Daikin GQI-Eco Series Service Manual page 57

ESIE15-13B
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
OR
Function and Control
• Suction SH > 12°C
• Suction SH > 10°C
&
• EV opening degree = 480 pls
Lowering upper limit frequency
for 1 step every 20 seconds
Normal operation
OR
• Suction SH < 4°C
• Suction SH < 8°C
OR
• Suction SH < 10°C
&
• EV opening degree < 450 pls
• Suction SH > 12°C
OR
• Suction SH > 10°C
&
• EV opening degree = 480 pls
Function Details
• Suction SH < 4°C
• Upper limit frequency = Maximum frequency
• &
• Suction SH < 8°C
• OR
• Suction SH < 10°C
• &
• EV opening degree < 450 pls
Raising upper limit frequency for
1 step every 20 seconds
43