2 Features and benefits
TCGB0070 rev.3 - 04/2012
35
2
PWM (pulse width modulation) concept of speed control
The switching element (a power MOSFET) switches back and forth at a frequency of several tens of kHz. This controls the
ON/OFF duty rate per cycle and changes the voltage applied to the fan motor to control the rotation speed.
HITACHI exclusive scroll compressor
Highly efficient scroll compressor
The HITACHI DC INVERTER scroll compressor has been developed to increase efficiency, reliability and to reduce power
input.
New drive
mechanism Oil
feeding mecha-
nism etc.,
DC-Inverter
Motor
Newly-
developped
scroll for
410A
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Asymmetric Scroll Lap
NEW
Sub-bearing
SHUT OUT
SHUT OUT
HIGH RELIABILITY
Decrease of bearing
load
Minimizing of shaft
swing
Oil returning pipe
Decrease of superheat loss
Decrease of leak loss
Decrease of intake loss
HIGH PERFORMANCE
NEW
NEW
NEW
High pressure shell
•
It acts as an oil separator reducing the amount of oil circulating in the cooling system giving better heat exchanger
efficiency.
•
Motor heat is not added to the suction gas before compression, which reduces the discharge gas temperature. This is
particularly important at low suction temperatures. The discharge gas cools the motor sufficiently.
•
Refrigerant cannot enter the shell during the off cycle causing oil dilution and oil foaming at start up.
• New system of regulating pressure (only for RAS-(4~6)HVRNME-AF), increasing the compressor’s efficiency and
reliability in part load mode. This system ensures the work pressure of the compressor is always at optimum level
regardless of the charge, so that the ratio between the discharge pressure (Pd) and the suction pressure (Ps) is opti-
mum as in the following graphic:
Pd
Ps
Overcompression
zone based
on the new pres-
sure regulation
system
Volume
Pressure
