Service manual
(1) Compressor frequency control
According to difference room temperature and set temperature(¥t = RT-ST), running
frequency of compressor is controlled by electronic controller. When room temperature is much
higher than set temperature, compressor will start at a high frequency, and as room temperature
goes down, compressor running frequency will go
down. When room temperature is lower than set
temperature, compressor will run at very low frequency. In general, unit will change its running
frequency according to¥t to make room temperature closing to set temperature.
(2) Outdoor temperature affects running frequency of compressor
Outdoor temperature affect compressor’s running frequency
. Difference inlet temperature of
outdoor unit is adapted by difference compressor running frequency. While outdoor temperature is
about 30ć, the compressor will run in high frequency.
If unit run in “cooling” mode and outdoor temperature is less than -1ćcontroller will shut down
compressor and show error code, while the ambient temperature is over 0ć the compressor will
run automatically
(3) Auto fan control in cooling mode
In cooling mode (include cooling in “I feel” mode), fan speed is determined by ¥t, as the
following diagram:
ć
įt come down
high fan
įt come up
medium fan
low fan
RT-ST
4. “DRY” Mode Operation
(1) The system for DRY operation used the same refrigerant circle as the cooling one.
(2) When the system operates in DRY mode, at first it operates in cooling mode at 16ć or
18ć for 3 minutes. After that, the system will operate in cooling mode with lowest fan
speed, meanwhile the set temperature (ST) is “RT-2ć” which means that the ST is room
temperature at then minus 2. During the course of this mode, the fan speed set operation
and room temperature set are restricted, except the vane motor adjusting.
5. “HEATING” Mode Operation (available for Heat Pump only)
(1) Frequency control
The same as the frequency control in cooing mode, running frequency of compressor is
controlled by controller. Unit change its running frequency according to ¥t to make room
temperature closing to the set temperature.
(2) Indoor fan motor control
1. Cold Air Prevention C
ontrol
z The function is intended to prevent cold air from being discharged when the heating
operation starts or when defrosting.
z The indoor fan speed will be controlled as following.
Service Manual • T-series Ducted Air Conditioner
Page 8