Panasonic U-10MX3XPA, Руководство по установке

Страница: 13 / 24

U-5~48MX3
Urban Multi air conditioner
4PW16235-1C Installation manual
9
6.4. Leak test and vacuum drying
The units were checked for leaks by the manufacturer.
Confirm that the valves are firmly closed before pressure test or
vacuuming.
Air tight test and vacuum drying
■
Air tight test: Make sure to use nitrogen gas. (For the service
port location, refer to the “Caution” label attached on the front
panel of the outdoor unit.)
(See figure 19)
Pressurize the liquid and gas pipes (and oil equalizing pipe in case of
U-18~48MX3 type) to 3.8 MPa (38 bar) (do not pressurize more than
3.8 MPa (38 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 and gas pipes (and oil
equalizing pipe in case of U-18~48MX3 type) 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.
Stop valve operation procedure
Introduction
Confirm the sizes of the stop valves connected to the system
referring to the table below.
Opening stop valve
1. Remove the cap and turn the valve counterclockwise with the
hexagon wrench.
2. Turn it until the shaft stops.
Do not apply excessive force to the stop valve. Doing so may break
the valve body, as the valve is not a backseat type. Always use the
special tool.
3. Make sure to tighten the cap securely.
Closing stop valve
1. Remove the cap and turn the valve clockwise with the hexagon
wrench.
2. Securely tighten the valve until the shaft contacts the main body
seal.
3. Make sure to tighten the cap securely.
For the tightening torque, refer to the table below.
(See figure 23)
<CAUTION>
■
Always use a charge hose for service port connection.
■
After tightening the cap, check that no refrigerant leaks are
present.
FLARE SHAPE and FLARENUT TIGHTENING TORQUE
〈
Precautions when connecting pipes
〉
■
See the following table for flare part machining dimensions.
■
When connecting the flare nuts, apply refrigerant oil to the inside
and outside of the flares and turn them three or four times at first.
(Use ester oil or ether oil.)
■
When loosening a flare nut, always use two wrenches in
combination. When connecting the piping, always use a spanner
and torque wrench in combination to tighten the flare nut.
■
See the following table for tightening torque.
(Applying too much torque may cause the flares to crack.)
■
After all the piping has been connected, use nitrogen to perform
a gas leak check.
1 Electric box lid
2 Service precautions
Label location
3 Caution
Label location
NOTE Make sure to perform airtightness test and vacuum
drying using the service ports of the stop valve shown
in the table below.
U-5~16MX3 Liquid line stop valve
Gas line stop valve
U-18~48MX3 Liquid line stop valve
Gas line stop valve
Oil-equalizing line stop valve
U-5MX3 U-8MX3 U-10MX3 U-12MX3 U-14MX3 U-16MX3
Liquid line stop
valve
Ø9.5 Ø12.7
Gas line stop valve Ø15.9 Ø22.2
(*)
(*) The model U-8MX3 supports on-site piping of Ø19.1 by the accessory pipes.
Ø25.4
(†)
(†) The model U-12~16MX3 supports on-site piping of Ø28.6 by the accessory
pipes.
Tightening torque N•m (Turn clockwise to close)
Stop
valve
size Shaft (valve body)
Cap
(valve lid)
Service
port Flare nut
Gas line
piping
attached
to unit
Ø6.4
5.4~6.6
Hexagonal
wrench
4 mm
13.5~16.5
11.5~13.9
14~17
—
Ø9.5 33~39
Ø12.7 8.1~9.9 18~22 50~60
Ø15.9 13.5~16.5
Hexagonal
wrench
6 mm
23~27 62~75
Ø22.2
27~33
Hexagonal
wrench
10 mm
36~44 — 22~28
Ø25.4
1 Service port
2 Cap
3 Hexagon hole
4 Shaft
5 Seal
Pipe size
Tightening
Torque (N•m) A (mm) Flare shape
Ø9.5 32.7~39.9 12.8~13.2
Ø12.7 49.5~60.3 16.2~16.6
Ø15.9 61.8~75.4 19.3~19.7
1 2 3 4
1 Piping union
2 Spanner
3 Flare nut
4 Torque wrench
R=0.4~0.8
45 ±2
90 ±2
A