Hitachi RAM-10MQ, Installation & Maintenance Manual

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4
3. Before
Installation
(1) The pressure of refrigerant R410A is 1.4 times higher than conventional refrigerant; it is contaminated easily by moisture,
oxide, oil and other impurities. New refrigerant is adopted; therefore refrigerant oil also needs to be changed. When
installing, make sure to prevent moisture, oxide, oil, conventional refrigerant or refrigerant oil, or other impurities from
getting into the refrigerant cycle.
(2) To avoid accidental mixing of different refrigerant or different refrigerant oil, the size of the charging connectors must be
changed. It is necessary to prepare the following special R410A tools before performing the installation work.
Measuring instrument or tool which is directly contact to refrigerant must be used only for refrigerant R410A.
Symbol Description
：
○
：
For new and old type refrigerant
□
：
Only for R410A(not for R22)
●
：
Only for R407C(not for R22)
※ ：
For both R410A and R407C
Measuring Instrument and Tool
Interchangeability
with R22
Reason of Non-Interchangeability and Attention
(only for new refrigerant)
(
◎
Strictly Required)
Use
R407C R410A
Refrigerant
Pipe
Pipe Cutter
○ ○
Cutting Pipe
；
Removing Burrs
Flaring Tool
○ ○□
To ensure the high pressure of R410A,
‧
if using flaring
tube, make dimension of tube larger for R410A. If
you continue to use existent products, shall be used
with the flaring tube adjustment gasket (1mm).
(R410A special flaring tool can be used directly in the
R407C)
Flaring for Tubes
Refrigerant
Pipe
Extrusion
Adjustment
Gauge
─
(
not use
)
□
Dimensional Control
for Extruded Portion
if Tube after Flaring
Pipe Bender
○ ○
‧
If using the 1/2H pipe, it can not be processed.
Please use the elbow welding to connect.
Bending
Expanding Tool
○ ○
‧
If using the 1/2H pipe, it can not be processed.
Please use the elbow welding to connect.
Expanding Tubes
Torque Wrench
○
□
R410A for Φ 12.7
‧
、
Φ 15.88; spanner size is up 2mm;
existent products can not be used.
Connection of Flare Nut
○
‧
For Φ 6.35
、
Φ 9.53
、
Φ 19.05;
spanner size is the same.
Brazing Tool
○ ○
‧
Perform correct brazing work. Brazing for Tubes
Nitrogen Gas
○ ○
‧
Strict control against contamination.
(Blow nitrogen during brazing) Prevention from Oxidation
during Brazing
Lubrication Oil
(for Flare
Surface)
● □
Use a synthetic oil(FVC68D) which is equivalent
‧
to the oil used in the refrigerant cycle.
Do not use R22 with mineral oil
‧
, and products must
be used the same synthetic oil.
Synthetic oil absorbs moisture quickly. Do not place
‧
it in the humid environment.
Applying Oil to the Flared
Surface
Vacuum
Drying
Refrigerant
Change
Refrigerant
Cylinder
●
(Brown)
□
(Pink)
‧
Check refrigerant cylinder color.
(R410A:Pink)
、
(R407C:Brown)
◎
Refrigerant must be charged in a state of liquid.
(Charging in a state of gas is strictly prohibited.)
Refrigerant Charging
Vacuum Pump
○ ○
◎
The conventional ones are applicable. However,
it is required to mount a vacuum pump adapter
which can
prevent from reverse flow when a
vacuum pump stops.
Vacuum Pumping
Adapter for
Vacuum Pump
(prevent from
reverse)
※● □
Manifold Valve
● □
‧
No interchangeability is available due to higher
pressure when compared with R22.
R410A connection diameter
：
1/2 UNF
R407C connection diameter
：
7/16 UNF
◎＜
Do not use conventional ones (R22) to the
different refrigerant
＞
; If used, mineral oil will
flow into the cycle and cause sludge, resulting in
clogging or compressor failure.
Vacuum Pumping;
Vacuum Holding;
Refrigerant Charging
and Check of Pressures
Charging Hose
●
□
Charging Cylinder Prohibited Please use the
‧
weight scale. Refrigerant Charging
The air-tight test pressure of the product is 4.15Mpa.