Carrier TOSHIBA MMK-UP0301HP-UL Service Manual page 121

* 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.
Tightening connection
CAUTION
• Do not apply excessive torque. Otherwise, the
nut may crack depending on the conditions.
Outer dia. of copper pipe
1/4" (6.4 mm) (dia.)
3/8" (9.5 mm) (dia.)
1/2" (12.7 mm) (dia.)
5/8" (15.9 mm) (dia.)
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.
Align the centres 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.
Work using double spanner
REQUIREMENT
Tightening with an excessive torque may crack the
nut depending on installation conditions.
Tighten the nut within the specified tightening
torque.
A
(Unit: in (mm))
Tightening torque
10-13 (14-18)
24-31 (33-42)
37-46 (50-62)
50-60 (68-82)
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Piping with outdoor unit
• Shape of valve differs according to the outdoor
unit.
For details of installation, refer to the Installation
Manual of the outdoor unit.
Insulation
Insulation for the pipes should be done
separately for the liquid side and gas side.
Because both of the liquid and gas side pipes
become a low temperature during cooling
operation, sufficient insulation should be
done to prevent condensation.
• Insulation with a heat resistance of
248°F (120°C) or more must be used for the gas
side pipe.
• The pipe connection section of the indoor unit
must be insulation securely and compactly
with the attached insulation.
Fix with vinyl tape
Insulation
(attached)
Airtight test/Air purge, etc.
For airtight test,air purge, addition of refrigerant,
and gas leak check, follow the Installation Manual
attached to the outdoor unit.
Open fully valves of the outdoor
unit
Gas leak check
Check with a leak detector or soap water whether
gas leaks or not, from the pipe connecting section
or cap of the valve.
REQUIREMENT
Use a leak detector manufactured exclusively
HFC refrigerant (R410A, R134a, etc.).
Local side pipe