Mitsubishi Electric TRANE HVAC US NTXCKS A112 Serie Manual De Instalación página 7

5. Refrigerant piping work
F
Fig. 5-7
A
,
Fig. 5-8
45°± 2°
Union joint
Male side
Lock the union joint
with a wrench.
Fig. 5-9
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
Flare nut
Female side
Tighten the fl are nut
with a torque wrench.
(inch) 5.4. Refrigerant and drainage piping locations (Fig. 5-7)
A Drain pipe
B Ceiling
A
C Grille
D Refrigerant pipe (liquid)
E Refrigerant pipe (gas)
F Main unit
Model
NTXCKS09/12A112BA
NTXCKS15/18A112BA
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
fl are 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 fl ared nut installed to this indoor unit.
• In case of reconnecting the refrigerant pipes after detaching, make the fl ared 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 fi rst align the center, then tighten the fi rst 3 to 4 turns of fl are 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 fl are
section.
• Flare the ends of the refrigerant pipes. A
• Apply refrigerating machine oil over the entire fl are seat surface. B
• Use the fl are nuts as follows. C
• Use 2 wrenches to tighten piping connections. D
Copper pipe O.D.
(mm, inch)
ø6.35, 1/4
ø9.52, 3/8
ø12.7, 1/2
Dimension (mm, inch)
A (liquid) B (gas)
63, 2-15/32 72, 2-27/32
63, 2-15/32 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
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