Manitowoc MD0420A User manual

Technician’s
Handbook
This manual is updated as new information and models are
released. Visit our website for the latest manual. www.welbilt.cn
M series
Ice Machines
Part Number 040005626 5/17
Manitowoc

Safety Notices
As you work on Manitowoc equipment, be sure to pay
close attention to the safety notices in this handbook.
Disregarding the notices may lead to serious injury
and/or damage to the equipment.
Throughout this handbook, you will see the following
types of safety notices:
! Warning
Text in a Warning box alerts you to a potential
personal injury situation. Be sure to read the
Warning statement before proceeding, and work
carefully.
!
Caution
Text in a Caution box alerts you to a situation in
which you could damage the equipment. Be sure
to read the Caution statement before proceeding,
and work carefully.

Procedural Notices
As you work on Manitowoc equipment, be sure to read
the procedural notices in this handbook. These notices
supply helpful information which may assist you as
you work.
Throughout this handbook, you will see the following
types of procedural notices:
NOTE: Text set off as a Note provides you with simple,
but useful, extra information about the procedure you
are performing.
Important
Text in an Important box provides you with
information that may help you perform a
procedure more efficiently. Disregarding this
information will not cause damage or injury, but it
may slow you down as you work.

Read These Before Proceeding:
!
Caution
Proper installation, care and maintenance are
essential for maximum performance and trouble-
free operation of your equipment. Visit our
website www.kool-aire.com for manual updates,
translations, or contact information for service
agents in your area.
Important
Routine adjustments and maintenance
procedures outlined in this handbook are not
covered by the warranty.
! Warning
Read this manual thoroughly before operating,
installing or performing maintenance on the
equipment. Failure to follow instructions in this
manual can cause property damage, injury or
death.
! Warning
Do not use electrical appliances or accessories
other than those supplied by Manitowoc for your ice
machine model.
! Warning
Two or more people or a lifting device are
required to lift this appliance.

!
Warning
This equipment contains high voltage electricity
and refrigerant charge. Installation and repairs are
to be performed by properly trained technicians
aware of the dangers of dealing with high voltage
electricity and refrigerant under pressure.The
technician must also be certified in proper
refrigerant handling and servicing procedures. All
lockout and tag out procedures must be followed
when working on this equipment.
! Warning
Do not damage the refrigeration circuit when
installing, maintaining or servicing the unit.
! Warning
Do not operate equipment that has been misused,
abused, neglected, damaged, or altered/modified
from that of original manufactured specifications.
This appliance is not intended for use by persons
(including children) with reduced physical, sensory
or mental capabilities, or lack of experience and
knowledge, unless they have been given
supervision concerning use of the appliance by a
person responsible for their safety. Do not allow
children to play with this appliance.
! Warning
All covers and access panels must be in place
and properly secured, before operating this
equipment.

! Warning
Do not obstruct machine vents or openings.
!
Warning
Do not store gasoline or other flammable vapors
or liquids in the vicinity of this or any other
appliance.
! Warning
Do not clean with water jet.
! Warning
It is the responsibility of the equipment owner to
perform a Personal Protective Equipment Hazard
Assessment to ensure adequate protection
during maintenance procedures.
! Warning
Two or more people are required to move this
equipment to prevent tipping.

!
Warning
When using electric appliances, basic
precautions must always be followed, including
the following:
a. Read all the instructions before using
the appliance.
b. To reduce the risk of injury, close
supervision is necessary when an
appliance is used near children.
c. Do not contact moving parts.
d. Only use attachments recommended or
sold by the manufacturer.
e. Do not use outdoors.
f. For a cord-connected appliance, the
following must be included:
• Do not unplug by pulling on cord. To
unplug, grasp the plug, not the cord.
• Unplug from outlet when not in use
and before servicing or cleaning.
• Do not operate any appliance with a
damaged cord or plug, or after the
appliance malfunctions or is dropped
or damaged in any manner. Contact
the nearest authorized service facility
for examination, repair, or electrical
or mechanical adjustment.
g. Follow applicable lock out tag out
procedures before working on
equipment.
h. Connect to a properly grounded outlet
only.
We reserve the right to make product
improvements at any time. Specifications and
design are subject to change without notice.

Part Number 040005626 5/17 9
Table of Contents
GENERAL INFORMATION
Model Numbers . . . . . . . . . . . . . . . . . . . . .13
How to Read a Model Number . . . . . . . . .14
Ice Machine Warranty Information . . . . .15
Commercial Warranty Coverage . . . . .15
Residential Warranty Coverage . . . . .18
INSTALLATION
Location of Ice Machine . . . . . . . . . . . . . .21
Ice Machine Clearance Requirements . .22
Clearance Requirements . . . . . . . . . . . . .22
Ice Machine Heat of Rejection . . . . . . . . .23
Leveling the Ice Machine . . . . . . . . . . . . .23
Electrical Requirements . . . . . . . . . . . . . .24
Water Service/Drains . . . . . . . . . . . . . . . .25
Water Supply . . . . . . . . . . . . . . . . . . . .25
Water Inlet Lines . . . . . . . . . . . . . . . . .25
Drain Connections . . . . . . . . . . . . . . . .26
Cooling Tower Applications . . . . . . . . .26
MAINTENANCE
Interior Cleaning and Sanitizing . . . . . . .29
General . . . . . . . . . . . . . . . . . . . . . . . .29
Cleaning and Sanitizing Procedure . . .29
Toggle switch Operation . . . . . . . . . . .30
Remove Parts for Cleaning . . . . . . . . .34
Preventative Maintenance Cleaning . . . .36
Ice Machine Inspection . . . . . . . . . . . . . .37
Cleaning the Condenser . . . . . . . . . . . . .38
Removal from Service/Winterization . . .39
Air-cooled Models . . . . . . . . . . . . . . . .39
Water-cooled Models . . . . . . . . . . . . .39

10 Part Number 040005626 5/17
OPERATION
Ice Making Sequence of Operation . . . . 41
Control Board Timers . . . . . . . . . . . . 42
Safety Limits . . . . . . . . . . . . . . . . . . . . 43
Energized Parts Chart . . . . . . . . . . . . 45
Operational Checks . . . . . . . . . . . . . . . . . 47
Ice Thickness Check . . . . . . . . . . . . . 47
TROUBLESHOOTING
Control Board Test Mode . . . . . . . . . . . . 49
Diagnosing an Ice Machine that Will Not Run
50
Ice Machine Does Not Cycle Into Harvest
when Water Loses Contact with the Harvest
Float Switch . . . . . . . . . . . . . . . . . . . . . . . 51
Ice Machine Cycles Into Harvest Before Water
loses Contact with the Harvest Float Switch
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Ice Production Check . . . . . . . . . . . . . . . 54
Installation/Visual Inspection Checklist 55
Water System Checklist . . . . . . . . . . . . . 56
Ice Formation Pattern . . . . . . . . . . . . . . . 57
Safety Limits . . . . . . . . . . . . . . . . . . . . 60
Analyzing Discharge Pressure . . . . . . . . 67
Analyzing Suction Pressure . . . . . . . . . . 69
Harvest Valve . . . . . . . . . . . . . . . . . . . . . . 73
Comparing Evaporator Inlet/Outlet
Temperatures . . . . . . . . . . . . . . . . . . . . . . 77
Discharge Line Temperature Analysis . 78
Refrigeration Component Diagnostics . 80
Final Analysis . . . . . . . . . . . . . . . . . . . 82
Refrigeration Component Diagnostic Chart
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83