Mitsubishi Electric PVA-A30AA4, Service Manual

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SAFETY PRECAUTION
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1-1. ALWAYS OBSERVE FOR SAFETY
Cautions for units utilising refrigerant R410A
Use new refrigerant 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.
Store the piping to be used indoors during
installation and both ends of the piping sealed
until just before brazing. (Leave elbow joints, etc.
in their packaging.)
Use ester oil, ether oil or alkylbenzene oil (small
amount) as the refrigerant oil applied to flares
and flange connections.
In case of using the existing pipes for R22, be careful with
the followings.
·
For A36 and A42, be sure to perform replacement oper-
ation before test run.
·
Change flare nut to the one provided with this product.
Use a newly flared pipe.
·
Avoid using thin pipes.
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.
Handle 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.
Flare tool
Electronic refrigerant
charging scale
Vacuum pump adaptor
Size adjustment gauge
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil etc.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
If large amount of mineral oil enters, that can cause deterio-
ration of refrigerant oil etc.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
·
Check that cylinder for R410A on the market is syphon type.
·
Charging should be performed with the cylinder of syphon stood vertically. (Refrigerant is charged from liquid phase.)
Before obtaining access to terminal, all supply
circuits must be disconnected.
1-2. CAUTIONS RELATED TO NEW REFRIGERANT
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