Controls At Mode Changing / Start-Up - Daikin FTX20K(2)V1B Service Manual

Control Specification
3.3

Controls at Mode Changing / Start-up

3.3.1 Preheating Control
The inverter operation in open phase starts with the conditions of the outdoor temperature, the
Outline
discharge pipe temperature, the radiation fin temperature, and the preheating command from
the indoor unit.
Outdoor temperature ≥ –2.5°C → Control A (preheating for normal state)
Detail
Outdoor temperature < –2.5°C → Control B (preheating of increased capacity)
Control A
 ON condition
 OFF condition
Control B
 ON condition
 OFF condition
3.3.2 Four Way Valve Switching
The four way valve coil is energized / not energized depending on the operation mode.
Outline
(Heating: ON, Cooling / Dry / Defrost: OFF) In order to eliminate the switching sound as the four
way valve coil switches from ON to OFF when the heating is stopped, the OFF delay switch of
the four way valve is carried out.
Detail OFF delay switch of four way valve
The four way valve coil is energized for 160 seconds after the operation is stopped.
29
Discharge pipe temperature < 0°C
Radiation fin temperature < 85°C
Discharge pipe temperature > 2°C
Radiation fin temperature ≥ 90°C
Discharge pipe temperature < 10°C
Radiation fin temperature < 85°C
Discharge pipe temperature > 12°C
Radiation fin temperature ≥ 90°C
SiBE041525F
Functions and Control