11-8
CONTROL SYSTEM
SM HDDHED 2-A.1 GB
11.11.4
Compressor over Current Protection
Detect an input current by the CT during the compressor is running, and set the frequency upper limit
from such input current. In case of heat pump model, this control is the upper limit control function of
the frequency which takes priority of the lower limit of four way valve activating compensation.
Detail
Compressor frequency will be decreased or stop increasing when AC current>=12.0A
Compressor will stop when AC current >= 17.0A for continious 2.5s
If the unit stops as such protection for 6 times, it can not resume running automatically and display
malfunction, it can resume by pressing ON/OFF.
11.11.5
Outdoor Coil Deicing Protection
This protection is for Heat Pump Only
This protection is carried out by the cooling cycle (reverse cycle). The defrosting time or outdoor heat
exchanger temperature must be more than its setting values when finishing the deicing protection.
In the deicing protection, IFAN is forced OFF.
11.11.5.1 Deicing Starting Conditions
The starting conditions must be made with the outdoor air temperature (OAT) and outdoor coil
temperature (OCT). Under the conditions that the system is in heating operation, 6 minutes after
the compressor is started and more than 44 minutes of accumulated time pass since the start of the
operation or ending the defrosting.
Deicing interval time is changed as a function of deicing time. If deicing time is shorter than former
deicing time, the deicing interval time will be increased. If deicing time is longer than former deicing
time, the deicing interval time will be decreased.
11.11.5.2 Deicing Protection Procedure
Start to defrost: Compressor stops and starts up 55S later
5.
Start to defrost: Outdoor fan will stop after compressor stops for 50S.
6.
Defrosting finish: Compressor stops and starts up 55S later.
7.
Defrosting finish: Outdoor fan will start up when the compressor is stopping.
8.
11.11.5.3 Exiting
Deicing
The deicing operation can exit when any of the conditions below is satisfied:
OCT>=12C
1.
OAT<-5C, and OCT>=6C lasts for more than 80s
2.
The continuous running time of deicing reaches to 8min.
3.
11.11.6
Drop off voltage
During compressor operation, the system will stop and malfunction of drop off voltage if voltage
downward fluctuates rapidly, and it will re-start up automatically 3min later.
11.11.7 Communication
malfunction
If the unit does not receive correct signal from Indoor unit for 3min continuously, the unit will stop as
communication malfunction protection; if communication malfunction resume and compressor has
stopped for 3min, the unit will resume running.
