Daikin FTXS09HVJU Service Manual page 55

SiUS04-904
3.11.1 Fully Closed with Power ON
Initialize the electronic expansion valve when turning on the power, set the opening position and
develop pressure equalizing.
3.11.2 Pressure Equalization Control
When the compressor is stopped, open and close the electronic expansion valve and develop
pressure equalization.
3.11.3 Opening Limit
Outline Limit a maximum and minimum opening of the electronic expansion valve.
 A maximum electronic expansion valve opening : 450 pulses
Detail
 A minimum electronic expansion valve opening : 52 pulses
The electronic expansion valve is fully closed in the room where cooling is stopped and is opened
with fixed opening during defrosting.
3.11.4 Starting Operation Control
Control the electronic expansion valve opening when the system is starting, and prevent the
system from being super heated or producing condensation.
3.11.5 High Discharge Pipe Temperature
When the compressor is operating, if the discharge pipe temperature exceeds a certain value, open
the electronic expansion valve and run the refrigerant from the low pressure side and lower
discharge pipe temperature.
3.11.6 Disconnection of the Discharge Pipe Thermistor
Outline Detect a disconnected discharge pipe thermistor by comparing the discharge pipe temperature with
the condensation temperature. If any are disconnected, open the electronic expansion valve
according to the outdoor air temperature and the operating frequency, operate for a specified time,
and then stop.
After 3 minutes of waiting, restart the unit and check if any are is disconnected. If any are
disconnected, stop the system after operating for a specified time. If the disconnection is detected 9
times in succession, then the system is shut down.
Detail
Detect Disconnection
If the timer for open control (cooling : 12min., heating : 15min.) goes over, and the 9-minute timer
for the compressor operation continuation is not counting time, the following adjustment must be
made.
1. When the operation mode is cooling
2. When the operation mode is heating
Adjustment when the thermistor is disconnected
When the compressor stop repeats after a specified time, the system should be shut down.
Function and Control
When the discharge pipe temperature is lower than the outdoor heat exchanger temperature,
the discharge pipe thermistor disconnection must be ascertained.
When the discharge pipe temperature is lower than the max temperature of indoor unit heat
exchanger, the discharge pipe thermistor disconnection must be ascertained.
Control Specification (09/12 Class)
45