Controls At Mode Changing / Start-Up - Daikin FTXZ25NV1B Service Manual

SiMT041311E
2.2

Controls at Mode Changing / Start-up

2.2.1 Preheating Control
Outline The inverter operation in open phase starts with the conditions of the preheating command from
the indoor unit, the outdoor temperature, and the discharge pipe temperature.
Preheating control is set to OFF by default.
Outdoor temperature ≥ 7°C
Detail
Outdoor temperature < 7°C
2.2.2 Four Way Valve Switching
Outline In heating operation, current is conducted, and in cooling and defrost control, current is not
conducted. 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 energised for 160 seconds after the operation is stopped.
2.2.3 Four Way Valve Operation Compensation
Outline At the beginning of the operation as the four way valve is switched, the pressure difference to
activate the four way valve is acquired when the output frequency is higher than a certain fixed
frequency, for a certain fixed time.
Detail Starting Conditions
1. When the compressor starts and the four way valve switches from OFF to ON
2. When the four way valve switches from ON to OFF during operation
3. When the compressor starts after resetting
4. When the compressor starts after the fault of four way valve switching
The lower limit of frequency keeps A Hz for B seconds with any conditions 1 through 4 above.
A (Hz)
B (seconds)
Function and Control
Discharge pipe temperature
10˚C
Discharge pipe temperature
20˚C
Cooling
46
60
Preheating OFF
12˚C
Preheating ON
Preheating OFF
22˚C
Preheating ON
Heating
52
60
Control Specification
(R5922)
(R5923)
46