11-5
CONTROL SYSTEM
SM PNXDCI 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 )ΔT(.
Unit will switch from cool to heat when compressor is off for 3 minutes, and ΔT < -3.
Unit will switch from heat to cool when compressor is off for 5 minutes, and ΔT < -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
ICTVL
ICTT
ICTH
ICTL
CONTENTS
