Refrigerant Piping Connection; Evacuating - Carrier 38VYX025-R Manual De Instalación

Refrigerant Piping Connection

Flaring
1. Cut the pipe with a pipe cutter.
90
2. Insert a flare nut into the pipe and flare the pipe.
• Projection margin in flaring : A (Unit : mm)
Rigid (clutch type)
Outer dia.
R410A tool used
of copper pipe
6.35 0 to 0.5
9.52 0 to 0.5
Imperial (wing nut type)
A
Outer dia. of copper pipe
Die
Pipe
Tightening connection
Align the centers of the connecting pipes and tighten the flare nut
as far as possible with your fingers. Then tighten the nut with a
spanner and torque wrench as shown in the figure.
Half union
Externally
threaded side
Use a wrench to secure.
CAUTION
Do not apply excess torque. Otherwise, the nut may crack
depending on the conditions.
Outer dia. of copper pipe
∅6.35 mm
∅9.52 mm
• Tightening torque of flare pipe connections
The operating pressure of R410A
is higher than that of R22
(approx. 1.6 times). It is therefore
necessary to firmly tighten the
flare pipe connecting sections
(which connect the indoor and
outdoor units) up to the specified
tightening torque. Incorrect
connections may cause not only
a gas leakage, but also damage
to the refrigeration cycle.
Shaping pipes
1. How to shape the pipes
Shape the pipes along the
incused line on the outdoor unit.
2. How to fit position of the pipes
Put the edges of the pipes to the
place with a distance of 85 mm
from the incused line.
GB
Obliquity
Roughness Warp
Conventional tool used
1.0 to 1.5
1.0 to 1.5
R410A
6.35 1.5 to 2.0
9.52 1.5 to 2.0
Flare nut
Internally
threaded side
Use a torque wrench to tighten.
(Unit : N·m)
Tightening torque
16 to 18 (1.6 to 1.8 kgf·m)
30 to 42 (3.0 to 4.2 kgf·m)
Flare at
indoor unit side
Flare at
outdoor unit side
Incused line
GB - 3

Evacuating

After the piping has been connected to the indoor unit, you can
perform the air purge together at once.
AIR PURGE
Evacuate the air in the connecting pipes and in the indoor unit
using a vacuum pump. Do not use the refrigerant in the outdoor
unit. For details, see the manual of the vacuum pump.
Using a vacuum pump
Be sure to use a vacuum pump with counter-flow prevention
function so that inside oil of the pump does not flow backward into
pipes of the air conditioner when the pump stops.
(If oil inside of the vacuum pump enters the air conditioner, which
use R410A, refrigeration cycle trouble may result.)
1. Connect the charge hose from the manifold valve to the service
port of the packed valve at gas side.
2. Connect the charge hose to the port of the vacuum pump.
3. Open fully the low pressure side handle of the gauge manifold
valve.
4. Operate the vacuum pump to start evacuating. Perform
evacuating for about 15 minutes if the piping length is 20 meters.
(15 minutes for 20 meters) (assuming a pump capacity of 27 liters
per minute) Then confirm that the compound pressure gauge
reading is –101 kPa (–76 cmHg).
5. Close the low pressure side valve handle of the gauge manifold
valve.
6. Open fully the valve stem of the packed valves (both gas and
liquid sides).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
Compound pressure gauge
–101 kPa
(–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Connecting
pipe
Packed valve at gas side
Service port (Valve core (Setting pin))
CAUTION
• KEEP IMPORTANT 4 POINTS FOR PIPING WORK.
(1) Take away dust and moisture (inside of the connecting pipes).
(2) Tighten the connections (between pipes and unit).
(3) Evacuate the air in the connecting pipes using a VACUUM
PUMP.
(4) Check gas leak (connected points).
3
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Charge hose
(For R410A only)
Vacuum pump adapter for
counter-flow prevention
(For R410A only)
Vacuum
pump
Packed valve at liquid side