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CDHH-SVX003C-EN
1. Regeneration solenoid valve
2. Pressure-relief valve
3. Exhaust solenoid valve
4. Pump-out compressor
5. Carbon tank heater
6. Automatic expansion valve
7. Pump-out solenoid valve
8. Pressure-relief device (fusible plug)
9. Carbon tank
10. Purge tank
11. Condensing unit
12. Chiller refrigerant supply line
Purge Tank Subsystem
Any non-condensables that have accumulated from the
refrigerant vapor are left behind to collect in the purge tank.
As the quantity of non-condensables increases, the heat
transfer efficiency of the purge evaporator coil is reduced,
causing the purge compressor suction temperature to
decrease.
A float switch, mounted in the bottom of the purge tank,
indicates if there is excessive accumulation of liquid
refrigerant in the tank. A liquid level sensor, which resides
in the purge control panel, monitors the status of the float
switch.
If the normally closed float switch is open for more than
20 minutes, the purge controls will turn off the refrigeration
system and generate a non-latching diagnostic—Purge
Liquid Level Too High Warning. If the float switch has re-
closed after 20 minutes, the purge controls will restart the
refrigeration system.
If the float switch remains open for more than 20 minutes,
or if the float switch/liquid level restart cycle has occurred
more than four times in four hours, a latching diagnostic—
Purge Liquid Level Too High Continuously—will be
generated. The purge system will not restart until it is reset.
If a Purge Liquid Level Too High Continuously diagnostic
occurs, check the purge lines for any type of restriction
(trapped liquid, closed valves, etc.) and ensure that the
filter-drier on the liquid return line is in good condition.
A UL-required pressure-relief device (fusible plug), which
protects against over-pressurization of the purge tank, is
mounted on the purge tank. The plug material will fuse at
210°F (98.9°C), which equates to approximately 132 psig
(910.1 kPaG) for refrigerant R-1233zd.
Operating Principles
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