High Performance - Hitachi RAK-25NH6 Information Booklet & User Manual

Compressor Technology
Digital DC Scroll
Compressor
The motor uses digital control to
maximise PAM control performance.
• Loss during high-speed revolution
is reduced thanks to digital control
of the motor.
• Shaft runout during high-speed
revolution is lessened by three
balancers mounted on the
crank shaft.
• Efficient operation with drastically
reduced refrigerant leakage is
ensured by the automatic
compression system, in which the
tip of the slewing scroll is kept in
absolute contact with the fixed
scroll, in addition to special
processing of the scroll surface.
DC Twin Rotary Compressor
Today all Monozone and two Multizone
room air conditioning units have Hitachi's
new twin rotary compressor which has even
less vibration and even higher performance
efficiency than conventional rotary compressors.
• Two rotating cylinders ensure well balanced
rotation unlike the conventional single-rotary
type, thus greatly reducing any vibration noise.
• The compressor's operation is magnificently
improved by the independent operation of
the cylinders leading to greater efficiency
and lower vibration.
Drawing of cylinder balance
Conventional single-rotary
Comparison of vibration
Single
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High performance

cooling at -10ºC and
heating at -15ºC
The cooling and heating performance
is even more impressive than
previously. The units have been
designed for cooling operation
under low temperatures down to
-10°C. At outdoor temperatures as
low as -15°C, the PAM controlled
range of inverter split systems
continue to provide high capacity
heating performance.
New twin-rotary
Twin
1/5
Cooling at
Heating at
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