Toshiba RAV-SM2242DT-E Installation Manual page 12

Tightening connection
CAUTION
Do not apply excessive torque. Otherwise, the nut
may crack depending on the conditions.
(Unit: N•m)
Outer dia. of copper pipe Tightening torque
12.7 mm (dia.) 50 to 62 (5.0 to 6.2 kgf•m)
▼ 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.
Half union Flare nut
Externally Internally
threaded side threaded side
Use a wrench to secure. Use a torque wrench to tighten.
REQUIREMENT
Tightening with an excessive torque may crack the nut
depending on installation conditions.
Tighten the nut within the specified tightening torque.
Gas side refrigerant pipe
connection
• Turn up the pipe heat insulator to the unit side.
• Wrap the pipe with wet cloth.
Turn up pipe heat
insulator
Wet cloth
Remove the all
brazed part.
• Remove the cup on the gas side piping by using a
brazing machine.
CAUTION
Do not burn the pipe heat insulator.
Remove the cap.
Attached joint part
Connection pipe
Locally procured
Ø28.6 mm
• Braze the attached joint part to the gas side piping
and braze the connection piping to the joint part.
brazing
Braze all around
brazing
• Turn back the pipe heat insulator and tie up with a
banding band.
Tie up with a banding
band.
Piping with outdoor unit
For details of installation, refer to the Installation
Manual of the outdoor unit.
Evacuation
Using a vacuum pump, perform vacuuming from the
charge port of valve of the outdoor unit.
For details, follow to the Installation Manual attached to
the outdoor unit.
• Never use the refrigerant sealed in the outdoor unit
for evacuation.
REQUIREMENT
For the tools such as charge hose, etc., use those
manufactured exclusively for R410A.
– 11 –
Refrigerant amount to be added
For addition of the refrigerant, add refrigerant "R410A"
referring to the attached Installation Manual of outdoor
unit.
Be sure to use a scale to charge the refrigerant of
specified amount.
REQUIREMENT
• Charging an excessive or too little amount of
refrigerant causes a trouble of the compressor.
Be sure to charge the refrigerant of specified amount.
• A personnel who charged the refrigerant should write
down the pipe length and the added refrigerant
amount in the nameplate attached to the service panel
of the outdoor unit. It is necessary to fix the
compressor and refrigeration cycle malfunction.
Open the valve fully
Open the valve of the outdoor unit fully. A 4 mm-
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 for HFC
refrigerant (R410A, R134a, etc.).
Heat insulation process
Apply heat insulation for the pipes separately at liquid
side and gas side.
For the heat insulation to the pipes at gas side, be sure
to use the material with heat-resisting temperature
120°C or higher.
Using the attached heat insulation material, apply the
heat insulation to the pipe connecting section of the
indoor unit securely without gap.
REQUIREMENT
• Apply the heat 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 heat insulator with its slits facing up (ceiling
side).