Manitowoc STH042 4/16, Technician'S Handbook

Page: 111 / 146

Part Number STH042 4/16 111
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.
Specifications
Cut-out: 450 psig ±10
Cut-in: Automatic reset
(Must be below 300 psig to reset)
Check Procedure
1. Switch to OFF.
2. Connect manifold gauge.
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 models, disconnect the fan motor.
5. Set to ON.
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.
n
Warning
If discharge pressure exceeds 460 psig and the HPCO
control does not cut out, press the power button to
stop ice machine operation.
Replace the HPCO control if it:
• Will not reset (below 300 psig)
• Does not open at the specified cut-out point