Daikin FTXS30LVJU, Service Manual

Page: 61 / 414

Control Specification SiUS091133
51 Function and Control
3.11 Electronic Expansion Valve Control
Outline The following items are included in the electronic expansion valve control.
Electronic expansion valve is fully closed
1. Electronic expansion valve is fully closed when turning on the power.
2. Pressure equalizing control
Open Control
1. Electronic expansion valve control when starting operation
2. Electronic expansion valve control when the frequency changes
3. Electronic expansion valve control for defrosting
4. Electronic expansion valve control when the discharge pipe temperature is abnormally high
5. Electronic expansion valve control when the discharge pipe thermistor is disconnected
Feedback Control
1. Target discharge pipe temperature control
Detail
The followings are the examples of electronic expansion valve control which function in each
operation mode.
Cooling
−
h
− − − − − −
− −
h
−
h
− − −
− − − h − − − −
− − − − −
h h
−
−
h h h h
h h h h h
− − −
h − − − − − − −
−
h
−
Heating
− h − − − − − −
− − h − h − − −
− − −
h
− − − −
− − − − − h h −
− h h h h − − −
− − − − − − −
h
h − − − − − − −
− h h h h h h −
h
: Holding Functions
— : No Functions
Starting control
Control when the frequency changes
Target discharge pipe temperature control
Control for disconnection of the discharge
pipe thermistor
High discharge pipe temperature control
Pressure equalizing control
Opening limit control
Starting control
Control when the frequency changes
Target discharge pipe temperature control
Control for disconnection of the discharge
pipe thermistor
High discharge pipe temperature control
Defrost control
Pressure equalizing control
Opening limit control
When the power turns on or when the compressor stops When the operation starts When the frequency changes under starting control During target discharge pipe temperature control When the frequency changes under target discharge pipe temperature control When the disconnection of the discharge pipe thermistor is ascertained When the frequency changes under the control for disconnection of the discharge pipe thermistor Under defrost control