Manitowoc Indigo Series, Technician'S Handbook

Page: 183 / 270

Part Number STH025 02/12 183
CHECK PROCEDURE
Symptom #1 Machine is off and the display
indicates “Delay xx min, HPCO Active”.
1. Leave all wiring connectors attached and perform
testing within the 60 minute time delay period
2. Check for line voltage at P9 connector on control
board (Two wire connector adjacent to 9 pin
connector).
A. Line voltage present - HPCO switch has reset
and closed.
B. No line voltage present - HPCO switch is
open. Verify pressure - Below cut-in replace
HPCO - Above cut-in find root cause
problem.
3. Depending on timing either wait for the delay
period to end or start a new freeze cycle. The ice
machine will go to an initial start sequence. When
the compressor relay closes the control board
checks the HPCO
A. HPCO is open - Another 60 minute delay
period starts.
B. HPCO closed - A 3.5 minute harvest cycle
starts followed by an ice making cycle.
4. Run the system to see if the control trips at the
rated pressure. If HPCO opens at a pressure
significantly lower or higher than the control
setting of 440 psig replace the HPCO.
5. If the control opens at the correct pressure find
the root cause - Fan motor, dirty condenser,
refrigeration system issue, etc.