Dacor EF42 Series, Руководство по обслуживанию

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Variable Capacity Compressor
The sealed system in the Dacor Built-in
Refrigerators incorporate Variable Capacity
Cooling.
Most conventional refrigeration systems use single
speed compressors. The capacity is constant
and the controls meet the cooling demand by
cycling the compressor on and off. With a Variable
Capacity Compressor (VCC), the compressor
speed is adjusted to better match the cooling
requirements of the refrigerator itself. This results
in longer run times at a lower capacity.
Since the most stress and instantaneous energy
usage occurs while a motor is starting; by
eliminating the number of times the system cycles
off, the stress on the system is minimized. The
other advantage of operation at a lower speed is
reduced sound levels. A compressor running at a
lower speed will produce less noise in the vicinity
of the refrigerator.
The Main Control Board uses information from
all six thermistors to determine the compressor
speed. The compressor will always start at high
speed but will quickly adjust to the calculated
capacity after starting.
The compressor motor is a three-winding motor.
These three windings are powered by the
Compressor PCB (Printed Circuit Board). The
Compressor PCB is controlled by the Main Control
Board.
The Compressor PCB is supplied power from the
AC line cord. This AC power is converted to DC
power on the board. The DC power is sequentially
switched to the three motor windings to drive
the compressor. By adjusting the speed at which
these three windings are switched, the speed of
the compressor can be adjusted. The switching
speed is determined by the Main Board and is
communicated by sending a variable frequency
signal from the Main Board to the Compressor
PCB. This signal can range from 150 cycles per
second (Hz) to 53 cycles per second. The resulting
compressor speed will adjust between 4500 RPM
to 1600 RPM.
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+170VDC
GND
+170VDC
GND
+170VDC
GND