12
SYSTEM FEATURES
4 ZONE
Watchdog :
There is a watchdog circuit to reset the MCU if it malfunctions due to voltage fluctuation or other abnormality.
Compressor delay protection :
There is a 3 minute delay time for the compressor to restart. However in case of power
interruption the compressor can be restarted in a range of 3-4 minutes in random order.
Compressor mimimum on time :
If T
room
reaches T
set
but the compressor operates less than 3 minutes, it will continuously
operate up to 3 minutes.
Auto restart :
In case of power interruption and back to normal, the control will automatically resume its operation with same
settings.
Freeze protection :
In Cool or Dry mode if T
indoor coil
< 3
o
C and Compressor runs continuously more than 10 minutes, this
function will be activated. It will stop the compressor, and runs the fan at low speed.
The system will resume its normal operation if T
indoor coil
> 7
o
C or the system is turned off.
Defrost function :
In HEAT mode if T
outdoor coil
is very low, the compressor cannot operate efficiently. This function will be
activated to protect the compressor.
Defrost process
As soon as T
outdoor coil
< 3
o
C , Defrost timer starts. If T
outdoor coil
is above 20
o
C for more than 2 minutes, Defrost timer will reset.
The Defrost function is activated if:
a) Compressor has been running continuously in heat mode for more than 5 minutes, and
b) Defrost timer meets one of the below conditions
T
outdoor coil
falls from +3 to -8
o
C (line AB) during 30-60 minutes and remains < -8
o
C more than 5 minutes.
T
outdoor coil
falls from +3 to -4
o
C (line AC) during 60-120 minutes and remains < -4
o
C more than 5 minutes.
T
outdoor
coil
falls from +3 to -2
o
C (line AD) after 120 minutes and remains < -2
o
C more than 5 minutes.
While defrost
The indoor & outdoor fans stop while the compressor operates in Cool mode.
Defrost ends
If T
outdoor coil
is above 14
o
C or Defrost function operates more than 10 minutes, the system will return to heat mode
automatically.