Suction Pipe Superheat Protection Control (Heating Mode) - Daikin SkyAir Service Manual

SiBE28-804
4.7 Suction Pipe Superheat Protection Control (Heating
Mode)
Outline 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 decreased.
Flow chart
OR
Functional Description
• Suction SH > 12°C
• Suction SH > 10°C
&
• EV opening degree = 480pls
OR
Lowering upper limit
frequency for 1-step
every 20 seconds
OR
Normal operation
• Suction SH < 6°C
OR
• &
• Suction SH < 6°C
• Suction SH < 8°C
• Suction SH < 10°C
&
• EV opening degree < 450pls
• Suction SH > 12°C
• Suction SH > 10°C
&
• EV opening degree = 480pls
Frequency Regulating Functions
• 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
71