Leak Test And Vacuum Drying; Field Wiring - Panasonic URBAN MULTI U-8ME4XPQ Manuel D'installation

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 figure 22, connect a nitrogen tank, a refrigerant tank
and a vacuum pump to the outdoor unit and perform the leak
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.
1 Gauge manifold
2 Nitrogen
3 Measuring instrument
4 Refrigerant R410A tank (siphon system)
5 Vacuum pump
6 Charge hose
7 Refrigerant charge port
8 High pressure/low pressure pipe stop valve
9 Suction gas pipe stop valve
10 Liquid pipe stop valve
11 Valve A
12 Valve B
13 Valve C
14 Outdoor unit
15 To HR unit or indoor unit
16 Stop valve
17 Service port
18 Field piping
19 Gas flow
2

Leak test and vacuum drying

NOTE Make sure to perform leak test and
vacuum drying using the service ports
of the stop valves of the high pressure/
low pressure 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
page 15 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.
Leak test:
NOTE Make sure to use nitrogen gas.
Pressurize the liquid pipe, the suction gas pipe and the high
pressure/low pressure gas 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.
U-8~16ME4XPQ
Urban Multi air conditioner
4PW40726-1A
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
and the high pressure/low pressure gas 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
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
compressor may break down.)
The reversed phase protection detector of this product only
functions when the product starts up. Consequently
reversed phase detection consequently is not performed
during normal operation of the product.
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.
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.)
thermistor, sensor, etc., the
Installation manual
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