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A5HL5-SF-1A-EN
decrease; When the exhaust temperature is higher than
the set value, the opening of the electronic expansion
valve will increase.
NNootteess::
1. The outdoor electronic expansion valve will
drive fully open during the transition from
heat pump heating to defrost.
2. The electronic expansion valve will re-
calibrate each time there is a power cycle.
The valve will be driven closed and open to
re-establish position. During this process, an
audible sound will be heard from the valve.
Defrost Mode
When the system is operating in heating, the outdoor
control determines the need for defrost by the outdoor
coil temperature.
The outdoor unit digital display will show a “5”, and
the unit will perform the following actions:
1. The compressor stops running.
2. The outdoor fan motor stops rotating.
3. The switchover valve is switched to the cooling
state.
4. The EEV valve of the outdoor unit is fully open.
5. The compressor runs at the preset defrosting
frequency.
6. The D terminal of outdoor unit sends a 24V
defrosting signal to the indoor unit.
Oil Return Operation
When the outdoor unit is in low frequency operation
for long periods of time the compressor speed will be
increased to ensure internal lubrication of the
compressor as well as ensuring that oil is returned to
the compressor. During this time, the digital display
(DPS1) will show a “4”. In this case, the operating
mode of the unit remains unchanged, and the
compressor speed, outdoor fan motor speed, and
electronic expansion valve opening will be adjusted to
the corresponding parameters of the oil return mode.
After 3 minutes, the system will exit the oil return mode
and restore the original operating state.
Outdoor Compressor Preheating
(Sump Heat)
To avoid the poor oil return or start-up difficulties
caused by refrigerant migration into the compressor at
low temperatures, the winding preheating function is
set. It is recommended that when the outdoor ambient
temperature is too low, the unit should be preheated
for 8 hours before starting the unit operation.
The preheating function is implemented as follows:
1. When the temperature of outdoor ambient
environment and unit exhaust temperature sensor
are lower than 10℃ (50℉), and the compressor is in
an off state, the controller will apply a certain
current value to the winding coil of the compressor,
so that the winding coil will heat up and play the
role of heating the compressor oil pool. When at
0~10℃ (32~50℉), the preheating power is about
20W, and then when the temperature decreases by
10℃ (50℉), the power will increase by about
15W~20W.
2. When the outdoor ambient temperature is higher
than 15℃ (59℉) or the temperature of unit exhaust
temperature sensor is higher than 20 ℃ (68℉), the
system will exit the winding preheating mode.
SSeeqquueennccee ooff OOppeerraattiioonn
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