Refrigeration Circuit Subsystem - Trane PRGD series Installation, Operation And Maintenance Manual

P P u u r r g g e e S S y y s s t t e e m m O O v v e e r r v v i i e e w w
– Exhaust solenoid valve
– Pressure-relief valve
– Temperature sensor
• Purge control subsystem
– Tracer® UC800 controller
– Tracer® AdaptiView™ display
Detailed descriptions of the various purge subsystems
are included after the figures.

Refrigeration Circuit Subsystem

The purge evaporator of the refrigeration circuit is
located in the purge tank. The purge tank is connected
to the chiller condenser by supply and return lines
through which chiller refrigerant can freely flow.
The purge evaporator coil presents a cold condensing
surface to the chiller refrigerant entering the purge
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tank. When the purge refrigeration system is running,
refrigerant from the chiller condenser is attracted to the
cold surface of the purge evaporator. When the
gaseous refrigerant contacts the surface of the purge
evaporator coil, it condenses into a liquid, leaving a
partial vacuum behind. More refrigerant vapor from the
chiller condenser migrates to the purge tank to fill the
vacuum.
The liquid refrigerant that has condensed in the purge
tank returns to the chiller condenser through the liquid
return line. The return line includes a filter-drier and a
moisture-indicating sight glass.
The condensing unit is air-cooled and is operable
whether the chiller is running or not. No additional
cooling source is required.
PRGD-SVX01F-EN