Installation manual
11
REMQ8~16P7Y1B
VRVIII System air conditioner
4PW37156-1
7.
L
EAK
TEST
AND
VACUUM
DRYING
The units were checked for leaks by the manufacturer.
After connecting the field piping, perform the following inspections.
1
Preparations
Referring to
, connect a nitrogen tank, a refrigerant
tank, and a vacuum pump to the outdoor unit and perform the
airtightness test and the vacuum drying.
The refrigerant tank and the charge hose connected to the
refrigerant charge port or valve A are needed to perform
refrigerant charging.
2
Airtightness test and vacuum drying
■
Airtightness test:
Pressurize the liquid pipe, the suction gas pipe, the high
pressure/low pressure gas pipe and the equalizer pipe from the
service ports of each stop valve to 4.0 MPa (40 bar) (do not
pressurize more than 4.0 MPa (40 bar)). If the pressure does not
drop within 24 hours, the system passes the test. If the pressure
drops, check where the nitrogen leaks from.
■
Vacuum drying: Use a vacuum pump which can evacuate to
–100.7 kPa (5 Torr, –755 mm Hg)
1.
Evacuate the system from the liquid pipe, the suction gas pipe,
the high pressure/low pressure gas pipe and the equalizer pipe
stop valve service ports by using a vacuum pump for more than
2 hours and bring the system to –100.7 kPa. After keeping the
system under that condition for more than 1 hour, check if the
vacuum gauge rises or not. If it rises, the system may either
contain moisture inside or have leaks.
2.
Following should be executed if there is a possibility of moisture
remaining inside the pipe (if piping work is carried out during the
raining season or over a long period of time, rainwater may enter
the pipe during work).
After evacuating the system for 2 hours, pressurize the system to
0.05 MPa (vacuum break) with nitrogen gas and evacuate the
system again using the vacuum pump for 1 hour to –100.7 kPa
(vacuum drying). If the system cannot be evacuated to
–100.7 kPa
within 2 hours, repeat the operation of vacuum break and vacuum
drying.
Then, after leaving the system in vacuum for 1 hour, confirm that
the vacuum gauge does not rise.
8.
F
IELD
WIRING
1
Gauge manifold
2
Nitrogen
3
Measuring instrument
4
Refrigerant R410A tank (siphon system)
5
Vacuum pump
6
Charge hose
7
Equalizer pipe stop valve
8
High pressure/low pressure pipe stop valve
9
Suction gas line stop valve
10
Liquid line stop valve
11
Refrigerant charge port
12
Valve A
13
Valve B
14
Valve C
15
To BS box or indoor unit
16
Stop valve
17
Service port
18
Field piping
19
Gas flow
NOTE
Make sure to perform airtightness test
and vacuum drying using the service
ports of the stop valves of the
equalizer pipe, HP/LP gas pipe,
suction gas pipe and liquid pipe. (For
the service port location, refer to the
"Caution" label attached on the front
panel of the outdoor unit.)
■
See
"11.3. Stop valve operation procedure" on
for details on handling the stop valve.
■
To prevent entry of any contamination and to
prevent insufficient pressure resistance, always
use the special tools dedicated for working with
R410A refrigerant.
NOTE
Make sure to use nitrogen gas.
All field wiring and components must be installed by a
licensed electrician and must comply with relevant local
and national regulations.
The field wiring must be carried out in accordance with the
wiring diagrams and the instructions given below.
Be sure to use a dedicated power circuit. Never use a
power supply shared by another appliance. This can lead
to electric shock or fire.
Be sure to install an earth leakage circuit breaker.
(Because this unit uses an inverter, install an earth
leakage circuit breaker that is capable of handling high
harmonics in order to prevent malfunctioning of the earth
leakage breaker itself.)
Do not operate until refrigerant piping work is completed.
(If operated before completion of the piping work, the
compressor may break down.)
Never remove a thermistor, sensor, etc., when connecting
power wiring and transmission wiring.
(If operated without thermistor, sensor, etc., the
compressor may break down.)
This product's reversed phase protection detector only
works when the product starts up.
The reversed phase protection detector is designed to stop
the product in the event of an abnormality when the
product is started up.
Replace two of the three phases (L1, L2, and L3) during
reverse-phase protection circuit operation.
Reversed phase detection is not performed while the
product is operating.
If there exists the possibility of reversed phase after an
momentary black out and the power goes on and off while
the product is operating, attach a reversed phase
protection circuit locally. Running the product in reversed
phase can break the compressor and other parts.
Means for disconnection must be incorporated in the field
wiring in accordance with the wiring rules.
(An all-pole disconnection switch must be available on the
unit.)
