Beckman Couler ALLEGRA X-12/R, Service Manual, Page: 46 / 83

Section 3: Service Procedures
Figure 3-2
3.2.4 Leak Test and Evacuation
LEAK
TEST
A. Remove front panel and instrument housing as outlined in the mechanical systems
section.
B. Connect the charging manifold per step 3.2.2.
C. Purge charging manifold and hoses of air before adding refrigerant to the system.
D. If system pressures are low, add refrigerant R404a as a liquid to the low-side with
compressor running.
E. Turn main power off. Allow pressures to equilibrate then test for leaks. (Requires a leak
detector that will detect R404a).
F. Correct all leaks found in the system.
EVACUATION
A. Evacuate the system to 50 microns by using an evacuation manifold and a high capacity
vacuum pump, as shown in figure 3-3. After a vacuum is obtained turn compressor on
for about 2-3 seconds to remove moisture trapped in compressor, turn compressor off and
allow system to achieve 50 microns of vacuum.
B. Close both access service valves at the compressor while the vacuum pump continues to
run. Once the valves are closed, turn off the vacuum pump and remove the evacuation
manifold.
B. Connect charging manifold and R404a refrigerant supply per procedure in step 3.2.3.
Vacuum Monitor
(338866)
High Vacuum
Pump
Evacuation Manifold
(341676)
Compressor
High Side
Service Valve
Compressor
Low side
Service Valve
FIGURE 3 - 3
Allegra X-12/R, X-15R Service Manual 07/07 3-13