Pr
oduct Featur
es
Page 75
1. Operation Modes and Functions
1.1 Abbreviation
Unit element abbreviations
Abbreviation
Element
T1
Indoor room temperature
T2
Coil temperature of evaporator
T3
Coil temperature of condenser
T4
Outdoor ambient temperature
T5
Compressor discharge temperature
1.2 Safety Features
Compressor three-minute delay at restart
Compressor functions are delayed for up to one minute
upon the first startup of the unit, and are delayed for up
to three minutes upon subsequent unit restarts.
Low Pressure Check Function(For 36K~55K)
The low pressure switch should be always closed. If it is
open, the system will stop until the fault is cleared. During
defrosting procedure , 4 minutes after defrosting ends and
5 minutes after compressor is on in heating mode, low
pressure switch won’t be checked.
Note: The system will not check if the protection could be
cleared in 30 seconds after the protection occurs. If this
protection occurs 3 times, it won’t recover automatically
until the main power is cut off.
Over-current protection
When compressor is running, if the current is over twice
of the rated for 3 seconds, the compressor will stop and
an error code will be displayed on the outdoor PCB. If the
current becomes normal, the indoor sends signal to the
outdoor, the outdoor will display normally.
Open Circuit/Disconnection Sensor Protection
Fan Speed Malfunction
If a fault occurs on the air volume regulator or the
regulator enters protection mode, it sends the error
message CF and an instruction to reduce fan speed to the
master. The message and the instruction can be inquired
with the remote controller or the wired controller. (Fault
and protection information are displayed for one minute).
After a fault occurs, the master unit shows the error code
E3 and the fault count for one minute.
If the fault occurs three times, then the fan is unable to
resolve the problem independently. External shutdown by
a remote controller, wired controller, or central controller
must be used to clear the fan fault and fault count. The
fan runs normally for 5 minutes while clearing fault count.
1.3 Display Function
Unit display functions
MANUAL
TIMER
ALARM
OPERATION
DEF./FAN
MANUAL
TIMER
ALARM
OPERATION
DEF./FAN
MANUAL
TIMER
ALARM
OPERATION
DEF./FAN
1.4 Fan
When fan mode is activated:
• The outdoor fan and compressor are stopped.
• Temperature control is disabled and no temperature
setting is displayed.
• The indoor fan speed can be set to high, medium, low,
or auto.
• The louver operations are identical to those in cooling
mode.
1.5 Cooling Mode
1.5.1 Compressor Control
• When T1-Ts-
∆
T is lower than setting value, the
compressor ceases operation.
• When T1-Ts-
∆
T is higher than setting value, the
compressor continues operation.
1.5.2 Indoor Fan Control
• In cooling mode, the indoor fan operates continuously.
The fan speed can be set to high, medium, low or auto.
• The auto fan acts according to the value of T1-TS.
1.5.3 Outdoor Fan Control
• The outdoor fan is controlled by T4 and compressor
frequency.
1.5.4 Evaporator Temperature Protection
When evaporator temperature drops below a configured
value for some time, the compressor ceases operation, the
outdoor fan motor ceases operation 30 seconds later.
