Refrigerant Piping - Toshiba Carrier MMU-UP0071HP-UL Manuel D'installation

6

Refrigerant piping

CAUTION
When the refrigerant pipe is long, provide support
brackets at intervals of 8'2" to 9'10" (2.5 m to 3 m) to
clamp the refrigerant pipe. Otherwise, abnormal sound
may be generated.
Use the flare nut attached with the indoor unit or
R410A flare nut.
 Permissible piping length and
height difference
They vary depending on the outdoor unit. For details,
refer to the Installation Manual attached to the outdoor
unit.
 Pipe size
UP007 UP015
Model MMU- to to
UP012 UP018
Gas
3/8"(9.5) 1/2"(12.7)
side
Pipe size
(Dia. : in (mm))
Liquid
1/4"(6.4) 1/4"(6.4)
side
 Connecting refrigerant piping
Flaring
1. Cut the pipe with a pipe cutter.
Remove burrs completely.
(Remaining burrs may cause gas leakage.)
2. Insert a flare nut into the pipe, and flare the pipe.
Use the flare nut provided with the unit or the one
used for the R410A refrigerant. The flaring
dimensions for R410A are different from the ones
used for the conventional R22 refrigerant. A new
flare tool manufactured for use with the R410A
refrigerant is recommended, but the conventional
tool can still be used if the projection margin of the
copper pipe is adjusted to be as shown in the
following table.
25-EN
Projection margin in flaring: B (Unit: in (mm))
Outer dia. of
R410A tool used
copper pipe
1/4"(6.4), 3/8"(9.5)
0 to 0.02"(0.5)
1/2"(12.7), 5/8"(15.9)
Flaring diameter size: A (Unit: in (mm))
Outer dia. of copper pipe
1/4"(6.4)
3/8"(9.5)
UP024
1/2"(12.7)
to
UP054
5/8"(15.9)
5/8"(15.9)
3/8"(9.5)
* In case of flaring for R410A with the conventional
flare tool, pull it out approx. 0.02" (0.5 mm) more
than that for R22 to adjust to the specified flare size.
The copper pipe gauge is useful for adjusting
projection margin size.
• The sealed gas was sealed at the atmospheric
pressure so when the flare nut is removed, there will
no "whooshing" sound: This is normal and is not
indicative of trouble.
• Use two wrenches to connect the indoor unit pipe.
Work using double spanner
– 13 –
• Use the tightening torque levels as listed in the
following table.
Outer dia of connecting
pipe (in (mm)
1/4" (6.4)
Conventional
3/8" (9.5)
tool used
1/2" (12.7)
0.04"(1.0) to 0.06"(1.5)
5/8" (15.9)
• Tightening torque of flare pipe connections.
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque
wrench, tighten the flare pipe connecting sections
which connect the indoor and outdoor units of the
specified tightening torque.
Incorrect connections may cause not only a gas
leak, but also a trouble of the refrigeration cycle.
CAUTION
Tightening with an excessive torque may crack the nut
A
+0
–0.02(0.4) depending on installation conditions.
0.4"(9.1)
0.5"(13.2)
0.7"(16.6)
Piping with outdoor unit
0.8"(19.7)
Shape of valve differs according to the outdoor unit.
For details of installation, refer to the Installation
Manual of the outdoor unit.
 Airtight test / Air purge, etc.
For airtight test, air purge, addition of refrigerant, and
Tightening torque
gas leak check, refer to the Installation Manual
(ft•lbs (N•m))
attached to the outdoor unit.
10.1 to 13.0 (14 to 18)
REQUIREMENT
24.6 to 30.4 (34 to 42)
Do not supply power to the indoor unit until the airtight
35.4 to 44.1 (49 to 61)
test and vacuuming are completed. (If the indoor un
45.5 to 55.7 (63 to 77)
it is powered on, the pulse motor valve is fully closed,
which extends the time for vacuuming.)
Open the valve fully
Open the valve of the outdoor unit fully.
For details, refer to the Installation Manual attached to
the outdoor unit.
Insulation process
Apply insulation for the pipes separately at liquid side
and gas side.
For the insulation to the pipes at gas side, be sure to
use the material with heat-resisting temperature
248 °F (120 °C) or higher.
Using the attached insulation material, apply the
insulation to the pipe connecting section of the indoor
unit securely without gap.
REQUIREMENT
• Apply the insulation to the pipe connecting section
of the indoor unit securely up to the root without
exposure of the pipe. (The pipe exposed to the
outside causes water leak.)
• Wrap insulation with its slits facing up
(ceilingside).
Wrap the pipe with the attached insulation
without any gap between the indoor unit.
The seam must be faced upward
Indoor unit
(ceiling side).
Insulation
Union
pipe
(Accessory)
Flare nut
Insulation
of the pipe
Banding band
(Locally
procured)
26-EN