Step 4-3 Evacuating The System - Samsung AR TXHZ Series Installation Manual

Step 4-3 Evacuating the system

CAUTION
• Because the system does not have filter driers, you
must perform this triple evacuation procedure to
remove all noncondensables and moisture from the
system before charging. Failure to do so will result in
reduced performance and shorter equipment life.
The time required to perform each evacuation will depend on
the capacity (CFM) of the vacuum pump used.
1 Install a micron vacuum gauge to the larger liquid/vapor
line's service port on the branch of a tee.
2 Install the red high-side hose of an R-32 gauge manifold
set to the smaller liquid/vapor line's service port on the
run of the tee.
3 Attach a vacuum pump to the common hose of the
manifold set.
4 To ensure optimal performance, verify that the vacuum
pump's oil has been changed recently.
5 With the service port closed and the manifold gauge
open, start the vacuum pump and make sure that the
vacuum level drops below 4000 microns (as read on the
micron gauge). If it is difficult to achieve a proper vacuum,
a leak in the hoses is likely. Repair the leak(s) and/ or
check performance of vacuum pump, then repeat this
step.
6 Open the service port to connect the system to the
manifold.
7 Evacuate until 4000 microns is achieved, for at least 10
minutes.
8 Close the gauge manifold valve, shut off the vacuum
pump, and remove the common hose.
9 Connect the hose to the nitrogen pressure regulator and
bleed the hose by opening the end of the common hose
closest to the manifold.
10 Open the high-pressure manifold valve and slowly bring
the system pressure to atmosphere (50 kPa).
11 Close the manifold and nitrogen cylinder and remove the
common hose.
12 Reconnect the common hose to the vacuum pump.
Repeat steps 6 through 12, alternating between breaking
the vacuum with dry nitrogen and evacuating, until
system evacuation has occurred three times, to the
following vacuum levels:
Evacution
First
Second
Third
13 After evacuating to at least 500 microns for the third
time, close the gauge manifold valve and wait 10 minutes,
making sure that the vacuum level in the system does not
decrease. If it does, a small leak is likely. Repair the leak
and repeat the evacuation process.
3
Valve
4
(Backward owing prevention)
Liquid service port <Low pressure>
5
Liquid service port <High pressure>
Microns
4000
2000
500
15 minutes
Vacuum
Pump
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