Controls At Mode Changing / Start-Up - Daikin FTKS20CVMB Service Manual

SiBE04-401
3.3

Controls at Mode Changing / Start-up

3.3.1 Preheating Operation
Outline Operate the inverter in the open phase operation with the conditions including the preheating
command (only for heat pump model) from the discharge pipe temperature.
Detail Preheating ON Condition
OFF Condition
3.3.2 Four Way Valve Switching
Outline of Heat Pump Only
Heating 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
Operation
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 160 sec after unit operation is stopped.
3.3.3 Four Way Valve Operation Compensation
Outline Heat Pump Only
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 Starting Conditions
1. When starting compressor for heating.
2. When the operating mode changes to cooling from heating.
3. When starting compressor for rushing defrosting or resetting.
4. When starting compressor for the first time after the reset with the power is ON.
5. When starting compressor for heating next to the suspension of defrosting.
6. When starting compressor next to the fault of switching over cooling / heating.
Set the lower limit frequency to 68 (model by model) Hz for 45 seconds (50 seconds for
(A)RK(X)H, R(Y)N models) with any conditions 1 through 4 above.
Function and Control
When the discharge pipe temperature is below 10ºC, inverter in open phase operation
starts.
When the discharge pipe temperature is higher than 12ºC, inverter in open phase operation
stops.
Control Specification
47