Service manual

Refrigeration System Section 7
7-8
Part No. 80-1206-3
ICE FORMATION PATTERN
Evaporator ice formation pattern analysis is helpful in ice
machine diagnostics.
Analyzing the ice formation pattern alone cannot
diagnose an ice machine malfunction. However, when
this analysis is used along with Manitowoc’s
Refrigeration System Operational Analysis Table, it can
help diagnose an ice machine malfunction.
Improper ice formation can be caused by any number of
problems.
Example: An ice formation that is “extremely thin at the
evaporator outlet” could be caused by a hot water
supply, a dump valve leaking water, a faulty water fill
valve, a low refrigerant charge, etc.
Evaporator Tubing Routing
Q0600C/IB0600C/Q0800C/IB0800C/Q1400C/QDUALC
Routing of the tubing on the back of the evaporator
determines the ice fill pattern failure mode. The
evaporator outlet tubing does not exit directly at the top
of the evaporator, but exits several inches below the top
of the evaporator. Extremely Thin at the Evaporator
Outlet will first be visible several inches below the top of
the evaporator. Extremely Thin at the Evaporator Inlet
will first be visible at the bottom of the evaporator.
IB1000C ONLY
Tubing routing for the IB1000C evaporator is different.
The evaporator outlet is at the bottom of the evaporator.
Extremely Thin at the Evaporator Outlet will first be
visible at the bottom and then the right side of the
evaporator. Extremely Thin at the Evaporator Inlet will
first be visible several inches above the bottom of the
evaporator.
v
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 at the evaporator inlet, than at the
evaporator outlet. At the end of the freeze cycle, ice
formation at the outlet will be close to, or just a bit thinner
than, ice formation at the inlet. The dimples in the cubes
at the outlet of the evaporator may be more pronounced
than those at the inlet. This is normal.
The ice thickness probe must be set to maintain the ice
bridge thickness at approximately 1/8". If ice forms
uniformly across the evaporator surface, but does not
reach 1/8" in the proper amount of time, this is still
considered normal.
Refer to Ice Thickness Probe Adjustment.
Important
Keep the water curtain in place while checking the
ice formation pattern to ensure no water is lost.
INLET
OUTLET
INLET
OUTLET
Thin at Outlet
Thin at Inlet
SV1575
SV1576
INLET
OUTLET
SV3101
SV3102
SV3103
Thin at Outlet
Thin at Inlet