Mitsubishi Electric TRANE NTXCKS09A112A Serie Manual De Instalación página 6

5. Refrigerant piping work
F
Fig. 5-7
A
G
F
,
B C
J
I
H
Fig. 5-8
A
B
Fig. 5-9
6
E 1/4 7-23/32 7-23/32
D
B
C
B
F
C
D
F
E
A Refrigerant pipe and insulating material
(Procure locally)
B Pipe cover (large) (Accessory)
C Pipe cover (small) (Accessory)
D Refrigerant pipe (gas)
E Refrigerant pipe (liquid)
F Band (Accessory)
G Cross-sectional view of connection
H Refrigerant pipe
I Insulating material
J Squeeze
C
5.4. Refrigerant and drainage piping locations (Fig. 5-7)
(inch)
A Drain pipe
B Ceiling
A C Grille
D Refrigerant pipe (liquid)
E Refrigerant pipe (gas)
F Main unit
Model
liquid
NTXCKS09
63, 2-15/32
NTXCKS12
NTXCKS15
63, 2-15/32
NTXCKS18
5.5. Pipe connection (Fig. 5-8)
Indoor unit
1) When using commercially available copper pipes:
• Apply thin layer of refrigerant oil to pipe and joint seating surface before tightening
flare nut.
• Use two wrenches to tighten piping connections.
• Air-purge the refrigerant piping using your own refrigerant gas (don't air-purge the
refrigerant charged in the outdoor unit).
• Use leak detector or soapy water to check for gas leaks after connections are
completed.
• Use flared nut installed to this indoor unit.
• In case of reconnecting the refrigerant pipes after detaching, make the flared part
of pipe re-fabricated.
• Use refrigerant piping insulation provided to insulate indoor unit connections. Insulate
carefully following shown below.
2) Heat insulation for refrigerant pipes:
1 Wrap the enclosed large-sized pipe cover around the gas pipe, making sure that
the end of the pipe cover touches the side of the unit.
2 Wrap the enclosed small-sized pipe cover around the liquid pipe, making sure that
the end of the pipe cover touches the side of the unit.
3 Secure both ends of each pipe cover with the enclosed bands. (Attach the bands
20 mm (25/32 inch) from the ends of the pipe cover.)
Make sure that the slit in the pipe cover is facing upward when it is installed.
See that stop valve on outdoor unit is fully shut (unit is shipped with valve shut). After
all piping connections between indoor and outdoor unit have been completed, vacuum-
purge air from system through the service port for the stop valve on the outdoor unit.
After completing procedures above, open outdoor unit stop valves stem fully. This
completes connection of refrigerant circuit between indoor and outdoor units. Stop
valve instructions are marked on outdoor unit.
Flare nut tightening
• Apply a thin coat of refrigeration oil on the seat surface of pipe. (Fig. 5-9)
• For connection first align the center, then tighten the first 3 to 4 turns of flare nut.
• Use tightening torque table below as a guideline for indoor unit side union joint
section, and tighten using two wrenches. Excessive tightening damages the flare
section.
A Apply refrigerating machine oil over the entire flare seat surface.
B Use correct flare nuts meeting the pipe size of the outdoor unit.
C Flare nut tightening torque
Copper pipe O.D.
(mm, inch)
ø6.35, 1/4
ø9.52, 3/8
ø12.7, 1/2
Dimension (mm, inch)
gas
72, 2-27/32
78, 3-1/16
Flare nut O.D. Tightening torque
(mm, inch) (N·m, ft·lbs)
17, 21/32 14 to 18, 10 to 13
22, 7/8 34 to 42, 25 to 31
26, 1-1/32 49 to 61, 36 to 45