Controls At Mode Changing / Start-Up - Daikin FTXM-K Series Service Manual

SiBE041434E
3.3

Controls at Mode Changing / Start-up

3.3.1 Preheating Control
Outline The inverter operation in open phase starts with the conditions of the preheating command from
the indoor unit, the outdoor temperature, the discharge pipe temperature, and the radiation fin
temperature.
Outdoor temperature ≥ A°C → Control I
Detail
Outdoor temperature < A°C → Control II
Control I
Control II
3.3.2 Four Way Valve Switching
Outline The four way valve coil is energized / not energized depending on the operation. (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.
Function and Control
ON condition
Discharge pipe temperature < B°C
Radiation fin temperature <85°C
OFF condition
Discharge pipe temperature > C°C
Radiation fin temperature ≥ 90°C
ON condition
Discharge pipe temperature < D°C
Radiation fin temperature <85°C
OFF condition
Discharge pipe temperature > E°C
Radiation fin temperature ≥ 90°C
A (°C) B (°C)
–2.5 0
C (°C) D (°C)
2 10
Control Specification
E (°C)
12
40