Daikin FTKE25BVM, Service Manual

Page: 111 / 298

Control Specification Si12-411A
100 Function and Control
3.12.1 Fully Closing with Power ON
Initialize the electronic expansion valve when turning on the power, set the opening position and
develop pressure equalizing.
3.12.2 Pressure Equalization Control
When the compressor is stopped, open and close the electronic expansion valve and develop
pressure equalization.
3.12.3 Opening Limit
Outline Limit a maximum and minimum opening of the electronic expansion valve in the operating room.
Detail
„
A maximum electronic expansion valve opening in the operating room: 450 pulses
„
A minimum electronic expansion valve opening in the operating room: 75 pulses
The electronic expansion valve is fully closed in the room where cooling is stopped and is
opened with fixed opening during defrosting.
3.12.4 Starting Operation Control / Changing Operation Room
Control the electronic expansion valve opening when the system is starting or the operating
room is changed, and prevent the system to be super heated or moistened.
3.12.5 High Temperature of the Discharge Pipe
When the compressor is operating, if the discharge pipe temperature exceeds a certain value,
open the electronic expansion valve and remove the refrigerant to the low pressure side and
lower discharge temperature.
3.12.6 Oil Recovery Function
Outline The electronic expansion valve opening in the cooling stopped room must be set as to open for
a certain time at a specified interval so that the oil in the cooling stopped room may not be
accumulated.
Detail During cooling operation, every 1 hour continuous operation, the electronic expansion valves in
the operation stopped room must be opened by 80 pulses for specified time.
3.12.7 Gas Pipe Isothermal Control During Cooling
When the units are operating in multiple rooms, detect the gas piping temperature and correct
the electronic expansion valve opening so that the temperature of the gas pipe in each room
becomes identical.
„
When the gas pipe temperature > the average gas pipe temperature,
→
open the electronic expansion valve in that room
„
When the gas pipe temperature < the average gas pipe temperature,
→
close the electronic expansion valve in that room