Coolpak PCA050, Operation Manual

Page: 18 / 43

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3 Sequence of Operation
3-1 Chilled Water Circuit
Figure 9, Figure 10, and Figure 11

Process cooling water supply and return connections are made at the pipe stubs at the rear of the
chiller.

Warm water returns from the process and enters the reservoir tank.

The process water is pumped through the evaporator where it is cooled.

The coolant flows to the process and returns to repeat the cycle.

A chilled water bypass assembly (patent pending) between the supply and return lines guarantees a
constant flow through the evaporator during intermittent low or no-flow conditions.

A flow switch in units without pumps will prevent the compressor from running without adequate
flow through the evaporator
3-2 Refrigeration Circuit

Liquid refrigerant from the condenser passes through a filter/dryer which removes moisture and other
contaminants.

The refrigerant then passes through the thermal expansion valve which allows the refrigerant to
expand and cool the inside of the heat exchanger. The refrigerant flows through the suction line to the
compressor.

The refrigerant gives up its heat as it re-condenses to a liquid in the condenser and the cycle starts
over again.
 
IMPORTANT!
•
The PCA unit has a leaving water temperature range of -1°C to 18°C. Do not
attempt to run the PCA unit outside this temperature range or
damage to the unit may occur.
•
When operating the PCA unit between -1°C and 5°C, you must
use a solution of 75% water and 25% industrial-grade ethylene glycol with a
suitable corrosion inhibitor to protect the PCA unit from freeze-up.
See Figure 6 on page 16 for more information.
Such damage is not covered by the Fleming Dynamics warranty.