CF-14
DUAL, TRIPLE, POKER DC Inverter : 5. Control Functions
Multi Liberty
DC Inverter
5.5.10 Communication error between Indoor Unit
↔
Outdoor Unit
If for max. 2 minutes one Indoor Unit does not receive any return signal by Outdoor Unit, the corresponding
malfunction indication will be shown on Indoor Unit’s LED display (HKEU X Models) or on Indoor Unit’s display
panel (all other Models: HTFU X, HFIU X, HSFU X, HRBU X). This causes the system stop.
5.5.11 Outdoor Unit’s heat exchanger overtemperature control, in Cooling mode
If in Cooling mode, outdoor heat exchanger temperature (T3) keeps higher than 65°C for 3 minutes, compressor
is stopped. The intervention of protection will end when T3 < 52°C. The intervention of protection function will be
shown only by 2-digit LED display on Outdoor Unit’s PCB.
5.5.12 Outdoor low temperature control, in Heating mode
If outdoor temperature (T4 sensor) keeps lower than -15°C for at least 1 hour, compressor and fan motor on Outdoor
Unit are stopped. Then, if outdoor temperature keeps higher than -12°C for at least 10 minutes after the compressor
has been stopped for at least 1 hour, or if outdoor temperature is higher than 5°C for at least 10 minutes, the system
can be restarted according to the previous operation mode (before the protection intervention). The intervention
of protection function will be shown only by 2-digit LED display on Outdoor Unit’s PCB.
5.5.13 Antifrost control on Indoor Unit, in Cooling mode (stop of indoor fan)
For HKEU X Models. If temperature detected by T2 sensor on Indoor Unit’s heat exchanger keeps < 4°C for 4
minutes and 10 seconds, indoor fan is stopped. The protection intervention will end when T2 > 8°C.
For HFIU X Models. If temperature detected by T2 sensor on Indoor Unit’s heat exchanger keeps
≤
4°C for 3
minutes, indoor fan is stopped. The protection intervention will end when T2 > 8°C.
For HTFU X, HFIU X, HSFU X, HRBU X Models. If temperature detected by T2 sensor on Indoor Unit’s heat
exchanger keeps
≤
3°C for 3 minutes, indoor fan is stopped. The protection intervention will end when T2 > 7°C.
5.5.14 Compressor oil recovering procedure from refrigerant circuit
Conditions for intervention of oil recovering procedure. If for 2 hours, operation frequency of compressor keeps lower
than “RECOILNFRE” value (for Outdoor Unit HCKU 1066 X4: 45Hz; for all other Models of Outdoor Unit: 50Hz)
set out by Manufacturer, control electronics will decide an increase in operation frequency up to “RECOILFRE”
value (for Outdoor Unit HCKU 1066 X4: 48Hz; for all other Models: 62Hz) set out by Manufacturer. This increase
in frequency will last for 3 minutes and at the end of this interval the previous operation frequency will be restored.
Outline of oil recovery procedure. During the 3-minute procedure for oil recovery, opening of EXV valves for Indoor
Units and current operation mode are kept. Limitations of operation frequency due to monitoring of compressor
discharge temperature and compressor current value are deactivated.
Advance stop of oil recovery procedure. If outdoor temperature (T4 sensor) is more than 15°C during oil revovery
procedure, it is stopped.
