Service manual

6-4
Section 6Service
Fan Cycle Control
Function
Cycles the fan motor on and off to maintain proper
operating discharge pressure.
The fan cycle control closes on an increase, and
opens on a decrease in discharge pressure.
Specifications
Model Cut-In (Close) Cut-Out (Open)
Q130
250 psig ±5 200 psig ±5
Q210
275 psig ±5 225 psig ±5
Q270
250 psig ±5 200 psig ±5
Check Procedure
1. Disconnect electrical power to the ice machine
at the electrical service disconnect.
2. Verify fan motor windings are not open or
grounded, and fan spins freely.
3. Connect manifold gauges to ice machine.
4. Hook voltmeter in parallel across the fan cycle
control, leaving wires attached.
5. Reconnect electrical power to the ice machine
and set the ON/OFF/WASH toggle switch to
ON.
6. Wait until water flows over the evaporator then
refer to chart below.
System
Pressure:
Reading Should
Be:
Fan Should
Be:
above cut-in 0 volts running
below cut-out line voltage off
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. Set ON/OFF/WASH switch to OFF.
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 models, disconnect the fan
motor.
5. Set ON/OFF/WASH 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.
WARNING
If discharge pressure exceeds 460 psig and the
HPCO control does not cut out, set
ON/OFF/WASH switch to OFF 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