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

Si04-306E
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 from the indoor, the outdoor air temperature and discharge pipe temperature.
Detail Preheating ON Condition
OFF Condition
3.3.2 Four Way Valve Switching
Outline Heat Pump Only
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.
3.3.3 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 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.
3.3.4 3-Minute Standby
Prohibit to turn ON the compressor for 3 minutes after turning it off.
(Except when defrosting. (Only for Heat Pump Model).)
3.3.5 Compressor Protection Function
When turning the compressor from OFF to ON, the upper limit of frequency must be set as
follows. (The function must not be used when defrosting (only for heat pump model).)
FCG 3
FCG 2
FCG 1
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 preheat 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.
Set the lower limit frequency to 55 (model by model) Hz for 70 seconds with any conditions 1
through 4 above.
2YC63 Others
85 85
70 70
40 55
Control Specification
63