21
REFRIGERATION
Using the vacuum pump
1. Completely tighten the flare nuts, A, B, C, D, E
connect the manifold valve charge hose to a
charge port of the low-pressure valve on the
gas pipe side.
2. Connect the charge hose connection to the
vacuum pump.
3. Fully open the Lo tap of the manifold gauges.
4. Turn on the vacuum pump to evacuate. After
starting evacuation, slightly loosen the flare nut
of the Lo tap on the gas pipe side and check
that air is entering. (The operating noise of the
vacuum pump changes and the compound
gauge indicates 0 instead of negative)
5. After the evacuation is complete, fully close
the Lo tap of the manifold gauges and turn
off the vacuum pump. Evacuate the system
for 15 minutes or more and check that the
compound gauges indicate -76cm Hg or
5
(-1x10 Pa).
o
6. Turn the stem of service valve B about 45
counterclockwise for 6~7 seconds after
the gas coming out, then tighten the flare nut
again. Make sure the pressure display in the
pressure gauge is higher than the
atmospheric pressure.
7. Remove the charge hose from the Lo
pressure charge hose.
8. Fully open the service valve stems B and A.
9. Securely tighten the caps of the service valve.
Manifold
Compound gauges
-76cm Hg
Lo tap
Hi tap
Charge hose
Charge hose
Vacuum pump
Low pressure valve
Fig.67
Perform a thorough electrical safety check after
completing installation:
1. Insulated resistance
The insulated resistance must be more than 2M
Ω
.
2. Earthing
After completing the wiring installation, visually
check the earthing and measure for earth
leakage, it must be less than 4
Ω
.
3. Electrical leakage check (performing during
test running)
After finishing the installation, test run the system.
The system must be check electrically using a
multi-meter and other test tools to perform the
check. Turn off the system immediately if leakage
is present. Diagnose the issue and resolve
before completing the system commissioning.
.
●
Electrical safety check
Electrical safety and leak check
Indoor unit
check point
Outdoor unit
check point
n
m k
j i h
A
B
C
a
c
b
d
e
f
Fig.68
