Safety Precaution - Mitsubishi Electric PUHZ-P200YHA Service Manual

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SAFETY PRECAUTION

2-1. ALWAYS OBSERVE FOR SAFETY
Before obtaining access to terminal, all supply
circuits must be disconnected.
2-2. 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 followings.
· 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 refrige-
rant piping is clean and it has no contamination
such as sulfur 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 enters 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 enters, 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.
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.
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.
Gauge manifold
Charge hose
Gas leak detector
Torque wrench
Keep the tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigera-
nt 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.
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Tools for R410A
Flare tool
Size adjustment gauge
Vacuum pump adaptor
Electronic refrigerant
charging scale