©Manitowoc Ice, Inc.
P/N 80-1099-9 8/03
Safety Notices
!
Warning
!
Caution
Important
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:
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.
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:
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: T ext set off as a Note provides you with simple,
but useful extra information about the procedure you
are performing.
Read These Before Proceeding:
!
Caution
Important
!
Warning
!
Warning
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.
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.
PERSONAL INJURY POTENTIAL
Do not operate equipment that has b een misused,
abused, neglected, damaged, or altered/modified
from that of original manufactured specifications.
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
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General Information
Q R 0450 A
ICE MACHINE
MODEL
ICE CUBE SIZE
R REGULAR
D DICE
Y HALF DICE
# C U BE 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
A SELF-CONTAINED AIR-COOLED
W SELF-CONTAINED WATER-COOLED
N REMOTE AIR-COOLED
9 REMOTE AIR-COOLED
CONDENSER TYPE
ICE MACHINE
SERI ES
HOW TO READ A MODEL NUMBER
ICE CUBE SIZES
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
Important
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.
Complete and mail the OWNER WARRANTY
REGISTRATION CARD as soon as possible to
validate the installation date.
If the OWNER WARRANTY REGISTRA TION 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
Important
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.
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)
Self-Contained
Air-Cooled
Water-Cooled
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)
Q1600 is not available as an air-cooled model.
Self-Contained
Air-Cooled
Self-Contained
Air-Cooled
–5–
Water-Cooled
and Remote
Water-Cooled
and Remote
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
!
Caution
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).
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
!
Caution
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.
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
SV1624
spring coils of the water regulating valve. Pry
upward to open the valve.
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® ACCESSORY
Refer to the AuCS Accessory manual for
winterization of the AuCS
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 fo rmed, the wate r 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–
Ice Making
Sequence of
Operation
Initial Start-Up
1. Water Purge
–17–
2. Refrigeration
System Start-up
Freeze Sequence
3. Prechill
4. Freeze On
Energized Parts Chart
Control Board Relays Contactor
1
Water
Pump
On Off On On Off Off Off
Off On On Off On On
Off
2
Water Fill
Valve
May Cycle
On/Off
during first
45 sec.
Cycles
On then Off
one more
time
3
Harvest
Valve
4
Water
Dump
Valve
5
Contactor
Coil
Compressor
Off Off On On
Off Off On On
5A
Condenser
Fan Motor
May Cycle
On/Off
May Cycle
On/Off
May Cycle
On/Off
5B
Length
of Time
45 Seconds
5 Seconds
30 Seconds
Unit 7 Sec.
Water Contact
w/Ice Thickness Probe
Energized Parts Chart (Continued)
Ice Making
Sequence of
Operation
1
Water
Pump
Harvest Sequence
5. Water Purge
–18–
6. Harvest Off Off On Off On On
7. Automatic
Shut-Off
On
Off Off Off Off Off Off Off
Control Board Relays Contactor
2
Water Fill
Valve
30 sec.
Off
15 sec.
On
3
Harvest
Valve
4
Water
Dump
Valve
5
Contactor
Coil
On On On On
5A
Compressor
5B
Condenser
Fan Motor
May Cycle
On/Off
May Cycle
On/Off
Length
of Time
Factory
Set at
45 Seconds
Bin Switch
Activation
Until Bin Switch
Re-closes
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 fo rmed, the wate r 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
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”) 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
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 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–
Ice Making
Sequence of
Operation
Initial Start-Up
–22–
1. Water Purge
2. Refrigeration
System Start-up
Freeze Sequence
3. Prechill
4. Freeze On
Remote Energized Parts Chart
Control Board Relays Contactor
1
Water
Pump
On Off On On Off Off Off
Off On On Off On On On
Off
2
Water Fill
Valve
May Cycle
On/Off
during first
45 sec.
Cycles
On then Off
one more
time
3
a. Harvest
Valve(s)
b. HPR
Solenoid
4
Water
Dump
Valve
5
a. Contactor
Coil
b. Liquid Line
Solenoid
5A
Compressor5BCondenser
Off Off On On On
Off Off On On On
Fan Motor
Length
of Time
45 Seconds
5 Seconds
30 Seconds
Unit 7 Sec.
Water Contact
w/Ice Thickness
Probe
Remote Energized Parts Chart (Continued)
Ice Making
Sequence of
Operation
1
Water
Pump
Harvest Sequence
5. Water Purge
–23–
On
6. Harvest Off Off On Off On On On
7. Automatic
Shut-Off
Off Off Off Off Off Off Off
Control Board Relays Contactor
2
Water Fill
Valve
30 sec.
Off
15 sec.
On
3
a. Harvest
Valve(s)
b. HPR
Solenoid
4
Water
Dump
Valve
5
a. Contactor
Coil
b. Liquid Line
Solenoid
5A
Compressor5BCondenser
On On On On On
Fan Motor
Length
of Time
Factory
Set at
45 Seconds
Bin Switch
Activation
Until Bin
Switch
Recloses
THIS PAGE INTENTIONALLY LEFT BLANK
–24–
Electrical System
!
Warning
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.
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)
C
S
R
TB31
TB37
TB32
TB35
L1
TB34
(53)
TB33
(52)
(51)
(48)
(50)
(49)
(47)
(55)
(61)
(77)
(76)
(60)
(98)
(57)
(74)
(58)
(59)
(73)
(99)
(85) (86)
1F
3
1
2
4
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
(75)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(80)
WATER
PUMP
TB30
TB30
TB30
TB30
CONTACTOR
COIL
HIGH PRES
CUTOUT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
TB35
TB30
CONTACTOR
CONTACTS
L1
(42)
COMPRESSOR
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
L2 (N)
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
PTCR
TB30
TB30
LOW D.C.
VOLTAGE
PLUG
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(66)
(62)
VIEW FOR WIRING
INTERNAL WORKING
VIEW
*OVERLOAD
CLEAN LIGHT
1C
WATER LEVEL LIGHT
WATER LEVEL PROBE
5
(21) (22)
WATER
VALVE
1G
NOT USED
SV1654
1 Phase With Terminal Board
–26–
Q280/Q370 - Self Contained -
5
2
1
4
START
CAPACITOR
POTENTIAL
RELAY
C
S
R
COMPRESSOR
TERMINAL LAYOUT
VIEWED FROM END
OF COMPRESSOR
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
SAFETY LIMIT CODE LIGHT
HARVEST LIGHT/
WATER LEVEL
CLEAN LIGHT
BIN SWITCH LIGHT
CLEAN
OFF
ICE
(68)
(69)
(62)
(49)
(47)
COMPRESSOR
OVERLOAD INTERNAL
{230V 50/60 HZ}
R
C
S
(86)(85)
(51)
(48)
CONTACTOR
CONTACTS
(42)
L1
FAN CYCLE CONTROL
RUN CAPACITOR**
FAN MOTOR
(AIR COOLED ONLY)
(50)
62
66
VIEW FOR
WIRING
67
68
69
SEE SERIAL PLATE FOR VOLTAGE
L2 (N)
(74)
TERMINATES AT
PIN CONNECTION
(59)
(58)
(56)
(98)
DUMP
SOLENOID
(57)
(81)
(99)
(75)
(80)
(76)
HARVEST
SOLENOID
(77)
WATER
VALVE
(21)
(22)
(60)
(61)
(55)
HIGH PRES
CUTOUT
WATER LEVEL PROBE
NOT USED
ICE THICKNESS PROBE
LOW D.C.
VOLTAGE
PLUG
1G
1F
1C
BIN SWITCH
(64)
(66)
(66)
(67)
(63)
(62)
CONTACTOR
COIL
WATER
PUMP
FUSE (7A)
TRANS.
5
3
1
4
2
(65)
(89)
(88)
(20)
(46)
(44)
(45)
SV3018
1 Phase Without Terminal Board
–27–
Q320 - Self Contained -
SV2070
1 Phase Without Terminal Board
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
L1
(89)
HIGH PRES
CUTOUT
(88)
(42)
CONTACTOR
CONTACTS
L1
DIAGRAM SHOWN DURING FREEZE CYCLE
(55)
ICE THICKNESS PROBE
WATER LEVEL PROBE
NOT USED
BIN SWITCH
(64)
*OVERLOAD
(48)
(85)
(51)
FAN CYCLE CONTROL
(20)
(61)
2
4
3
1
5
TRANS.
FUSE (7A)
1C
1F
1G
LOW D.C.
PLUG
(62)
(63)
(65)
(67)
(66)
COMPRESSOR
S
R
C
(86)
TOGGLE SWITCH
ICE
(68)
(69)
OFF
CLEAN
(62)
(49)
OVERLOAD
(48)
(60)
CLEAN LIGHT
WATER LEVEL
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
(47)
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
COMPRESSOR
SEE SERIAL PLATE FOR VOLTAGE
(21)
WATER
VALVE
(77)
HARVEST
SOLENOID
(76)
DUMP
SOLENOID
(57)
(98)
TERMINATES AT
(59)
PIN CONNECTION
(58)
(56)
VIEW FOR WIRING
68
66
67
62
69
PTCR
(49)
(47)
(22)
(80)
(81)
(99)
WATER
PUMP
CONTACTOR
COIL
(74)
(50)
RUN CAPACITOR
(46)
PTCR
L2 (N)
(75)
R
R
(50)
(45)
–28–
Q420/Q450/Q600/Q800/Q1000 - Self Contained-
R
R
C
S
R
TB31
TB37
TB32
L1
TB34
*OVERLOAD
(53)
TB33
(52)
(51)
(48)
(45)
(46)
(50)
(49)
(47)
(55)
(61)
(21)
(76)
(60)
(98)
(57)
(74)
(58)
(59)
(73)
(99)
(85) (86)
1F
1C
4
1
3
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
(75)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(22)
WATER
PUMP
TB30
TB30
TB30
TB30
CONTACTOR
COIL
HIGH PRES
CUTOUT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
LOW D.C.
VOLTAGE
PLUG
TB30
CONTACTOR
CONTACTS
L1
(42)
COMPRESSOR
RUN CAPACITOR
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
L2 (N)
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
PTCR
TB30
(64)
(63)
BIN SWITCH
(62)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(66)
(62)
VIEW FOR WIRING
INTERNAL WORKING
VIEW
CLEAN LIGHT
WATER LEVEL LIGHT
WATER LEVEL PROBE
(77)
(80)
WATER
VALVE
2
1G
NOT USED
(20)
SV1646
1 Phase With Terminal Board
–29–
Q420/Q450/Q600/Q800/Q1000 - Self Contained-
C
S
R
L1
*OVERLOAD
(51)
(48)
(45)
(46)
(49)
(50)
(50)
(47)
(55)
(61)
(20) (21)
(76)
(60)
(98)
(57)
(74)
(58)
(59)
(99)
(85)
(86)
1F
1C
4
2
1
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
(75)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(22)
WATER
PUMP
CONTACTOR
COIL
HIGH PRES
CUTOUT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
LOW D.C.
VOLTAGE
PLUG
CONTACTOR
CONTACTS
L1
(42)
COMPRESSOR
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
L2 (N)
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
PTCR
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(62)
VIEW FOR WIRING
CLEAN LIGHT
WATER LEVEL
WATER LEVEL PROBE
(77)
(80)
WATER
VALVE
3
1G
NOT USED
(89)
(88)
SV2071
1 Phase Without Terminal Board
–30–
Q800/Q1000 - Self Contained -
TB31
TB37
(77)
(76)
(98)
(74)
(59)
(73)
(99)
(85)
(86)
(75)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(80)
WATER
PUMP
TB30
TB30
TB30
CONTACTOR
COIL
TB30
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
(61)
(60)
(57)
(58)
1F
1C
4
1
3
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
TB30
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
LOW D.C.
VOLTAGE
PLUG
TB32
TB35
TB34
(53)
TB33
(52)
HIGH PRES
CUTOUT
L1
(96)
(42)
COMPRESSOR
L3
L2
L1
L2
TB35
T2
T3
T1
(55)
TB30
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(66)
(62)
VIEW FOR WIRING
INTERNAL WORKING
VIEW
CLEAN LIGHT
WATER LEVEL LIGHT
(21)
(22)
WATER
VALVE
WATER LEVEL PROBE
2
1G
NOT USED
(20)
SV1647a
3 Phase With Terminal Board
–31–
Q800/Q1000 - Self Contained -
L1L2L3
(51)
(55)
(61)
(20) (21)
(76)
(60)
(98)
(57)
(74)
(58)
(59)
(99)
(85)
(86)
1F
1C
4
2
1
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
(75)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(22)
WATER
PUMP
CONTACTOR
COIL
HIGH PRES
CUTOUT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
LOW D.C.
VOLTAGE
PLUG
CONTACTOR
CONTACTS
L1
L2
L3
T2
T1T3
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(62)
VIEW FOR WIRING
CLEAN LIGHT
WATER LEVEL
WATER LEVEL PROBE
(77)
(80)
WATER
VALVE
3
1G
NOT USED
(89)
(88)
(42)
SV2072
3 Phase Without Terminal Board
–32–
Q1300/Q1800 - Self Contained -
1 Phase With Terminal Board
L1
TB35
HIGH PRES
CUTOUT
ICE THICKNESS PROBE
WATER LEVEL PROBE
TB35
TB35
(42)
CONTACTOR
CONTACTS
L1
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
(55)
TB32
2
4
1
3
5
TRANS.
FUSE (7A)
1C
1F
LOW D.C.
1G
AUCS DISPENSE TIME
(64)
BIN SWITCH
(66)
(95)
*OVERLOAD
(48)
(51)
(52)
TB33
VOLTAGE
PLUG
(62)
(63)
(65)
(67)
(66)
CRANKCASE HEATER
COMPRESSOR
R
S
C
(85) (86)
FAN CYCLE CONTROL
(20)
(61)
(60)
CLEAN LIGHT
WATER LEVEL LIGHT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
TOGGLE SWITCH
(68)
ICE
(69)
OFF
CLEAN
(62)
(49)
(47)
(53)
TB34
RUN CAPACITOR**
SEE SERIAL PLATE FOR VOLTAGE
(21)
RH HARVEST
SOLENOID
(88)
(77)
LH HARVEST
SOLENOID
(76)
DUMP
SOLENOID
(57)
(98)
TB31
(58)
TB37
(59)
TERMINATES AT
PIN CONNECTION
(73)
(56)
INTERNAL WORKING
VIEW
RUN CAPACITOR
R
R
(46) (50)
(45)
PTCR
(44)
FAN MOTOR
(AIR COOLED ONLY)
WATER
VALVE
(22)
(87)
(80)
(81)
(99)
WATER
PUMP
CONTACTOR
COIL
VIEW FOR WIRING
66
62
(94)
CONTACTOR
CONTACTS
L2(N)
(75)
TB30
TB30
(74)
TB30
TB30
68
67
69
TB30
(96)
TB30
L2
–33–
SV1652
Q1300/Q1600/Q1800 - Self Contained -
C
S
R
L1
*OVERLOAD
(51)
(48)
(95)
(45)
(46)
(49)
(47)
(50)
(94)
(96)
(55)
(61)
(20) (21)
(76)
(60)
(98)
(57)
(74)
(58)
(59)
(99)
(85)
(86)
1F
1C
4
2
1
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
(75)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(22)
WATER
PUMP
CONTACTOR
COIL
HIGH PRES
CUTOUT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
LOW D.C.
VOLTAGE
PLUG
CONTACTOR
CONTACTS
CONTACTOR
CONTACTS
L1 L2
COMPRESSOR
CRANKCASE HEATER
RUN CAPACITOR
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
L2 (N)
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
PTCR
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(62)
VIEW FOR WIRING
CLEAN LIGHT
WATER LEVEL LIGHT
WATER LEVEL PROBE
AUCS DISPENSE TIME
(77)
(80)
WATER
VALVE
3
1G
(89)
(88)
(42)
SV2075
1 Phase Without Terminal Board
–34–
Q1300/Q1800 - Self Contained -
(20)
TB31
TB37
(77)
(76)
(98)
(74)
(59)
(73)
(99)
(85)
(86)
(75)
LH HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(80)
WATER
PUMP
TB30
TB30
TB30
CONTACTOR
COIL
TB30
TB30
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
(61)
(60)
(57)
(58)
1F
1C
4
1
3
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
TB30
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
TB32
TB35
TB34
(53)
TB33
(52)
HIGH PRES
CUTOUT
TB35
CRANKCASE HEATER
(94)
(95)
L1
(96)
(42)
COMPRESSOR
L3 L2 L1
L2L3
TB35
T2
T3
T1
(55)
LOW D.C.
VOLTAGE
PLUG
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(66)
(62)
VIEW FOR WIRING
INTERNAL WORKING
VIEW
N - 50HZ
ONLY
TB30
NOTE: WIRE (96) IS NOT USED ON 50HZ
TB30
CLEAN LIGHT
WATER LEVEL LIGHT
2
WATER
VALVE
(21)
(22)
(87)
(88)
RH HARVEST
SOLENOID
1G
AUCS DISPENSE TIME
WATER LEVEL PROBE
SV1653
3 Phase With Terminal Board
–35–
Q1300/Q1600/Q1800 - Self Contained -
(77)
(76)
(98) (99)
(85)
(86)
(75)
LH HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(80)
WATER
PUMP
CONTACTOR
COIL
FAN CYCLE CONTROL
FAN MOTOR
(AIR COOLED ONLY)
RUN CAPACITOR**
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
TERMINATES AT
PIN CONNECTION
(61)
(60)
(57)
(59)
(58)
1F
1C
4
2
1
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
(51)
HIGH PRES
CUTOUT
CRANKCASE HEATER
(94)
(95)
CONTACTOR
CONTACTS
L1
(96)
COMPRESSOR
L3 L2 L1
L2
L3
T2
T3
T1
LOW D.C.
VOLTAGE
PLUG
(64)
(88)
(89) (55)
(42)
(63)
BIN SWITCH
(62)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(66)
(62)
VIEW FOR WIRING
N - 50HZ
ONLY
NOTE: WIRE (96) IS NOT USED ON 50HZ
CLEAN LIGHT
WATER LEVEL LIGHT
3
WATER
VALVE
(21)
(20)
(22)
(87)
RH HARVEST
SOLENOID
1G
AUCS DISPENSE TIME
WATER LEVEL PROBE
(88)
SV3008
3 Phase Without Terminal Board
–36–
Q450/Q600/Q800/Q1000 - Remote -
TB31
TB37
TB32
TB35
L1
(55)
(77)
(76)
(98)
(59)
(99)
(75)
HPR
SOLENOID
(79)(78)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(80)
WATER
PUMP
LIQUID LINE
SOLENOID
TB30
TB30
(82)
(83)
HIGH PRES
CUTOUT
REMOTE
FAN MOTOR
RUN CAPACITOR
L2 (N)
SEE SERIAL PLATE FOR VOLTAGE
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
REMOTE CONDENSER
TERMINATES AT
PIN CONNECTION
(F1)
(F2)
(61)
(60)
(57)
(58)
1F
1C
4
1
3
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
TB30
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
(74)
(73)
TB30
CONTACTOR
COIL
R
R
C
S
R
TB34
*OVERLOAD
(53)
TB33
(52)
(51)
(48) (45)
(46)
(50)
(49)
(47)
TB35
CONTACTOR
CONTACTS
L1
(42)
COMPRESSOR
RUN CAPACITOR
PTCR
TB30
TB30
LOW D.C.
VOLTAGE
PLUG
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(66)
(62)
VIEW FOR WIRING
INTERNAL WORKING
VIEW
CLEAN LIGHT
WATER LEVEL LIGHT
WATER LEVEL PROBE
(22)(21)
WATER
VALVE
2
5
1G
NOT USED
(20)
SV1648
1 Phase With Terminal Board
–37–
Q450/Q600/Q800/Q1000 - Remote -
SV2073
1 Phase Without Terminal Board
L1
HIGH PRES
CUTOUT
(88)
(42)
ICE THICKNESS PROBE
(89)
(55)
WATER LEVEL PROBE
AUCS DISPENSE TIME
BIN SWITCH
(64)
CONTACTOR
CONTACTS
(48)
L1
(51)
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
2
4
1
3
5
TRANS.
FUSE (7A)
1C
1F
1G
(62)
(63)
(65)
(67)
(66)
COMPRESSOR
SR
*OVERLOAD
C
F1 F2
LOW D.C.
VOLTAGE
PLUG
TOGGLE SWITCH
(68)
ICE
(69)
OFF
CLEAN
(62)
(20) (21)
(61)
(60)
(57)
CLEAN LIGHT
WATER LEVEL LIGHT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
VIEW FOR WIRING
66
62
(49)
RUN CAPACITOR
(47)
(46)
PTCR
REMOTE
FAN MOTOR
RUN CAPACITOR**
SEE SERIAL PLATE FOR VOLTAGE
(22)
WATER
VALVE
HPR
SOLENOID
(78) (79)
(88) (80)
HARVEST
SOLENOID
(77)
(81)
DUMP
SOLENOID
(99)
(98)
WATER
PUMP
(59) (83) (82)
LIQUID LINE
SOLENOID
(58)
CONTACTOR
COIL
(56)
(74)
68
67
69
RR
(94)
(50)
(45)
REMOTE CONDENSER
L2 (N)
(75)
–38–
Q800/Q1000 -Remote -
TB31
TB37
TB32
TB35
TB34
(53)
TB33
(52)
(55)
(77)
(76)
(98)
(59)
(99)
(75)
HPR
SOLENOID
(79)
(78)
HARVEST
SOLENOID
DUMP
SOLENOID
(81)
(80)
WATER
PUMP
LIQUID LINE
SOLENOID
TB30
TB30
(82)
(83)
HIGH PRES
CUTOUT
TB30
TB30
CONTACTOR
CONTACTS
L1
(96)
(42)
COMPRESSOR
REMOTE
FAN MOTOR
RUN CAPACITOR
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
REMOTE CONDENSER
L3 L2 L1
L2
L3
TB35
T2
T3
T1
TERMINATES AT
PIN CONNECTION
(F1)
(F2)
(61)
(60)
(57)
(58)
1F
1C
4
1
3
5
FUSE (7A)
TRANS.
(56)
ICE THICKNESS PROBE
TB30
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
LOW D.C.
VOLTAGE
PLUG
(74)
(73)
TB30
CONTACTOR
COIL
(64)
(63)
BIN SWITCH
(62)
(66)
(65)
(69)
(67)
(68)
TOGGLE SWITCH
68
67
69
66
62
ICE
OFF
CLEAN
(62)
VIEW FOR WIRING
INTERNAL WORKING
VIEW
CLEAN LIGHT
WATER LEVEL LIGHT
WATER LEVEL PROBE
2
(22)
(21)
WATER
VALVE
1G
AUCS DISPENSE TIME
(20)
SV1649
3 Phase With Terminal Board
–39–
Q800/Q1000 - Remote -
SV2074
3 Phase Without Terminal Board
SEE SERIAL PLATE FOR VOLTAGE
L3 L2 L1
(55)
(89)
HIGH PRES
CUTOUT
(88)
(42)
ICE THICKNESS PROBE
WATER LEVEL PROBE
NOT USED
BIN SWITCH
(64)
L1
L2
L3
CONTACTOR
CONTACTS
(51)
T2
T3
T1
COMPRESSOR
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
(60)
2
4
3
1
5
TRANS.
FUSE (7A)
1C
1F
LOW D.C.
1G
VOLTAGE
PLUG
(62)
(63)
(65)
(85)
TOGGLE SWITCH
(68)
(67)
(69)
OFF
(66)
CLEAN
(62)
(F2)
CLEAN LIGHT
WATER LEVEL LIGHT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
ICE
(21)
(20)
HPR
(61)
SOLENOID
(78)
(77)
HARVEST
SOLENOID
(76)
DUMP
SOLENOID
(98)
(57)
WATER
PUMP
(59)
(83)
(58)
(56)
INTERNAL WORKING
VIEW
REMOTE
FAN MOTOR
REMOTE CONDENSER
RUN CAPACITOR
(22)
WATER
VALVE
(79)
(80)
(81)
(75)
(99)
(82)
LIQUID LINE
SOLENOID
CONTACTOR
COIL
(74)
VIEW FOR WIRING
68
66
67
62
69
(F1)
–40–
Q1300/Q1800 - Remote -
SV1650
1 Phase With Terminal Board
L1
TB35
HIGH PRES
CUTOUT
ICE THICKNESS PROBE
WATER LEVEL PROBE
TB35
(42)
TB35
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
(55)
TB32
AUCS DISPENSE TIME
CONTACTOR
CONTACTS
L1
TB33
(51)
(64)
(66)
BIN SWITCH
*OVERLOAD
(48)
(52)
(F1)
(62)
(63)
(65)
R
TERMINATES AT
PIN CONNECTION
(20)
2
4
1
3
5
TRANS.
FUSE (7A)
1C
1F
1G
LOW D.C.
VOLTAGE
PLUG
TOGGLE SWITCH
(68)
(67)
(69)
(66)
(62)
CRANKCASE HEATER
COMPRESSOR
S
C
(53)
TB34
(21)
RH HARVEST
SOLENOID
(61)
(60)
(57)
(58)
TB37
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)
PTCR
(44)
REMOTE
FAN MOTOR
RUN CAPACITOR
SEE SERIAL PLATE FOR VOLTAGE
WATER
VALVE
(22)
HPR
SOLENOID
(79)(78)
(87)(88)
(77)
LH HARVEST
(80)
SOLENOID
(76)
(81)
DUMP
SOLENOID
TB31
(98)
(99)
WATER
PUMP
(83)
(59)
LIQUID LINE
SOLENOID
(73)
CONTACTOR
COIL
(56)
VIEW FOR WIRING
68
66
67
62
(94)(95)
R
R
(50)
CONTACTOR
CONTACTS
(45)
(F2)
REMOTE CONDENSER
L2 (N)
(75)
TB30
TB30
(82)
(74)
TB30
TB30
69
TB30
(96)
TB30
L2
–41–
Q1300/Q1600/Q1800 - Remote -
SV2076
1 Phase Without Terminal Board
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
L1
(55)(89)
HIGH PRES
CUTOUT
(88)
ICE THICKNESS PROBE
WATER LEVEL PROBE
AUCS DISPENSE TIME
BIN SWITCH
(64)
(95)
(42)
*OVERLOAD
CONTACTOR
CONTACTS
(48)
L1
(51)
SEE SERIAL PLATE FOR VOLTAGE
(21)
HPR
(20)
2
4
1
3
5
TRANS.
FUSE (7A)
1C
1F
1G
LOW D.C.
VOLTAGE
PLUG
(62)
(63)
(65)
TOGGLE SWITCH
(68)
ICE
(67)
(69)
OFF
(66)
CLEAN
(62)
CRANKCASE HEATER
COMPRESSOR
RS
C
(F1) (F2)
SOLENOID
RH HARVEST
SOLENOID
(61)
(77)
LH HARVEST
(60)
SOLENOID
DUMP
SOLENOID
(57)
TB37
(59)
(58)
(56)
CLEAN LIGHT
WATER LEVEL LIGHT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
INTERNAL WORKING
VIEW
(49)
RUN CAPACITOR
(47)
RR
(46) (50)
(45)
PTCR
(44)
REMOTE
FAN MOTOR
RUN CAPACITOR
(78)
(88)
(76)
(98)
(83)
CONTACTOR
COIL
(94)
REMOTE CONDENSER
(22)
WATER
VALVE
(79)
(87)
(80)
(75)
(81)
(99)
WATER
PUMP
(82)
LIQUID LINE
SOLENOID
VIEW FOR WIRING
68
67
66
62
69
(F2)
CONTACTOR
CONTACTS
L2
L2 (N)
(74)
(96)
–42–
Q1300/Q1800 - Remote -
Z
SV1651
3 Phase With Terminal Board
L3 L2 L1
L3
L1
L2
T2
T1
T3
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
DIAGRAM SHOWN DURING FREEZE CYCLE
SEE SERIAL PLATE FOR VOLTAGE
GROUND
TB35
TB35
(42)
CONTACTOR
CONTACTS
COMPRESSOR
TB32
HIGH PRES
CUTOUT
ICE THICKNESS PROBE
WATER LEVEL PROBE
AUCS DISPENSE TIME
BIN SWITCH
(64)
(95)
TB35
TB33 (52)(51)
(55)
(62)
(63)
(65)
(66)
(62)
(F1)
TERMINATES AT
PIN CONNECTION
(20)
RH HARVEST
SOLENOID
(61)
(60)
2
4
1
3
5
TRANS.
FUSE (7A)
1C
1F
1G
LOW D.C.
VOLTAGE
PLUG
(68)
TOGGLE SWITCH
(67)
(69)
CLEAN
CRANKCASE HEATER
(96)
NOTE: WIRE (96) IS NOT USED ON 50HZ
(53)
TB34
(77)
LH HARVEST
SOLENOID
(57)
TB31
(58)
TB37
(59)
(56)
CLEAN LIGHT
WATER LEVEL LIGHT
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
ICE
INTERNAL WORKING
OFF
VIEW
REMOTE
FAN MOTOR
RUN CAPACITOR
REMOTE CONDENSER
WATER
VALVE
(21)
HPR
SOLENOID
(78)
(88)
(76)
DUMP
SOLENOID
(98)
(83)
(73)
CONTACTOR
COIL
VIEW FOR WIRING
66
62
(79)
(87)
(81)
(99)
WATER
PUMP
LIQUID LINE
SOLENOID
(94)
(22)
N - 50H
(82)
ONLY
(80)
TB30
(75)
TB30
TB30
(74)
TB30
TB30
68
67
69
TB30
TB30
(F2)
–43–
Q1300/Q1600/Q1800 - Remote -
Z
Y
SV2077
3 Phase Without Terminal Board
CAUTION: DISCONNECT POWER BEFORE WORKING
ON ELECTRICAL CIRCUITRY.
SEE SERIAL PLATE FOR VOLTAGE
L3 L2 L1
L1
L2
L3
T2
T3
T1
COMPRESSOR
DIAGRAM SHOWN DURING FREEZE CYCLE
(55)(89)
HIGH PRES
CUTOUT
(88)
(42)
ICE THICKNESS PROBE
WATER LEVEL PROBE
NOT USED
BIN SWITCH
(64)
CONTACTOR
CONTACTS
(51)
2
4
3
1
5
TRANS.
FUSE (7A)
1C
1F
LOW D.C.
1G
VOLTAGE
CLEAN LIGHT
PLUG
WATER LEVEL LIGHT
(62)
(63)
(65)
(95) (94)
NOTE: WIRE (96) IS NOT USED ON 50HZ
(F1)
BIN SWITCH LIGHT
HARVEST LIGHT/
SAFETY LIMIT CODE LIGHT
TOGGLE SWITCH
(68)
(67)
(69)
(66)
(62)
REMOTE CONDENSER
(20)
LH HARVEST
SOLENOID
(61)
(60)
RH HARVEST
SOLENOID
(57)
(58)
(56)
ICE
INTERNAL WORKING
OFF
VIEW
CLEAN
REMOTE
FAN MOTOR
RUN CAPACITOR
(21)
HPR
SOLENOID
(78)
(88)
(77)
(76)
DUMP
SOLENOID
(98)
WATER
PUMP
(59)
(96) (96)
(22)
WATER
VALVE
(79)
(87)
(80)
(75)
(81)
(99)
(82)(83)
LIQUID LINE
SOLENOID
CONTACTOR
COIL
(74)
VIEW FOR WIRING
68
66
67
62
(F2)
N - 50 H
69
ONL
–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
!
Warning
!
Warning
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.
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.
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
!
Caution
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.
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
ADJUSTING
SCREW
SV3114
ICE THICKNESS ADJUSTMENT
1/8” ICE BRIDGE THICKNESS
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
–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
WATER
LEVEL
ABOVE
HOUSING
SV1616
WATER
PUMP
IMPELLER
HOUSING
WATER
LEVEL
SENSOR
PROBE
WATER
PUMP
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.
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
15
30
45
CONTROL
BOARD
HARVEST
WATER PURGE
ADJUSTMENT
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.
–57–
DIAGNOSING WATER LEVEL CONTROL
Important
Important
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.
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.
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 st arting, 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:
Cause
The water
level probe is
causing the
No On De-energized
problem.
Clean or
replace the
water level
probe.
The control
Yes Off Energized
board is
causing the
problem.
The water fill
Yes Off De-energized
valve is
causing the
problem.
–60–
Problem: Water Will Not Run into the Sump Trough
Important
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.
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), and then refer to the
chart.
Step 2. Checking for Normal Operation
Is Water
Flowing
into the
Water
Trough?
Yes Off Energized
No
The
Water
Level
Light Is:
On or
Off
The Water
Inlet Valve
Solenoid
Coil Is:
Energized
or
De-energized
Cause
This is
normal
operation.
Do not
change any
parts.
Proceed to
step 3.
–61–
Step 3. Leave the ice machine run, and then
Important
disconnect the water level probe from control board
terminal 1F.
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?
Yes Off Energized
No Off Energized
No
The
Water
Level
Light Is:
On or
Off
The Water
Inlet Valve
Solenoid
Coil Is:
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 Se ction
!
Warning
that Will Not Run
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
!
Warning
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.
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 re ach 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
Manitowoc PTCR’s 8505003 & 8504993
Manitowoc PTCR’s 8504913
Q200
Q280
Q320
Q420
Q450
Q600
Q800
Q1000
Q1300
Q1600
Q1800
Manitowoc
Part Number
8505003 305C20 22-50 Ohms
8504993 305C19 18-40 Ohms
8504913 305C9 8-22 Ohms
Cera-Mite
Part Number
Room
Temperature
Resistance
–68–
THIS PAGE INTENTIONALLY LEFT BLANK
–69–
THIS PAGE INTENTIONALLY LEFT BLANK
–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 th e 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 condi ti o ns 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 Inspecti on 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 c los ed
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 evapora tor
Correct the water flow
Plastic extrusions and gaskets are not secured to
the evaporator
Remount/replace as needed
–74–
Ice Formation Pattern
Important
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.
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
Important
There is no ice, or a considerab le lack of ice format ion,
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.
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
Orange Label
CONTROL BOARD WTH ORANGE
LABEL ON MICROPROCESSOR
(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.
–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 77 for control board identification and
safety limit operation.
Control Board with Black Microprocessor - Freeze
Time exceeds 60 minutes for 3 consecutive freeze
cycles
or
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 77 for control board identification and
safety limit operation.
Control Board with Black Microprocessor - Harvest
time exceeds 3.5 minutes for 3 consecutive harvest
cycles.
or
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 inst al l e d on wa te r ou tlet 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 discha rge 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
135791214
55 52 48 44 41 38 36
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.
3. Perform an actual sucti on
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.
Procedure
Example Using
QY0454A Model Ice Machine
Air temp. entering condenser:
90°F/32.2°C
Air temp. around ice machine:
Water temp. entering water fill valve:
13.7-14.1 minutes
Published Freeze cycle time:
55-36 psig
Published Freeze cycle suction pressure:
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:
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
80°F/26.7°C
70°F/21.1°C
Published Freeze Cycle Time
(minutes)
Published Freeze Cycle Suction
Pressure (psig)
psig
–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–
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