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22
Figure 23 General piping details
3.5.1 Evacuation and Leak Check—R-134a Pumped Circuit
1. Open all service valves, including those outside the Liebert XDP.
2. Attach a jumper hose from one of the Schrader valve fittings on a pump outlet before the check
valve to a Schrader valve fittings after the check valve.
3. Place 150psig (1034kPa; 10.34 bars) of dry nitrogen with a tracer of R-134a in the system.
NOTICE
Risk of overpressurization. Can cause equipment damage.
Do not exceed 150 psig (1034 kPa; 10.34 bars) in the R-134a circuit.
4. Check the system for leaks with a suitable leak finder on the pumps’ suctions lines.
5. After completion of the leak testing, release the test pressure (per local code) and connect to
vacuum pump(s) at the Schrader valves.
6. After pulling a deep vacuum for four hours, check the vacuum level and, if it has not changed,
break the vacuum with dry nitrogen.
7. Pull a second vacuum to 250 microns or less. Recheck the vacuum level after 2 hours.
3.5.2 Insulation
Insulate all piping between the Liebert XDP and its connected cooling modules to prevent
condensation where the piping passes through non-conditioned areas.
NOTE
Do not insulate piping before checking it for leaks. Insulating pipes before checking them for
leaks would prevent easy detection of leaks.
Liebert
XDP A
Liebert
XDP B
Return
Supply
Return
Supply
Floor
Building Chilled Water Supply
Building Chilled Water Return
Isolation
valves
Isolation
valves
Emerson recommends
field-installation of shutoff
valves at these points to
permit isolating the
Liebert XDP for
maintenance.