High Pressure Cutout (Hpco) Control - Manitowoc Q450 Service Technician's Handbook

High Pressure Cutout (HPCO) Control

FUNCTION
Stops the ice machine if subjected to excessive high-
side pressure.
The HPCO control is normally closed, and opens on a
rise in discharge pressure.
Cut-Out
450 psig ±10
(3103 kPa ±69)
(Must be below 300 psig (2068 kPa) to reset.)
CHECK PROCEDURE
1. Set ICE/OFF/CLEAN switch to OFF, (Manual reset
HPCO reset if tripped).
2. Connect manifold gauges.
3. Hook voltmeter in parallel across the HPCO,
leaving wires attached.
4. On water-cooled models, close the water service
valve to the water condenser inlet. On self-
contained air-cooled and remote models,
disconnect the fan motor.
5. Set ICE/OFF/CLEAN switch to ICE.
6. No water or air flowing through the condenser will
cause the HPCO control to open because of
excessive pressure. Watch the pressure gauge and
record the cut-out pressure.
If discharge pressure exceeds 460 psig (3172 kPa)
and the HPCO control does not cut out, set ICE/
OFF/CLEAN switch to OFF to stop ice machine
operation.
Replace the HPCO control if it:
1. Will not reset [below 300 psig (2068 kPa)].
2. Does not open at the specified cut-out point.
Specifications
Manual or Automatic
!
Warning
–116–
Cut-In
Reset