Refrigerant Piping - Toshiba RAV-SM407MUT-E Installation Manual

6

Refrigerant piping

 Refrigerant piping
1. Use the following item for the refrigerant piping.
Material : Seamless phosphorous deoxidized
copper pipe.
Wall thickness : 0.8 mm or more (C1120T-0)
2. Flare nut and flare works are also different from
those of the conventional refrigerant.
Take out the flare nut attached to the main unit of the
air conditioner, and use it.
REQUIREMENT
When the refrigerant pipe is long, provide support
brackets at intervals of 2.5 - 3 m to clamp the refrigerant
pipe. Otherwise, abnormal sound may be generated.
CAUTION CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Remove dust and moisture from the inside of the
connecting pipes.
2. Tight connection (between pipes and unit)
3. Evacuate the air in the connecting pipes by using
VACUUM PUMP.
4. Check the gas leakage. (Connected points)
 Pipe size
Model SM40, 45, 56
RAV- SM30 type
name
Gas side 9.5 mm
Pipe size
Liquid side 6.4 mm
25-EN
 Permissible piping length and
height difference
They vary according to the outdoor unit.
For details, refer to the Installation Manual attached to
the outdoor unit.
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.
As the flaring sizes of R410A differ from those of
refrigerant R22, the flare tools newly manufactured
for R410A are recommended.
However, the conventional
tools can be used by adjusting
projection margin of the
copper pipe.
▼ Projection margin in
flaring: B (Unit: mm)
Rigid (Clutch type)
R410A tool
used
Outer dia. of copper pipe
R410A
6.4, 9.5
0 - 0.5
12.7
▼ Flaring dia. meter size: A (Unit: mm)
type
12.7 mm
Outer dia. of copper pipe
6.4 mm
6.4
9.5
12.7
* 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.
Tightening connection
CAUTION CAUTION
Do not apply excessive torque. Otherwise, the nut may
crack depending on the conditions.
Outer dia. of copper pipe
6.4 mm
9.5 mm
12.7 mm
▼ Tightening torque of flare pipe connections
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times) Use a torque wrench, tighten the
flare pipe connecting sections which connect the
indoor and outdoor units of the specified tightening
torque.
B
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.
Conventional
tool used
R410A
1.0 - 1.5
Work using double spanner
REQUIREMENT
+0
A
–0.4
Tightening with an excessive torque may crack the nut
R410A
depending on installation conditions.
9.1
Tighten the nut within the specified tightening torque.
13.2
16.6
A
– 13 –
 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.
Unit: N•m
REQUIREMENT
Tightening torque
14 - 18 (1.4 to 1.8 kgf•m) For the tools such as charge hose, use those
manufactured exclusively for R410A.
34 - 42 (3.4 to 4.2 kgf•m)
49 - 61 (4.9 to 6.1 kgf•m)
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).
26-EN