Pressure Equalizing Control - Daikin 2MXS-N Series Service Manual

Control Specification
3.13.1 Fully Closing with Power on
The electronic expansion valve is initialized when the power is turned on. The opening position is
set and the pressure equalization is developed.

3.13.2 Pressure Equalizing Control

When the compressor is stopped, the pressure equalizing control is activated. The electronic
expansion valve opens, and develops the pressure equalization.
3.13.3 Opening Limit Control
Outline The maximum and minimum opening of the electronic expansion valve are limited.
Detail
The electronic expansion valve is fully closed in a room where cooling operation is stopped and is
opened at a fixed degree during defrosting.
3.13.4 Starting Operation Control / Changing Operation Room
The electronic expansion valve opening is controlled when the operation starts, and prevents
superheating or liquid compression.
3.13.5 Control when the Frequency Changes
When the target discharge pipe temperature control is active, if the target frequency is changed to a
specified value in a certain time period, the target discharge pipe temperature control is canceled
and the target opening of the electronic expansion valve is changed.
3.13.6 Oil Recovery Function
Outline The electronic expansion valve opening in the cooling stopped room is 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 is opened by 80 pulses for specified time.
3.13.7 High Discharge Pipe Temperature Control
When the compressor is operating, if the discharge pipe temperature exceeds a certain value, the
electronic expansion valve opens and the refrigerant runs to the low pressure side.
This procedure lowers the discharge pipe temperature.
74
Maximum electronic expansion valve opening in the operating room: 450 pulse
Minimum electronic expansion valve opening in the operating room: 64 pulse
SiUS121502E
Function and Control