Charging Additional Refrigerant - Toshiba RAV-GM562ATP-TR Service Manual

• (Airtight test), Vacuum dry, Refrigerant charge, Gas
leak check
Test run
6-6-5. Handling of Existing Pipe
When using the existing pipe, carefully check it for
the following:
• Wall thickness (within the specified range)
• Scratches and dents
• Water, oil, dirt, or dust in the pipe
• Flare looseness and leakage from welds
• Deterioration of copper pipe and heat insulator
• Before recovering the refrigerant in the existing
system, perform a cooling operation for at least 30
minutes.
Cautions for using existing pipe
• Do not reuse a flare nut to prevent gas leaks.
Replace it with the supplied flare nut and then
process it to a flare.
• Blow nitrogen gas or use an appropriate means to
keep the inside of the pipe clean.
If discolored oil or much residue is discharged,
wash the pipe.
• Check welds, if any, on the pipe for gas leaks.
There may be a problem with the pressure
•
resistance of the branching pipes of the existing
piping.
Replace them with branch pipes (sold separately).
When the pipe corresponds to any of the
following, do not use it. Install a new pipe instead.
• The pipe has been opened (disconnected from
indoor unit or outdoor unit) for a long period.
• The pipe has been connected to an outdoor unit
that does not use refrigerant R32 or R410A
• The existing pipe must have a wall thickness equal
to or larger than the following thicknesses.
Reference outside Wall thickness
diameter (mm)
6.4
9.5
12.7
15.9
19.1
22.2
28.6
• Do not use any pipe with a wall thickness less than
these thicknesses due to insufficient pressure
capacity.
Material
(mm)
0.8 —
0.8 —
0.8 —
1.0 —
1.2 —
1.0 Half hard
1.0 Half hard
6-6-6. Recovering Refrigerant
Use the refrigerant recovery equipment to recover
the refrigerant.

6-7. Charging additional refrigerant

Amount of additional refrigerant shall be restricted by the
following explanation to ensure the reliability.
Miss-charging leads to the abnormal high pressure in the
refrigerant cycle, causing a rupture, a injury and
a compressor malfunction.
6-7-1. [Assumed gas leak]
The refrigerant can be charged only when the amount of a
leak such as a slow-leak found at the installation work can
be ensured that it is within the additional limits shown in the
following.
Recharge the refrigerant, as the amount of leakage is
unknown when calling " Cooling is not good" or "Warming is
not good".
6-7-2. [Limiting the additional charge]
• The maximum amount of additional refrigerant shall be
up to 10 % of the normal amount of the refrigerant.
If no improvement in symptoms can be found at the above
limitation, recover all gases and recharge the normal
amount of refrigerant.
• If the slow leak is found at the installation work and the
connection pipe length is 15 m or less, tighten the flare
nut at the leak point and do not add the refrigerant.
6-7-3. [Cautions on charging additional refrigerant]
• When adding, use a balance with an accuracy of more
than 10 g scale. Do not use a health-meter etc.
• If the refrigerant gas leaks, find the leakage point and
repair it securely. Though the refrigerant gas itself is
innocuous, if it touch a fire source such as fan heater,
stove or kitchen stove, noxious gas may occur.
• When charging the refrigerant, charge with liquid refrigerant.
Work carefully and charge it little by little since it may be
rapidly charged due to the liquid state.
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