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

SiUS04-924_A
3.3

Controls at Mode Changing / Start-up

3.3.1 Preheating Operation
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.
Outdoor temperature  10°C (50°F)  Control A (preheating for normal state)
Detail
Outdoor temperature < 10°C (50°F)  Control B (preheating of increased capacity)
Control A
 ON condition
 OFF condition
Control B
 ON condition
 OFF condition
Note: The power consumption of compressor during preheating operation is 35 W.
3.3.2 Four-Way Valve Switching
Outline In heating operation, current is conducted, and in cooling and defrosting, current is not conducted.
In order to eliminate the switching sound when the heating is stopped, as the four-way valve coil
switches from ON to OFF, and the OFF delay switch of the four-way valve is carried out after the
operation stopped.
Detail
OFF delay switch of four way valve:
The four-way valve coil is energized for 150 seconds after the operation is stopped.
30
Discharge pipe temperature < 6°C (42.8°F)
Radiation fin temperature < 85°C (185°F)
Discharge pipe temperature > 8°C (46.4°F)
Radiation fin temperature  90°C (194°F)
Discharge pipe temperature < 10.5°C (50.9°F)
Radiation fin temperature < 85°C (185°F)
Discharge pipe temperature > 12°C (53.6°F)
Radiation fin temperature  90°C (194°F)
Control Specification
Function and Control