Compressor Pi Control - Daikin REYQ-XA Service Manual

Basic Control
5.2

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.
On multi-outdoor-unit systems, this control is made according to values of the first-priority unit,
which is detected with the pressure sensor.
Cooling
Controls compressor capacity to adjust Te to
achieve target value (TeS).
Te set value (Make this setting while in Setting
mode 2.)
Te setting
∗1. Min.: 6°C (42.8°F), max.: 17°C (62.6°F)
Heating
Controls compressor capacity to adjust Tc to
achieve target value (TcS).
Tc set value (Make this setting while in Setting
mode 2.)
Tc setting
∗1. Min.: 38°C (100.4°F), max.: 46°C (114.8°F)
111
L M
3°C 6°C 7°C
(37.4°F) (42.8°F) (44.6°F)
L
41°C 42°C 43°C
(105.8°F) (107.6°F) (109.4°F)
Ta(C): Outdoor air temperature in Celsius (°C)
Ta(F): Outdoor air temperature in Fahrenheit (°F)
Te: Low pressure equivalent saturation
temperature
TeS: Target temperature of Te
(Varies depending on Te setting, operating
frequency, etc.)
H
8°C 9°C 10°C
(46.4°F) (48.2°F) (50°F)
Ta(C): Outdoor air temperature in Celsius (°C)
Ta(F): Outdoor air temperature in Fahrenheit (°F)
Tc: High pressure equivalent saturation
temperature
TcS: Target temperature of Tc
(Varies depending on Tc setting, operating
frequency, etc.)
M
44°C 45°C 46°C
(111.2°F) (113.0°F) (114.8°F)
SiUS371901E
A (∗1)
(factory setting)
11°C 28.75 – Ta(C) × 0.65 (°C)
(51.8°F) (104.55 – Ta(F) × 0.65 (°F))
A (∗1)
H
(factory setting)
48°C 48 – Ta(C) (°C)
(118.4°F) (150.4 – Ta(F) (°F))
Functions and Control