Mitsubishi Electric SUZ-SWM40VA Technical & Service Manual page 3

2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Cautions for units utilizing refrigerant R32
Preparation before the repair service
• Prepare the proper tools.
• Prepare the proper protectors.
• Provide adequate ventilation.
• After stopping the operation of the air to water heat
pump, turn off the power-supply breaker.
• Discharge the condenser before the work involving the
electric parts.
Use new refrigerant pipes.
In case of using the existing pipes for R22, be careful
with the following.
· Be sure to clean the pipes and make sure that the
insides of the pipes are clean.
· Change flare nut to the one provided with this product.
Use a newly flared pipe.
· Avoid using thin pipes.
Make sure that the inside and outside of
refrigerant piping is clean and it has no
contaminants such as sulfur, oxides, dirt,
shaving particles, etc., which are hazard to
refrigerant cycle.
In addition, use pipes with specified thickness.
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil, etc.
Store the piping indoors, and keep both ends of
the piping sealed until just before brazing.
(Leave elbow joints, etc. in their packaging.)
If dirt, dust or moisture enters into refrigerant cycle, that
can cause deterioration of refrigerant oil or malfunction of
compressor.
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a small amount.
If large amount of mineral oil enters, that can cause
deterioration of refrigerant oil, etc.
Do not use refrigerant other than R32.
If other refrigerant (R22, etc.) is used, chlorine in
refrigerant can cause deterioration of refrigerant oil, etc.
OCH718A
Precautions during the repair service
• Do not perform the work involving the electric parts
with wet hands.
• Do not pour water into the electric parts.
• Do not touch the refrigerant.
• Do not touch the hot or cold areas in the refrigerating cycle.
• When the repair or the inspection of the circuit needs
to be done without turning off the power, exercise great
caution not to touch the live parts.
Use a vacuum pump with a reverse flow check
valve.
Vacuum pump oil may flow back into refrigerant cycle
and that can cause deterioration of refrigerant oil, etc.
Use the following tools specifically designed for
use with R32 refrigerant.
The following tools are necessary to use R32 refrigerant.
Gauge manifold
Charge hose
Gas leak detector
Torque wrench
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that
can cause deterioration of refrigerant oil or malfunction of
compressor.
Use the specified refrigerant only.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when
the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the
spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
3 3
Tools for R32
Flare tool
Size adjustment gauge
Vacuum pump adaptor
Electronic refrigerant
charging scale