Trane CVHH Installation, Operation And Maintenance Manual page 73

Figure 40. Components of a Trane EarthWise purge system (back view )
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1. Regenerat ion solenoid valve
2. Pressure- relief valve
3. Exhaust solenoid valve
4. Pum p- out com pressor
5. Carbon t ank heat er
6. Aut om at ic expansion valve
7. Pum p- out solenoid valve
8. Pressure- relief device ( fusible plug)
9. Carbon t ank
10. Purge t ank
11. Condensing unit
12. Chiller refrigerant supply line
Purge Tank Subsystem
Any non-condensables that have accum ulated 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 com pressor suction
tem perature to decrease.
A float sw itch, m ounted in the bottom of the purge tank,
indicates if there is excessive accum ulation of liquid
refrigerant in the tank. A liquid level sensor, w hich resides
CVHH-SVX001A-EN
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in the purge control panel, m onitors the status of the float
sw itch.
If the norm ally closed float sw itch is open for m ore than
20 m inutes, the purge controls w ill turn off the
refrigeration system and generate a non-latching
diagnostic—Purge Liquid Level Too High Warning. If the
float sw itch has re-closed after 20 m inutes, the purge
controls w ill restart the refrigeration system .
If the float sw itch rem ains open for m ore than 20 m inutes,
or if the float sw itch/liquid level restart cycle has occurred
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Operating Principles
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