after the clean cycle: Place the toggle switch in the Ice positi on more than 2 minut es int o the c lean cycle.

Step 1 Place the toggle switch in the clean position after ice falls from the evaporator at the end of a Harvest cycle. Or, place the toggle switch in the off position and allow the ice to melt off the evaporator.

Never use anything to force ice from the evaporator. Damage may result.

Step 2 Remove all ice from the bin.

Wear rubber gloves and safety goggles (and/or face shield) when handling Ice Machine Cleaner or Sanitizer.

30 Part Number 040005626 5/17

Caution

Do not mix Ice Machine Cleaner and Sanitizer solutions together. It is a violation of Federal law to use these solutions in a manner inconsistent with their labeling.

Step 3 To start a cleaning cycle, move the toggle switch to Clean. Water will flow through the water dump valve and down the drain. Wait until the water trough refills, then add the proper amount of ice machine cleaner to the water trough.

Model Amount of Cleaner

M0420 3 ounces (90 ml)

M0500 M0700 M1000 5 ounces (150 ml)

M1400 9 ounces (265 ml)

Step 4 Wait until the clean cycle is complete (approximately 24 minutes) then place the toggle switch in the off position and disconnect power and water supplies to the ice machine.

Step 5 Remove parts for cleaning. Refer to the proper parts removal for your machine. Continue with step 6 when the parts have been removed.

Part Number 040005626 5/17 31

Step 6 Mix a solution o f clea ner and l ukewarm water. Depending on the amount of mineral buildup, a larger quantity of solution may be required. Use the ratio in the table below to mix enough solution to thoroughly clean all parts.

Solution Type Water Mixed with

Cleaner 1 gal. (4 l) 16 oz (500 ml) cleaner

Step 7 Use half of the clea ner/wate r solut ion to c lean all compo ne nt s . Th e c le aner solution will f oam whe n i t contacts lime scale and mineral deposits; once the foaming s tops use a sof t b r ist le bru sh , s pon ge or cl oth (not a wire bru sh) to ca refully c lean the p art s. Soak th e parts for 5 minu tes (15 – 20 minute s for heav ily scal ed parts). Rinse all components with clean water.

Step 8 Whil e component s are soaking , use half of the cleaner/water solution to clean all foodzone surfaces of the ice machin e and bin. Use a nylon brush or cl oth to thoroughly clean the following ice machine areas:

• Evaporator pl astic parts – including top, bottom and sides

• Bin bottom, sides and top

• Rinse all areas thoroughly with clean water.

32 Part Number 040005626 5/17

Step 9 Mix a solution of sanitizer and warm water.

Solution Type Water Mixed With

Sanitizer 3 gal. (12 l) 2 oz (60 ml) sanitizer

Step 10 Use half of the sanitizer/water solution to sanitize all remov ed co mpo n e nt s . Use a spray bot tle to liberally apply the solution to all surfaces of the removed parts or soak the removed parts in the sanitizer/water solution. Do not rinse parts after sanitizing.

Step 11 Use half of the sanitizer/water solution to sanitize all foodzone surfaces of the ice machine and bin. Use a spray bottle to liberally apply the solution. When sanitizing, pay particular attention to the following areas:

• Evaporator p lastic p arts - in cluding top , bottom and sides

• Bin bottom, sides and top

Do not rinse the sanitized areas. Step 12 Replace all removed components.

Step 13 Wait 25 minutes. Step 14 Reapply power a nd w ater to the i ce ma chine

and place the toggle switch in the ice position. Step 15 W a ter will flow throu gh the wate r dump valve

and down the drain. Wait until the water trough refills, then add th e proper a mount of ice mac hine sa nitizer to the water trough.

Model Amount of Sanitizer

M0420 M0500 M0700

M1000 M1350 6 ounces (180 ml)

3 ounces (90 ml)

Wa it until the sani tize cycle is complete (app roximately 24 minutes) then place the toggle switch in the ice position to start ice making.

Part Number 040005626 5/17 33

REMOVE PARTS FOR CLEANING

Warning

Disconnect electric power to the ice machine at the electric switch box before proceeding.

1. Remove the water curt ai n

• Gently flex the curtain in the center and remove it from the right side.

• Slide the left pin out.

2. Remove the water trough

• Depress t abs on ri ght and left side of the water trough.

• Allow front of water trough to drop as you pull forward to disengage the rear pins.

3. Remove the ice thickness and harvest float switches

• Pull the float switch straight down to disengage.

• Lower the float switch until the wiring connector is visible.

• Disconnect the wire lead from the float switch.

• Remove the float switch from the ice machine.

4. Remove the water distri buti on tube

NOTE: Distribution tube thumbscrews are retaine d to prevent loss. Loosen thumbscrews but do not pull thumbscrews out of distribution tube.

• Loosen the two outer screws (do not remove screws completely they are retained to prevent loss) and pull forward on the distri buti on tub e to release from slip joint.

• Disassemble distribution tube by loosening the two (2) middle thumbscrews and dividing the distribution tube into two pieces.

• Proceed to page 32 Step 6.

34 Part Number 040005626 5/17

5. Remove the Water Trough

• Depress tabs on right and left side of the water trough.

• Allow front of water trough to drop as you pull forward to disengage the rear pins.

• Remove the water trough from the bin area.

Part Number 040005626 5/17 35

Preventative Maintenance Cleaning

Caution

Warning

This cleaning procedure can be performed between the bi-annual cleaning and sanitizing cycles. This procedure does not require removing the ice from the bin.

Step 1 Place the to ggle s witch in the of f pos ition afte r ice falls from the evaporator at the end of a Harvest cycle. Or, place the toggle switch in the off position and allow the ice to melt off the evaporator.

Never use anything to force ice from the evaporator. Damage may result.

Wear rubber gloves and safety goggles (and/or face shield) when handling Ice Machine Cleaner or Sanitizer.

Step 2 To start a cleaning cycle, place the toggle switch in th e clean po sition. W a ter will flow through th e water dump valve and down the drain. Wait until the water trough refills, then add the proper amount of ice machine cleaner to the water trough.

Model Amount of Cleaner

M0420 3 ounces (90 ml)

M0500 M0700 M1000 5 ounces (150 ml)

M1400 9 ounces (265 ml)

Step 3 Wait until the clean cycle is complete (approximately 24 minutes) then place the toggle switch in the off position.

36 Part Number 040005626 5/17

Ice Machine Inspection

Check all water fittings and lines for leak s. Al so, mak e sure the refrigeration tubing is not rubbing or vibrating against other tubing, panels, etc.

There must be adequate airflow through and around the ice machine to maximize ice production and ensure long component life.

Exterior Cleaning

Clean the area around the ice machine as often as necessary to maintain cleanliness and efficient operation.

Sponge any dust and dirt off the outside of the ice machine with mild soap and water. Wipe dry with a clean, sof t clot h.

Cleanup any fallen ice or water spills as they occur.

Part Number 040005626 5/17 37

Cleaning the Condenser

Warning

General

Disconnect electric power to the ice machine head section and the remote condensing unit at the electric service switches before cleaning the condenser.

A dirty condenser restricts airflow, resulting in excessively high operating temperatures. This reduces ice production and shortens component life.

• Clean the condenser at least every six months.

The condenser fins are sharp. Use care when cleaning them.

• Shine a flashlight through the condenser to check for dirt between the fins.

• Blow compressed air or rinse with water from the inside out (opposite direction of airflow).

• If dirt still remains call a service agent to clean the condenser.

38 Part Number 040005626 5/17

Removal from Service/Winterization

AIR-COOLED MODELS

1. Clean and sanitize the ice machine.

2. Place the toggle switch in the off position to turn off the ice machine.

3. Turn off the water supply, disconnect and drain the incoming ice-making water line at the rear of the ice machine and dra in the water trough.

4. Energize the i ce m achin e, wait one minute for the water inlet valv e to open and blow co mpressed air in both the incomin g water and the dra in openings in the rear of the ice machine to remove all water.

5. Place the toggle switch in the off position and disconnect the electric power at the circuit breaker or the electric service switch.

6. Fill spray bottle with sanitiz er and spray all interior food zone surfaces. Do not rinse and allow to air dry .

7. Replace all panels.

WATER-COOLED MODELS

1. Perform steps 1-6 under “ Air-Cooled Models.”

2. Disconnect the incoming w ater and drai n line from the water-cooled condenser.

3. Energize the ice ma ch ine in the freeze cycle. The increasing ref rigerant pre ssure will ope n the water regulating valve .

4. Blow compressed air through the condenser until no water remains.

Part Number 040005626 5/17 39

40 Part Number 040005626 5/17

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Operation

Ice Making Sequence of Operation

NOTE: The toggle switch must be in the ON position and the water curtain must be closed before the ice machine will start.

Water Purge Cycle

The ice m ac hin e purg es an y rem ain ing w at er f rom the water trough down the drain.

Freeze Cycle

Prechill - The ref rigeration system chills the evaporat or before water flow over the evaporator starts. The water inlet valve energizes during the pre-chill and remains on until the ice thickness float switch is satisfied.

Freeze - Water flowing across the evaporator freezes and builds ice on the evaporator. After a sheet of ice has formed , the Harvest fl oat switch si gnals the co ntrol board to start a harvest cy cle.

Harvest Cycle

Any remaining water is purged down the drain as refrigerant gas warms the evaporator. When the evaporator warms, the sheet of cubes slides off the evaporator and into the storage bin. If all cubes fall clear of the water curtain, the ice machine starts another freeze cycle.

Full Bin Cycle

If the water curtain is held open by ice cubes the ice machine shuts off. When the water curtain closes the ice machine starts a new cycle at the water purge.

Part Number 040005626 5/17 41

CONTROL BOARD TIMERS

• The ice machine is locked into the freeze cycle for 6 minutes before a harvest cycle can be initiated. The freeze time lock in feature is bypassed on the initial cycle (manual start or after a full bin/safety limit conditio n). If the Harvest float Switch is in the down position for 10 continuous seconds during the start of a freeze cycle, a harvest sequence is initiated.

• The maximum freeze time is 60 minutes at which time the control board automatically initiates a harvest sequence.

• The maximum harvest time is 3.5 minutes. The control board automatically initiates a freeze sequence when these times are exceeded.

• The ice machine will continue to fill with with water for up to six minutes, or until the high water float opens for 5 continuous seconds. Th e control boa rd will energize the water inlet valve one more time 3 minutes into the freeze cycle.

42 Part Number 040005626 5/17

SAFETY LIMITS

Safety limits are stored and indicated by the control board. The number of cycles required to stop the ice machine varies for each safety limit.

Safety limits can be reset by cycling the toggle switch Off/On and starting a new ice making cycle.

A safety limit is indicated by a flashing light on the control board.

Safety Limit 1

If the freeze time reaches 60 minutes, the control board automatically initiates a harvest cycle.

• After 3 consecutive 60 minute cycles control board light SL#1 light will flash on/off at 1 second intervals.

• If 6 consecuti ve 60-mi nute freeze cycles occur, the ice machine stops and the SL#1 light on the control board will be on continuously.

Safety Limit 2

If the harvest time reaches 3.5 minutes, the control board automatically returns the ice machine to the freeze cycle.

• If three consecutive 3.5 minute harvest cycles occur the SL#2 light on the control board will flash on/off at 1 second intervals. After 75 consecutive

3.5 minutes harvest cycles the SL#2 light will be energized con tin uou sl y.

• If 100 consecutive 3.5 minute harvest cycles occur, the ice machine stops and the SL#2 light on the control board will be on continuously.

Part Number 040005626 5/17 43

Safety Limit 3

If the harvest float switch hasn’t opened for 10 continuous seconds w ithin 4 mi nutes of the water inlet valve energizing the ice machine stops.

• Safety Limit 3 is bypassed on the initial cycle (manual start or after a full bin/safety limit condition). For all subsequent cycles the ice machine sto p s for 30 minutes when the wat er i nle t valve is energized for 4 minutes and the harvest float valve didn’t open. Control board lights SL#1 and SL#2 will flash on/off at 1 second intervals.

• The ice machi ne auto matically res tarts at th e end of the 30 minute delay period and stops flashing the control board lights.

• If 100 consecutive failures occur the ice machine stops and the SL#1 & SL#2 lights flash on/off at 1 second intervals.

• SL#1 & SL#2 will flash 3 times on startup and automa tically erase after 100 normal cycles.

44 Part Number 040005626 5/17

Time

Length of

Float Switch

Ice Thickness

5 seconds

45 seconds

5 seconds

120

Seconds

initial cycle

Thereafter

60 seconds

Harvest

Float Switch

Motor*

Compressor

Condenser Fa n

Valve

Dump

Valve

Water Inlet

Valve

Harvest

Water Pump

ON ON OFF ON OFF CLOSED CLOSED

OFF OFF OFF OFF OFF CLOSED CLOSED

OFF ON OFF OFF OFF CLOSED CLOSED

OFF ON OFF OFF ON CLOSED CLOSED

OFF OFF ON OFF ON OPEN CLOSED

ENERGIZED PARTS CHART

Self-Contained Ice Machines

Part Number 040005626 5/17 45

ICE MAKING

Start-up

Pressure

OPERATION

SEQUENCE OF

Initial Start-up

1a. Water p urge

1b. Delay period

2a. Equalize

2. Refrigeration

System Start-up

2b. Compressor

3. Pre chill

Freeze Sequence

Until

Harvest

Float Swi tch

THEN

CLOSED

closes for

OPEN

10 continual

seconds

activation

Bin switch

45 seconds

Until bin

switch

re-closes

THEN

CLOSED

ON OFF ON OFF ON OPEN

4. Freeze

46 Part Number 040005626 5/17

ON ON OFF ON ON CLOSED CLOSED

Harvest

Sequence

5. Water Purge

OFF ON OFF OFF ON CLOSED CLOSED

6. Harvest

7. Automatic

OFF OFF OFF OFF OFF CLOSED CLOSED

Shut-off

* Condenser Fan Motor: The fan motor is wired through a fan cycle pressure control; therefore, it may cycle on and off.

Operational Checks

Ice Thickness Float

Switch Adjustment

ICE THICKNESS CHECK

After a harvest cycle, inspect the ice cubes in the ice storage bin. Th e ice bridge connec ts the ice cu bes and must be set to maintain an ice bridge thickness of 1/8" (3.2 mm). To adjust the thic kness of the bridg e refer to ice thickness adjustment.

The ice thicknes s fl oat s witch is f act ory-se t to maint ain the ice bridge thickness at 1/8" (3 mm).

NOTE: Make sure the water curtain is in place when performing this check. It prevents water from splashing out of the water trough.

1. Inspect the bridge connecting the cubes. It should be about 1/8" (3 mm) thick.

2. If adjustment is necessary, turn the ice thickness float switch clockwise to increase bridge thickness, counterclockwise to decrease bridge thickness. Adjust to achieve a 1/8" (3 mm) bridge thickness.

NOTE: The float can be adjusted with a 3/4" wrench while the water trough is in-place.Test run two cycles to verify ice bridge thickness.

Part Number 040005626 5/17 47

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Troubleshooting

Control Board Test Mode

NOTE: The water curtain/bin switch can be open or closed and does not effect the operation of the test mode.

To enter the test mode move the toggle switch to off, then press and hold the test button on the control board for 3 seconds. The control board test mode performs the following functions for a 2 minute time period:

• Energizes all control board relay s

• Energizes all control board lights After 2 minutes the control board will automatically

initiate and complete one ice making cycle, then stop.

Canceling a test cycle:

To cancel a test cycle press the test button a second time.

Restarting a test cycle:

The test cycle will restart each time the test button is pressed for a 3 second time period.

Part Number 040005626 5/17 49

Diagnosing an Ice Machine

Warning

that

NOTE: If any control board lights are on, the fuse is okay.

Will Not Run

High (line) voltage is applied to the control board at all times. Removing the control board fuse or cycling the toggle switch Off/On will not remove the power supplied to the control board.

1. Verify primary voltage is supplied to ice machine and the fuse/circuit breaker is closed.

2. Verify control board fuse is okay.

3. Verify the bin switch functions properly. A defective bin switch can falsely indicate a full bin of ice.

4. V erify togg le switch f unctions pr operly . A defective toggle switch may keep the ice machine in the OFF mode. Refer to toggle switch diagnostics when steps 1-3 tes t good.

5. Be sure Steps 1 – 4 were followed thoroughly. Intermittent problems are not usually related to the control board. Replace control board if toggle switch operation is correct.

50 Part Number 040005626 5/17

Ice Machine Does Not Cycle Into Harvest

HARVEST FLOAT SWITCH

ICE THICKNESS FLOAT

SWITCH

when Water Loses Contact with the Harvest Float Switch

NOTE: The ice machine will make a thick or double slab when a new freeze cycle is started with ice already present on the evaporator. Two of the most common scenarios are:

• Power is cycled off/on with ice on the evaporator.

• The water curtain/bin switch is opened/closed in

the harvest cycle before the ice releases.

Remove all ice from the evaporator before starting diagnostic procedures.

Freeze Time Lock-In Feature

The ice machine control system incorporates a freeze time lock-in feature. This prevents the ice machine from short cycling in and out of harvest. The control board locks the ice machine in the freeze cycle for six minutes. After six minutes a harvest cycle can be initiated. To allow the service technician to initiate a harvest cy cl e wi thou t delay, this feature is not use d o n the first cycle after moving the toggle switch to OFF and back to ON.

Part Number 040005626 5/17 51

Step 1 Disconnec t pow er to the ice mac hine, remov e the electrical panel to allow viewing of the control board lights. Disconnect the harvest float switch wire from the control board and place a jumper on the control board harvest switch terminals.

Step 2 Bypass the freeze time lock-in feature by moving the toggle switch Off/On to cycle the ice machine on. W ait until wate r flows ov er the evapo rator , then refer to chart.

Result Correction

10 seconds into the freeze cycle the ice machine cycles from freeze to harvest and the control board harvest light energizes.

The harvest light comes on, but the ice machine remains in the freeze cycle.

The harvest light stays off and the ice machine remains in freeze.

The ice thickness float switch, connectors or wiring are causing the malfunction.

The ice machine is in a 6 minute freeze lock - Cycle on/off and retest.

Replace the control board.

52 Part Number 040005626 5/17

Ice Machine Cycles Into Harvest Before

HARVEST FLOAT SWITCH

ICE THICKNESS FLOAT

SWITCH

Water loses Contact with the Harvest Float Switch

Step 1 Disconnec t pow er to the ice mac hine, remov e

the electrical panel to allow viewing of the control board lights and disconnect the harvest float switch from the control board.

Step 2 Reapp ly power an d mo ve the tog gle switc h to ice to bypass the freeze time lock-in feature. Wait until water flows over the evaporator, then refer to chart.

Result Correction

The harvest light does not come on and the ice machine stays in freeze.

10 seconds into the freeze cycle the ice machine cycles from freeze to harvest and the control board harvest light energizes.

The ice thickness float switch, connectors or wiring are causing the malfunction. Refer to fl o a t sw itch diagnostics.

Replace the control board.

Part Number 040005626 5/17 53

Ice Production Check

The amount of ice a machine produces directly relates to the operating water and air temperatures. This means an ice machine with a 70°F (21°C) ambient temperature and 50°F (10°C) water produces more ice than the same ice machine with 90°F (32°C) ambient and 70°F (21°C) water.

1. Determine the ice machine operating conditions: Air temp entering condenser: ____° Air temp around ice machine: ____° Water temp entering sump trough: ____°

2. Refer to the appropriate 24-Hour Ice Production Chart. Use the operating conditions determined in Step 1 to find published 24 hr. ice production:____

Times are in minutes. Example: 1 min., 15 sec. converts to 1.25 min. (15 seconds ÷ 60 seconds = .25 minutes)

Weights are in pounds. Example: 2 lb., 6 oz. converts to 2.375 lb. (6 oz. ÷16 oz. = .375 lb.)

3. Perform an ice production check using the formula below.

1. _______ + _______ = _______

Freeze Time Harvest Time Total Cycle Time

2. 1440 ÷ _______ = _______

Mins in 24 hrs Total Cycle Time Cycles Per Day

3. _______ x _______ = _______

Weight of One Cycles Per Day Actual 24 Hr

Harvest Production

Weighing the ice is the only 100% accurate check.

4. Compare the results of step 3 with step 2. Ice production is normal when these numbers match closely. If they match closely, determine if:

Another larger ice machine is required. Relocating the existing equipment to lower the load

conditions is required.

Contact the local distributor for information on available options and accessories.

54 Part Number 040005626 5/17

Installation/Visual Inspection Checklist

Ice machine is not level

• Level the ice machine

Condenser is dirty

• Clean the condenser

Water filtration is plugged (if used)

• Install a new water filter

Water drains are not run separately and/or are not vented

• Run and vent drains according to the Installation

Manual

Part Number 040005626 5/17 55

Water System Checklist

A water-related problem often causes the same symptoms as a refrigeration system component malfunction.

Example: A water dump valve leaking during the freeze cycle, a system low on charge, and a starving TXV have similar symptoms.

Water system problems must be identified and eliminated prior to replacing refrigeration components.

Water area (evaporator) is dirty

• Clean as needed

Water inlet pressure not between 20 and 80 psig (1–5 bar, 138–552 kPa)

• Install a water regulator valve or increase the water pressure

Incoming water temperature is not between 35°F (1.7°C) and 90°F (32.2°C)

• If too hot, check the hot water line check valves in other store equipment

Water filtration is plugged (if used)

• Install a new water filter

Vent tube is not installed on water outlet drain

• See Installation Instructions

Hoses, fittings, etc., are leaking water

• Repair/replace as needed

Water valve is stuck open, closed or is leaking

• Clean/replace as needed

Water is spraying out of the sump trough area

• Stop the water spray

Uneven water flow across the evaporator

• Clean the ice machine

Water is freezing behind the evaporator

• Correct the water flow

Plastic extrusions and gaskets are not secured to the evaporator

• Remount/replace as needed

56 Part Number 040005626 5/17

Ice Formation Pattern

INLET

OUTLET

Evaporator ice formation pattern analysis is helpful in ice machine diagnostics.

Analyzing the ice formation pattern alone cannot diagnose an ice machine malfunction. However, when this analysis is used along with the Refrigeration System Operational Analysis Table, it can help diagnose an ice machin e malfun ction.

Example of Ev aporato r Tubing Rout ing

Normal Ice Formation

Ice forms across the entire evaporator surface. At the beginning of the Freeze cycle, it may appear

that more ice is forming on the inlet of the evaporator than at the outlet. At the end of the Freeze cycle, ice formation at the outlet will be close to, or just a bit thinner than, ice formation at the inlet. The dimples in the cubes at the outlet of the evaporator may be more pronounced than those at the inlet. This is normal.

If ice forms uniformly across the evaporator surface, but does n ot do so in the pro per am ount o f time , this is still considered a normal ice fill pattern.

Part Number 040005626 5/17 57

Extremely Thi n at Evaporator Outlet

There is no ice, or a consi der able lack of ic e format ion on the outlet of the evaporator.

Examples: No ice at all at the outlet of the evaporator, but ice forms at the inle t hal f of th e evaporator. Or, the ice at the outlet of the evaporator reaches the correct thickness, but the outlet of the evaporator already has 1/2" to 1" of ice formation.

Possible cause: Water loss, low on refrigerant, starving TXV, faulty water inlet valve, etc.

Extremely Thin at Evaporator Inlet

There is no ice, or a consi der able lack of ic e format ion at the inlet of the eva porator. Examples: The ice at the outlet of the eva por ator reaches the correct th ic kn ess , but there is no ice formation at all at the inlet of the evaporator.

Possible cause: Insufficient water flow, flooding TXV, etc.

No Ice Formation

The ice machine operates for an extended period, but there is no ice formation at all on the evaporator.

Possible cause: water inlet valve, water pump, starving expansion valve, low refrigerant charge, compressor, etc.

58 Part Number 040005626 5/17

Evaporator Tubing Routing

Outlet

Inlet

Thin at Outlet

Thin at Inlet

ICE

Routing of the tubing on the back of the evaporator determines the ice fill pattern failure mode.

One Evaporator, One TXV Models

The evaporator outl et tubing does not exit directly at the top of the evaporator, but exits several inches below the top of the evaporator. Extremely Thin at the Evaporator Outlet will first be visible several inches below the top of the evaporator. Extremely Thin at Evaporator Inle t will first be visible at the bottom of the evaporator.

Part Number 040005626 5/17 59

SAFETY LIMITS

Safety limits are stored and indicated by the control board. The number of cycles required to stop the ice machine varies for each safety limit.

Safety limits can be reset by cycling the toggle switch Off/On and starting a new ice making cycle.

A safety limit is indicated by a flashing light on the control board.

Safety Limit 1

If the freeze time reaches 60 minutes, the control board automatically initiates a harvest cycle.

• After 3 consecutive 60 minute cycles control board light SL#1 light will flash on/off at 1 second intervals.

• If 6 consecuti ve 60-mi nute freeze cycles occur, the ice machine stops and the SL#1 light on the control board w i ll be on continuously.

Safety Limit 2

If the harvest time reaches 3.5 minutes, the control board automatically returns the ice machine to the freeze cycle.

• If three consecutive 3.5 minute harvest cycles occur the SL#2 light on the control board will flash on/off at 1 second intervals. After 75 consecutive

3.5 minutes harvest cycles the SL#2 light will be energized con tin uou sl y.

• If 100 consecutive 3.5 minute harvest cycles occur, the ice machine stops and the SL#2 light on the control board will be on continuously.

60 Part Number 040005626 5/17

Safety Limit 3

If the harvest float switch hasn’t opened for 10 continuous seconds w ithin 4 mi nutes of the water inlet valve energizing the ice machine stops.

• The ice machi ne auto matically res tarts at th e end of the 30 minute delay period and stops flashing the control board lights.

• If 100 consecutive failures occur the ice machine stops and the SL#1 & SL#2 lights flash on/off at 1 second intervals.

• SL#1 & SL#2 will flash 3 times on startup and automa tically erase after 100 normal cycles.

Part Number 040005626 5/17 61

Determining Which Safety Limit Stopped

Ice Machine:

the

1. Cycle the toggle switch Off.

2. Cycle the toggle switch On to start ice making.

3. Watch the safety limit lights.

• One will fla sh c orre sp ond ing to safety limi t s 1 or 2.

4. Safety limit 3 is indicated by both SL#1 & SL#2 flashing.

After safety li mit ind ication, th e ice m achin e will res tart and run until a safety limit is exceeded again.

Safety Limit Notes

• A continuous run of 100 harvests automatically erases the safety limit code.

• The co ntrol board will store and indicate only one safety limit – the last one exceeded.

• If the toggle switch is cycled OFF and then ON prior to reaching the 100-harvest point, the last safety limit exceeded will be indicated.

62 Part Number 040005626 5/17

Safety Limit Checklist

The following checklists are designed to assist the service technician in analysis. However, because there are many possible external problems, do not limit your diagnosis to only the items listed.

Safety Limit #1 Freeze time exceeds 60 minutes for 3 consecutive

freeze cycles.

Possible Cause Checklist

Improper installation

• Refer to “Installation/Visual Inspection Checklist” on page 55

Water System

• Float switch or water escaping water trough

• Low water pressure (20 psig min.)

• High water pressure (80 psig max.)

• High water temperature (90°F/32.2°C max.)

• Clogged water distrib uti on tube

• Dirty/defective water inlet valve

• Defective water pump

Electrical System

• Harvest cycle not initiated electrically

• Contactor not energizing

• Compressor ele ctri ca lly non-o pera tio nal

• Restricted condenser air flow

• High inlet air temperature (110°F/43.3°C max.)

• Condenser discha rge air re-c irc ula tio n

• Dirty condenser fins

• Defective fan cycling control

• Defective fan motor

• Dirty condenser

Part Number 040005626 5/17 63

Refrigeration System

• Non- OEM components

• Improper refrigerant charge

• Defect ive compressor

• TXV starving or flooding (check bulb mounting)

• Non-condensible in refrigeration system

• Plugged or restricted high side refrigerant lines or component

• Defective harvest valve

64 Part Number 040005626 5/17

Safety Limit #2 Harvest time exceeds 3.5 minutes for 100

Consecutive harvest cycles.

Possible Cause Checklist

Improper installation

• Refer to “Installation/Visual Inspection Checklist” on page 55.

Water System

• Water area (evaporator) dirty

• Dirty/defective water dump valve

• Vent tube not installed on water outlet drain

• Water freezing behind evaporator

• Plastic extrusions and gaskets not securely mounted to the evaporator

Electrical system

• Bin switch defective

• Premature harvest

Refrigeration system

• Non-OEM components

• Improper refrigerant charge

• Defective harvest valve

• TXV flooding (check bulb mounting)

• Defective fan cycling control

Part Number 040005626 5/17 65

Safety Limit 3 The harvest float switch hasn’t opened for 10

continuous seconds within 4 minutes of the water inlet valve energizing.

Possible Cause Checklist

Improper installation

• Refer to “Installation/Visual Inspection Checklist” on page 55.

Water System

• Water dump va lve

• Harvest float valve dirty or defective

• Low water pressure (20 psig min.)

• Dirty defective water filter (when used)

• Loss of water from sump area

• Dirty/defective water inlet valve

Electrical system

• Water inlet valve coil defective

• Harvest float valve defective

66 Part Number 040005626 5/17

Analyzing Discharge Pressure

1. Determine the ice machi ne ope rati ng con di tion s: Air temp. entering condenser ______ Air temp. around ice machine ______ Water temp. entering sump trough ______

2. Refer to “Cycle Times, 24 Hr. Ice Production and Refrigerant Pressure Charts” on page 117 for ice machine being checked.

Use the operating conditions determined in step 1 to find the published normal discharge pressures.

Freeze Cycle ______ Harvest Cycle ______

3. Perform an actual discharge pressure check.

Beginning of

Cycle

Middle of

Cycle

End of

Cycle

Freeze

Cycle PSIG

__________ __________

Harvest

Cycle PSIG

4. Compare the actual discharge pressure (step 3) with the published discharge pressure (step 2).

The discharge pressure is normal when the act ual pressure falls within the published pressure range for the ice mach in e’s operating conditions. It is normal for the dischar ge pressure to be high er at the beginnin g of the freeze cycle (when load is greatest), then drop through out the freeze cy cl e.

Part Number 040005626 5/17 67

Discharge Pressure High Checklist

Improper Installation

• Refer to “Installation/Visual Inspection Checklist” on page 55.

Condenser Air Flow

• High inlet air temperature

• Condenser discha rge air re-c irc ula tio n

• Dirty conden se r fins

• Defective fan cycling control

• Defective fan motor

Improper Refrigerant Charge

• Overcharged

• Non-condensible in system

• Wrong type of refrigerant

Other

• Non-OEM components in system

• High side refrigerant lines/component restricted (before mid-condenser)

Freeze Cycle Discharge Pressure Low Checklist

Improper Installation

• Refer to “Installation/Visual Inspection Checklist” on page 55.

Improper Refrigerant Charge

• Undercharged

• Wrong type of refrigerant

Other

• Non-OEM components in system

• High side refrigerant lines/component restricted (before mid-condenser)

• Defective fan cycle con trol

NOTE: Do not limit your diagnosis to only the items listed in the checkli st s .

68 Part Number 040005626 5/17

Analyzing Suction Pressure

The suction pressure gradually drops throughout the freeze cycle. The actual suction pressure (and drop rate) changes as the air and water temperature entering the ice machine changes. These variables also determine the freeze cycle times.

To analyze and identify the proper suction pressure drop throughout the freeze cycle, compare the published suction pressure to the published freeze cycle time.

NOTE: Analyze discharge pressure before analyzing suction press ure . H igh or lo w dis c harg e pre ss ure ma y be causing high or low suction pressure.

Part Number 040005626 5/17 69

Procedure

Step

1. Determine the ice machine operating conditions.

Example: Air temp. entering condenser: 90°F/32.2°C Air temp. around ice machine: 80°F/26.7°C Water temp. entering water fill valve: 70°F/21.1°C

2A. Refer to “Cycle Time” and “Operating Pressure” charts for ice machine model being checked. Using operating conditions from Step 1, determine published freeze cycle time and published freeze cycle suction pressure.

Example: Published freeze cycle time: 14.8 - 15.9 minutes Published freeze cycle suction pressure: 65 - 26 psig

2B. Compare the published freeze cycle time and published freeze cycle suction pressure. Develop a chart.

Example: Published Freeze Cycle Time (minutes)

1247101214

|||||||

65 55 47 39 34 30 26

Published Freeze Cycle Suction Pressure (psig) In the example, the proper suction pressure should be approximately 39 minutes; etc.

psig at 7 minutes; 30 psig at 12

3. Perform an actual suction pressure check at the beginning, middle and end of the freeze cycle. Note the times at which the readings are taken.

Example: Manifold gauges were connected to the example ice machine and suction pressure readings taken as follows: ________ PSIG Beginning of Freeze cycle: 79 (at 1 min.) Middle of freeze cycle: 48 (at 7 min.) End of freeze cycle: 40 (at 14 min.)

4. Compare the actual freeze cycle suction pressure (Step

3) to the published freeze cycle time and pressure comparison (Step 2B). Determine if the suction pressure is high, low or acceptable.

Example: In this example, the suction pressure is considered high throughout the freeze cycle. It should have been: Approximately 65 psig (at 1 minute) – not 79 Approximately 39 psig (at 7 minutes) – not 48 Approximately 26 psig (at 14 minutes) – not 40

70 Part Number 040005626 5/17

Suction Pressure High Checklist

Improper Installation

• Refer to “Installation/Visual Inspection Checklist” on page 55.

Discharge Pressure

• Discharge pressure is too high, and is affecting suction pressure, refer to

“Discharge Pressure

High Checklist” on page 68.

Improper Refrigerant Charge

• Overcharged

• Wrong type of refrigerant

• Non-condensible in system

Other

• Non-OEM components in system

• Harvest valve leaking

• TXV flooding (check bulb mounting)

• Defect ive compressor

Part Number 040005626 5/17 71

Suction Pressure Low Checklist

Improper Installation

• Refer to “Installation/Visual Inspection Checklist” on page 55.

Discharge Pressure

• Discharge pressure is too low, and is affecting suction press ure, refer to “Fre eze Cycle Disc harge Pressure Low Checklist”

Improper Refrigerant Charge

• Undercharged

• Wrong type of refrigerant

Other

• Non-OEM components in system

• Improper water supply over evaporator refer to “Water System Checklist” on page 56.

• Loss of heat transfer from tubing on back side of evaporator

• Restricted/plugged liquid line drier

• Restricted/plugged tubing in suction side of refrigeration system

• TXV starving

NOTE: Do not limit your diagnosis to only the items listed in the checkli st s .

72 Part Number 040005626 5/17

Harvest Valve

General

The harvest v alve is an elec trically operate d val ve tha t opens when energized, and closes when de-energized.

Normal Operation

The valve is de-energized (closed) during the freeze cycle and energized (open) during the harvest cycle. The valve is positioned between the compressor discharge line and the evaporator and performs two functions:

1. Prevents refrigerant from entering the evaporator during the freeze cycle.

The harvest valve is not used during the freeze cycle. The harvest valve is de-energized (closed) preventing refrigerant flow from the receiver into the evaporator.

2. Allows refriger ant va por to en ter the e vapora tor in the harvest cycle.

During the harvest cycle, the harvest valve is energized ( open) allowing refrigerant gas from the discharge line of the compressor to flow into the evaporator. The heat is absorbed by the evaporator and allows release of the ice slab.

Exact pressures vary according to ambient temperature and ice machine model. Harvest pressures c an be f ound in the Cycle Time/24 Hour Ice Production/ Refrigerant Pressure Charts in this book.

Part Number 040005626 5/17 73

Harvest Valve Analysis

The valve can fail in two positions:

• Valve will not open in the harvest cycle.

• Valve remai ns open d uring the freeze cycle. VALVE WILL NOT OPEN IN THE HARVEST CYCLE

Although the ci rcuit board has initi ated a harvest cy cle, the evaporator temperature remains unchanged from the freeze cycle.

VALVE REMAINS OPEN IN THE FREEZE CYCLE: Symptoms of a harvest valve remaining partially open

during the freeze cycle can be similar to symptoms of an expansion valve or compressor problem. Symptoms are de pendent on th e amount of l eakage in the freeze cycle.

A small amount of leakage w ill cause increased freeze times and an ice fill pattern that is “Thin at the Outlet”, but fills in at the end of the cycle.

As the amount of leakage increases the length of the freeze cycle increases and the amount of ice at the outlet of the evaporator decreases.

Refer to the Parts Manua l for prope r valve applicati on. If replacement is necessary, use only “original” replacement parts.

74 Part Number 040005626 5/17

Use the following procedure and table to help

Important

Warning

determine i f a harvest va lve is re maining partial ly open during the freeze cycle.

1. Wait five minutes into the freeze cycle.

2. Feel the inlet of the harvest valve(s).

Feeling the harvest valve outlet or across the harvest valve itself will not work for this comparison.

The harvest valve outlet is on the suction side (cool refrigerant). It may be cool enough to touch even if the valve is leaking.

3. Feel the compressor discharge line.

The inlet of the harvest valve and the compressor discharge line could be hot enough to burn your hand. Just touch them momentarily.

4. Compare the temperature of the inlet of the harvest valves to the temperature of the compressor discharge line.

Part Number 040005626 5/17 75

Findings Comments

The inlet of the harvest valve is cool enough to

touch and the compressor

discharge line is hot.

Cool & Hot

The inlet of the harvest

valve is hot and approaches

the temperature of a hot

compressor discharge line.

Hot & Hot

This is normal as the

discharge line should

always be too hot to touch

and the harvest valve inlet,

although too hot to touch

during harvest, should be

cool enough to touch after 5

minutes into the freeze

cycle.

This is an indication

something is wrong, as the

harvest valve inlet did not

cool down during the freeze

cycle. If the compresso r

dome is also entirely hot,

the problem is not a harvest

valve leaking, but rather

something causing the

compressor (and the entire

ice machine) to get hot.

Both the inlet of the harvest

valve and the compressor

discharge line are cool

enough to touch.

This is an indication

something is wrong, causing

the compressor discharge

line to be cool to the touch.

This is not caused by a

Cool & Cool

harvest valve leaking.

5. Record your findin gs on the t abl e.

76 Part Number 040005626 5/17

Comparing Evaporator Inlet/Outlet

Important

Temperatures

The temperatures of the suction lines entering and leaving the evaporator alone cannot diagnose an ice machine. How eve r, comparing these temperat ures during the freeze cycle, along with the Refrigeration System Op erational Anal ysis Table, can hel p diagnose an ice machine malfunction.

The actual temperatures entering and leaving the evaporator va ry by model, an d cha nge throughout the freeze cycle. This makes documenting the “normal” inlet and outlet temperature readings difficult. The key to the diagnosis lies in the difference between the two temperatures five minutes into the freeze cycle. These temperatures must be within 7°F (4°C) of each other.

Use this proc edu re to doc um ent free ze c yc le inl et a nd outlet temperatures.

1. Use a quali ty temperature meter, capable of taking temperature readings on curved copper lines.

2. Attach the temperature meter sensing device to the copper lines entering and leaving the evaporator.

Do not simply insert the sensing device under the insulation. It must be attached to and reading the actual temperature of the copper line.

3. Wait five minutes into the freeze cycle.

4. Record the temperatures below and determine the difference between them.

___________ ___________ ___________

Inlet

Temperature

Difference must be

within 7°F (4°C) at

minutes into the

freeze cycle

Outlet

Temperature

5. Use this with other information gathered on the Refrigeration System Operational Analysis Table to determine the ice machine malfunction.

Part Number 040005626 5/17 77

Discharge Line Temperature Analysis

GENERAL Knowing if the discharge line temperature is

increasing, decreasing or remaining constant can be an important diagnostic tool. Maximum compressor discharge l ine temp erature on a norm ally operat ing ice machine steadily increases throughout the freeze cycle. Comparing the temperatures over several cycles will resul t in a consistent maximum di scharge line temperature.

Ambient air temperatures affect the maximum discharge line temperature.

Higher ambient air temperatures at the condenser = higher discharge line temperatures at the compressor.

Lower ambient air temperatures at the condenser = lower discharge line temperatures at the compressor.

Regardless of ambient temperature, the freeze cycle discharge line temperature will be higher than 150°F (66°C) on a normally operating ice machine.

PROCEDURE Connect a temperature probe on the compressor

discharge line within 6" (15 cm) of the compressor. Observe the discharge line temperature for the last three minutes of the freeze cycle and record the maximum discharge line temperature.

78 Part Number 040005626 5/17

Discharge Line Temperature Above 150°F (66°C) a t End of Freeze Cycle:

Ice machines that are operating normally will have consistent maximum discharge line temperatures above 150°F (66°C).

Verify the expansion valve sensing bulb is positioned and secured correctly.

Discharge L ine Temperature Below 150 °F (66°C) at End of Freeze Cycle

Ice machines that h ave a floodi ng ex pan sion valve will have a maximum discharg e line temperature that decreases each cycle.

Verify the expansion valve sensing bulb is 100% insulated and sealed airtight. Condenser air contacting an incorrectly insulated sensing bulb will cause overfeeding of the expansion valve.

Part Number 040005626 5/17 79

Refrigeration Component Diagnostics

All electrical and water related problems must be corrected b efore these cha rts will w ork properly. These tables must be used with charts, checklists and other references to eliminate refrigeration components not listed and external items and problems that will cause good refrigeration components to appear defective.

The tabl es list fo ur dif fer ent def ect s that may af fect th e ice machine’s operation.

NOTE: A low-on-charge ice machine and a starving expansion valve have very similar characteristics and are listed under the same column.

80 Part Number 040005626 5/17

PROCEDURE Step 1 Complete each item individually in the

“Operational Analysis” column. Enter check marks (✓) in the boxes. Each time the actual findings of an item in the

“Operational Analysis” column matches the published findings on the table, enter a check mark.

Example: Freez e cycle s uction pres sure is de termined to be low. Enter a check mark in the “low” box.

Perform the procedures and check all information listed. Each item in this column has supporting reference material.

While analyzing each item separately, you may find an “external problem” causing a good refrigerant component to appear bad. Correct proble m s as th ey

are found. If t he o pe rational problem i s fo un d, it is not necessary to complete the remaining procedures.

Step 2 Add the check marks listed under each of the

four columns. Note the column number with the highest total and proceed to “Final Analysis.”

NOTE: If two columns have matching high numbers, a procedure was not performed properly and/or supporting materi al was not ana ly ze d correc tl y.

Part Number 040005626 5/17 81

FINAL ANALYSIS

The column with the highest number of check marks identifies the refrigeration problem.

Column 1 – Harvest Valve Leaking

A leaki ng harvest valve must be replaced.

Colum n 2 – Low Charge/TXV Starving

Normally, a starving expansion valve only affects the freeze cycle pressures, not the harvest cy cle pressures. A low refrigerant charge normally affects both pressures. Verify the ice machine is not low on charge before replacing an expansion valve.

Add refrigerant charge in 2 oz. increments as a diagnostic procedure to verify a low charge. (Do not add more than the total charge of refrigerant). If the problem is corrected, the ice machine is low on charge. Find the refrigerant leak.

The ice machine must operate with the nameplate charge. If the leak cannot be found, proper refrigerant procedures must still be followed. Change the liquid line drier , ev acuate the system and weigh in th e proper charge.

If the problem is not corrected by adding charge, the expansion valve is faulty.

Column 3 – TXV Flooding

A loose or improperly mounted expansion valve bulb causes the expansion valve to flood. Check bulb mounting, insulation, etc., before changing the valve.

Column 4 – Compressor

Replace the compressor and start components. To receive warranty credit, the compressor ports must be properly sealed by crimping and soldering them closed. Old start components must be returned with the faulty compressor.

82 Part Number 040005626 5/17

Refrigeration Component Diagnostic Chart

normal

Ice formation is

before proceeding with chart.

Ice formation is

-or-

extremely thin on

normal

outlet of

-or-

ice formation is

evaporator

on entire

No ice formation

the bottom of the

extremely thin on

-or-

No ice formation

evaporator

evaporator or

No ice formation

on entire

on evaporator

evaporator

production is within 10% of charted capacity.

Published 24 hour ice production ____________

Calculated (actual) 24 hour ice production ____________

Note: The ice machine is operating properly if the ice fill patterns is normal and ice

Analysis

Operational

Ice Production

All installation and water related problems must be corrected

Water system

Installation and

Ice formation is

extremely thin on

outlet of evaporator

Ice Formation

-or-

Pattern

No ice formation

on entire

evaporator

Part Number 040005626 5/17 83

Stops on

safety limit:

High

Suction

pressure is

1 or 2

Stops on

safety limit:

St ops on

safety limit:

1 or 2

Stop s on

safety limit:

and/or components not listed on this table before proceeding.

low discharge pressure problem checklist to eliminate problems

If discharge pressure is High or Low, refer to freeze cycle high or

suction pressure problem checklist to eliminate problems and/or

If suction pressure is High or Low refer to freeze cycle high or low

components not listed on this table before proceeding.

Suction

pressure is

Suction

pressure is

Suction

pressure is

High

Low

High

Safety limits

Operational Analysis

Refer to “Ana lyzing Safety

Limits” to eliminate all non-

84 Part Number 040005626 5/17

_______

Freeze cycle

refrigeration problems.

Discharge Pressure

Freeze cycle

_______ _______

1 minute Middle End

_______

Suction Pressure

_______ _______

1 minute Middle End

The harvest valve

inlet is

COOL

and

The compressor

HOT

discharge line is

temp 150°F

Discharge line

at the end of

(66°C) or higher

freeze cycle

Compressor

The harvest valve

inlet is

COOL

inlet is

COOL

HOT

inlet is

and

discharge line is

The compressor

discharge line is

The compressor

discharge line is

The compressor

COOL

HOT

Discharge line

temp less than

temp 150°F

Discharge line

temp 150°F

Discharge line

150°F (66°C) at

(66°C) or higher

cycle

the end of freeze

freeze cycle

at the end of

freeze cycle

at the end of

TXV Flooding

-orTXV Starving

Low On Charge

Leaking

Harvest Valve

Operational Analysis

Part Number 040005626 5/17 85

Harvest Valve

end of freeze cycle.

Record freeze cycle

Discharge Line Temp.

discharge line temp at the

Final Analysis

each column.

boxes checked in

Enter total number of

86 Part Number 040005626 5/17

This Page Intentionally Left Blank

Component Check Procedures

Warning

Main Fuse

Function

The control board fuse stops ice machine operation if electrical components fail causing high amp draw.

Specifications

• The main fuse is 250 Volt, 3.15 amp.

High (line) voltage is applied to the control board at all times. Removing the control board fuse or cycling the toggle switch Off/On will not remove the power supplied to the control board.

Check Procedure

1. If the curtain light is on with the water curtain closed, the fuse is good.

Disconnect electrical power to the entire ice machine before proceeding.

2. Remove the fuse. Check the resistance across the fuse with an ohmmeter.

Reading Result

Open (OL) Replace fuse

Closed (O) Fuse is good

Part Number 040005626 5/17 87

Bin Switch

Important

Function

Bin switch operation is controlled by the movement of the water curtain. The bin switch has two main functions:

1. Terminating the harvest cycle and returning the ice machine to the freeze cy cl e.

This occurs when the bin switch is opened and closed ag ain withi n 3 0 s eco nds of opening during the harvest cycle.

2. Automatic ice machine shut-off. If the storage bin is full at the end of a harvest

cycle, the sheet of cubes fails to clear the water curtain and holds it down. After the water curtain is held down for 30 seconds, the ice machine shuts off.

The ice machine remains off until enough ice is removed from the storage bin to allow the sheet of cubes to drop clear of the water curtain. As the water curtain swings back to the operating position, the bin switch closes and the ice machine restarts.

The water curtain must be up (bin switch cl osed) to start ice making.

Check Procedure

1. Cycle the toggle switch OFF.

2. Watch the curtain light on the control board.

3. Move the water curtain upward, toward the evaporator. The bin switch must close. The curtain light “on” indicates the bin switch has closed properly.

4. Move the water cu rtai n awa y from the ev aporat or. The bin switch must open. The curtain light “off” indicates the bin switch has opened properly.

88 Part Number 040005626 5/17

Ohm Test

1. Disconnect the bin switch wires from the control board.

2. Connect an ohmmeter to the disconnected bin switch.

3. Cycle the bin switch open and closed numerous times by openin g and clo si ng the water curtain.

NOTE: To prevent misdiagnosi s:

• Always use the water curtain magnet to cycle the switch (a larger or sm aller magnet will affect swi tch operation).

• Wa tch f or co nsi st ent re adi ngs when the bi n sw it ch is cycled open and closed (bin switch failu re co uld be erratic).

Part Number 040005626 5/17 89

Float Switch

Function

Open and close to indicate to the control board the level of water in the water trough.

Specifications

Normally closed, float operated magnetic reed switch. The float switch contacts are closed in the down

position. W hen wate r raise s the float to t he up p ositio n the magnet in the float opens the contacts.

Check Procedure

The ice machine uses two float switches. Ice Thickness Float -Indicates the water level has

been reached. Harvest Float - Indicates a harvest cycle needs to be

initiated. Initial testing can be performed by viewing the control

board light(s) while raising and lowering the float. The corresponding control board light must turn on and off when the float is raised and lowered.

Harvest Float switch:

A. The light must be on in the up position. B. The light must be off in the down position.

Ice Thickness Float Switch:

A. The light must be off in the down position. B. The light must be on in the up position.

90 Part Number 040005626 5/17

If the control board light does not respond to the float

ICE

THICKNESS

FLOAT

WATER

LEVEL FLOAT

proceed with step 1 below.

1. Disconnect pow er to the ice m ach in e and pu ll the float switch and connector through the ice machine base and disconnect.

2. Attach an ohm meter lead to each float switch wire.

3. Place the float in the down position - The float switch must be close d.

4. Place the float in the up p ositio n - The flo at switc h must be open.

5. If the float tests good, ohm the interconnecting wires to the control board and inspect connectors.

NOTE: Make adjustments with the ice machine in the off position. Making adjustments during the freeze cycle may produce an initial sheet of ice that is thicker than future cycles.

Part Number 040005626 5/17 91

Compressor Electrical Diagnosti cs

The compressor does not start or will trip repeatedly on overload.

Check Resistance (Ohm) Values

NOTE: Compressor windings can have very low ohm values. Use a properly calibrated meter.

Perform the resistance test after the compressor cools. The compressor dome should be cool enough to touch (below 120°F/49°C) to ensure that the overload is closed and the resistance readings will be accurate.

Single Phase Compressors

1. Disconnect power and remove the wires from the compressor terminals.

2. The resistance values between C and S and between C and R, when added together should equal the resistance value between S and R.

3. If the overload is open, there will be a resistance reading between S and R, and open readings between C and S an d betwe en C and R. Allow the compressor to cool, then check the readings again.

Check Motor Windings to Ground

Check continuity between all three terminals and the compressor shell or copper refrigeration line. Scrape metal surface to get good contact. If continuity is present, the compressor windings are grounded and the compressor should be replaced.

To determine if the compressor is seized check the amp draw while the compressor is trying to start.

92 Part Number 040005626 5/17

Compressor Drawing Locked Rotor

The two likely causes of this are:

• Defective starting component

• Mechanicall y sei ze d com pre ss or To determine which you have:

1. Install high and low side gauge.

2. Try to start the compressor.

3. Watch the pressures closely.

• If the pressures do not move, the compressor is seized. Replace the compressor.

• If the pressures move, the compressor is turning slowly and is not seized. Check the start components.

Compressor Drawing High Amps

The contin uous ampe rage dr aw o n st art-up shou ld no t be near the ma xi mu m fuse size indica ted on the se rial tag.

The wiring mus t be correc tly siz ed to mi nimiz e volt age drop at compressor start-up. The voltage when the compressor is trying to start must be within ±10% of the nameplate voltage.

Part Number 040005626 5/17 93

Fan Cycle Control

Function

Cycles the fan motor on and off to maintain proper operating discharge pressure.

The fan cycle control closes on an increase, an d opens on a decrease in discharge pressure.

Specifications

Cut-In

(Close)

335 psig ±5 275 psig ±5

Cut-Out

(Open)

Check Procedure

Disconnect electrical power to the ice machine at the electrical service disconnect.

Verify fan motor windings are not open or grounded, and fan spins freely.

Connect man ifo ld gau ge to ice mach ine . Hook voltme ter in p aralle l acros s the fan cyc le cont rol,

leaving wires attached. Reconnect electrical power to the ice machine and

Cycle the toggle switch On. Wa it until water flow s over the e vapora tor then ref er to

chart below.

System

Pressure:

above cut-in 0 volts running

below cut-out line voltage off

94 Part Number 040005626 5/17

Reading

Should Be:

Fan Should

Be:

High Pressure Cutout (HPCO) Control

Warning

Function

Stops the ice machine if subjected to excessive highside pressure.

The HPCO con trol is n ormall y c los ed , and ope ns on a rise in discharge pressure.

Specifications

Cut-out: 600 psig ±10 Cut-in: 450 psig ±10 (Must be below 450 psig to reset).

Check Procedure

1. Move toggle switch to OFF.

2. Connect manifold gauge.

3. Hook voltmeter in parallel across the HPCO, leaving wires attached.

4. On water-cooled models, close the water service valve to the water condenser inlet. On selfcontained air-cooled models, disconnect the fan motor.

5. Move toggle switch to ON.

6. No water or ai r fl ow in g t hrou gh the c ond ens er will cause the HPCO control to open because of excessive pressure. Watch the pressure gauge and record the cut-out pressure.

If discharge pressure exceeds 600 psig and the HPCO control does not cut out, cycle the toggle switch Off t o stop ice machine operation.

Replace the HPCO control if it:

• Will not reset (below 450 psig)

• Does not open at the specified cut-out point

Part Number 040005626 5/17 95

Refrigeration Components

HEAD PRESSURE CONTROL VALVE

Manitowoc remote systems require head pressure control valves wi th spe cial setti ngs . Repl ac e defe cti ve head pressure control valves only with “original” Manitowoc replacement parts.

Refrigerant Charge Verification

The correct amo unt of ref r ige ran t (na me p late c harg e) is required to operate correctly at all ambient conditions.

An ice machine with an ov ercharge or undercharge of refrigerant may function properly at higher ambient temperatures and fails at lowe r ambient tempe ratu res. Symptoms of incorrect refrigerant amount are:

• Works during the day and malfunctions at night, and/or fails whenever the outdoor temperature drops.

• A Safety limit is stored in control board memory.

Refrigerant loss and ambient temperature are directly related to each other. As the ambient temperature drops, more refrigerant is stored in the condenser.

When the refrige rant charge an d ambient temp erature create an undercharge of refrigerant in the freeze cycle, the receiver dip tube will lose it’s liquid seal. Without liquid refrigerant to the TXV, the ice machine fails to make a full sheet of ice in 60 minutes and a safety limit #1 results.

NOTE: When a head pressure control valve is being replaced or refrigerant charge is suspected, verify the refrigerant charge is correct by recovering the refrigerant, weighing and comparing to the nameplate amount. Refer to Refrigerant Recovery/Evacuation” for recovery procedures.

96 Part Number 040005626 5/17

Freeze Cycle Operation All Models

The head pressure control valve is non adjustable. At ambient temper atures of approximately 70° F (21°C)

or above, refrigerant flows through the valve from the condenser to the re ceive r inlet. At tempe ratures below this (or at higher te mp eratures if i t is rain ing), th e head pressure control dome’s nitrogen charge closes the condenser port and opens the bypass port from the compressor discharge line.

In this modu lating mo de, the val ve maint ains m inimum head pressure by building up liquid in the condenser and bypassing discharge gas directly to the receiver.

HARVEST CYCLE OPERATION

Remote Condenser Models

The head pressure control cycles into full bypass due to the pressure drop when the harvest valve opens. Refrigerant flows from the compressor to the evaporator through the harvest valve and the head pressure valve is out of the circuit.

Diagnostics

FREEZE CYCLE - REMOTE CONDENSER

1. Determine if the coil is clean.

2. Determine the air temperature entering the condenser.

3. Determine if the head pressure is high or low in relationship to the outside temperature. (Refer to the proper “Cycle Times/24-Hour Ice Production/ Refrigerant Pressure Charts”).

4. Determine the temperature of the liquid line entering the receiver by feeling it. This line is normally warm; “body temperature.”

5. Using the information gathered, refer to the chart.

Part Number 040005626 5/17 97

NOTE: A head pressure control valve that will not bypass, will function properly with condenser air temperatures of approximately 70°F (21°C) or above. When the temperature drops below 70°F (21°C), the head press ure c ontrol valv e fail s to byp ass and th e ice machine malfunctions. Lower ambient conditions can be simulated by rinsing the condenser with cool water during the freeze cycle.

Condition

Discharge Pressure - High

Liquid Line Temperature -

Hot

Discharge Pressure - Low Liquid Line Temperature -

Cold

Discharge Pressure - Low Liquid Line Temperature -

Hot

Probable

Cause

V alve stuck in

bypass

Valve not

bypassing

Ice Machine

Low on Charge

Corrective

Measure

Replace

valve

Replace

valve

Refrigerant

Charge

Verification

98 Part Number 040005626 5/17

Harvest Cycle

REMOTE CONDENSER The head pressure control cycles into full bypass due

to the pressure drop when the harvest valve opens. Refrigerant flows from the compressor to the evaporator through the harvest valve and the head pressure valve is out of the circuit.

Undercharge Symptoms

• Safety limit #1 or Safety limit #2 in control board memory.

• Harvest cycle suction pressure is low.

• Harvest cycle discharge pressure is low.

• Liquid line entering receiver feels warm to hot in the freeze cycle.

Overcharge Symptoms

• Safety limit #2 in control board memory.a flashin g triangle alert and after pressing left arrow long harvest is displayed.

• Harvest cycle discharge pressure is normal.

• Freeze cy cle time , suc tion a nd dis charg e pres sure are normal and the ice machine will not harvest. The sheet of ice cubes show little or no sign of melting when removed from the evaporator after the harvest cycle has been completed. (If the cubes are melted you have a release problem, clean the ice machine).

Part Number 040005626 5/17 99

HARVEST PRESSURE REGULATING (HPR)

INLET

OUTLET

FLOW

HPR SOLENOID

SV3053

OUTLET

INLET

HPR V ALVE

SYSTEM REMOTE CONDENSER ONLY

GENERAL The harvest pressure regulating (HPR) system

includes:

• Harvest pressure regulating solenoid valve (HPR solenoid). This is an electrically operated valve which opens when energized, and closes when de-energized.

• Harvest pressure regulating valve (HPR valve). This is a pressure regulating valve which modulates open and closed, based on the refrigerant pressure at the outlet of the valve. The valve closes completely and stops refrigerant flow when the pressure at the outlet rises above the valve settin g.

100 Part Number 040005626 5/17

Manitowoc MD0420A, MY0500A, MY0420A, MD0700A, MD0500A Technician's Manual

Specifications and Main Features

Frequently Asked Questions

User Manual