PCA Series Chillers
Page 15
Process Water Bypass
All PCA chillers have an internal bypass device (patent pending). If the process flow
becomes blocked during chiller operation, this component allows water to flow through
the chiller. This protects the chiller from freeze-up, excessive pressures, and pump
damage, and allows other safety features to remain effective.
2-3 PCA Condenser Air Supply
PCA chillers use the surrounding air to cool the condenser.
;
Condenser air entering the PCA unit should be at least 65
°
F (18
°
C). Operation with
air below 65
°
F (18
°
C) can cause the low pressure cutout to shut down the chiller
due to the low refrigerant pressure.
;
Install the chiller in an area where there is free passage of air for condensing.
;
Provide 18" (46 cm) or more clearance for the chiller's air intake.
;
Make provisions to exhaust the heated air discharged from the chiller.
;
Do not put the PCA unit where steam, hot air or fume exhausts will be drawn into
the condenser.
;
Air-cooled condensers must be cleaned frequently. Neglect reduces capacity,
increases operating costs, and leads to possible chiller failure. See Chapter 7 on
Page 29 for cleaning instructions.
;
Normal condensing pressure with 95
°
F (35
°
C) air is approximately 180 psi (1,241
kPa) for the PCA050 and PCA100; 275 psi (1,897 kPa) for the PCA150.
PCA Ambient Temperature Ranges
Ambient Temperature Range
Minimum Temperature
Maximum Temperature
Operation
65°F (18°C)
100°F (38°C)
Storage
40°F (4°C)
120°F (49°C)
2-4 Water
Reservoir
During startup and when additional solution is required, see Figure 6 on page 16 for the
recommended ethylene glycol/water solution. This chart shows the proportions needed
to provide freeze protection to 20
°
F/
°
C below the desired process setpoint.
;
Add a pre-mixed solution to provide freeze protection to a temperature 20
°
F/
°
C
below the normal operating temperature of the chiller.
;
Use industrial quality (
not
automotive) ethylene glycol.
