Manitowoc Ice Chiplet QC0700 - Manual (Page 55)

Section 5 Before Calling Service
Part Number 000002688 5-3
Analyzing Why SafeGuards May Stop the
Ice Machine
According to the refrigeration industry, a high percentage
of compressor failure are the result of external causes.
These can include flooding or starving expansion valves,
dirty condensers, water loss to the ice machine, etc.
SafeGuards protect the ice machine (primarily the
compressor) from external failures by stopping ice
machine operation before major component damage
occurs.
Refrigeration and electrical component failures may also
trip a safeguard. Eliminate all electrical components and
external causes first. If it appears that the refrigeration
system is causing the problem, use the charts,
checklists, and other references to determine the cause.
NOTE: 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.
SAFEGUARD MODES
No Water
During the Freeze cycle if the water level probe opens or
remains open for more than 30* continuous seconds, the
ice machine will de-energize the compressor and gear
motor, continuously flash the water level light and initiate
a 60 minute Standby Mode.
During the Standby Mode the water level light will
continually flash to indicate a Standby Mode.
After the 60 -minute Standby Mode, the ice machine will
de-energize the water level light and initiate a start-up
sequence.
WATER CONTACTS THE WATER LEVEL PROBE:
The ice machine continues to make ice.
WATER LEVEL PROBE OPENS OR REMAINS OPEN
FOR MORE THAN 90 CONTINUOUS SECONDS:
The ice machine will start another 60-minute Standby
Mode.
The ice machine repeats the above sequence until:
Water contacts the water level probe
or
The toggle switch is moved to the OFF position.
*Note: There are two control boards, early version
boards must remain open for 90 seconds before de-
energizing.
INDICATOR LIGHT
Before 48 hours have elapsed:
After a Standby Mode has been initiated the water level
light will flash anytime the toggle switch is placed in the
OFF position.
After 48 hours have elapsed:
The SafeGuard will be automatically erased from
memory and the water level will not flash.
No Water Checklist
Possible Problem List Corrective Action List
No water Restore water supply.
Quick disconnect removed from water float valve Restore water supply.
Water float valve screen blocked Clean screen.
Water float valve solenoid coil defective Replace coil (see Water float valve diagnostics).
Water float valve improperly adjusted Adjust valve (see Water level check).
Dump valve leaking Repair or replace dump valve.
Water level probes disconnected or removed Connect and correctly position probes.