Service manual
Table Of Contents
- DNG DC Inverter Series
- LIST OF EFFECTIVE PAGES
- TABLE OF CONTENTS
- INTRODUCTION
- PRODUCT DATA SHEET
- RATING CONDITIONS
- OUTLINE DIMENSIONS
- PERFORMANCE DATA & PRESSURE CURVES
- AIRFLOW CURVES
- SOUND LEVEL CHARACTERISTICS
- ELECTRICAL DATA
- WIRING DIAGRAMS
- REFRIGERATION DIAGRAMS
- TUBING CONNECTIONS
- CONTROL SYSTEM
- TROUBLESHOOTING
- EXPLODED VIEWS AND SPARE PARTS LISTS
- APPENDIX A
12-8
CONTROL SYSTEM
SM DNGDCI 2-E.1 GB
12.7 Auto Cool/Heat Mode
When in auto cool heat mode unit will automatically select between cool and heat mode according to
the difference between actual room temperature and user set point temperature (T).
Unit will switch from cool to heat when compressor is off for 3 minutes, and .T < -3.
Unit will switch from heat to cool when compressor is off for 5 minutes, and .T < -3.
12.8 Dry Mode
As long as room temperature is higher then the set point, the indoor fan will work in low speed and
compressor will work between 0 and MaxNLOADIF1C Hz.
When the room temperature is lower than the set point, compressor will be switched OFF and the
indoor fan will cycle 3 minutes OFF, 1 minute ON.
12.9 Protections
There are 5 protection codes.
Normal (Norm) – unit operate normally.
Stop Rise (SR) – compressor frequency can not be raised but does not have to be decreased.
HzDown1 (D1) – Compressor frequency is reduced by 2 to 5 Hz per minute.
HzDown2 (D2) – Compressor frequency is reduced by 5 to 10 Hz per minute.
Stop Compressor (SC) – Compressor is stopped.
12.9.1 Indoor Coil Defrost Protection
ICT
ICT Trend
Fast
Increasing
Increasing
No
Change
Decreasing
Fast
Decreasing
ICT< -2 SC SC SC SC SC
-2 = ICT<0 D1 D1 D2 D2 D2
0 = ICT < 2 SR SR D1 D2 D2
2 = ICT< 4 SR SR SR D1 D2
4 = ICT < 6 Norm Norm SR SR D1
6 = ICT = 8 Norm Norm Norm SR SR
ICT> 8 Norm
CONTENT