Gas Leak Check; Air Purge - Toshiba RAV-SM404SDT-E Installation Manual

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
6.4 mm (dia.) 14 to 18 (1.4 to 1.8 kgf•m)
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 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.
◆ 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.
23-EN

Air purge

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 air
purge.
REQUIREMENT
For the tools such as charge hose, etc., use those
manufactured exclusively for R410A.
◆ Refrigerant amount to be added
Flare at For addition of the refrigerant, add refrigerant "R410A"
indoor
referring to the attached Installation Manual of outdoor unit.
unit side
Be sure to use a scale to charge the refrigerant of specified
amount.
REQUIREMENT
• Charging an excessive or too little amount of refrigerant
causes of the compressor.
Flare at
Be sure to charge the refrigerant of specified amount.
outdoor
• A personnel who charged the refrigerant should write
unit side
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 troubleshoot 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, use the
material with heat-resisting temperature 120 °C or higher.
• To use the attached heat insulation pipe, 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).
Wrap the pipe with the attached heat insulator
without any gap between the indoor unit.
The seam must be faced upward
Indoor unit
(ceiling side).
Flare nut
Heat insulator
Heat insulation
of the pipe
Union Banding band
pipe
(locally
(Accessory)
procured)
– 12 –
EN
24-EN