Manitowoc indigo series Technician's Handbook page 185

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 by cycling
the power button.
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 450 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.The ice machine will go to an initial
start sequence if the HPCO is closed. If the HPCO is
open, another 60 minute delay period starts. When
the compressor relay closes the control board checks
the HPCO.
Part Number STH025 11/16 185