Daikin RZQ100B8V3B Service Manual page 135

ESIE05-03
3.3.6 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
Part 2 – 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
• & • Upper limit frequency = Maximum frequency
• Suction SH < 6°C
•OR
• Suction SH < 8°C
• Suction SH < 10°C
&
• EV opening degree < 450pls
Raising upper limit
frequency for 1-step
• Suction SH > 12°C
• Suction SH > 10°C
&
• EV opening degree = 480pls
Outdoor Unit Functional Concept
• Suction SH < 8°C
• Suction SH < 10°C
• EV opening degree < 450 pls
• &
every 20 seconds
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