MXS Service Manual

SiUS121736EA Control Specification
Functions and Control 106
4.13.1 Initialization as Power Supply On
The electronic expansion valve is initialized (fully closed) when the power is turned on. Then, the
valve opening is set and the pressure is equalized.
4.13.2 Pressure Equalizing Control
When the compressor is stopped, the pressure equalizing control is activated. The electronic
expansion valve opens, and develops the pressure equalization.
4.13.3 Opening Limit Control
Outline The maximum and minimum opening of the electronic expansion valve are limited.
Details  Maximum electronic expansion valve opening in the operating room: 450 pulse
 Minimum electronic expansion valve opening in the operating room: 64 pulse
The electronic expansion valve is fully closed in a room where cooling operation is stopped and is
opened at a fixed degree during defrosting.
4.13.4 Starting Operation Control/Changing Operation Room
The electronic expansion valve opening is controlled when the operation starts, and prevents
superheating or liquid compression.
4.13.5 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 period of time, the target discharge pipe temperature control is canceled
and the target opening of the electronic expansion valve is changed.
4.13.6 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.
Details 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.
4.13.7 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.