Toshiba RAS-M07G3DV-E Service Manual page 14

2. Safety and Cautions on Installation/Service
<Safety items>
When gas concentration and ignition energy are
happened at the same time, R32 has a slight
possibility of burning. Although it will not ignite under
normal work environment conditions, be aware that
the flame spreads if ignition should occur.
It is necessary to carry out installation/servicing
safely while taking the following precautions into
consideration.
1) Never use refrigerant other than specified
refrigerant (R32) in an air conditioner which is
designed to operate with the specified refrigerant
(R32).
If other refrigerant than R32 is used, it may cause
personal injury, etc. by a malfunction, a fire, a
rupture.
2) Since R32 is heavier than air, it tends to accumulate
on the bottom (near the floor).
Ventilate properly for the working environment to
prevent its combustion.
Especially in a basement or a closed room where is
the high risk of the accumulation,
ventilate the room with a local exhaust ventilation.
If refrigerant leakage is confirmed in the room or the
place where the ventilation is insufficient, do not
work until the proper ventilation is performed and
the work environment is improved.
3) When performing brazing work, be sure to check for
leakage refrigerant or residual refrigerant.
If the leakage refrigerant comes into contact with
fire, a poisonous gas may occur or it may cause a
fire. Keep adequate ventilation during the work.
4) When refrigerant gas leaks during work, execute
ventilation. If the leakage refrigerant comes into
contact with a fire, a poisonous gas may occur or it
may cause a fire.
5) In places where installing / repairing air-conditioning
equipment, etc., keep the source of ignition such as
gas combustion equipment, petroleum combustion
equipment, electric heater etc. away. Do not smoke
in the place.
6) When installing or removing an air conditioner, do
not mix air in the refrigerant cycle.
If air or others is mixed with the refrigerant,
abnormal high pressure generates in the
refrigerating cycle, causing injury due to the
breakage.
7) After installation work complete, confirm that
refrigerant gas is not leaking on the flare connection
part or others. If leaked refrigerant comes to contact
with a fire, toxic gas may occur, causing a fire.
8) Perform the installation work and re-installation
according to the installation manual.
Pay attention especially to the area of application.
Improper installation may cause refrigeration
trouble or water leakage, electric shock and fire etc.
9) Unauthorized modifications to the air conditioner
may be dangerous. If a breakdown occurs please
call a qualified air conditioner technician or
electrician.
Improper repair may result in water leakage, electric
shock and fire, etc.
10) Carry out the airtight test with nitrogen at a
specified pressure. Do not use oxygen or
acetylene gas absolutely as it may cause an
explosion.
11) Always carry a refrigerant leakage detection
sensor during the work and work while
checking that no refrigerant leaks around working
environment.
12) If the leakage refrigerant comes into contact with
fire, it may cause a fire.
Have a dry powder or CO2 fire extinguisher
adjacent to the charging area.
<Caution items>
1) The opposite side dimension of the air-conditioner's
flared nut using R32 and the shape of the charge
port are the same as those of R410A.
2) Be careful not to charge refrigerant by mistake.
Should the different type of refrigerant mix in, be
sure to recharge the refrigerant
3) Do not mix the other refrigerant or refrigerating oil
with the refrigerant.
4) Since the pressure of R32 is high 1.6 times of that
of the former refrigerant (R22), use tools and parts
with high pressure withstand specification similar to
R410A.
5) In the installation time, use clean pipe materials and
work with great attention so that water and others
do not mix in because pipes are affected by
impurities such as water, oxide film, oil, etc. Use the
clean pipes. Be sure to braze while flowing nitrogen
gas in the pipe. (Never use gas other than nitrogen
gas.)
6) For the earth protection, use a vacuum pump for air
purge.
7) R32 refrigerant is Single-component refrigerant that
does not change its composition.
Although it is possible to charge the refrigerant with
either liquid or gas, charge it with liquid.
(If using gas for charging, composition of the
refrigerant changes and then characteristics of the
air conditioner change.)
3. Pipe Materials
For the refrigerant pipes, copper pipe and joints are
mainly used.
It is necessary to select the most appropriate pipes
to conform to the standard.
Use clean material in which impurities adhere inside
of pipe or joint to a minimum.
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