Daikin RZQG71L9V1, Service Manual

Page: 57 / 215

ESIE15-13C Function Details
Function and Control 43
3.2.14 Suction Pipe Superheat Protection Control (Only in Heating
Operation)
In case the suction superheat value in heating mode is too high, the oil return to the compressor
will be insufficient. In order to avoid that the compressor oil will be accumulated in the outdoor
unit heat exchanger, the upper limit frequency will be controlled.
SH: Superheat degree
EV: Electronic expansion valve
Normal operation
• Suction SH > 12°C
• Suction SH < 8°C
• Suction SH < 10°C
• EV opening degree < 450 pls
• Suction SH > 10°C
• EV opening degree = 480 pls
• Suction SH < 4°C
• Suction SH < 4°C
• Suction SH < 8°C
• Suction SH < 10°C
• EV opening degree < 450 pls
• Upper limit frequency = Maximum frequency
&
&
OR
OR
OR
• Suction SH > 12°C
• Suction SH > 10°C
• EV opening degree = 480 pls
&
OR
Lowering upper limit frequency
for 1 step every 20 seconds
Raising upper limit frequency for
1 step every 20 seconds
• &
• &
• OR