Electronic Expansion Valve Control - Daikin FTK Series Service Manual

Control Specification
3.12.2 Full Close as Power Supply ON
When the power is turned ON, the electronic expansion valve is initialized to position the valve opening and
facilitate pressure equalization. (Prevent the compressor from being locked by start-up with differential pressure)
Processes as power supply ON

Turn the power ON, close 700 pulses and set the current opening at 0 pulse.

Open 400 pulses after the full close process completed.
Process after resuming from stand-by electricity saving (suspend) mode
Set the electronic expansion valve opening at 400 pulses after resuming from stand-by electricity saving mode.
3.12.3 Pressure Equalization Control
When the compressor is switched from ON to OFF, open the electronic expansion valve to facilitate pressure
equalization while preventing the sound produced from refrigerant flow at pressure equalization.
Summary of operation
Open the electronic expansion valve in a phased manner for 90-120 seconds when operation stop (including abnormal
stoppage) or the thermostat is turned OFF.
 
Fully closed open 400 pluses
3.12.4 Initialization as Power Supply On
The electronic expansion valve is initialized (fully closed) when the power is turned on. Then,
the valve opening position is set and the pressure is equalized.
3.12.5 Pressure Equalizing Control
When the compressor is stopped, the pressure equalizing control is activated. The electronic
expansion valve opens and the pressure is equalized.
3.12.6 Opening Limit Control
The maximum and minimum opening of the electronic expansion valve are limited.
Expansion valve
opening (pulse)
3.12.7 Starting Operation Control
The electronic expansion valve opening is controlled when the operation starts, thus preventing
superheating or liquid compression.
3.12.8 Control when the Frequency Changes
When the target discharge pipe temperature control is active, if the target frequency changes to
a specified value in a certain period of time, the target discharge pipe temperature control is
canceled and the target opening of the electronic expansion valve is changed according to the
frequency shift.
46
Electronic
09
Maximum 470
Minimum 32
12 18
470 480
32 54
DAMA-SM-21-001
24
480
54
Functions and Control