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143
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'16 • PAC-T-240
(12) Compressor overheat protection
(a) Purpose:
It is designed to prevent deterioration of oil, burnout of motor coil and other trouble resulting from the
compressor overheat.
(b) Detail of operation
(i) Speeds are controlled with temperature detected by the sensor mounted on the discharge pipe.
Discharge pipe temperature (˚C)
Lower limit
(4)
After lapse of 3 min. or over
(3)
After lapse of 3 min. or over
(3)
After lapse of 3 min. or over
(3)
4 rps
4 rps
(1)
0 rps
(Example) Fuzzy
95
105
115
Notes (1) When the discharge pipe temperature is in the range of 105-115ºC, the speed is reduced by 4 rps.
(2) When the discharge pipe temperature is raised and continues operation for 20 seconds without changing, then the speed is reduced again by 4 rps.
(3) If the discharge pipe temperature is in the range of 95-105ºC even when the compressor command speed is maintained for 3 minutes when the tem-
perature is in the range of 95-105ºC, the speed is raised by 1 rps and kept at that speed for 3 minutes. This process is repeated until the command
speed is reached.
(4) Lower limit speed
(ii) If the temperature of 115ºC is detected by the sensor on the discharge pipe, then the compressor will stop immediately.
When the discharge pipe temperature drops and the time delay of 3 minutes is over, the unit starts again within 1
hour but there is no start at the third time.
(13) Current safe
(a) Purpose:
Current is controlled not to exceed the upper limit of the setting operation current.
(b) Detail of operation:
Input current to the converter is monitored with the current sensor fixed on the printed circuit
board of the outdoor unit and, if the operation current value reaches the limiting current value, the
compressor command speed is reduced.
If the mechanism is actuated when the compressor command speed is less than 20 rps, the compres-
sor is stopped immediately. Operation starts again after a delay time of 3 minutes.
Cooling
Heating
Lower limit speed
20 rps
25 rps
(10) Heating overload protective control
Ⅱ
(a) Starting condition :
When the indoor heat exchanger t
emperature (Thi-R) has risen to a specified temperature while
the compressor is turned on.
(b) Detail of operation :
The lower limit of compressor
command speed is set to 20rps.
32
35
OFF
ON
Indoor heat exchanger temperature (ºC)
(11) Heating low outdoor temperature protective control
(a) Operating conditions :
When the outdoor air temperature (TH2) is 4
℃
or lower continues for 30 seconds while
the compressor command speed is other than 0 rps.
(b)
Detail of operation :
The lower limit compressor comm
a
nd speed is change as shown in the figure below.
-4
-6
-8
-10
-12
Lower limit 40 rps
Lower limit 45 rps
Lower limit 50 rps
Lower limit 30 rps
Normal operation
Outdoor air temperature(°C)
(c) Reset condition:
When either of the following
c
ondition is satisfied.
(i) The outdoor air temperature (TH2) is higher than 6ºC
(ii) The compressor command speed is 0 rps.
6
4
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