Toshiba RAV-SM1104CT-E Installation Manual Download Page 11

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Ceiling Type

Installation Manual

Ceiling Type

Installation Manual

Refrigerant Piping

CAUTION

When the refrigerant pipe is long, provide support
brackets at intervals of 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

Connecting refrigerant piping

Flaring

Cut the pipe with a pipe cutter.

Remove burrs completely. (Remaining burrs may
cause gas leakage.)

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.

Projection margin in flaring: B (Unit: mm)

Flaring diameter size: A (Unit: mm)

Model: RAV-

Pipe size (mm)

Gas side

Liquid side

SM56

Ø12.7

Ø6.4

SM80, SM110,

SM140

Ø15.9

Ø9.5

Outer dia. of

copper pipe

R410A tool used

Conventional

tool used

6.4, 9.5

0 to 0.5

1.0 to 1.5

12.7, 15.9

Outer dia. of copper pipe

–0.4

6.4

9.1

9.5

13.2

12.7

16.6

15.9

19.7

* In case of flaring for 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.

• 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.

• Use the tightening torque levels as listed in the table

below.

• 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
depending on installation conditions.

Evacuation

Perform vacuuming from the charge port of valve of the
outdoor unit by using a vacuum pump.

For details, follow to the Installation Manual attached to
the outdoor unit.
• Do not use the refrigerant sealed in the outdoor unit

for evacuation.

REQUIREMENT

For the tools such as charge hose, use those
manufactured exclusively for R410A.

Refrigerant amount to be added

For addition of the refrigerant, add refrigerant “R410A”
referring to the attached Installation Manual of outdoor
unit.

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.

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 F-GAS label 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).

Outer dia. of connecting

pipe (mm)

Tightening torque (N•m)

6.4

14 to 18 (1.4 to 1.8 kgf•m)