11-5
CONTROL SYSTEM
SM PNXADCI 1-A.1 GB
11.4.2
Indoor Fan Control in Heat Mode
Indoor fan speed depends on the indoor coil temperature:
11.5
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.
11.6
Dry Mode
As long as room temperature is higher then the set point, 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
indoor fan will cycle 3 minutes OFF, 1 minute ON.
11.7
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.
11.7.1
Indoor Coil Defrost Protection
ICT Trend
ICT
ICT < -2
SC
SC
SC
SC
SC
Fast
Increasing
Increasing
No change
Decreasing
Fast
Decreasing
-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
8
ICT
Normal
ICTST
T
T
C
I
L
V
T
C
I
ICTH
ICTL
