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8-12. Expansion valve control (LEV control)
(1) Outline of LEV control
The LEV basic control is comprised of setting LEV opening degree to the standard opening degrees set for each opera-
tional frequency of the compressor. However, when any change in indoor/outdoor temperatures or other factors cause
air conditioning load fluctuation, the LEV control also works to correct LEV opening degree based on discharge temper-
ature (Shell temperature) of the compressor, developing the unit’s performance.
Control range
from min. 33 pulse to max. 500 pulse.
Actuating speed
LEV opens 40 pulse/sec. and close 90 pulse/sec.
Opening degree adjustment
LEV opening degree is always adjusted in opening direction.
(When reducing the opening degree, LEV is once over-
closed, and then adjusted to the proper degree by opening.
Unit OFF
LEV remains at max. opening degree (reaches max. opening
degree approx. 15 minutes after compressor stops)
Remote controller ON
LEV is positioned. (first full-closed at zero pulse and then
positioned.)
During 2 to 13 minutes after compressor starts
Opening degree is adjusted according to standard opening
degree.
(Standard opening degree is set for each rotational frequen-
cy of compressor)
More than 13 minutes have passed since compressor
start-up
LEV opening degree is corrected to get target discharge
temperature of compressor.
(For discharge temperature lower than target temperature,
LEV is corrected in closing direction.)
(For discharge temperature higher than target temperature,
LEV is corrected in opening direction.)
w
It may take more than 30 minutes to reach target tempera-
ture, depending on operating conditions.
Thermostat OFF
LEV starts to open every 3 pulse/sec.
from
the same opening degree as that when the Unit turned OFF
(and becomes full-opened after approx. 15 minutes.)
Thermostat ON
LEV is controlled in the same way as that is after the com-
pressor has started up.
Defrosting in HEAT mode
LEV is adjusted to open 500 pulse.
general operation
standard
specification
OB297--2.qxp 04.2.4 4:21 PM Page 37
Содержание Mr.Slim MSZ09UN W
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