Daikin RXYQ96PYDN, Service Manual

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SiUS34-801A_b Basic Control
VRVIII R-410A Heat Recovery 60Hz 189
* 1 and 2 : Refer to Chapter 6: Control of Electonic Expansion Valve on page 293.
6.2 Compressor PI Control
Compressor PI Control
Carries out the compressor capacity PI control to maintain Te at constant during cooling operation
and Tc at constant during heating operation to ensure stable unit performance.
[Cooling operation]
[Heating operation]
Rotation of outdoor units
In order to make operating time equal for each compressor of multi connection outdoor units,
outdoor units are used in rotation.
However this is not applicable to single units.
[Rotation of outdoor units]
For multiple outdoor units, an operational priority order is assigned to each outdoor unit on the
control purpose.
The operational priority orders of each outdoor unit are switched by means of outdoor unit rotation.
[System with two outdoor units]
[Timing of outdoor rotation]
In start of startup control
BS unit actuator
Electric
symbol
Normal cooling
Normal heating / Normal simultaneous Cooling /
Heating operation
Electronic expansion valve (EVH) Y4E 760 pls (fully opened) 760 pls (fully opened)
Electronic expansion valve (EVL) Y5E 760 pls (fully opened) 0 pls
Electronic expansion valve (EVHS) Y2E 480 pls (fully opened) 480 pls (fully opened)
Electronic expansion valve (EVLS) Y3E 480 pls (fully opened) 0 pls
Electronic expansion valve (EVSC) Y1E 0 pls 0 pls (simultaneous Cooling / Heating operation : PI control)
Controls compressor capacity to adjust Te to
achieve target value (TeS). Te : Low pressure equivalent saturation temperature
(°F)
Te set value (Make this setting while in Setting
mode 2.) TeS : Target Te value
(Varies depending on Te setting, operating
frequency, etc.)
*On multi-outdoor-unit systems, this control is made
according to values of the first-priority unit, which is
detected with the pressure sensor.
Te setting
L M (Normal)
(factory
setting)
H
37 43 45 46 48 50 52
Controls compressor capacity to adjust Tc to
achieve target value (TcS). Tc : High pressure equivalent saturation temperature
(°F)
Te set value (Make this setting while in Setting
mode 2.) TcS : Target Tc value
(Varies depending on Tc setting, operating
frequency, etc.)
*On multi-outdoor-unit systems, this control is made
according to values of the first-priority unit, which is
detected with the pressure sensor.
Tc setting
L M (Normal)
(factory
setting)
H
109 115 118
Outdoor Unit 1 Outdoor Unit 2
Previous time Priority 1 Priority 2
This time Priority 2 Priority 1
Next time Priority 1 Priority 2