Manitowoc Indigo Series Technician's Handbook page 173

Diagnostics
ICE MACHINE CYCLES INTO HARVEST BEFORE ICE
CONTACTS THE ICE THICKNESS PROBE
Premature harvest symptoms
• Low ice production
• Thin ice in bin
• Freeze cycles are faster than published cycle times
1. Turn off power and inspect ice thickness probe for
physical damage. Look for bulging, cracks around
the nipple or deformed pivot pins.
2. Verify ice thickness probe gap is approximately 9/32"
(7 mm)
3. Make sure the ice thickness probe wire doesn't
restrict movement.
4. Perform Ice Thickness Probe tap test:
• Press the menu button, scroll down to Service,
press the right arrow, scroll down to Real Time
Data, press right arrow - With the brackets
around Time & Temp press the right arrow - Scroll
down until 100Hz &120Hz are displayed. Slowly
increasing and decreasing numbers typically in
the 200Hz to 300Hz range will display to the right
of 100Hz &120Hz.
• Lift the Ice Thickness Probe and continuously tap
the nipple while watching the numbers to the
right of the 100Hz and 120Hz. There is a slight
delay while tapping.
Pass Numbers increasing into the thousands indicates a
properly working ice thickness probe and control
Fail Numbers do not move or do not increase into the
Part Number STH026 6/15
thousands - Ohm the ice thickness probe.
board.
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