Manitowoc Q450, Q800, Q100, Q1300, Q1600 User Manual

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©Manitowoc Ice, Inc.

P/N 80-1099-9 8/03

Safety Notices

As you work on a Q Model Ice Machine, 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 ice machine.

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

Warning

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

Caution

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

Procedural Notices

As you work on a Q Model Ice Machine, be sure to read the procedural notices in this handbook. These notices supply helpful information that may assist you as you work.

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

Important

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

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

Read These Before Proceeding:

Caution

Proper installation, care and maintenance are essential for maximum ice production and trouble free operation of your Manitowoc Ice Machine. If you encounter problems not covered by this manual, do not proceed; contact Manitowoc Ice, Inc. We will be happy to provide assistance.

Important

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

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

Warning

PERSONAL INJURY POTENTIAL

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

Warning

PERSONAL INJURY POTENTIAL

The ice machine head section contains refrigerant charge. Installation and brazing of the line sets must be performed by a properly trained refrigeration technician aware of the dangers of dealing with refrigerant charged equipment. The technician must also be U.S. Government Environmental Protection Agency (EPA) certified in proper refrigerant handling and servicing procedures.

Table of Contents

General Information

How to Read a Model Number.............................. 1

Ice Cube Sizes ...................................................... 1

Model/Serial Number Location .............................. 2

Ice Machine Warranty Information ........................ 2

Owner Warranty Registration Card .................. 2

Warranty Coverage .......................................... 3

Installation

Location of Ice Machine ........................................ 5

Ice Machine Head Section Clearance

Requirements........................................................ 5

Stacking Two Ice Machines on a

Single Storage Bin ................................................ 6

Calculating Remote Condenser

Installation Distances........................................ 7

Removal from Service/Winterization

General ............................................................... 11

Self-Contained Air-Cooled Ice Machines ............ 11

Water-Cooled Ice Machines................................ 11

Remote Ice Machines.......................................... 12

AuCS® Accessory............................................... 12

Ice Making Sequence of Operation

Self-Contained Air- and Water-Cooled................ 13

Initial Start-Up or Start-Up After

Automatic Shut-Off ......................................... 13

Freeze Sequence ........................................... 14

Harvest Sequence.......................................... 15

Automatic Shut-Off ......................................... 16

Energized Parts Chart .................................... 17

Remote................................................................ 19

Initial Start-Up or Start-Up After

Automatic Shut-Off ......................................... 19

Freeze Sequence ........................................... 20

Harvest Sequence.......................................... 21

Automatic Shut-Off ......................................... 21

Remote Energized Parts Chart....................... 22

Electrical System

Wiring Diagrams.................................................. 25

Wiring Diagram Legend.................................. 25

Q200/Q280/Q320 - Self Contained -

1 Phase With Terminal Board......................... 26

Q280/Q370 - Self Contained -

1 Phase Without Terminal Board.................... 27

Q320 - Self Contained -

1 Phase Without Terminal Board.................... 28

Q420/Q450/Q600/Q800/Q1000 - Self Contained-

1 Phase With Terminal Board......................... 29

Q420/Q450/Q600/Q800/Q1000 - Self Contained-

1 Phase Without Terminal Board.................... 30

Q800/Q1000 - Self Contained -

3 Phase With Terminal Board......................... 31

Q800/Q1000 - Self Contained -

3 Phase Without Terminal Board.................... 32

Q1300/Q1800 - Self Contained -

1 Phase With Terminal Board......................... 33

Q1300/Q1600/Q1800 - Self Contained -

1 Phase Without Terminal Board.................... 34

Q1300/Q1800 - Self Contained -

3 Phase With Terminal Board......................... 35

Q1300/Q1600/Q1800 - Self Contained -

3 Phase Without Terminal Board.................... 36

Q450/Q600/Q800/Q1000 - Remote -

1 Phase With Terminal Board......................... 37

Q450/Q600/Q800/Q1000 - Remote -

1 Phase Without Terminal Board.................... 38

Q800/Q1000 -Remote -

3 Phase With Terminal Board......................... 39

Q800/Q1000 - Remote -

3 Phase Without Terminal Board.................... 40

Q1300/Q1800 - Remote -

1 Phase With Terminal Board......................... 41

Q1300/Q1600/Q1800 - Remote -

1 Phase Without Terminal Board.................... 42

Q1300/Q1800 - Remote -

3 Phase With Terminal Board......................... 43

Q1300/Q1600/Q1800 - Remote -

3 Phase Without Terminal Board.................... 44

Component Specifications and

Diagnostics.......................................................... 45

General........................................................... 45

Safety Limits ................................................... 45

Inputs.............................................................. 45

Main Fuse....................................................... 46

Bin Switch....................................................... 47

Water Curtain Removal Notes........................ 49

ICE/OFF/CLEAN Toggle Switch..................... 50

Ice Thickness Probe (Harvest Initiation)......... 51

Ice Thickness Probe Diagnostics ................... 53

Diagnosing Ice Thickness Control Circuitry.... 54

Water Level Control Circuitry.......................... 56

Diagnosing an Ice Machine Head Section

that Will Not Run............................................. 63

Compressor Electrical Diagnostics................. 64

Diagnosing Capacitors ................................... 66

Refrigeration System

Refrigeration System Diagnostics ....................... 71

Before Beginning Service ............................... 71

Ice Production Check ..................................... 72

Installation/Visual Inspection Checklist........... 73

Water System Checklist ................................. 74

Ice Formation Pattern..................................... 75

Safety Limits................................................... 77

Analyzing Discharge Pressure ....................... 85

Analyzing Suction Pressure............................ 88

Single Expansion Valve Ice Machines Comparing Evaporator Inlet and

Outlet Temperatures....................................... 92

Discharge Line Temperature Analysis............ 96

How to Use the Refrigeration System

Operational Analysis Tables........................... 98

Refrigeration System Operational Analysis

Tables........................................................... 101

Pressure Control Specifications

and Diagnostics................................................. 108

Harvest Pressure Regulating (HPR) System

Remotes Only............................................... 108

Headmaster Control Valve ........................... 112

Fan Cycle Control

(Self-Contained Air-Cooled Models Only) .... 115

High Pressure Cutout (HPCO) Control......... 116

Refrigeration Tubing Schematics ...................... 117

Self-Contained Air- or

Water -Cooled Models.................................. 117

Remote Models ............................................ 118

Cycle Times/24-Hour Ice Production/

Refrigerant Pressure Charts.............................. 119

Q200 Series

Self-Contained Air-Cooled ......................... 120

Self-Contained Water-Cooled.................... 121

Q280 Series

Self-Contained Air-Cooled ......................... 122

Self-Contained Water-Cooled.................... 123

Q320 Series

Self-Contained Air-Cooled ......................... 124

Self-Contained Water-Cooled.................... 125

Q370 Series

Self-Contained Air-Cooled ......................... 126

Self-Contained Water-Cooled.................... 127

Q420/450 Series

Self-Contained Air-Cooled ......................... 128

Self-Contained Water-Cooled.................... 129

Remote ...................................................... 130

Q600 Series

Self-Contained Air-Cooled ......................... 131

Self-Contained Water-Cooled.................... 132

Remote ...................................................... 133

Q800 Series

Self-Contained Air-Cooled ......................... 134

Self-Contained Water-Cooled.................... 135

Remote ...................................................... 136

Q1000 Series

Self-Contained Air-Cooled ......................... 137

Self-Contained Water-Cooled.................... 138

Remote ...................................................... 139

Q1300 Series

Self-Contained Air-Cooled ......................... 140

Self-Contained Water-Cooled.................... 141

Remote ...................................................... 142

Q1600 Series

Self-Contained Water-Cooled.................... 143

Remote ..................................................... 144

Q1800 Series

Self-Contained Air-Cooled ......................... 145

Self-Contained Water-Cooled.................... 146

Remote ...................................................... 147

Refrigerant Recovery/Evacuation...................... 148

Normal Self-Contained Model Procedures ... 148

Normal Remote Model Procedures .............. 152

System Contamination Clean-Up ...................... 157

General......................................................... 157

Determining Severity Of Contamination ....... 157

Cleanup Procedure ...................................... 159

Replacing Pressure Controls Without Removing

Refrigerant Charge....................................... 162

Filter-Driers................................................... 164

Total System Refrigerant Charge................. 165

Additional Refrigerant Charges ......................... 166

For Line Sets Between 50’ - 100’. ................ 166

THIS PAGE INTENTIONALLY LEFT BLANK

General Information

HOW TO READ A MODEL NUMBER

9 REMOTE AIR-COOLED

ICE MACHINE

MODEL

ICE CUBE SIZE

R REGULAR D DICE Y HALF DICE

ICE CUBE SIZES

# C U B E S I Z E

0 REGULAR 1 REGULAR 2 DICE 3 DICE 4 HALF-DICE 5 HALF-DICE

CONDENSER TYPE

AIR-COOLED WATER-COOLED AIR-COOLED WATER-COOLED AIR-COOLED WATER-COOLED

Q R 0450 A

ICE MACHINE

SERIES

CONDENSER TYPE

A SELF-CONTAINED AIR-COOLED W SELF-CONTAINED WATER-COOLE N REMOTE AIR-COOLED

Regular

1-1/8" x 1-1/8" x 7/8"

2.86 x 2.86 x

2.22 cm

Dice

7/8" x 7/8" x 7/8"

2.22 x 2.22 x

2.22 cm

–1–

Half Dice

3/8" x 1-1/8" x 7/8"

0.95 x 2.86 x

2.22 cm

MODEL/SERIAL NUMBER LOCATION

These numbers are required when requesting information from your local Manitowoc Distributor, service representative, or Manitowoc Ice, Inc. The model and serial number are listed on the OWNER WARRANTY REGISTRATION CARD. They are also listed on the MODEL/SERIAL NUMBER DECAL affixed to the ice machine.

ICE MACHINE WARRANTY INFORMATION

Owner Warranty Registration Card

Warranty coverage begins the day the ice machine is installed.

Important

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

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

–2–

Warranty Coverage

GENERAL

The following Warranty outline is provided for your convenience. For a detailed explanation, read the warranty bond shipped with each product.

Contact your local Manitowoc representative or Manitowoc Ice, Inc. if you need further warranty information.

Important

This product is intended exclusively for commercial application. No warranty is extended for personal, family, or household purposes.

PARTS

1. Manitowoc warrants the ice machine against defects in materials and workmanship, under normal use and service for three (3) years from the date of original installation.

2. The evaporator and compressor are covered by an additional two (2) year (five years total) warranty beginning on the date of the original installation.

LABOR

1. Labor required to repair or replace defective components is covered for three (3) years from the date of original installation.

2. The evaporator is covered by an additional two (2) year (five years total) labor warranty beginning on the date of the original installation.

EXCLUSIONS

The following items are not included in the ice machine’s warranty coverage:

1. Normal maintenance, adjustments and cleaning as outlined in this manual.

2. Repairs due to unauthorized modifications to the ice machine or use of non-standard parts without prior written approval from Manitowoc Ice, Inc.

–3–

3. Damage caused by improper installation of the ice machine, electrical supply, water supply or drainage, or damage caused by floods, storms, or other acts of God.

4. Premium labor rates due to holidays, overtime, etc.; travel time; flat rate service call charges; mileage and miscellaneous tools and material charges not listed on the payment schedule. Additional labor charges resulting from the inaccessibility of equipment are also excluded.

5. Parts or assemblies subjected to misuse, abuse, neglect or accidents.

6. Damage or problems caused by installation, cleaning and/or maintenance procedures inconsistent with the technical instructions provided in this manual.

This product is intended exclusively for commercial application. No warranty is extended for personal, family, or household purposes.

AUTHORIZED WARRANTY SERVICE

To comply with the provisions of the warranty, a refrigeration service company qualified and authorized by your Manitowoc Distributor, or a Contracted Service Representative must perform the warranty repair.

NOTE: If the dealer you purchased the ice machine from is not authorized to perform warranty service, contact your Manitowoc Distributor or Manitowoc Ice, Inc. for the name of the nearest authorized service representative.

SERVICE CALLS

Normal maintenance, adjustments and cleaning as outlined in this manual are not covered by the warranty. If you have followed the procedures listed in this manual, and the ice machine still does not perform properly, call your Local Distributor or the Service Department at Manitowoc Ice, Inc.

–4–

Installation

LOCATION OF ICE MACHINE

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

• The location must be free of airborne and other

contaminants.

• The air temperature must be at least 35°F (1.6°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 not obstruct air flow through or

around the ice machine. Refer to chart below 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. See “Removal from Service/Winterization”

ICE MACHINE HEAD SECTION CLEARANCE REQUIREMENTS

Q370

Top/Sides 12" (30.5 cm) 5" (12.7 cm)

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

Q1300 Q1600

Q1800

Top/Sides 24" (61 cm) 8" (20.3 cm)

Back 12" (30.5 cm) 5" (12.7 cm)

All other

Q models

Top/Sides 8" (20.3 cm) 5" (12.7 cm)

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

Self-Contained

Air-Cooled

Self-Contained

Air-Cooled

Self-Contained

Air-Cooled

Water-Cooled

and Remote

Water-Cooled

and Remote

Q1600 is not available as an air-cooled model.

–5–

STACKING TWO ICE MACHINES ON A SINGLE STORAGE BIN

A stacking kit is required for stacking two ice machines. Installation instructions are supplied with the stacking kit.

Q450/Q600/

Q800/Q1000

Top/Sides 16" (40.64 cm) 5" (12.70 cm)

Back 5" (12.70 cm) 5" (12.70 cm)

Q1300 Q1600 Q1800

Top/Sides 48" (121.92 cm) 24" (60.96 cm)

Back 12" (30.48 cm) 12" (30.48 cm)

Q1600 is not available as an air-cooled model.

Stacked

Self-Contained

Air-Cooled

Stacked

Self-Contained

Air-Cooled

Stacked

Water-Cooled and

Remote

Stacked

Water-Cooled and

Remote

–6–

Calculating Remote Condenser Installation Distances

LINE SET LENGTH

The maximum length is 100' (30.5 m).

The ice machine compressor must have the proper oil return. The receiver is designed to hold a charge sufficient to operate the ice machine in ambient temperatures between -20°F (-28.9°C) and 120°F (49°C), with line set lengths of up to 100' (30.5 m).

LINE SET RISE/DROP

The maximum rise is 35' (10.7 m).

The maximum drop is 15' (4.5 m).

Caution

If a line set has a rise followed by a drop, another rise cannot be made. Likewise, if a line set has a drop followed by a rise, another drop cannot be made.

–7–

CALCULATED LINE SET DISTANCE

The maximum calculated distance is 150' (45.7 m).

Line set rises, drops, horizontal runs (or combinations of these) in excess of the stated maximums will exceed compressor start-up and design limits. This will cause poor oil return to the compressor.

Make the following calculations to make sure the line set layout is within specifications.

1. Insert the measured rise into the formula below. Multiply by 1.7 to get the calculated rise. (Example: A condenser located 10 feet above the ice machine has a calculated rise of 17 feet.)

2. Insert the measured drop into the formula below. Multiply by 6.6 to get the calculated drop. (Example. A condenser located 10 feet below the ice machine has a calculated drop of 66 feet.)

3. Insert the measured horizontal distance into the formula below. No calculation is necessary.

4. Add together the calculated rise, calculated drop, and horizontal distance to get the total calculated distance. If this total exceeds 150' (45.7 m), move the condenser to a new location and perform the calculations again.

MAXIMUM LINE SET DISTANCE FORMULA

Step 1.

Measured Rise ____ X 1.7 = ______Calculated Rise (35 ft. Max)

Step 2.

Measured Drop ____ X 6.6 = ______Calculated Drop (15 ft. Max.)

Step 3.

Measured Horizontal Distance = _________Horizontal (100 ft. Max.) Distance

Step 4.

Total Calculated Distance = ________Total Calculated (150 ft. Max.) Distance

–8–

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–9–

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–10–

Removal from Service/Winterization

GENERAL

Special precautions must be taken if the ice machine is to be removed from service for an extended period of time or exposed to ambient temperatures of 32°F (0°C) or below.

Caution

If water is allowed to remain in the ice machine in freezing temperatures, severe damage to some components could result. Damage of this nature is not covered by the warranty.

Follow the applicable procedure below.

SELF-CONTAINED AIR-COOLED ICE MACHINES

1. Disconnect the electric power at the circuit breaker or the electric service switch.

2. Turn off the water supply.

3. Remove the water from the water trough.

4. Disconnect and drain the incoming ice-making water line at the rear of the ice machine.

5. Blow compressed air in both the incoming water and the drain openings in the rear of the ice machine until no more water comes out of the inlet water lines or the drain.

6. Make sure water is not trapped in any of the water lines, drain lines, distribution tubes, etc.

WATER-COOLED ICE MACHINES

1. Perform steps 1-6 under “Self-Contained AirCooled Ice Machines.”

2. Disconnect the incoming water and drain lines from the water-cooled condenser.

–11–

3. Insert a large screwdriver between the bottom spring coils of the water regulating valve. Pry upward to open the valve.

SV1624

4. Hold the valve open and blow compressed air through the condenser until no water remains.

REMOTE ICE MACHINES

1. Move the ICE/OFF/CLEAN switch to OFF.

2. “Frontseat” (shut off) the receiver service valves. Hang a tag on the switch as a reminder to open the valves before restarting.

3. Perform steps 1-6 under “Self-Contained AirCooled Ice Machines.”

AUCS

Refer to the AuCS winterization of the AuCS

ACCESSORY

Accessory manual for

Accessory.

–12–

Ice Making Sequence of Operation

SELF-CONTAINED AIR- AND WATER-COOLED

Initial Start-Up or Start-Up After Automatic Shut-Off

1. Water Purge

Before the compressor starts, the water pump and water dump solenoid are energized for 45 seconds to purge the ice machine of old water. This ensures that the ice-making cycle starts with fresh water.

The harvest valve(s) is also energized during the water purge, although it stays on for an additional 5 seconds (50-second total on time) during the initial refrigeration system start-up.

2. Refrigeration System Start-Up

The compressor starts after the 45 second water purge, and it remains on throughout the entire Freeze and Harvest Sequences. The water fill valve is energized at the same time as the compressor. It remains on until the water level sensor closes for 3 continuous seconds, or until a six-minute time period has expired. The harvest valve(s) remains on for 5 seconds during initial compressor start-up and then shuts off.

At the same time the compressor starts, the condenser fan motor (air-cooled models) is supplied with power throughout the entire Freeze and Harvest Sequences. The fan motor is wired through a fan cycle pressure control, therefore it may cycle on and off. (The compressor and condenser fan motor are wired through the contactor. As a result, anytime the contactor coil is energized, the compressor and fan motor are supplied with power.)

–13–

Freeze Sequence

3. Prechill

The compressor is on for 30 seconds prior to water flow to prechill the evaporator.

4. Freeze

The water pump restarts after the 30-second prechill. An even flow of water is directed across the evaporator and into each cube cell, where it freezes. The water fill valve will cycle on, then off one more time to refill the water trough.

When sufficient ice has formed, the water flow (not the ice) contacts the ice thickness probe. After approximately 7 seconds of continual water contact, the Harvest sequence is initiated. The ice machine cannot initiate a Harvest sequence until a 6-minute freeze lock has been surpassed.

–14–

Harvest Sequence

5. Water Purge

The water pump continues to run, and the water dump valve energizes for 45 seconds to purge the water in the sump trough. The water fill valve energizes (turns on) and de-energizes (turns off) strictly by time. The water fill valve energizes for the last 15 seconds of the 45-second water purge. The water purge must be at the factory setting of 45 seconds for the fill valve to energize during the last 15 seconds of the Water Purge. If set at less than 45 seconds the water fill valve does not energize during the water purge.

After the 45 second water purge, the water fill valve, water pump and dump valve de-energize. (Refer to “Water Purge Adjustment” for details.) The harvest valve also opens at the beginning of the water purge to divert hot refrigerant gas into the evaporator.

6. Harvest

The harvest valve(s) remains open and the refrigerant gas warms the evaporator causing the cubes to slide, as a sheet, off the evaporator and into the storage bin. The sliding sheet of cubes swings the water curtain out, opening the bin switch. The momentary opening and re-closing of the bin switch terminates the harvest sequence and returns the ice machine to the freeze sequence (Step 3 - 4.)

–15–

Automatic Shut-Off

7. Automatic Shut-Off

When the storage bin is full at the end of a harvest sequence, the sheet of cubes fails to clear the water curtain and will hold it open. After the water curtain is held open for 7 seconds, the ice machine shuts off. The ice machine remains off for 3 minutes before it can automatically restart.

The ice machine remains off until enough ice has been removed from the storage bin to allow the ice to fall clear of the water curtain. As the water curtain swings back to the operating position, the bin switch re-closes and the ice machine restarts (steps 1 - 2), provided the 3 minute delay period is complete.

–16–

Length

of Time

Condenser

Compressor

Contactor

Fan Motor

Coil

45 Seconds

5 Seconds

On/Off

May Cycle

30 Seconds

On/Off

May Cycle

Unit 7 Sec.

Water Contact

On/Off

May Cycle

w/Ice Thickness Probe

Energized Parts Chart

Control Board Relays Contactor

Water

Harvest

Water Fill

Water

Val ve

Dump

Valve

Pump

Off Off On On

On/Off

May Cycle

during first

On Off On On Off Off Off

Off On On Off On On

Off

Cycles

45 sec.

On then Off

Off Off On On

time

one more

Operation

Ice Making

Sequence of

Initial Start-Up

1. Water Purge

2. Refrigeration

System Start-up

Freeze Sequence

3. Prechill

4. Freeze On

–17–

Length

of Time

Condenser

Compressor

Contactor

Fan Motor

Coil

Set at

Factory

On/Off

May Cycle

Activation

Bin Switch

45 Seconds

On/Off

May Cycle

Re-closes

Until Bin Switch

Val ve

Water

Dump

Valve

Harvest

On On On On

Energized Parts Chart (Continued)

Control Board Relays Contactor

Valve

Water Fill

Water

Pump

Off

30 sec.

15 sec.

Off Off Off Off Off Off Off

Operation

Ice Making

Sequence of

Harvest Sequence

Shut-Off

5. Water Purge

6. Harvest Off Off On Off On On

7. Automatic

–18–

REMOTE

Initial Start-Up or Start-Up After Automatic Shut-Off

1. Water Purge

Before the compressor starts, the water pump and water dump solenoid are energized for 45 seconds, to completely purge the ice machine of old water. This feature ensures that the ice making cycle starts with fresh water.

The harvest valve and harvest pressure regulating (HPR) solenoid valves also energize during water purge, although they stay on for an additional 5 seconds (50 seconds total on time) during the initial refrigeration system start-up.

2. Refrigeration System Start-Up

The compressor and liquid line solenoid valve energize after the 45 second water purge and remain on throughout the entire Freeze and Harvest Sequences. The water fill valve is energized at the same time as the compressor. It remains on until the water level sensor closes for 3 continuous seconds, or until a six-minute time period has expired. The harvest valve and HPR solenoid valves remain on for 5 seconds during initial compressor start-up and then shut off.

The remote condenser fan motor starts at the same time the compressor starts and remains on throughout the entire Freeze and Harvest Sequences.

–19–

Freeze Sequence

3. Prechill

The compressor is on for 30 seconds prior to water flow, to prechill the evaporator.

4. Freeze

The water pump restarts after the 30 second prechill. An even flow of water is directed across the evaporator and into each cube cell, where it freezes. The water fill valve will cycle on and then off one more time to refill the water trough.

When sufficient ice has formed, the water flow (not the ice) contacts the ice thickness probe. After approximately 7 seconds of continual water contact, the harvest sequence is initiated. The ice machine cannot initiate a harvest sequence until a 6 minute freeze lock has been surpassed.

–20–

Harvest Sequence

5. Water Purge

After the 45 second water purge, the water fill valve, water pump and dump valve de-energize. (Refer to “Water Purge Adjustment”) The harvest valve(s) and HPR solenoid valve also open at the beginning of the water purge.

6. Harvest

The HPR valve and the harvest valve(s) remain open and the refrigerant gas warms the evaporator causing the cubes to slide, as a sheet, off the evaporator and into the storage bin. The sliding sheet of cubes swings the water curtain out, opening the bin switch. The momentary opening and re-closing of the bin switch terminates the harvest sequence and returns the ice machine to the freeze sequence (Step 3 - 4.)

Automatic Shut-Off

7. Automatic Shut-Off

The ice machine remains off until enough ice has been removed from the storage bin to allow the ice to drop clear of the water curtain. As the water curtain swings back to the operating position, the bin switch re-closes and the ice machine restarts (steps 1 - 2) provided the 3 minute delay period is complete.

–21–

Length

Condenser

Compressor

a. Contactor

of Time

Fan Motor

Coil

45 Seconds

Solenoid

b. Liquid Line

5 Seconds

30 Seconds

Unit 7 Sec.

Probe

Water Contact

w/Ice Thickness

Remote Energized Parts Chart

Control Board Relays Contactor

Water

a. Harvest

Water Fill

Water

Val ve

Dump

b. HPR

Valve(s)

Valve

Pump

Solenoid

Off Off On On On

45 sec.

On/Off

May Cycle

during first

On Off On On Off Off Off

Off On On Off On On On

Off

Off Off On On On

Cycles

one more

On then Off

time

Ice Making

Sequence of

Operation

Initial Start-Up

1. Water Purge

2. Refrigeration

System Start-up

Freeze Sequence

3. Prechill

4. Freeze On

–22–

Set at

Solenoid

Factory

Bin Switch

45 Seconds

Length

of Time

Fan Motor

Condenser

Compressor

Coil

a. Contactor

b. Liquid Line

Switch

Until Bin

Activation

Recloses

Val ve

Water

Dump

b. HPR

Valve(s)

a. Harvest

Control Board Relays Contactor

Remote Energized Parts Chart (Continued)

Valve

Water Fill

Water

Pump

Solenoid

30 sec.

On On On On On

15 sec.

Off Off Off Off Off Off Off

Off

Ice Making

Sequence of

Operation

Harvest Sequence

5. Water Purge

6. Harvest Off Off On Off On On On

Shut-Off

7. Automatic

–23–

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–24–

Electrical System

WIRING DIAGRAMS

The following pages contain electrical wiring diagrams. Be sure you are referring to the correct diagram for the ice machine which you are servicing.

Warning

Always disconnect power before working on electrical circuitry.

Wiring Diagram Legend

The following symbols are used on all of the wiring diagrams:

* Internal Compressor Overload

(Some models have external compressor overloads)

** Fan Motor Run Capacitor

(Some models do not incorporate fan motor run capacitor)

TB Terminal Board Connection

(Terminal board numbers are printed on the actual terminal board)

( ) Wire Number Designation

(The number is marked at each end of the wire)

—>>— Multi-Pin Connection

(Electrical Box Side) —>>— (Compressor Compartment Side)

–25–

Q200/Q280/Q320 - Self Contained -

(20)

1 Phase With Terminal Board

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

TB35

ICE THICKNESS PROBE

TB35

DIAGRAM SHOWN DURING FREEZE CYCLE

SEE SERIAL PLATE FOR VOLTAGE

TB32

HIGH PRES CUTOUT

WATER LEVEL PROBE

CONTACTOR CONTACTS

(42)

(55)

NOT USED

(62)

BIN SWITCH

(64)

(66)

(48)

(51)

TB33

(63)

(65)

*OVERLOAD

(52)

(85) (86)

FAN CYCLE CONTROL

4 1

3 5

TRANS.

FUSE (7A)

LOW D.C. VOLTAGE PLUG

TOGGLE SWITCH

(67)

(66)

COMPRESSOR

(53)

(61)

(60)

(57)

(58)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

(62)

(49)

(47)

TB34

INTERNAL WORKING

OFF

VIEW

CLEAN

RUN CAPACITOR**

WATER

VALVE

(21) (22)

HARVEST

SOLENOID

(77)

DUMP

SOLENOID

(76)

TB31

(98)

TB37

(59)

(73)

(56)

PTCR

FAN MOTOR (AIR COOLED ONLY)

(81)

WATER

PUMP

TERMINATES AT PIN CONNECTION

CONTACTOR

COIL

VIEW FOR WIRING

66 62

(50)

(80)

(99)

(74)

(75)

L2 (N)

TB30

SV1654

–26–

Q280/Q370 - Self Contained 1 Phase Without Terminal Board

(88)

(42)

CAUTION: DISCONNECT POWER BEFORE WORKING

(89)

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

CONTACTOR

CONTACTS

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(55)

NOT USED

(62)

BIN SWITCH

(64)

OVERLOAD INTERNAL

{230V 50/60 HZ}

(51)

(65)

(66)

4 2

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE PLUG

(63)

(67)

COMPRESSOR

(48)

(46)

POTENTIAL

RELAY

FAN CYCLE CONTROL

(86)(85)

(20)

(61)

(60)

(58)

CLEAN LIGHT

WATER LEVEL

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

OFF

CLEAN

(62)

(47)

(44)

START CAPACITOR

(45)

RUN CAPACITOR**

SEE SERIAL PLATE FOR VOLTAGE

(21)

WATER VALVE

(77)

HARVEST SOLENOID

(76)

DUMP SOLENOID

(57)

INTERNAL WORKING

(98)

(59)

TERMINATES AT PIN CONNECTION

(56)

TOGGLE SWITCH

VIEW

(49)

(50)

FAN MOTOR (AIR COOLED ONLY)

COMPRESSOR TERMINAL LAYOUT VIEWED FROM END

OF COMPRESSOR

(22)

(80)

(75)

(81)

(99)

WATER PUMP

CONTACTOR COIL

(74)

VIEW FOR WIRING

L2 (N)

SHUNT ON

CONTACTOR

SV3018

–27–

Q320 - Self Contained 1 Phase Without Terminal Board

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

HIGH PRES CUTOUT

(88)

ICE THICKNESS PROBE

(42)

DIAGRAM SHOWN DURING FREEZE CYCLE SEE SERIAL PLATE FOR VOLTAGE

(55)

(89)

WATER LEVEL PROBE

NOT USED

(62)

BIN SWITCH

(64)

CONTACTOR CONTACTS

(48)

(63)

(65)

*OVERLOAD

(51)

FAN CYCLE CONTROL

(85)

4 2 1 5

TRANS.

FUSE (7A)

LOW D.C. VOLTAGE PLUG

(86)

TOGGLE SWITCH

(68)

(67)

(69)

(66)

(62)

COMPRESSOR

OVERLOAD

(20)

(61)

(60)

(57)

CLEAN LIGHT

WATER LEVEL

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

(49)

(47)

RUN CAPACITOR**

COMPRESSOR

(48)

HARVEST SOLENOID

(77)

(76)

DUMP SOLENOID

(98)

(59)

(58)

PTCR

FAN MOTOR (AIR COOLED ONLY)

(49)

(47)

WATER

VALVE

(22)

(80)

(81)

(99)

WATER PUMP

TERMINATES AT PIN CONNECTION

CONTACTOR COIL

(56)

(74)

VIEW FOR WIRING

66 62

(50)

RUN CAPACITOR

(46)

PTCR

(75)

(45)

L2 (N)

(50)

SV2070

–28–

Q420/Q450/Q600/Q800/Q1000 - Self Contained-

1 Phase With Terminal Board

TB32

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

NOT USED

CONTACTOR CONTACTS

(42)

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(55)

4 1 3 5

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE PLUG

(62)

BIN SWITCH

(64)

(51)

TB33

(63)

(65)

(66)

*OVERLOAD

(48)

(85) (86)

(52)

FAN CYCLE CONTROL

(67)

COMPRESSOR

TOGGLE SWITCH

(68)

(69)

(62)

(49)

(47)

(46)

(53)

TB34

SEE SERIAL PLATE FOR VOLTAGE

(20)

(61)

(60)

(58)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

RUN CAPACITOR

PTCR

FAN MOTOR

(AIR COOLED ONLY)

(57)

TB31

TB37

(21)

WATER VALVE

(77)

HARVEST

SOLENOID

(76)

DUMP SOLENOID

(59)

(73)

(56)

(45)

(98)

(22)

(80)

(75)

(81)

(99)

WATER PUMP

TERMINATES AT PIN CONNECTION

CONTACTOR COIL

VIEW FOR WIRING

(74)

(50)

L2 (N)

TB30

TB3

TB30

RUN CAPACITOR**

SV1646

–29–

Q420/Q450/Q600/Q800/Q1000 - Self Contained-

)

1 Phase Without Terminal Board

HIGH PRES CUTOUT

(88)

ICE THICKNESS PROBE

WATER LEVEL PROBE

CONTACTOR CONTACTS

(42)

(89)

NOT USED

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

SEE SERIAL PLATE FOR VOLTAGE

(55)

4 2 1 5

TRANS.

FUSE (7A)

LOW D.C. VOLTAGE

PLUG

BIN SWITCH

(64)

(48)

(51)

(62)

(63)

(65)

COMPRESSOR

*OVERLOAD

(85)

FAN CYCLE CONTROL

(67)

(66)

(86)

TOGGLE SWITCH

(68) (69)

(62)

(20) (21)

(61)

(60)

(57)

(58)

(56)

CLEAN LIGHT

WATER LEVEL

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

(49)

(47)

(46)

RUN CAPACITOR**

RUN

CAPACITOR

PTCR

FAN MOTOR (AIR COOLED ONLY)

WATER VALVE

HARVEST

SOLENOID

(77)

DUMP SOLENOID

(76)

WATER

PUMP

(98)

(59)

TERMINATES AT PIN CONNECTION

CONTACTOR

COIL

(45)

(22)

(80)

(81)

(99)

(74)

VIEW FOR WIRING

(50)

67 69

L2 (N

(75)

SV2071

–30–

Q800/Q1000 - Self Contained -

3 Phase With Terminal Board

SEE SERIAL PLATE FOR VOLTAGE

TB35

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

CAUTION: DISCONNECT POWER BEFORE WORKING

TB32

NOT USED

(64)

BIN SWITCH

(66)

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(20)

(61)

(60)

2 4

1 3

(55)

(62)

(63)

(65)

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE PLUG

(67)

(66)

TOGGLE SWITCH

(68)

(69)

(62)

(57)

(58)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

TB31

TB37

(21)

WATER VALVE

(77)

HARVEST

SOLENOID

(76)

DUMP SOLENOID

(98)

(59)

TERMINATES AT PIN CONNECTION

(73)

(56)

(22)

(80)

(75)

(81)

(99)

WATER PUMP

CONTACTOR

COIL

(74)

VIEW FOR WIRING

TB3

(42)

TB35

COMPRESSOR

TB33

(52)

(85)

FAN CYCLE CONTROL

(86)

(96)

(53)

TB34

RUN CAPACITOR**

FAN MOTOR (AIR COOLED ONLY)

SV1647a

TB3

–31–

Q800/Q1000 - Self Contained 3 Phase Without Terminal Board

L1L2L3

(88)

(42)

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(55)

(89)

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

NOT USED

BIN SWITCH

(64)

(62)

(63)

(65)

4 2 1 5

TRANS.

FUSE (7A)

(67)

(66)

LOW D.C. VOLTAGE PLUG

TOGGLE SWITCH

SEE SERIAL PLATE FOR VOLTAGE

(20) (21)

(61)

(60)

(57)

(58)

(56)

CLEAN LIGHT

WATER LEVEL

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

(62)

INTERNAL WORKING

OFF

VIEW

CLEAN

WATER VALVE

HARVEST SOLENOID

(77)

DUMP

SOLENOID

(76)

(98)

(59)

TERMINATES AT PIN CONNECTION

CONTACTOR

COIL

(22)

(80)

(75)

(81)

WATER

PUMP

(99)

(74)

VIEW FOR WIRING

68 66 62

T1T3

CONTACTOR CONTACTS

(51)

(85)

FAN CYCLE CONTROL

(86)

FAN MOTOR (AIR COOLED ONLY)

RUN CAPACITOR**

SV2072

–32–

Q1300/Q1800 - Self Contained 1 Phase With Terminal Board

TB35

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

TB35

(42)

TB32

AUCS DISPENSE TIME

(64)

(66)

(95)

CONTACTOR CONTACTS

(51)

TB33

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(55)

(62)

(63)

BIN SWITCH

*OVERLOAD

(48)

(85) (86)

(52)

FAN CYCLE CONTROL

(65)

2 4

TRANS.

(20)

(61)

(60)

FUSE (7A)

LOW D.C. VOLTAGE PLUG

TOGGLE SWITCH

(67)

(66)

CRANKCASE HEATER

COMPRESSOR

(53)

RUN CAPACITOR**

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

OFF

CLEAN

(62)

(49)

(47)

TB34

(57)

(58)

INTERNAL WORKING VIEW

RUN CAPACITOR

(46) (50)

PTCR

SEE SERIAL PLATE FOR VOLTAGE

WATER

(21)

RH HARVEST SOLENOID

(88)

(77)

LH HARVEST SOLENOID

DUMP SOLENOID

TB31

TB37

(59)

(73)

(56)

(45)

(44)

FAN MOTOR (AIR COOLED ONLY)

VALVE

(80)

(76)

(81)

(98)

WATER PUMP

TERMINATES AT PIN CONNECTION

CONTACTOR COIL

VIEW FOR WIRING

(94)

CONTACTOR CONTACTS

(22)

(87)

(99)

(74)

(75)

(96)

L2(N)

TB30

SV1652

–33–

Q1300/Q1600/Q1800 - Self Contained 1 Phase Without Terminal Board

(89)

HIGH PRES CUTOUT

(88)

(42)

ICE THICKNESS PROBE

WATER LEVEL PROBE

CONTACTOR CONTACTS

CAUTION: DISCONNECT POWER BEFORE WORKING

DIAGRAM SHOWN DURING FREEZE CYCLE

(55)

AUCS DISPENSE TIME

BIN SWITCH

(64)

(95)

*OVERLOAD

(48)

(51)

FAN CYCLE CONTROL

ON ELECTRICAL CIRCUITRY.

3 4 2

1 5

TRANS.

FUSE (7A)

LOW D.C. VOLTAGE PLUG

(62)

(63)

(65)

COMPRESSOR

(85)

TOGGLE SWITCH

(68)

(67)

(69)

(66)

(62)

CRANKCASE HEATER

(86)

SEE SERIAL PLATE FOR VOLTAGE

(20) (21)

WATER VALVE

(61)

(77)

HARVEST

(60)

SOLENOID

(76)

DUMP SOLENOID

(98)

(57)

WATER PUMP

(59)

(58)

CONTACTOR COIL

(56)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

(49)

RUN CAPACITOR

(47)

(46)

(45)

PTCR

FAN MOTOR (AIR COOLED ONLY)

RUN CAPACITOR**

(22)

(80)

(81)

(99)

TERMINATES AT PIN CONNECTION

(74)

VIEW FOR WIRING

66 62

(94)

(50)

CONTACTOR CONTACTS

L2 (N)

(75)

(96)

SV2075

–34–

Q1300/Q1800 - Self Contained 3 Phase With Terminal Board

SEE SERIAL PLATE FOR VOLTAGE

L3 L2 L1

TB35

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

TB35

CAUTION: DISCONNECT POWER BEFORE WORKING

DIAGRAM SHOWN DURING FREEZE CYCLE

TB32

AUCS DISPENSE TIME

(64)

BIN SWITCH

(66)

(95)

ON ELECTRICAL CIRCUITRY.

(20)

(61) (60)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

OFF

CLEAN

(62)

(55)

(62)

(63)

2 4 1 3

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE PLUG

(65)

(67)

(66)

CRANKCASE HEATER

TOGGLE SWITCH

(21)

RH HARVEST SOLENOID

(88)

(77)

LH HARVEST

SOLENOID

(76)

DUMP

SOLENOID

(57)

TB31

(98)

(58)

TB37

(59)

TERMINATES AT PIN CONNECTION

(73)

CONTACTOR COIL

(56)

VIEW FOR WIRING

INTERNAL WORKING VIEW

66 62

WATER VALVE

(22)

(87)

(80)

(81)

(99)

WATER PUMP

(94)

(74)

(75)

N - 50HZ ONLY

TB30 TB30

TB30

L2L3

COMPRESSOR

(42)

TB35

TB33

(52)

(85)

FAN CYCLE CONTROL

(96)

NOTE: WIRE (96) IS NOT USED ON 50HZ

(53)

TB34

FAN MOTOR (AIR COOLED ONLY)

RUN CAPACITOR**

(86)

TB30

SV1653

–35–

Q1300/Q1600/Q1800 - Self Contained 3 Phase Without Terminal Board

SEE SERIAL PLATE FOR VOLTAGE

L3 L2 L1

(88)

(42)

ICE THICKNESS PROBE

WATER LEVEL PROBE

CAUTION: DISCONNECT POWER BEFORE WORKING

DIAGRAM SHOWN DURING FREEZE CYCLE

(89) (55)

HIGH PRES CUTOUT

AUCS DISPENSE TIME

BIN SWITCH

(64)

ON ELECTRICAL CIRCUITRY.

3 4

2 1 5

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE PLUG

(62)

(63)

(65)

(95)

TOGGLE SWITCH

(68)

(67)

(69)

(66)

(62)

CRANKCASE HEATER

NOTE: WIRE (96) IS NOT USED ON 50HZ

WATER

VALVE

(21)(20)

RH HARVEST

SOLENOID

(61)

(60)

LH HARVEST

SOLENOID

(76) DUMP

SOLENOID

(98) (99)

(57)

WATER PUMP

(59)

(58)

CONTACTOR

(56)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

(22)

(88) (77)

(87)

(81)

TERMINATES AT PIN CONNECTION

COIL

(94)

(96)

N - 50HZ ONLY

(80)

(75)

VIEW FOR WIRING

L2L3

COMPRESSOR

(51)

(85)

(86)

FAN CYCLE CONTROL

FAN MOTOR (AIR COOLED ONLY)

RUN CAPACITOR**

SV3008

–36–

Q450/Q600/Q800/Q1000 - Remote 1 Phase With Terminal Board

TB35

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

(42)

TB35

TB32

NOT USED

BIN SWITCH

CONTACTOR CONTACTS

(51)

TB33

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(20)

(55)

4 1 3

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE

(65)

PLUG

TOGGLE SWITCH

(67)

(66)

COMPRESSOR

(62)

(64)

(66)

(63)

*OVERLOAD

(48) (45)

(52)

TERMINATES AT

PIN CONNECTION

(F1)

(53)

(61)

(60)

(57)

(58)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

(62)

OFF

CLEAN

(49)

(47)

TB34

INTERNAL WORKING VIEW

RUN CAPACITOR

(46)

PTCR

SEE SERIAL PLATE FOR VOLTAGE

(22)(21)

WATER VALVE

(79)(78)

(80)

(81)

(98)

WATER PUMP

(83)

CONTACTOR COIL

VIEW FOR WIRING

66 62

(50)

(75)

(99)

(82)

LIQUID LINE SOLENOID

(74)

68 67

(F2)

TB31

TB37

HPR SOLENOID

(77)

HARVEST

SOLENOID

(76)

DUMP SOLENOID

(59)

(73)

(56)

L2 (N)

TB30

–37–

REMOTE

FAN MOTOR

RUN CAPACITOR

REMOTE CONDENSER

SV1648

Q450/Q600/Q800/Q1000 - Remote 1 Phase Without Terminal Board

(88)

ICE THICKNESS PROBE

WATER LEVEL PROBE

AUCS DISPENSE TIME

(42)

CONTACTOR CONTACTS

(89)

HIGH PRES CUTOUT

BIN SWITCH

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(55)

4 1

3 5

TRANS.

FUSE (7A)

(64)

(48)

*OVERLOAD

(51)

(62)

(63)

(65)

COMPRESSOR

LOW D.C. VOLTAGE PLUG

TOGGLE SWITCH

(67)

(66)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

OFF

CLEAN

(62)

(49)

(47)

(46)

SEE SERIAL PLATE FOR VOLTAGE

(20) (21)

HPR SOLENOID

(61)

(60)

(57)

INTERNAL WORKING VIEW

RUN CAPACITOR

PTCR

(78)

(88) (80)

HARVEST SOLENOID

(77) DUMP SOLENOID

(98)

(59) (83) (82)

(58)

(56)

(45)

(50)

(22)

WATER VALVE

(79)

(75)

(81)

(99)

WATER PUMP

LIQUID LINE SOLENOID

CONTACTOR COIL

(74)

VIEW FOR WIRING

66 62

(94)

L2 (N)

F1 F2

REMOTE

FAN MOTOR

REMOTE CONDENSER

RUN CAPACITOR**

SV2073

–38–

Q800/Q1000 -Remote 3 Phase With Terminal Board

EE SERIAL PLATE FOR VOLTAGE

L3 L2 L1

TB35

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

AUCS DISPENSE TIME

(64)

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

TB32

4 1

(55)

TRANS.

FUSE (7A)

LOW D.C.

VOLTAGE

(65)

PLUG

TOGGLE SWITCH

(68)

(67)

(69)

(66)

(62)

(63)

BIN SWITCH

(20)

(61)

(60)

(57)

TB31

(58)

TB37

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

INTERNAL WORKING

OFF

VIEW

CLEAN

(21)

HPR SOLENOID

(78)

(77)

HARVEST

SOLENOID

(76)

DUMP SOLENOID

(98)

(59)

(83)

(73)

CONTACTOR COIL

(56)

VIEW FOR WIRING

66 62

(22)

WATER VALVE

(79)

(80)

(75)

(81)

(99)

WATER PUMP

(82)

LIQUID LINE SOLENOID

(74)

68 67

TB30

COMPRESSOR

(42)

TB35

CONTACTOR CONTACTS

TB33

(F1)

(52)

TERMINATES AT

PIN CONNECTION

(96)

(53)

TB34

REMOTE CONDENSER

RUN CAPACITOR

REMOTE

FAN MOTOR

(F2)

SV1649

TB30

–39–

Q800/Q1000 - Remote 3 Phase Without Terminal Board

L3 L2 L1

CAUTION: DISCONNECT POWER BEFORE WORKING

DIAGRAM SHOWN DURING FREEZE CYCLE

(88)

(89)

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

NOT USED

BIN SWITCH

(64)

(42)

ON ELECTRICAL CIRCUITRY.

SEE SERIAL PLATE FOR VOLTAGE

(55)

3 4 2 1 5

TRANS.

FUSE (7A)

(62)

(63)

(65)

(66)

LOW D.C.

VOLTAGE PLUG

(68)

TOGGLE SWITCH

(67)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/

SAFETY LIMIT CODE LIGHT

ICE

(69)

OFF

CLEAN

(62)

WATER VALVE

(21)

(20)

(61)

(60)

(57)

(58)

(56)

INTERNAL WORKING VIEW

HPR

SOLENOID

(78)

(77)

HARVEST SOLENOID

(76)

DUMP SOLENOID

(98)

WATER PUMP

(59)

(83)

CONTACTOR

COIL

(22)

(79)

(80)

(81)

(99)

(82)

LIQUID LINE SOLENOID

(74)

VIEW

FOR

WIRING

66 62

(75)

68 67

COMPRESSOR

CONTACTOR CONTACTS

(51)

(85)

(F2)

REMOTE CONDENSER

REMOTE

FAN MOTOR

RUN CAPACITOR

(F1)

SV2074

–40–

Q1300/Q1800 - Remote 1 Phase With Terminal Board

TB35

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

TB35

(42)

TB35

TB32

AUCS DISPENSE TIME

(64)

(66)

CONTACTOR CONTACTS

(51)

TB33

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

(20)

(55)

BIN SWITCH

*OVERLOAD

(48)

(52)

(F1)

4 1 3

TRANS.

FUSE (7A)

LOW D.C. VOLTAGE

(62)

(63)

TERMINATES AT

PIN CONNECTION

PLUG

(65)

CRANKCASE HEATER

TOGGLE SWITCH

(67)

(66)

COMPRESSOR

(53)

(61)

(60)

(58)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

(62)

OFF

CLEAN

(49)

(47)

TB34

INTERNAL WORKING VIEW

RUN CAPACITOR

PTCR

(21)

HPR SOLENOID

RH HARVEST SOLENOID

(77)

LH HARVEST SOLENOID

(57)

TB31

TB37

(46)

(45)

(44)

SEE SERIAL PLATE FOR VOLTAGE WATER

VALVE

(76)

DUMP SOLENOID

(98)

(59)

(73)

(56)

(83)

CONTACTOR COIL

VIEW FOR WIRING

66 62

(94)(95)

(50)

(22)

(79)(78)

(87)(88)

(80)

(75)

(81)

(99)

WATER PUMP

(82)

LIQUID LINE SOLENOID

(74)

CONTACTOR CONTACTS

(F2)

L2 (N)

(96)

TB30

–41–

REMOTE

FAN MOTOR

RUN CAPACITOR

REMOTE CONDENSER

SV1650

Q1300/Q1600/Q1800 - Remote 1 Phase Without Terminal Board

HIGH PRES CUTOUT

(88)

ICE THICKNESS PROBE

WATER LEVEL PROBE

(42)

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

SEE SERIAL PLATE FOR VOLTAGE

(55)(89)

2 4

1 3

TRANS.

FUSE (7A)

AUCS DISPENSE TIME

BIN SWITCH

(64)

(95)

CONTACTOR CONTACTS

(48)

(51)

*OVERLOAD

(62)

(63)

(65)

CRANKCASE HEATER

COMPRESSOR

(F1) (F2)

LOW D.C. VOLTAGE PLUG

TOGGLE SWITCH

(67)

(66)

(20)

(60)

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

(68)

ICE

(69)

INTERNAL WORKING

OFF

VIEW

CLEAN

(62)

(49)

(47)

PTCR

(44)

(21)

HPR SOLENOID

RH HARVEST

SOLENOID

(61)

LH HARVEST

SOLENOID

(57)

(59)

(58)

(56)

RUN CAPACITOR

(46) (50)

(45)

WATER VALVE

(78)

(88)

(77)

(76)

DUMP SOLENOID

(98)

(83)

CONTACTOR

COIL

(94)

(22)

(79)

(87)

(80)

(75)

(81)

(99)

WATER PUMP

(82)

LIQUID LINE

SOLENOID

(74)

VIEW FOR WIRING

68 67

66 62

(F2)

CONTACTOR CONTACTS

L2 (N)

(96)

–42–

REMOTE

FAN MOTOR

RUN CAPACITOR

REMOTE CONDENSER

SV2076

Q1300/Q1800 - Remote -

3 Phase With Terminal Board

L3 L2 L1

TB35

(42)

CONTACTOR CONTACTS

COMPRESSOR

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

SEE SERIAL PLATE FOR VOLTAGE

GROUND

TB32

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

AUCS DISPENSE TIME

BIN SWITCH

(64)

(95)

TB35

TB33 (52)(51)

(62)

(66)

(F1)

4 1

(55)

TRANS.

FUSE (7A)

LOW D.C. VOLTAGE PLUG

(63)

(65)

(62)

TERMINATES AT

PIN CONNECTION

(68)

TOGGLE SWITCH

(67)

CRANKCASE HEATER

NOTE: WIRE (96) IS NOT USED ON 50HZ

(53)

(20)

RH HARVEST

SOLENOID

(61)

(60)

(57)

TB31

(58)

TB37

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

(69)

OFF

CLEAN

(96)

TB34

INTERNAL WORKING VIEW

FAN MOTOR

RUN CAPACITOR

REMOTE CONDENSER

WATER

VALVE

(21)

SOLENOID

(78)

(88)

(77)

LH HARVEST

SOLENOID

(76)

DUMP SOLENOID

(98)

(59)

(83)

(73)

(56)

VIEW FOR WIRING

REMOTE

HPR

(79)

(87)

(80)

(81)

(99)

WATER PUMP

LIQUID LINE SOLENOID

CONTACTOR COIL

(94)

(F2)

(74)

(22)

(82)

(75)

N - 50H ONLY

TB30

SV1651

–43–

Q1300/Q1600/Q1800 - Remote -

3 Phase Without Terminal Board

CAUTION: DISCONNECT POWER BEFORE WORKING

ON ELECTRICAL CIRCUITRY.

DIAGRAM SHOWN DURING FREEZE CYCLE

L3 L2 L1

(88)

(42)

SEE SERIAL PLATE FOR VOLTAGE

(89)

HIGH PRES CUTOUT

ICE THICKNESS PROBE

WATER LEVEL PROBE

NOT USED

BIN SWITCH

(64)

NOTE: WIRE (96) IS NOT USED ON 50HZ

(55)

(62)

(63)

(66)

(95) (94)

(65)

(62)

3 4 2 1

TRANS.

FUSE (7A)

(67)

LOW D.C. VOLTAGE PLUG

(68)

TOGGLE SWITCH

CRANKCASE HEATER

CLEAN LIGHT

WATER LEVEL LIGHT

BIN SWITCH LIGHT

HARVEST LIGHT/ SAFETY LIMIT CODE LIGHT

ICE

(69)

OFF

CLEAN

WATER

VALVE

(21)

LH HARVEST

SOLENOID

(77)

RH HARVEST

SOLENOID

(76)

DUMP SOLENOID

(57)

WATER PUMP

(58)

CONTACTOR

(56)

VIEW

(96)

HPR SOLENOID

(78)

(88)

(98)

(59)

COIL

(20)

(61)

(60)

INTERNAL WORKING

(22)

N - 50 HZ

ONL

(79)

(87)

(80)

(75)

(81)

(99)

(82)(83)

LIQUID LINE SOLENOID

(74)

VIEW FOR WIRING

(96)

COMPRESSOR

CONTACTOR CONTACTS

(51)

(F1)

REMOTE

FAN MOTOR

RUN CAPACITOR

REMOTE CONDENSER

(F2)

SV2077

–44–

COMPONENT SPECIFICATIONS AND DIAGNOSTICS

General

Q-Model control boards use a dual voltage transformer. This means only one control board is needed for both 115V and 208-230V use.

Safety Limits

In addition to standard safety controls, such as the high pressure cut-out, the control board has built-in safety limits.

These safety limits protect the ice machine from major component failures. For more information, see “Safety Limits”

Inputs

The control board, along with inputs, controls all electrical components, including the ice machine sequence of operation. Prior to diagnosing, you must understand how the inputs affect the control board operation.

Refer to specific component specifications (inputs), wiring diagrams and ice machine sequence of operation sections for details.

As an example, refer to “Ice Thickness Probe” for information relating to how the probe and control board function together.

This section will include items such as:

• How a harvest cycle is initiated

• How the harvest light functions with the probe

• Freeze time lock-in feature

• Maximum freeze time

• Diagnosing ice thickness control circuitry

–45–

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, 7 amp.

Warning

High (line) voltage is applied to the control board (terminals #55 and #56) at all times. Removing the control board fuse or moving the toggle switch to OFF will not remove the power supplied to the control board.

CHECK PROCEDURE

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

Warning

Disconnect electrical power to the entire ice machine before proceeding.

2. Remove the fuse. Check for continuity across the fuse with an ohmmeter.

Reading Result

Open (OL) Replace fuse

Closed (O) Fuse is good

–46–

Bin Switch

FUNCTION

Movement of the water curtain controls bin switch operation. The bin switch has two main functions:

1. Terminating the Harvest cycle and returning the ice machine to the Freeze cycle. This occurs when the bin switch is opened and closed again within 7 seconds 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 open. After the water curtain is held open for 7 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, provide the 3-minute delay has expired.

Caution

The water curtain must be ON (bin switch(s) closed) to start ice making.

SPECIFICATIONS

The bin switch is a magnetically operated reed switch. The magnet is attached to the lower right corner of the water curtain. The switch is attached to the evaporator-mounting bracket.

The bin switch is connected to a varying D.C. voltage circuit. (Voltage does not remain constant.)

NOTE: Because of a wide variation in D.C. voltage, it is not recommended that a voltmeter be used to check bin switch operation.

–47–

CHECK PROCEDURE

1. Set the toggle switch to OFF.

2. Watch the bin switch light on the control board.

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

4. Move the water curtain away from the evaporator. The bin switch must open. The bin switch light “off” indicates the bin switch has opened properly.

OHM TEST

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

2. Connect an ohmmeter to the disconnected bin switch wires.

3. Cycle the bin switch by opening and closing the water curtain.

NOTE: To prevent misdiagnosis:

• Always use the water curtain magnet to cycle the

switch. Larger or smaller magnets will affect switch operation.

• Watch for consistent readings when the bin switch is

open and closed. Bin switch failure could be erratic.

–48–

Water Curtain Removal Notes

The water curtain must be on (bin switch closed) to start ice making. While a Freeze cycle is in progress, the water curtain can be removed and installed at any time without interfering with the electrical control sequence.

If the ice machine goes into Harvest sequence while the water curtain is removed, one of the following will happen:

• Water curtain remains off:

When the Harvest cycle time reaches 3.5 minutes and the bin switch is not closed, the ice machine stops as though the bin were full.

• Water curtain is put back on:

If the bin switch closes prior to reaching the

3.5-minute point, the ice machine immediately returns to another Freeze sequence prechill.

–49–

ICE/OFF/CLEAN Toggle Switch

FUNCTION

The switch is used to place the ice machine in ICE, OFF or CLEAN mode of operation.

SPECIFICATIONS

Double-pole, double-throw switch. The switch is connected into a varying low D.C. voltage circuit.

CHECK PROCEDURE

NOTE: Because of a wide variation in D.C. voltage, it is not recommended that a voltmeter be used to check toggle switch operation.

1. Inspect the toggle switch for correct wiring.

2. Isolate the toggle switch by disconnecting all wires from the switch, or by disconnecting the Molex connector and removing wire #69 from the toggle switch.

3. Check across the toggle switch terminals using a calibrated ohmmeter. Note where the wire numbers are connected to the switch terminals, or refer to the wiring diagram to take proper readings.

Switch

Setting

Terminals Ohm Reading

66-62 Open

ICE

67-68 Closed 67-69 Open 66-62 Closed

CLEAN

67-68 Open 67-69 Closed 66-62 Open

OFF

67-68 Open 67-69 Open

4. Replace the toggle switch if ohm readings do not match all three switch settings.

–50–

Ice Thickness Probe (Harvest Initiation)

HOW THE PROBE WORKS

Manitowoc’s electronic sensing circuit does not rely on refrigerant pressure, evaporator temperature, water levels or timers to produce consistent ice formation.

As ice forms on the evaporator, water (not ice) contacts the ice thickness probe. After the water completes this circuit across the probe continuously for 6-10 seconds, a Harvest cycle is initiated.

HARVEST/SAFETY LIMIT LIGHT

This light’s primary function is to be on as water contacts the ice thickness probe during the freeze cycle, and remain on throughout the entire harvest cycle. The light will flicker as water splashes on the probes.

The light’s secondary function is to continuously flash when the ice machine is shut off on a safety limit, and to indicate which safety limit shut off the ice machine.

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. If water contacts the ice thickness probe during these six minutes, the harvest light will come on (to indicate that water is in contact with the probe), but the ice machine will stay in the freeze cycle. After the six minutes are up, a harvest cycle is initiated. This is important to remember when performing diagnostic procedures on the ice thickness control circuitry.

To allow the service technician to initiate a harvest cycle without delay, this feature is not used on the first cycle after moving the toggle switch OFF and back to ICE.

–51–

MAXIMUM FREEZE TIME

The control system includes a built-in safety which will automatically cycle the ice machine into harvest after 60 minutes in the freeze cycle.

ICE THICKNESS CHECK

The ice thickness probe is factory-set to maintain the ice bridge thickness at 1/8 in. (.32 cm).

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 in. (.32 cm) thick.

2. If adjustment is necessary, turn the ice thickness probe adjustment screw clockwise to increase bridge thickness or counterclockwise to decrease bridge thickness.

NOTE: Turning the adjustment 1/3 of a turn will change the ice thickness about 1/16 in. (.15 cm). The starting point before final adjustment is approximately a 3/16 in. gap. Make sure the ice thickness probe wire and the bracket do not restrict movement of the probe

ADJUSTING

SCREW

1/8” ICE BRIDGE THICKNESS

ICE THICKNESS ADJUSTMENT

SV3114

–52–

Ice Thickness Probe Diagnostics

Before diagnosing ice thickness control circuitry clean the ice thickness probe using the following procedure.

1. Mix a solution of Manitowoc ice machine cleaner and water (2 ounces of cleaner to 16 ounces of water) in a container.

2. Soak ice thickness probe in container of cleaner/ water solution while disassembling and cleaning water circuit components (soak ice thickness probe for 10 minutes or longer).

3. Clean all ice thickness probe surfaces including all plastic parts (do not use abrasives). Verify the ice thickness probe cavity is clean. Thoroughly rinse ice thickness probe (including cavity) with clean water, then dry completely. Incomplete rinsing

and drying of the ice thickness probe can cause premature harvest.

4. Reinstall ice thickness probe, then sanitize all ice machine and bin/dispenser interior surfaces.

–53–

Diagnosing Ice Thickness Control Circuitry

ICE MACHINE DOES NOT CYCLE INTO HARVEST WHEN WATER CONTACTS THE ICE THICKNESS CONTROL PROBE

Step 1. Bypass the freeze time lock-in feature by moving the ICE/OFF/CLEAN switch to OFF and back to ICE. Wait until the water starts to flow over the evaporator.

Step 2. Clip the jumper wire leads to the ice thickness probe and any cabinet ground.

Monitor the Harvest light.

Harvest Light On

• The Harvest light comes on, and 6-10 seconds later,

the ice machine cycles from Freeze to Harvest.

The ice thickness control circuitry is functioning properly. Do not change any parts.

• The Harvest light comes on, but the ice machine

stays in the Freeze sequence.

The ice thickness control circuitry is functioning properly. The ice machine is in a six-minute freeze time lock-in. Verify step 1 of this procedure was followed correctly.

Harvest Light Off

• The Harvest light does not come on. Proceed to step 3.

–54–

Step 3. Disconnect the ice thickness probe from the control board at terminal 1C. Clip the jumper wire leads to terminal 1C on the control board and any cabinet ground.

Monitor the Harvest light.

Harvest Light On

• The harvest light comes on, and 6-10 seconds later,

the ice machine cycles from Freeze to Harvest.

The ice thickness probe is causing the malfunction.

• The Harvest light comes on, but the ice machine

stays in the Freeze sequence.

The control circuitry is functioning properly. The ice machine is in a six-minute freeze time lock-in (verify step 1 of this procedure was followed correctly).

Harvest Light Off

• The Harvest light does not come on.

The control board is causing the malfunction.

ICE MACHINE CYCLES INTO HARVEST BEFORE WATER CONTACT WITH THE ICE THICKNESS PROBE

Step 1. Bypass the freeze time lock-in feature by moving the ICE/OFF/CLEAN switch to OFF and back to ICE. Wait until the water starts to flow over the evaporator, then monitor the Harvest light.

Step 2. Disconnect the ice thickness probe from the control board at terminal 1C

• The Harvest light stays off, and the ice machine

remains in the Freeze sequence.

The ice thickness probe is causing the malfunction. Verify that the ice thickness probe is adjusted correctly and clean.

• The Harvest light comes on, and 6-10 seconds later,

the ice machine cycles from Freeze to Harvest.

The control board is causing the malfunction.

–55–

Water Level Control Circuitry

The water level probe circuit can be monitored by watching the water level light. The water level light is on when water contacts the probe, and off when no water is in contact with the probe. The water level light functions any time power is applied to the ice machine, regardless of toggle switch position.

WATER

PUMP

WATER

LEVEL

ABOVE

HOUSING

WATER

PUMP

IMPELLER

HOUSING

WATER

LEVEL

SENSOR

PROBE

SV1616

FREEZE CYCLE WATER LEVEL SETTING

During the Freeze cycle, the water level probe is set to maintain the proper water level above the water pump housing. The water level is not adjustable. If the water level is incorrect, check the water level probe for damage (probe bent, etc.). Repair or replace the probe as necessary.

WATER INLET VALVE SAFETY SHUT-OFF

In the event of a water level probe failure, this feature limits the water inlet valve to a six-minute on time. Regardless of the water level probe input, the control board automatically shuts off the water inlet valve if it remains on for 6 continuous minutes. This is important to remember when performing diagnostic procedures on the water level control circuitry.

–56–

FREEZE CYCLE CIRCUITRY

Manitowoc’s electronic sensing circuit does not rely on float switches or timers to maintain consistent water level control. During the Freeze cycle, the water inlet valve energizes (turns on) and de-energizes (turns off) in conjunction with the water level probe located in the water trough.

During the first 45 seconds of the Freeze cycle:

The water inlet valve is ON when there is no water in contact with the water level probe.

• The water inlet valve turns OFF after water contacts

the water level probe for 3 continuous seconds.

• The water inlet valve will cycle ON and OFF as

many times as needed to fill the water trough.

After 45 seconds into the Freeze cycle:

The water inlet valve will cycle ON, and then OFF one more time to refill the water trough. The water inlet valve is now OFF for the duration of the Freeze sequence.

HARVEST CYCLE CIRCUITRY

The water level probe does not control the water inlet valve during the Harvest cycle. During the Harvest cycle water purge, the water inlet valve energizes (turns on) and de-energizes (turns off) strictly by time. The harvest water purge adjustment dial may be set at 15, 30 or 45 seconds.

NOTE: The water purge must be at the factory setting of 45 seconds for the water inlet valve to

energize during the last 15 seconds of the water purge. If set at 15 or 30 seconds, the water inlet valve will not energize during the harvest water purge.

CONTROL

BOARD

HARVEST

WATER PURGE

ADJUSTMENT

–57–

DIAGNOSING WATER LEVEL CONTROL CIRCUITRY

Problem: Water Trough Overfilling During the Freeze Cycle

Step 1. Start a new Freeze sequence by moving the

ICE/OFF/CLEAN toggle switch to OFF and then back to ICE.

Important

This restart must be done prior to performing diagnostic procedures. This assures the ice machine is not in a Freeze cycle water inlet valve safety shutoff mode. You must complete the entire diagnostic procedure within 6 minutes of starting.

Step 2. Wait until the Freeze cycle starts (approximately 45 seconds – the Freeze cycle starts when the compressor energizes), then connect a jumper from the water level probe to any cabinet ground. Refer to the chart on the next page.

Important

For the test to work properly, you must wait until the Freeze cycle starts, prior to connecting the jumper wire. If you restart the test, you must disconnect the jumper wire, restart the ice machine (step 1), and then reinstall the jumper wire after the compressor starts.

–58–

Step 2. Jumper Wire Connected

from Probe to Ground

Is Water

Flowing

into the

Water

Trough?

The

Water

Level

Light Is:

The Water

Inlet Valve

Solenoid

Coil Is:

No On De-energized

Yes On De-energized

Yes Off Energized

Cause

This is normal

operation.

Do not

change any

parts.

The water

inlet valve is

causing the

problem.

Proceed to

step 3.

–59–

Step 3. Allow ice machine to run. Disconnect the water level probe from control board terminal 1F, and connect a jumper wire from terminal 1F to any cabinet ground.

Remember, if you are past 6 minutes from starting, the ice machine will go into a Freeze cycle water inlet valve safety shut-off mode, and you will be unable to complete this test. If past 6 minutes, you must restart this test by disconnecting the jumper wire, restarting the ice machine (step 1), and then reinstalling the jumper wire to terminal 1F after the compressor starts.

Step 3. Jumper Wire Connected from Control Board Terminal 1F to Ground

Is Water

Flowing

into the

Water

Trough?

The

Water

Level

Light Is:

The Water

Inlet Valve

Solenoid

Coil Is:

No On De-energized

Yes Off Energized

Yes Off De-energized

Cause

The water

level probe is

causing the

problem. Clean or

replace the

water level

probe.

The control

board is

causing the

problem.

The water fill

valve is

causing the

problem.

–60–

Problem: Water Will Not Run into the Sump Trough During the Freeze Cycle

Step 1. Verify water is supplied to the ice machine,

and then start a new Freeze sequence by moving the ICE/OFF/CLEAN toggle switch to OFF, then back to ICE.

Important

Step 2. Wait until the Freeze cycle starts (approximately 45 seconds – the Freeze cycle starts when the compressor energizes), and then refer to the chart.

Step 2. Checking for Normal Operation

Is Water

Flowing

into the

Water

Trough?

The

Water

Level

Light Is:

The Water

Inlet Valve

Solenoid

Coil Is:

Yes Off Energized

Energized

De-energized

On or

Off

Cause

This is

normal

operation.

Do not

change any

parts.

Proceed to

step 3.

–61–

Step 3. Leave the ice machine run, and then disconnect the water level probe from control board terminal 1F.

Important

For the test to work properly you must wait until the Freeze cycle starts, prior to disconnecting the water level probe. If you restart the test, you must reconnect the water level probe, restart the ice machine (step 1), and then disconnect the water level probe after the compressor starts.

Step 3. Disconnect Probe from 1F

Is Water

Flowing

into the

Water

Trough?

The

Water

Level

Light Is:

The Water

Inlet Valve

Solenoid

Coil Is:

Yes Off Energized

No Off Energized

On or

Off

De-energized

Cause

The water

level probe is

causing the

problem. Clean or

replace the

water level

probe.

The water

inlet valve is

causing the

problem.

The control

board is

causing the

problem.

–62–

Diagnosing an Ice Machine Head Section that Will Not Run

Warning

High (line) voltage is applied to the control board (terminals #55 and #56) at all times. Removing control board fuse or moving the toggle switch to OFF will not remove the power supplied to the control board.

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

2. Verify the High Pressure cutout is closed. The HPCO is closed if primary power voltage is present at terminals #55 and #56 on the control board.

3. Verify control board fuse is okay. If the bin switch or water level probe light functions, the fuse is okay.

4. Verify all bin switches function properly. A defective bin switch can falsely indicate a full bin of ice.

5. Verify ICE/OFF/CLEAN toggle switch functions properly. A defective toggle switch may keep the ice machine in the OFF mode.

6. Verify low DC voltage is properly grounded. Loose DC wire connections may intermittently stop the ice machine.

7. Replace the control board. Be sure steps 1-6 were followed thoroughly. Intermittent problems are not usually related to the control board.

–63–

Compressor Electrical Diagnostics

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 assure that the overload is closed and the resistance readings will be accurate.

SINGLE PHASE COMPRESSORS

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

2. The resistance values must be within published guidelines for the compressor. 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 and between C and R. Allow the compressor to cool, then check the readings again.

THREE PHASE COMPRESSORS

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

2. The resistance values must be within published guidelines for the compressor. The resistance values between L1 and L2, between L2 and L3, and between L3 and L1 should all be equal.

3. If the overload is open, there will be open readings between L1 and L2, between L2 and L3, and between L3 and L1. Allow the compressor to cool, then check the readings again.

–64–

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.

COMPRESSOR DRAWING LOCKED ROTOR

The two likely causes of this are a defective starting component and a mechanically seized compressor.

To determine which you have:

• Install high and low side gauges.

• Try to start the compressor.

• 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 capacitors and relay.

COMPRESSOR DRAWING HIGH AMPS

The continuous amperage draw on start-up should not be near the maximum fuse size indicated on the serial tag.

The wiring must be correctly sized to minimize voltage drop at compressor start-up. The voltage when the compressor is trying to start must be within ±10% of the nameplate voltage.

–65–

Diagnosing Capacitors

• If the compressor attempts to start, or hums and

trips the overload protector, check the starting components before replacing the compressor.

• Visual evidence of capacitor failure can include a

bulged terminal end or a ruptured membrane. Do not assume a capacitor is good if no visual evidence is present.

• A good test is to install a known good substitute

capacitor.

• Use a capacitor tester when checking a suspect

capacitor. Clip the bleed resistor off the capacitor terminals before testing.

TROUBLESHOOTING PTCR’S

WHY A GOOD PTCR MAY FAIL TO START THE COMPRESSOR

A good PTCR might not operate properly at start-up because:

• The ice machine’s 3-minute delay has been

overridden. Opening and closing the service disconnect or cycling the toggle switch from OFF to ICE will override the delay period.

• The control box temperature is too high. Though

rare, very high air temperatures (intense sunlight, etc.) can greatly increase the temperature of the control box and its contents. This may require a longer off time to allow the PTCR to cool.

• The compressor has short-cycled, or the

compressor overload has opened. Move the toggle switch to OFF and allow the compressor and PTCR to cool.

–66–

• The voltage at the compressor during start-up is too

low. Manitowoc ice machines are rated at ±10% of nameplate voltage at compressor start-up. (Ex: An ice machine rated at 208-230 should have a compressor start-up voltage between 187 and 253 volts.)

• The compressor discharge and suction pressures

are not matched closely enough or equalized. These two pressures must be somewhat equalized before attempting to start the compressor. The harvest valve (and HPR valve on remotes) energizes for 45 seconds before the compressor starts, and remains on 5 seconds after the compressor starts. Make sure this is occurring and the harvest valve (and HPR solenoid) coil is functional before assuming that the PTCR is bad.

Warning

Disconnect electrical power to the entire ice machine at the building electrical disconnect box before proceeding.

CHECKING THE PTCR

1. Visually inspect the PTCR. Check for signs of physical damage.

NOTE: The PTCR case temperature may reach 210°F (100°C) while the compressor is running. This is normal. Do not change a PTCR just because it is hot.

2. Wait at least 10 minutes for the PTCR to cool to room temperature.

3. Remove the PTCR from the ice machine.

4. Measure the resistance of the PTCR as shown on the next page. If the resistance falls outside of the acceptable range, replace it.

–67–

Model

Q200 Q280 Q320 Q420 Q450

Q600 Q800

Q1000

Q1300 Q1600 Q1800

Manitowoc

Part Number

Cera-Mite

Part Number

Room

Temperature

Resistance

8505003 305C20 22-50 Ohms

8504993 305C19 18-40 Ohms

8504913 305C9 8-22 Ohms

Manitowoc PTCR’s 8505003 & 8504993

Manitowoc PTCR’s 8504913

–68–

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–69–

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–70–

Refrigeration System

REFRIGERATION SYSTEM DIAGNOSTICS

Before Beginning Service

Ice machines may experience operational problems only during certain times of the day or night. A machine may function properly while it is being serviced, but malfunctions later. Information provided by the user can help the technician start in the right direction, and may be a determining factor in the final diagnosis.

Ask these questions before beginning service:

• When does the ice machine malfunction? (night,

day, all the time, only during the Freeze cycle, etc.)

• When do you notice low ice production? (one day a

week, every day, on weekends, etc.)

• Can you describe exactly what the ice machine

seems to be doing?

• Has anyone been working on the ice machine?

• During “store shutdown,” is the circuit breaker, water

supply or air temperature altered?

• Is there any reason why incoming water pressure

might rise or drop substantially?

–71–

Ice Production Check

The amount of ice a machine produces directly relates to the operating water and air temperatures. This means a condensing unit with a 70°F (21.2°C) outdoor ambient temperature and 50°F (10.0°C) water produces more ice than the same model condensing unit with a 90°F (32.2°C) outdoor ambient temperature and 70°F (21.2°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-Hour 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

2. 1440

_________

Minutes in

24 Hrs.

3. _________

Weight of One

Harvest

+ _________

Harvest Time

÷ _________

Total Cycle

Time

× _________

Cycles per Day

= _________

Total Cycle

Time

= _________

Cycles per Day

= _________

Actual 24-Hour

Production

Weighing the ice is the only 100% accurate check. However, if the ice pattern is normal and the 1/8 in. thickness is maintained, the ice slab weights listed with the 24-Hour Ice Production Charts may be used.

–72–

4. Compare the results of step 3 with step 2. Ice production checks that are within 10% of the chart are considered normal. This is due to variances in water and air temperature. Actual temperatures will seldom match the chart exactly. If they match closely, determine if:

• Another ice machine is required.

• More storage capacity is required.

• Relocating the existing equipment to lower the load

conditions is required.

Contact the local Manitowoc Distributor for information on available options and accessories.

Installation/Visual Inspection Checklist

Possible Problem List

• Corrective Action List

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

Line set is improperly installed

• Reinstall according to the Installation Manual

–73–

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.

Possible Problem List

• Corrective Action List

Water area (evaporator) is dirty

• Clean as needed

Water inlet pressure not between 20 and 80 psig

• 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

Water dump valve leaking during the Freeze cycle

• Clean/replace dump valve as needed

Vent tube is not installed on water outlet drain

• See Installation Instructions

Hoses, fittings, etc., are leaking water

• Repair/replace as needed

Water fill valve is stuck open or closed

• 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

–74–

Ice Formation Pattern

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 Manitowoc’s Refrigeration System Operational Analysis Table, it can help diagnose an ice machine malfunction.

Any number of problems can cause improper ice formation.

Example: An ice formation that is “extremely thin on top” could be caused by a hot water supply, a dump valve leaking water, a faulty water fill valve, a low refrigerant charge, etc.

Important

Keep the water curtain in place while checking the ice formation pattern to ensure no water is lost.

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

The ice thickness probe must be set to maintain the ice bridge thickness at approximately 1/8 in. If ice forms uniformly across the evaporator surface, but does not reach 1/8 in. in the proper amount of time, this is still considered normal.

–75–

2. Extremely Thin at Evaporator Outlet

There is no ice, or a considerable lack of ice formation, on the top of the evaporator (tubing outlet).

Examples: No ice at all on the top of the evaporator, but ice forms on the bottom half of the evaporator. Or, the ice at the top of the evaporator reaches 1/8 in. to initiate a harvest, but the bottom of the evaporator already has 1/2 in. to 1 in. of ice formation.

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

3. Extremely Thin at Evaporator Inlet

There is no ice, or a considerable lack of ice formation on the bottom of the evaporator (tubing inlet). Examples: The ice at the top of the evaporator reaches 1/8 in. to initiate a harvest, but there is no ice formation at all on the bottom of the evaporator.

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

4. Spotty Ice Formation

There are small sections on the evaporator where there is no ice formation. This could be a single corner or a single spot in the middle of the evaporator. This is generally caused by loss of heat transfer from the tubing on the backside of the evaporator.

5. 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.

Important

Q1300, Q1600, and Q1800 model machines have left and right expansion valves and separate evaporator circuits. These circuits operate independently from each other. Therefore, one may operate properly while the other is malfunctioning.

Example: If the left expansion valve is starving, it may not affect the ice formation pattern on the right side of the evaporator.

–76–

Safety Limits

GENERAL

In addition to standard safety controls, such as high pressure cut-out, the control board has two built in safety limit controls which protect the ice machine from major component failures. There are two control boards with different safety limit sequences. Original production control boards have a black microprocessor. Current production and replacement control boards have an orange label on the control board microprocessor.

Safety Limit #1: If the freeze time reaches 60 minutes, the control board automatically initiates a harvest cycle.

Control Board with Black Microprocessor

•If 3 consecutive 60-minute freeze cycles occur, the ice machine stops.

Control Board with Orange Label on Microprocessor

•If 6 consecutive 60-minute freeze cycles occur, the ice machine stops.

Safety Limit #2: If the harvest time reaches 3.5 minutes, the control board automatically returns the ice machine to the freeze cycle.

Control Board with Black Microprocessor

•If three consecutive 3.5 minute harvest cycles occur, the ice machine stops.

Control Board with Orange Label on Microprocessor

•If 500 consecutive 3.5 minute harvest cycles occur, the ice machine stops.

–77–

SAFETY LIMIT INDICATION

Control Board with Black Microprocessor

When a safety limit condition is exceeded for 3 consecutive cycles the ice machine stops and the harvest light on the control board continually flashes on and off. Use the following procedures to determine which safety limit has stopped the ice machine.

1. Move the toggle switch to OFF.

2. Move the toggle switch back to ICE.

3. Watch the harvest light. It will flash one or two times, corresponding to safety limits 1 and 2, to indicate which safety limit stopped the ice machine.

After safety limit indication, the ice machine will restart and run until a safety limit is exceeded again.

Control Board with Orange Label on Microprocessor

When a safety limit condition is exceeded for 3 consecutive cycles the control board enters the limit into memory and the ice machine continues to run. Use the following procedures to determine if the control board contains a safety limit indication.

1. Move the toggle switch to OFF.

2. Move the toggle switch back to ICE.

3. Watch the harvest light. If a safety limit has been recorded, the harvest light will flash one or two times, corresponding to safety limit 1 or 2.

–78–

When a safety limit condition is exceeded (6 consecutive cycles for Safety Limit #1 or 500 cycles for Safety Limit #2) the ice machine stops and the harvest light on the control board continually flashes on and off. Use the following procedures to determine which safety limit has stopped the machine.

1. Move the toggle switch to OFF.

2. Move the toggle switch back to ICE.

3. Watch the harvest light. It will flash one or two times, corresponding to safety limit 1 or 2 to indicate which safety limit stopped the ice machine.

After safety limit indication, the ice machine will restart and run until a safety limit is exceeded again.

Orange Label

CONTROL BOARD WTH ORANGE

LABEL ON MICROPROCESSOR

–79–

ANALYZING WHY SAFETY LIMITS MAY STOP THE ICE MACHINE

According to the refrigeration industry, a high percentage of compressors fail as a result of external causes. These can include: flooding or starving expansion valves, dirty condensers, water loss to the ice machine, etc. The safety limits protect the ice machine (primarily the compressor) from external failures by stopping ice machine operation before major component damage occurs.

The safety limit system is similar to a high pressure cut-out control. It stops the ice machine, but does not tell what is wrong. The service technician must analyze the system to determine what caused the high pressure cut-out, or a particular safety limit, to stop the ice machine.

The safety limits are designed to stop the ice machine prior to major component failures, most often a minor problem or something external to the ice machine. This may be difficult to diagnose, as many external problems occur intermittently.

Example: An ice machine stops intermittently on safety limit #1 (long freeze times). The problem could be a low ambient temperature at night, a water pressure drop, the water is turned off one night a week, etc.

When a high pressure cut-out or a safety limit stops the ice machine, they are doing what they are supposed to do. That is, stopping the ice machine before a major component failure occurs.

Refrigeration and electrical component failures may also trip a safety limit. Eliminate all electrical components and external causes first. If it appears that the refrigeration system is causing the problem, use Manitowoc’s Refrigeration System Operational Analysis Table, along with detailed charts, checklists, and other references to determine the cause.

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.

–80–

SAFETY LIMIT NOTES

• Because there are many possible external

problems, do not limit your diagnosis to only the items listed in these charts.

• A continuous run of 100 harvests automatically

erases the safety limit code.

• The control board will store and indicate only one

safety limit – the last one exceeded.

• If the toggle switch is moved to the OFF position and

then back to the ICE position prior to reaching the 100-harvest point, the last safety limit exceeded will be indicated.

• If the Harvest light did not flash prior to the ice

machine restarting, then the ice machine did not stop because it exceeded a safety limit.

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.

–81–

Safety Limit #1

Refer to page 75 for control board identification and safety limit operation.

Control Board with Black Microprocessor

- Freeze

Time exceeds 60 minutes for 3 consecutive freeze cycles

Control Board with Orange Label on Microprocessor - Freeze time exceeds 60 minutes

for 6 consecutive freeze cycles

Possible Cause Checklist

Improper Installation

• Refer to “Installation/Visual Inspection Checklist”

Water System

• Low water pressure (20 psig min.)

• High water pressure (80 psig max.)

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

• Clogged water distribution tube

• Dirty/defective water fill valve

• Dirty/defective water dump valve

• Defective water pump

Electrical System

• Ice thickness probe out of adjustment

• Harvest cycle not initiated electrically

• Contactor not energizing

• Compressor electrically non-operational

• Restricted condenser airflow

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

• Condenser discharge air recirculation

• Dirty condenser fins

• Dirty condenser filter

• Defective fan cycling control

• Defective fan motor

• Restricted condenser water flow

• Low water pressure (20 psig min.)

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

• Dirty condenser

• Dirty/defective water regulating valve

• Water regulating valve out of adjustment

–82–

Refrigeration System

• Non-Manitowoc components

• Improper refrigerant charge

• Defective head pressure control (remotes)

• Defective harvest valve

• Defective compressor

• TXV starving or flooding (check bulb mounting)

• Non-condensable in refrigeration system

• Plugged or restricted high side refrigerant lines or

component

Safety Limit #2

Refer to page 75 for control board identification and safety limit operation.

Control Board with Black Microprocessor

- Harvest time exceeds 3.5 minutes for 3 consecutive harvest cycles.

Control Board with Orange Label on Microprocessor - Harvest time exceeds 3.5 minutes

for 500 consecutive harvest cycles.

Possible Cause Checklist

Improper Installation

• Refer to “Installation/Visual Inspection Checklist”

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

• Low water pressure (20 psig min.)

• Loss of water from sump area

• Clogged water distribution tube

• Dirty/defective water fill valve

• Defective water pump

–83–

Electrical System

• Ice thickness probe out of adjustment

• Ice thickness probe dirty

• Bin switch defective

• Premature harvest

Refrigeration System

• Non-Manitowoc components

• Water regulating valve dirty/defective

• Improper refrigerant charge

• Defective head pressure control valve (remotes)

• Defective harvest valve

• TXV flooding (check bulb mounting)

• Defective fan cycling control

–84–

Analyzing Discharge Pressure

1. Determine the ice machine operating conditions:

Air temp. entering condenser ______

Air temp. around ice machine ______

Water temp. entering sump trough ______

2. Refer to Operating Pressure Chart 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.

Freeze

Cycle psig

Beginning of Cycle __________ __________

Middle of Cycle __________ __________

End of Cycle __________ __________

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 actual pressure falls within the published pressure range for the ice machine’s operating conditions. It is normal for the discharge pressure to be higher at the beginning of the Freeze cycle (when load is greatest), then drop throughout the Freeze cycle.

–85–

DISCHARGE PRESSURE HIGH CHECKLIST

Problem

• Cause

Improper Installation

• Refer to “Installation/Visual Inspection Checklist”

Restricted Condenser Air Flow

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

• Condenser discharge air recirculation

• Dirty condenser filter

• Dirty condenser fins

• Defective fan cycling control

• Defective fan motor

Restricted Condenser water flow

• Low water pressure (20 psi min.)

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

• Dirty condenser

• Dirty/Defective water regulating valve

• Water regulating valve out of adjustment

Improper Refrigerant Charge

• Overcharged

• Non-condensable in system

• Wrong type of refrigerant

Other

• Non-Manitowoc components in system

• High side refrigerant lines/component restricted

(before mid-condenser)

• Defective head pressure control valve

–86–

FREEZE CYCLE DISCHARGE PRESSURE LOW CHECKLIST

Problem

• Cause

Improper Installation

• Refer to “Installation/Visual Inspection Checklist”

Improper Refrigerant Charge

• Undercharged

• Wrong type of refrigerant

Water regulating valve (water cooled condensers)

• Out of adjustment

• Defective

Other

• Non-Manitowoc components in system

• High side refrigerant lines/component restricted

(after mid-condenser)

• Defective head pressure control valve

• Defective fan cycle control

NOTE: Do not limit your diagnosis to only the items listed in the checklists.

–87–

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 pressure. High or low discharge pressure may be causing high or low suction pressure.

–88–

Step

1. Determine the ice machine operating conditions.

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.

2B. Compare the published

Freeze cycle time and published Freeze cycle suction pressure. Develop a chart.

Procedure

Example Using

QY0454A Model Ice Machine

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

13.7-14.1 minutes Published Freeze cycle time:

55-36 psig Published Freeze cycle suction pressure:

Published Freeze Cycle Time

135791214

(minutes)

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.

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.

55 52 48 44 41 38 36

Published Freeze Cycle Suction

Pressure (psig)

In the example, the proper suction pressure should be approximately 44 psig at 7 minutes; 41 psig at 9 minutes; etc.

Manifold gauges were connected to the example ice machine and suction pressure readings taken as follows:

psig

Beginning of Freeze cycle: 59 (at 1 min.)

Middle of Freeze cycle: 48 (at 7 min.)

End of Freeze cycle: 40 (at 14 min.)

In this example, the suction pressure is considered high throughout the Freeze cycle. It should have been:

Approximately 55 psig (at 1 minute) – not 59

Approximately 44 psig (at 7 minutes) – not 48

Approximately 36 psig (at 14 minutes) – not 40

–89–

SUCTION PRESSURE HIGH CHECKLIST

Problem

• Cause

Improper Installation

• Refer to “Installation/Visual Inspection Checklist”

Discharge Pressure

• Discharge pressure is too high and is affecting low

side – refer to “Freeze Cycle Discharge Pressure High Checklist”

Improper Refrigerant Charge

• Overcharged

• Wrong type of refrigerant

Other

• Non-Manitowoc components in system

• HPR solenoid leaking

• Harvest valve leaking

• TXV flooding (check bulb mounting)

• Defective compressor

–90–

Manitowoc Q450, Q800, Q100, Q1300, Q1600 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual