Panasonic CS-BE20TKD / CU-BE20TKD Service Manual ▷ View online
37
13. Protection
Control
13.1 Protection Control for All Operations
13.1.1 Restart
Control
(Time Delay Safety Control)
The Compressor will not turn on within 3 minutes from the moment operation stops, although the unit is turned on
again by pressing OFF/ON button at remote control within this period.
This control is not applicable if the power supply is cut off and on again.
This phenomenon is to balance the pressure inside the refrigerant cycle.
13.1.2 Total Running Current
1 When the outdoor unit total running current (AC) exceeds X value, the frequency instructed for compressor
operation will be decreased.
2 If the running current does not exceed X value for 5 seconds, the frequency instructed will be increased.
3 However, if total outdoor unit running current exceeds Y value, compressor will be stopped immediately for
3 However, if total outdoor unit running current exceeds Y value, compressor will be stopped immediately for
3 minutes.
Model BE20TKD
Operation Mode
X (A)
Y (A)
Cooling / Soft Dry (A)
3.78
15.02
Cooling / Soft Dry (B)
3.30
Cooling / Soft Dry (C)
3.30
Heating 3.46
4 The first 30 minutes of cooling operation, (A) will be applied.
13.1.3 IPM (Power transistor) Prevention Control
Overheating Prevention Control
1 When the IPM temperature rises to 120°C, compressor operation will stop immediately.
2 Compressor operation restarts after 3 minutes the temperature decreases to 110°C.
3 If this condition repeats continuously 4 times within 20 minutes, timer LED will be blinking (“F96” is indicated).
2 Compressor operation restarts after 3 minutes the temperature decreases to 110°C.
3 If this condition repeats continuously 4 times within 20 minutes, timer LED will be blinking (“F96” is indicated).
DC Peak Current Control
1 When electric current to IPM exceeds set value of 16.0 ± 2.0A the compressor will stop operate. Then,
operation will restart after 3 minutes.
2 If the set value is exceeded again more than 30 seconds after the compressor starts, the operation will
restart after 3 minute.
3 If the set value exceeded again within 30 seconds after the compressor starts, the operation will restart after
1 minute. If this condition repeats continuously for 7 times, all indoor and outdoor relays will be cut off, timer
LED will be blinking (“F99” is indicated).
LED will be blinking (“F99” is indicated).
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13.1.4 Compressor
Overheating Prevention Control
Instructed frequency for compressor operation will be regulated by compressor discharge temperature. The
changes of frequency are as below.
If compressor discharge temperature exceeds 103°C, compressor will be stopped, occurs 4 times per 20 minutes,
timer LED will be blinking. (“F97” is indicated.)
13.1.5 Low Pressure Prevention Control (Gas Leakage Detection)
Control start conditions
o
For 5 minutes, the compressor continuously operates and outdoor total current is between 1.22A and 1.38 A.
o
During Cooling and Soft Dry operations:
Indoor suction temperature - indoor piping temperature is below 4°C.
o
During Heating operations :
Indoor piping temperature - indoor suction is under 5°C.
Control
contents
o
Compressor stops (and restart after 3 minutes).
o
If the conditions above happen 2 times within 20 minutes, the unit will:
Stop
operation
Timer LED blinks and “F91” indicated.
13.1.6 Low
Frequency
Protection Control 1
When the compressor operate at frequency lower than 24 Hz continued for 20 minutes, the operation frequency
will be changed to 23 Hz for 2 minutes.
13.1.7 Low
Frequency
Protection Control 2
When all the below conditions comply, the compressor frequency will change to lower frequency.
Temperature, T, for:
Cooling/Soft Dry
Heating
Indoor intake air (°C)
T < 14 or T ≥ 30
T < 14 or T ≥ 28
Outdoor air (°C)
T < 13 or T ≥ 38
T < 4 or T ≥ 24
Indoor heat exchanger (°C)
T < 30
T ≥ 0
Frequency
103°C
88°C
Free
OFF
8Hz/45s Down
min A Hz
max B Hz
Comp temp
99°C
87°C
96°C
86°C
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13.2 Protection Control for Cooling & Soft Dry Operation
13.2.1 Outdoor Air Temperature Control
The compressor operating frequency is regulated in accordance to the outdoor air temperature as shown in the
diagram below.
This control will begin 1 minute after the compressor starts.
Compressor
frequency will adjust base on outdoor air temperature.
13.2.2 Cooling Overload Control
Detects the Outdoor pipe temperature and carry out below restriction/limitation (Limit the compressor Operation
frequency).
The compressor stop if outdoor pipe temperature exceeds 61°C.
If the compressor stops 4 times in 20 minutes, Timer LED blinking (F95 indicated: outdoor high pressure rise
protection).
13.2.3 Freeze Prevention Control 1
When indoor heat exchanger temperature is lower than 0°C continuously for 6 minutes, compressor will stop
operating.
Compressor will resume its operation 3 minutes after the indoor heat exchanger is higher than 5°C.
At the same time, indoor fan speed will be higher than during its normal operation.
If indoor heat exchanger temperature is higher than 5°C for 5 minutes, the fan speed will return to its normal
operation.
13.2.4 Freeze Prevention Control 2
Control start conditions
o
During Cooling operation and soft dry operation
During thermo OFF condition, indoor intake temperature is less than 10°C or
Compressor stops for freeze prevention control
o
Either one of the conditions above occurs 5 times in 60 minutes.
Control
contents
o
Operation
stops
o
Timer LED blinks and “H99” indicated
13.2.5 Dew Prevention Control 1
To prevent dew formation at indoor unit discharge area.
This control will be activated if:
o
Outdoor air temperature and Indoor pipe temperature judgment by microcontroller is fulfilled.
o
When Cooling or Dry mode is operated more than 20 minutes or more.
This control stopped if:
o
Compressor
stopped.
o
Remote control setting changed (fan speed / temperature).
o
Outdoor air temperature and indoor intake temperature changed.
Fan speed will be adjusted accordingly in this control.
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13.2.6 Odor
Cut
Control
To reduce the odor released from the unit.
o
Start
Condition
AUTO FAN Speed is selected during COOL or DRY operation.
During freeze prevention control and timer preliminary operation, this control is not applicable.
o
Control
content
Depends on compressor conditions:
1. Compressor
OFF
→
Compressor ON.
The indoor unit fan stops temporarily and then starts to blow at minimum airflow for 30 seconds.
2. Compressor
ON
→
Compressor OFF.
The indoor unit fan stops for 90 seconds and then blows at minimum airflow for 20 seconds.
13.3 Protection Control for Heating Operation
13.3.1 Intake Air Temperature Control
Compressor will operate at limited freq., if indoor intake air temperature is 30°C or above.
13.3.2 Outdoor Air Temperature Control
The Max current value is regulated when the outdoor air temperature rise above 14°C in order to avoid
compressor overloading.
13.3.3 Overload Protection Control
The compressor operating frequency is regulated in accordance to indoor heat exchanger temperature as shown
below.
If the heat exchanger temperature exceeds 60°C, compressor will stop.
13.3.4 Low Temperature Compressor Oil Return Control
In heating operation, if the outdoor temperature falls below -10°C when compressor starts, the compressor
frequency will be regulated up to 600 seconds.
13.3.5 Cold Draught Prevention Control
When indoor pipe temperature is low, cold draught operation starts where indoor fan speed will be reduced.
13.3.6 Deice
Operation
When outdoor pipe temperature and outdoor air temperature is low, deice operation start where indoor fan motor
and outdoor fan motor stop and operation LED blinks.
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