2-9
12PHR-N
[3] FUNCTION
1. Function
1.1. Restart control
Once the compressor stops operating, it will not restart for 180
seconds to protect the compressor.
Therefore, if the operating compressor is shut down from the
remote control and then turned back on immediately after, the
compressor will restart after a preset delay time.
(The indoor unit will restart operation immediately after the ON
switch is operated on the remote control.)
Compressor operation
ON operation on
remote control
OFF operation on
remote control
Compressor ON
Compressor can
turn ON
Compressor ON
Compressor remains OFF
for 180 seconds
1.2. Indoor unit heat exchanger freeze prevention control
If the temperature of the indoor unit heat exchanger remains
below 0°C for 4 consecutive minutes during cooling or
dehumidifying operation, the compressor operation stops
temporarily in order to prevent freezing.
When the temperature of the indoor unit heat exchanger rises to
2°C or higher after about 180 seconds, the compressor restarts
and resumes normal operation.
1.3. Outdoor unit 2-way valve freeze prevention control
If the temperature of the outdoor unit 2-way valve remains below
0°C for 10 consecutive minutes during cooling or dehumidifying
operation, the compressor operation stops temporarily in order to
prevent freezing.
When the temperature of the 2-way valve rises to 10°C or higher
after about 180 seconds, the compressor restarts and resumes
normal operation.
1.4. Indoor unit overheat prevention control
During heating operation, if the temperature of the indoor unit
heat exchanger exceeds the indoor unit heat exchanger overheat
prevention temperature (about 45 to 54°C) which is determined
by the operating frequency and operating status, the operating
frequency is decreased by about 4 to 15 Hz. Then, this operation
is repeated every 60 seconds until the temperature of the
indoor unit heat exchanger drops below the overheat protection
temperature.
Once the temperature of the indoor unit heat exchanger drops
below the overheat protection temperature, the operating
frequency is increased by about 4 to 10 Hz every 60 seconds until
the normal operation condition resumes.
If the temperature of the indoor unit heat exchanger exceeds
the overheat protection temperature for 60 seconds at minimum
operating frequency, the compressor stops operating and then
restarts after about 180 seconds, and the above mentioned
control is repeated.
1.5. Outdoor unit overheat prevention control
During cooling operation, if the temperature of the outdoor
unit heat exchanger exceeds the outdoor unit heat exchanger
overheat prevention temperature (about 55°C), the operating
frequency is decreased by about 4 to 15 Hz. Then, this operation
is repeated every 60 seconds until the temperature of the outdoor
unit heat exchanger drops to about 54°C or lower.
Once the temperature of the outdoor unit heat exchanger drops
to about 54°C or lower, the operating frequency is increased by
about 4 to 10 Hz every 60 seconds until the normal operation
condition resumes.
If the temperature of the outdoor unit heat exchanger exceeds
the outdoor unit heat exchanger overheat protection temperature
for (120 sec: outdoor temperature ≥ 40°C · 60 sec : outdoor
temperature < 40°C) at minimum operating frequency, the
compressor stops operating and then restarts after about 180
seconds, and the abovementioned control is repeated.
1.6. Compressor overheat prevention control
If the temperature of the compressor exceeds the compressor
overheat prevention temperature (110°C), the operation frequency
is decreased by about 4 to 10 Hz. Then, this operation is repeated
every 60 seconds until the temperature of the compressor drops
below the overheat protection temperature (100°C).
Once the temperature of the compressor drops below the
overheat protection temperature, the operating frequency is
increased by about 4 to 10 Hz every 60 seconds until the normal
operation condition resumes.
If the temperature of the compressor exceeds the overheat
protection temperature (for 120 seconds in cooling operation or
60 seconds in heating operation) at minimum operating frequency,
the compressor stops operating and then restarts after about 180
seconds, and the above mentioned control is repeated.
1.7. Startup control
When the air to air heat pump starts in the cooling or heating
mode, if the room temperature is 2°C higher than the set
temperature (in cooling operation) or 3.5°C lower (in heating
operation), the air to air heat pump operates with the operating
frequency at maximum. Then, when the set temperature is
reached, the air to air heat pump operates at the operating
frequency determined by fuzzy logic calculation, then enters the
normal control mode after a while.
1.8. Peak control
If the current flowing in the air to air heat pump exceeds the peak
control current the operation frequency is decreased until the
current value drops below the peak control current regardless of
the frequency control demand issued from the indoor unit based
on the room temperature.
1.9. Outdoor unit fan delay control
The compressor stops immediately after cooling, dehumidifying or
heating operation is shut down, but the outdoor unit fan continues
operation for 50 seconds before it stops.
1.10. Defrosting
1.10.1 Reverse defrosting
The defrost operation starts when the compressor operating time
exceeds 20 minutes during heating operation, as shown below,
and the outside air temperature and the outdoor unit heat
exchanger temperature meet certain conditions. When the defrost
operation starts, the indoor unit fan stops. The defrost operation
stops when the outdoor unit heat exchanger temperature rises to
about 13°C or higher or the defrosting time exceeds 10 minutes.
20 min or more
6 min or more 6 min or more
Defrosting
Max. 10 min
Defrosting
Max. 10 min
Start of
heating
operation
12PHR-N_S530612PHRN.indd 9
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Summary of Contents for 12PHR-N
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