Mitsubishi Electric Mr. Slim PEAD Series Service Manual page 5

CAUTIONS RELATED TO NEW REFRIGERANT
<Cautions for units utilizing refrigerant R410A>
Use new refrigerant pipes.
In case of using the existing pipes for R22, be careful with
the following.
· For RP100,125 and 140 be sure to perform pipe
replacement operation before test run.
· Use flare nut as provided with this product.
Use a newly flared pipe.
· Avoid using thin pipes. For the detail, please refer to the
outdoor unit service manual.
Make sure that the inside and outside of refrige-
rant piping is clean and it has no contamination
such as sulfur which is hazardous for use,
oxides, dirt, shaving particles, etc.
In addition, use pipes with specified thickness.
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil etc.
Store the piping to be used during installation
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 enter into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Use ester oil, ether oil or alkylbenzene oil (small
amount) as the refrigerant oil applied to flares
and flange connections.
If large amount of mineral oil enter, that can cause deterio-
ration of refrigerant oil etc.
Charge refrigerant from liquid phase of gas
cylinder.
If the refrigerant is charged from gas phase, composition
change may occur in refrigerant and the efficiency will be
lowered.
[1] Cautions for installing or relocation of unit
(1) Perform service after collecting the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the system with the specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
Do not use refrigerant other than R410A.
If other refrigerant (R22 etc.) is used, chlorine in refrige-
rant can cause deterioration of refrigerant oil etc.
Use a vacuum pump with a reverse flow check
valve.
If no reverse flow check valve is used, 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 R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Tools (for R410A)
Gauge manifold
Charge hose
Gas leak detector
Torque wrench
Keep the tools with care.
If dirt, dust or moisture enter into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder without syphone
tube.
If a charging cylinder is used without syphone tube, the
composition of refrigerant will change and the efficiency
will be lowered.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
Flare tool
Size adjustment gauge
Vacuum pump adaptor
Electronic refrigerant
charging scale
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