Evacuation And Charging; Evacuation - Fisher & Paykel RX256DT4X1 FP Service Manual

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7. Remove and replace restricted device.
8. Evacuate sealed system.
9. Charge system to specification.
NOTE: Do not use captured or recycled refrigerant in units. Captured or recycled refrigerant voids
any compressor manufacturer's warranty.
NOTE: Charge system with exact amount of refrigerant. Refer to unit serial plate for correct
refrigerant charge. Inaccurately charged system will cause future problems.
13.10

Evacuation and Charging

13.10.1

Evacuation

To avoid risk of fire, sealed refrigeration system must be air free.
contamination, follow evacuation procedures exactly.
NOTE: Before opening any refrigeration system, EPA regulations require refrigerant in system to be
captured for safe disposal.
Proper evacuation of sealed refrigeration system is an i mp o r t a n t s e r vi c e p r o c e d u r e . U s a b l e
l i f e a n d operational efficiency greatly depends upon how completely air, moisture and other non-
condensables are evacuated from sealed system.
Air in sealed system causes high condensing temperature and pressure, resulting in increased power
requirements and reduced performance.
Moisture in sealed system chemically reacts with refrigerant and oil to form corrosive hydrofluoric and
hydrochloric acids. These acids attack motor windings and parts, causing premature breakdown.
Before opening system, evaporator coil must be at ambient temperature to minimize moisture
infiltration into system.
Evacuation
To evacuate sealed refrigeration system:
1. Connect vacuum pump, vacuum tight manifold set with high vacuum hoses, thermocouple vacuum
gauge and charging cylinder as shown in illustration.
Evacuation should be done through I.D. opening of tubes, not through line piercing valve.
2. Connect low side line to compressor process tube.
3. Connect high side line to drier/process tube.
4. Evacuate both simultaneously. With valve "C" and "F" closed, open all other valves and start
vacuum pump.
CAUTION
98
To avoid risk of air