Specifications
Table Of Contents
- Cover
- Table of Contents
- Part 1 General Information
- Part 2 Specifications
- Part 3 Refrigerant Circuit
- Part 4 Function
- Part 5 Test Operation
- Part 6 Troubleshooting
- Part 7 Appendix
- 1. Piping Diagrams
- 2. Wiring Diagrams for Reference
- 3. List of Electrical and Functional Parts
- 4. Option List
- 5. Piping Installation Point
- 6. Example of connection (R-410A Type)
- 7. Thermistor Resistance / Temperature Characteristics
- 8. Pressure Sensor
- 9. Method of Checking the Inverter’s Power Transistors and Diode Modules
- Part 8 Precautions for New Refrigerant (R-410A)
- Index
- Drawings & Flow Charts

Protection Control Si34-704
108 Function
4.4 Inverter Protection Control
Inverter current protection control and inverter fin temperature control are performed to prevent
tripping due to a malfunction, or transient inverter overcurrent, and fin temperature increase.
★
In the case of multi-outdoor-unit system, each INV compressor performs these controls in
the following sequence.
[Inverter overcurrent protection control]
[Inverter fin temperature control]
Nomal operation
Under inverter current
protection control
Invertercurrent >14.7A
Inverter current standby
Inverter current <14.7A
INV upper limit frequency
= max
INV upper limit frequency: 1-step down
from current compressor frequency
INV upper limit frequency: 1-step up from
current compressor frequency
Inverter current >14.7A
Inverter current<14.7A continues
for 20 sec. or more.
Inverter current > 16.1A continues for 260 sec.
&
•
When occurring 4 times within 60 min.,
the malfunction code “L8 ” is output.
Tfin>84˚C
Fin temp. standby
Tfin<81˚C
INV upper limit rps = max
Under fin temperature
protection control
INV upper limit frequency: 1-step / 1 min up
from current compressor frequency Interval
Inverter fin temp.<81˚C continues
for 3 min. or more.
&
Tfin>84˚C
Tfin>93˚C
•
When occurring 4 times within 60 min.,
the malfunction code “L4” is output.
Nomal operation
INV upper limit frequency: 1-step /
1 min down from current compressor
rps