41
Technical Information
Service Manual
6.5 Brief Description of Modes and Functions
1. Temperature Parameters
Indoor preset temperature(Tpreset)
Indoor ambient temperature (Tamb.)
2. Basic Functions
Once energized, in no case should the compressor be restarted within less than 3 minutes. In the situation that memory functionis
available, for the first energization, if the compressor is at stop before de-energization, the compressor will be started withouta 3-minute
lag; if the compressor is in operation before de-energization, the compressor will be started with a 3-minute lag; andonce started, the
compressor will not be stopped within 6 minutes regardless of changes in room temperature;
(1) Cooling Mode
①
Working conditions and process of cooling
When Tamb. ≥ Tpreset, the unit will enter cooling operation, in which case the indoor fan, the outdoor fan and the compressor willwork and
the indoor fan will run at preset speed.
When Tamb.≤28.4°F, the compressor will stop, the outdoor fan will stop with a time lag of 60s, and the indoor fan will run atpreset
speed.
When 28.4°F < Tamb.< Tpreset, the unit will remain at its previous state.
Under this mode, the four-way valve will be de-energized and temperature can be set within a range from 61°F~86°F. If the compressor is
shut down for some reason, the indoor fan and the swing device will operate at original state.
②
Protection
Antifreeze protection
Under cooling and dehumidifying mode, 6 minutes after the compressor is started:
If Tevap
≤
35.6°F, the compressor will operate at reduced frequency.
If Tevap
≤
30.2°F is detected for durative 3 minutes, the compressor will stop, and after 60 seconds, the outdoor fan will stop;and under
cooling mode, the indoor fan and the swing motor will remain at the original state.
If Tevap.
≥
42.8°F and the compressor has remained at OFF for at least 3 minutes, the compressor will resume its original operation state.
Total current up and frequency down protection
If I
total
≤
16A, frequency rise will be allowed; if I
total
≥
17A, frequency rise will not be allowed; if I
total
≥
18A, the compressor will run at reduced
frequency; and if I
total
≥
20A, the compressor will stop and the outdoor fan will stop with a time lag of 60s.
(2) Dehumidifying Mode
①
Working conditions and process of dehumidifying
If Tamb. > Tpreset, the unit will enter cooling and dehumidifying mode, in which case the compressor and the outdoor fan will operate and
the indoor fan will run at low speed.
If 28.4°F ≤ Tamb. ≤ Tpreset the compressor remains at its original operation state.
If Tamb.< Tpreset , the compressor will stop, the outdoor fan will stop with a time lag of 60s, and the indoor fan will
operate at low speed.
②
Protection
Protection is the same as that under the cooling mode.
(3) Heating Mode
①
Working conditions and process of heating
If Tamb. ≤ 35.6°F(T
indoor ambient
≤ T
setting
+ 2
℃
, start with heating mode)
,
the unit enters heating mode, in which case the four-way
valve, the compressor and the outdoor fan will operate simultaneously, and the indoor fan will run at preset speed in the condition of preset
cold air prevention.
If Tamb. ≥ 37.4°F(T
indoor ambient
≥T
setting
+3
℃
, it stops when reaches temperature point), the compressor will stop, the outdoor fan will
stop with a time lag of 60s, and the indoor fan will stop after 60-second blow at low speed.
If Tpreset < Tamb.<37.4°F(T
setting
＜
T
indoor ambient
＜
T
setting
+3
℃
, maintain heating mode), the unit will maintain its original operating
status.
Under this mode, the four-way valve is energized and temperature can be set within a range of 61°F~86°F. The operatingsymbol, the
heating symbol and preset temperature are revealed on the display.
②
Condition and process of defrost
Tpreset
T3˚F
Compressor
Outdoor fan
Indoor fan
Run
Tamb.
Stop
Stop cooling
Start cooling
Original working state
≥ 6 min.
≥ 3 min.
≥ 6 min.
Set fan speed
