Evacuation, Leak-Testing, And Charging Air-Cooled Systems With Txv And Without Receivers - Liebert PX018 Installer's/User's Manual

5.2.4 Evacuation, Leak-testing, and Charging Air-cooled Systems with TXV
and without Receivers
A discharge line and liquid line must be field-installed between the indoor unit and the outdoor
condenser. See the appropriate piping schematic, listed in Table 5.1 on page 29.
Evacuation and Leak-testing Air-cooled Systems without Receivers
For proper leak-check and evacuation, you must open all system valves and account for all check valves.
NOTE: The system includes a factory-installed check valve and an additional downstream Schrader
valve with core in the compressor discharge line. Proper evacuation of the condenser side of the
compressor can be accomplished only using the downstream Schrader valve. See the appropriate
piping schematic for your system in the submittal-drawings appendix.
1. If unit power is available, open the unit liquid-line solenoid valves using the evacuation function
for System #1 in the diagnostic section of the Liebert iCOM™ controller.
– or –
If unit power is not available, connect a field-supplied 24-VAC/75-VA power source directly to
the unit solenoid valve.
2. Connect refrigerant gauges to the suction rotalock valves and discharge-line Schrader valves.
3. Open the service valves and place a 150 PSIG (1034 kPa) of dry nitrogen with a tracer of
refrigerant. Check system for leaks with a suitable leak detector.
4. After completion of leak testing, release the test pressure, (observe local code) and pull an
initial deep vacuum of 500 microns on the system with a suitable pump.
5. After 4 hours, check the pressure readings and, if they have not changed, break vacuum with
dry nitrogen. Pull a second and third vacuum to 500 microns or less. Re-check the pressure
after 2 hours.
When the 3 checks are complete, proceed to
below.
Charging Air-cooled Systems without Receivers
NOTICE
Risk of improper refrigerant charging. Can cause equipment damage.
R-410A is a blended refrigerant and must be introduced and charged from the cylinder only as
a liquid.
When adding liquid refrigerant to an operating system, it may be necessary to add the
refrigerant through the compressor suction service valve.service . Care must be exercised to
avoid damage to the compressor. We recommend connecting a sight glass between the
charging hose and the compressor suction service valve. This will permit adjustment of the
cylinder hand valve so that liquid can leave the cylinder while allowing vapor to enter the
compressor.
Vertiv | Liebert® PDX™ and PCW™ Installer/User Guide |
Charging Air-cooled Systems without Receivers
39