Pressure Control Specifications And Diagnostics; High Pressure Cut-Out (Hpco) Control - Manitowoc MARINE MODEL S1800 Service Manual

Section 7

Pressure Control Specifications and Diagnostics

HIGH PRESSURE CUT-OUT (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.
Specifications
Cut-out: 450 psig ±10 (3103 kPa ±69, 31 Bar ±.69)
Cut-in: Manual or automatic reset
Must be below 300 psig (2068 kPa, 20.68
Bar ±.69) to reset
Check Procedure
1. Set ICE/OFF/CLEAN switch to OFF.
2. Connect manifold gauges.
3. Hook voltmeter in parallel across the HPCO, leaving
wires attached.
4. Close the water service valve to the water
condenser inlet.
5. Set ICE/OFF/CLEAN switch to ICE.
6. No water 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 (2068 kPa,
20.68 Bar ) 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:
• Will not reset [below 300 psig (2068 kPa, 20.68 Bar )]
• Does not open at the specified cut-out point
Part Number 80-1634-3
! Warning
Refrigeration System
7-19