Manitowoc S300, Technician'S Handbook

Page: 158 / 300

158 Part Number 80-1479-3 7/10
Refrigeration Components
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.
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.
Replace the HPCO control if it:
7. Will not reset [below 300 psig (2068 kPa 20.68
bar).
8. Does not open at the specified cut-out point.
Specifications
Cut-Out Cut-In
450 psig ±10
(3103 kPa ±69 31 bar ±.69)
Automatic Reset
(Must be below 300 psig (2068 kPa 20.68 bar) to reset.)
!
Warning
If di scharge pressure excee ds 4 60 psig (3172 kPa
31.72 bar) and the HPCO control does not cut out,
set ICE/ OFF/CLEAN switch to OF F to stop ice
machine operation.