![background image](http://html1.mh-extra.com/html/daikin/fhq100buv1b-x-2/fhq100buv1b-x-2_service-manual_2459261082.webp)
SiBE28-804
Frequency Regulating Functions
Functional Description
71
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
Normal operation
Lowering upper limit
frequency for 1-step
every 20 seconds
Raising upper limit
frequency for 1-step
every 20 seconds
• Suction SH > 12°C
• Suction SH > 10°C
• EV opening degree = 480pls
• Suction SH > 12°C
• Suction SH > 10°C
• EV opening degree = 480pls
• Suction SH < 10°C
• EV opening degree < 450pls
• Suction SH < 8°C
• Suction SH < 6°C
• Suction SH < 6°C
• Upper limit frequency = Maximum frequency
• Suction SH < 8°C
• Suction SH < 10°C
• EV opening degree < 450 pls
OR
OR
OR
OR
&
&
&
• &
•OR
• &
Summary of Contents for FHQ100BUV1B x 2
Page 13: ...SiBE28 804 2 ...
Page 19: ...Model Name and Power Supply SiBE28 804 8 General Information ...
Page 29: ...Specifications SiBE28 804 18 Specifications ...
Page 33: ...Wired Remote Controller SiBE28 804 22 Remote Controller 1 2 Installation ...
Page 34: ...SiBE28 804 Wired Remote Controller Remote Controller 23 ...
Page 93: ...Outdoor Unit Fan Speed Control SiBE28 804 82 Functional Description ...
Page 131: ...Test Run and Operation Data SiBE28 804 120 Test Operation ...
Page 251: ...Troubleshooting by Remote Controller Display LED Display SiBE28 804 240 Troubleshooting ...
Page 277: ...PCB Layout SiBE28 804 266 Appendix ...
Page 297: ...RZQ100 140C7 RZQS125 140C7V1B SiBE28 804 286 Removal Procedure ...
Page 311: ...SiBE28 804 iv Index ...