Important Considerations - Hitachi UTOPIA R32 Series Installation And Operation Manual

10.1 Important considerations

Appropriate refrigerant
The refrigerant used in each unit is identified on the specification label and manuals of the unit.
Hitachi shall not be held liable for any failure, trouble, malfunction or accident caused by units
illegally charged with refrigerants other than the specified one.
Consequences of charging non-specified refrigerant
It may cause mechanical failure, malfunction and other accidents.
It may cause operational failure of protection and safety devices of air conditioners.
It may also cause lubrication failure of the sliding part of the compressor due to deterioration of
refrigerant oil.
In particular, hydrocarbon refrigerants (such as propane, R441A, R443A, GF-08, etc.) are not
allowed, since these are combustible and may cause major accidents such as fire and explosion in
case of improper handling.
Once a non-specified refrigerant has been charged, no further servicing (including draining of
refrigerant) shall be performed, even in case of malfunction. Improper handling of refrigerant may
be a cause of fire and explosion, and servicing in such cases may be considered an illegal act.
End clients and costumers shall be informed that servicing is not approved, and the installer who
charged the non-specified refrigerant shall be asked to fix the unit.
Hitachi will accept no responsibility for units that have been charged with non-specified refrigerant
once.
!
DANGER
Use refrigerant R32 according to the outdoor units model in the refrigerant cycle. Do not charge
oxygen, acetylene or other flammable and poisonous gases into the refrigerant cycle when
performing a leakage test or an air-tight test. These types of gases are extremely dangerous and
can cause an explosion. It is recommended that compressed air, nitrogen or refrigerant be used
for these types of test.
• After vacuum pumping work, keep the gas valve and liquid valve fully closed.
• Check if the system needs an additional charge of refrigeration.
• If the total refrigerant amount of the system is insufficient, charge the additional refrigerant,
which amount is calculated, from the check joint of the liquid valve. (Additional refrigerant
tolerance shall be +0.5 kg.) according to follows:
✓ Fully open the gas valve.
✓ For charging refrigerant, connect the gauge manifold using charging hoses with a refrigerant
charging cylinder to the check joint of the liquid line stop valve.
PMEN0654 rev.0 - 12/2023
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