Manitowoc I0320 Technician's Handbook page 106

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 Freeze
Cycle Refrigeration System Operational Analysis
Tables, it can help diagnose an ice machine
malfunction.
Any number of problems can cause improper ice
formation.
Keep the water curtain/ice dampers 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 inlet of the evaporator
than on the 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 on the inlet. This is normal.
It is normal for ice thickness to vary up to 1.5 mm
across the surface of the evaporator. The ice bridge
thickness at the ice thickness control probe should be
at least 3 mm.
The ice thickness probe must be set to maintain the
ice bridge thickness at approximately 3 mm. If ice
forms uniformly across the evaporator surface, but
does not reach 3 mm. in the proper amount of time,
this is still considered a normal ice fill pattern.
104
Important
Part Number STH038 5/12