Features - Hitachi RAF-25NH4 Service Manual

EATURES
1. NEW RE RIGERANT
(1) New refrigerant R410A with no harmful effect on the ozone layer
Refrigerant R410A, which does not damage the ozone layer, was adopted instead of HCFC-22 which is planned
to be phased out globally by 2020.
(2) New refrigerating oil
The new refrigerant HFC-R410A is not compatible with conventional mineral oils and no lubrication can be
expected with those oils. To solve this, the artificial synthetic ester oil is newly adopted.
NEW TECHNOLOGY
Cautions in relation to HFC (R410A)
1. Safety during Servicing
This air conditioner uses the new refrigerant HFC (R410A) for protecting the ozone layer. R410A has
several different characteristic features from HCFC-22. Therefore keep the following care items during
servicing for safety.
(1) Since the working pressure of R410A model is about 1.6 times higher than that of HCFC-22 models, it
becomes necessary to use part of piping materials and servicing tools exclusive for R410A model.
(2) It is necessary to exercise more care to prevent the foreign matters (oil, moisture, etc.) from mixing into
the piping than in the case of HCFC-22 model. Also, when storing the piping, securely seal its
openings with pinching and taping, etc..
(3) Be sure to charge the refrigerant from the liquid-phase side, as the liquid-phase/gas-phase-composition
changes a little in the case of R410A model.
(4) Never use refrigerant other than R410A in an air conditioner which is designed to operate with R410A.
(5) If a refrigeration gas leakage occurs during servicing, be sure to ventilate fully.
If the refrigerant gas comes into contact with fire, a poisonous gas may occur.
(6) When installing or removing an air conditioner, do not allow air or moisture to remain in the
refrigeration cycle. Otherwise, pressure in the refrigeration cycle may become abnormally high so that a
rupture or personal injury may be caused.
(7) After completion of service work, check to make sure that there is no refrigeration gas leakage.
If the refrigerant gas leaks into the room, coming into contact with fire in the fandriven heater, space
heater, etc., a poisonous gas may occur.
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