Daikin REYQ-AATJA, Service Manual, Page: 137 / 495

SiUS372201EA Basic Control
Part 4 Functions and Control 130
5.2 Compressor PI Control
Carries out the compressor capacity PI control so that Te reaches the target value during cooling
and Tc during heating.
Controls compressor capacity to adjust Te to achieve target value (TeS).
1. VRT control (default)
When the indoor temperature approaches the set temperature in all indoor units and the
required capacity decreases, TeS is automatically increased to adjust the capacity.
2. Constant control
TeS is fixed to the set value.
Te setting
Te: Low pressure equivalent saturation temperature
TeS: Target temperature of Te (Varies depending on Te setting, operating frequency, etc.)
Controls compressor capacity to adjust Tc to achieve target value (TcS).
1. VRT control (default)
When the indoor temperature approaches the set temperature in all indoor units and the
required capacity decreases, TcS is automatically decreased to adjust the capacity.
2. Constant control
TcS is fixed to the set value.
Tc setting
Te: High pressure equivalent saturation temperature
TeS: Target temperature of Tc (Varies depending on Tc setting, operating frequency, etc.)
Branch Selector unit actuator Normal cooling
Normal simultaneous cooling/heating
Normal heating
Cooling Heating
Electronic
expansion
valve (EVSC)
Y1E
Thermostat ON 0 pulse 0 pulse
Subcooling degree
control
0 pulse
Non-operating 0 pulse 0 pulse 0 pulse 0 pulse
Thermostat OFF 0 pulse 0 pulse 0 pulse 0 pulse
Electronic
expansion
valve (EVH)
Y2E
Thermostat ON 6,000 pulse 0 pulse 6,000 pulse 6,000 pulse
Non-operating 6,000 pulse 0 pulse 6,000 pulse 6,000 pulse
Thermostat OFF 6,000 pulse 0 pulse 6,000 pulse 6,000 pulse
Electronic
expansion
valve (EVL)
Y3E
Thermostat ON 6,000 pulse 6,000 pulse 0 pulse 0 pulse
Non-operating 6,000 pulse 6,000 pulse 0 pulse 0 pulse
Thermostat OFF 6,000 pulse 6,000 pulse 0 pulse 0 pulse
Cooling
L M H
3°C
(37.4°F)
6°C
(42.8°F)
7°C
(44.6°F)
8°C
(46.4°F)
9°C
(48.2°F)
10°C
(50.0°F)
11°C
(51.8°F)
Heating
L M H
41°C
(105.8°F)
42°C
(107.6°F)
43°C
(109.4°F)
44°C
(111.2°F)
45°C
(113.0°F)
46°C
(114.8°F)
48°C
(118.4°F)