Controls At Mode Changing / Start-Up - Daikin CTXU25G2V1B Service Manual

SiBE12-908
3.4

Controls at Mode Changing / Start-up

3.4.1 Preheating Operation
Outline Operate the inverter in the open phase operation with the conditions including the preheating
command from the indoor, the outdoor air temperature and discharge pipe temperature.
Detail Preheating ON Condition
OFF Condition
3.4.2 Four Way Valve Switching
Outline During the heating operation current must be conducted and during cooling and defrosting
current must not be 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 delay switch of the four way
valve must be carried out after the operation stopped.
Detail The OFF delay of four way valve
Energize the coil for 150 sec after unit operation is stopped.
3.4.3 Four Way Valve Operation Compensation
Outline At the beginning of the operation as the four way valve is switched, acquire the differential
pressure required for activating the four way valve by having output the operating frequency,
which is more than a certain fixed frequency, for a certain fixed time.
Detail Staring Conditions
1. When starting compressor for heating.
2. When the operating mode changes from the previous time.
3. When starting compressor for starting defrosting or resetting.
4. When starting compressor for the first time after the reset with the power is ON.
5. When starting compressor after operation stop by the cooling / heating mode change-over
Set the lower limit frequency to
above.
3.4.4 3-Minute Standby
Prohibit to turn ON the compressor for 3 minutes after turning it off.
(Except when defrosting. )
Function and Control
When outdoor air temperature is below 10.5ºC and discharge pipe temperature is below
10.5ºC, inverter in open phase operation starts. (The power consumption of compressor
during preheating operation is 35 W.)
When outdoor air temperature is higher than 12ºC or discharge pipe temperature is higher
than 12ºC, inverter in open phase operation stops.
malfunction.
Cooling
Heating
Hz for 60 seconds with any conditions with 1 through 5
40 class 50 class
56Hz 40Hz
68Hz 54Hz
Control Specification
31