Manitowoc MD0420A, Technician'S Handbook

Page: 95 / 132

Part Number 040005626 5/17 95
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: 600 psig
±
10
Cut-in: 450 psig
±
10
(Must be below 450 psig to reset).
Check Procedure
1. Move toggle 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. Move toggle switch 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.
Replace the HPCO control if it:
• Will not reset (below 450 psig)
• Does not open at the specified cut-out point
!
Warning
If discharge pressure exceeds 600 psig and the
HPCO control does not cut out, cycle the toggle
switch Off to stop ice machine operation.