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53
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'14 • SR-T-157
(h) Compressor overheat protection
(i) Purpose:
It is designed to prevent deterioration of oil, burnout of motor coil and other trouble resulting from the
compressor overheat.
(ii) Detail of operation
1) Speeds are controlled with temperature detected by the sensor mounted on the discharge pipe.
Notes (1) When the discharge pipe temperature is in the range of 100~110ºC, 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 90~100ºC even when the compressor command speed is maintained for 3 minutes when the
temperature is in the range of 90~100ºC, 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
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
100
110
(Example) Fuzzy
90
Cooling
Heating
Lower limit speed
20 rps
30 rps
Item
Model
2) If the temperature of 110ºC 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.
(i)
Current safe
(i) Purpose:
Current is controlled not to exceed the upper limit of the setting operation current.
(ii) 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 30 rps, the compressor
is stopped immediately. Operation starts again after a delay time of 3 minutes.
(j)
Current cut
(i) Purpose:
Inverter is protected from overcurrent.
(ii) Detail of operation:
Output current from the inverter is monitored with a shunt resistor and, if the current exceeds the
setting value, the compressor is stopped immediately. Operation starts again after a delay time of
3 minutes.
(m) Serial signal transmission error protection
(i) Purpose:
Prevents malfunction resulting from error on the indoor
↔
outdoor signals.
(ii) Detail of operation:
If the compressor is operating and a serial signal cannot be received from the indoor control with
outdoor control having serial signals continues for 7 minute and 35 seconds, the compressor is
stopped.After the compressor has been stopped, it will be restarted after the compressor start delay if
a serial signal can be received again from the indoor control.
(k) Outdoor unit failure
This is a function for determining when there is trouble with the outdoor unit during air conditioning.
The compressor is stopped if any one of the following in item (i), (ii) is satisfied. Once the unit is stopped by this function, it is not
restarted.
(i) When the input current is measured at 1 A or less for 3 continuous minutes or more.
(ii) If the outdoor unit sends a 0 rps signal to the indoor unit 3 times or more within 20 minutes of the power being turned on.
(l)
Indoor fan motor protection
When the air conditioner is operating and the indoor fan motor is turned ON, if the indoor fan motor has operated at 300 rpm or
under for more than 30 seconds, the unit enters first in the stop mode and then stops the entire system.
(n) Rotor lock
If the motor for the compressor does not turn after it has been started, it is determined that a compressor lock has occurred and
the compressor is stopped.
'09•SRK-DB-087D
(f) Heating overload protective control
(i) Indoor unit side
1) Operating conditions :
2) Detail of operation :
3) Reset conditions :
(ii) Outdoor unit side
1) Operating conditions :
2) Detail of operation
21
22
Normal operation
Protective
control
Outdoor air temperature(°C)
Model 50
A
B
C
D
RPSmin < 40
40 <= RPSmin < 80
80 <= RPSmin < 90
90 <= RPSmin < 102
102 <= RPSmin
49
53
41
53 ~ 47
47 ~ 41
53
57
45
57 ~ 51
51 ~ 45
55
59
47
59 ~ 53
53 ~ 47
58
62
51
58
51
When the outdoor air temperature (TH2) is 22ºC or higher continues for 30 seconds while
the compressor command speed other than 0 rps.
a)
b)
c)
d)
Taking the upper limit of compressor command speed range at 60 rps, if the output speed obtained with the fuzzy
calculation exceeds the upper limit, the upper limit value is maintained.
The lower limit of compressor command speed is set to 40 rps and even if the calculated result becomes lower than
that after fuzzy calculation, the speed is kept to 40 rps. However, when the
thermo OFF, the speed is reduced to
0 prs.
rps.
(iii) Reset conditions:
.
