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Outdoor Unit Functional Concept
ESIE05-03
2–60
Part 2 – Functional Description
3
1
2
4
5
3.4.2
General Expansion Valve Control
Outline
After the start up control function has been terminated the general expansion valve control function will
regulate the expansion valve opening in function of the target suction SH value.
The discharge SH value will be used to set the target SH value.
The measured suction SH value will be used to control the opening of the expansion to the target SH
value.
Details
When the unit is in cooling or heating operation the opening of the expansion valve will be controlled
in order to keep the amount of superheat at the evaporator outlet constant. This way the evaporator
can be used at maximum efficiency under all conditions. The initial target heat exchanger outlet
superheat value = 5°C.
The target heat exchanger outlet superheat value can be increased in case the discharge superheat
value decreases.
The target heat exchanger outlet superheat value can be decreased in case the discharge superheat
value increases.
Control
During normal control 2 situations can decide on the expansion valve opening degree:
1
Target superheat amount:
When the target heat exchanger outlet superheat > actual heat exchanger
outlet superheat --> the expansion valve will close.
When the target heat exchanger outlet superheat < actual heat exchanger
outlet superheat --> the expansion valve will open.
The superheat amount is checked every 10 seconds.
2
Frequency change: At the time of compressor frequency change, the expansion valve opening will
be changed with a fixed value. This value will be in function of the amount of compressor frequency
change.
Calculations RZQ71
The heat exchanger outlet superheat value is calculated from the saturated suction temperature
Te(using LP sensor) and the suction pipe temperature R4T : SH = R4T-Te
The discharge superheat value is calculated from the saturated discharge temperature Td (HP value
calculated out of PI, frequency and LP) and the discharge pipe temperature R3T : SH = R3T-Td
Calculations
RZQ100~140
The heat exchanger outlet superheat value is calculated from the saturated suction temperature
Te(using indoor coil sensor in cooling, outdoor coil sensor in heating) and the suction pipe temperature
R4T : SH = R4T-Te
The discharge superheat value is calculated from the saturated discharge temperature Td (HP value
calculated out of PI, frequency and Te) or Tc and the discharge pipe temperature R3T : SH = R3T-Td
or R3T or SH = R3T-Tc (whichever is the lowest)
ESIE05-03.book Page 60 Wednesday, April 6, 2005 4:09 PM
Summary of Contents for RZQ100B7W1B
Page 1: ...Service Manual ESIE05 03 RZQ71 125B8V3B RZQ100 140B7W1B Sky Air Inverter R 410A B series...
Page 2: ......
Page 10: ...ESIE05 03 viii Table of Contents 3 1 4 5...
Page 24: ...ESIE05 03 1 2 Part 1 System Outline 3 1 1 5...
Page 32: ...General Outline Outdoor Units ESIE05 03 1 10 Part 1 System Outline 3 1 1 4 5...
Page 42: ...Specifications ESIE05 03 1 20 Part 1 System Outline 3 1 1 4 5...
Page 56: ...Functional Diagrams ESIE05 03 1 34 Part 1 System Outline 3 1 1 4 5...
Page 58: ...ESIE05 03 1 36 Part 1 System Outline...
Page 70: ...Wiring Diagrams ESIE05 03 1 48 Part 1 System Outline 3 1 1 4 5...
Page 84: ...PCB Layout ESIE05 03 1 62 Part 1 System Outline 3 1 1 4 5...
Page 86: ...ESIE05 03 2 2 Part 2 Functional Description 3 1 2 5...
Page 110: ...General Functionality ESIE05 03 2 26 Part 2 Functional Description 3 1 2 4 5...
Page 150: ...ESIE05 03 3 2 Part 3 Troubleshooting 3 1 3 5...
Page 188: ...Troubleshooting ESIE05 03 3 40 Part 3 Troubleshooting 3 1 3 4 5...
Page 264: ...Additional Checks for Troubleshooting ESIE05 03 3 116 Part 3 Troubleshooting 3 1 3 4 5...
Page 266: ...ESIE05 03 4 2 Part 4 Commissioning and Test Run 3 1 4 5...
Page 306: ...ESIE05 03 5 2 Part 5 Disassembly and Maintenance 3 1 5...