Toshiba MMK-UP0051DHPL-E Installation Manual page 27

* In case of flaring for R32 or R410A
with the conventional flare tool,
pull it out approx. 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
6.4 mm (dia.)
9.5 mm (dia.)
12.7 mm (dia.)
▼ Tightening torque of flare pipe connections
Pressure of R32 or 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.
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.
A
(Unit: N•m)
Tightening torque
14 to 18 (1.4 to 1.8 kgf•m)
33 to 42 (3.3 to 4.2 kgf•m)
50 to 62 (5.0 to 6.2 kgf•m)
Heat insulation
Heat 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 heat insulation should be
done to prevent condensation.
• Heat insulator with a heat resistance of 120°C
or more must be used for the gas side pipe.
• The pipe connection section of the indoor unit
must be heat insulated securely and compactly
with the attached heat insulator.
Fix with vinyl tape
Heat insulator
(attached)
Airtight test / Air purge, etc.
For air tightness test, vacuum drying and adding
refrigerant, refer to the Installation Manual
attached to the outdoor unit.
Do not supply power to the indoor unit until the
airtight test and vacuuming are completed.
(If the indoor unit is powered on, the pulse
motor valve is fully closed, which extends the
time for vacuuming.)
Open fully valves of the outdoor
unit
Open the valve of the outdoor unit fully.
A hexagonal wrench is required for opening the
valve.
For details, refer to the Installation Manual
attached to 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, R32, etc.).
‒ 26 ‒
Installation Manual
Local side pipe
CAUTION
26-EN