Panasonic CU-XE15SKUA User manual

© Panasonic Corporation 2016.
Order No: PAPAMY1608072AE
Air Conditioner
Indoor Unit Outdoor Unit
CS-XE15SKUA CU-XE15SKUA
Destination
U.S.A.
Canada
CLOCK
AIRCO NDITIONER
OFF/ON
SET CHECK RESET
AC RC
ON
OFF
SET
123
TIMER
AUTO
COMFORT
POWERFUL /
QUIET
MODE
TEMP
FAN SPEED
AIR SWING
ECONA VI
RFP
MODE
O
FF/
O
N
C
HE
C
K
O
N
O
FF
SET
1
2
3
T
I
M
E
R
T
E
M
P
CANCEL
IMPORTANT SAFETY NOTICE
There are special components used in this equipment which are important for safety. These parts are marked by in the Schematic
Diagrams, Circuit Board Diagrams, Exploded Views and Replacement Parts List. It is essential that these critical parts should be replaced
with manufacturer’s specified parts to prevent shock, fire or other hazards. Do not modify the original design without permission of
manufacturer.
!
This service information is designed for experienced repair technicians only and is not designed for use by the general public.
It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service
or repair the products dealt with in this service information by anyone else could result in serious injury or death.
WARNING
PRECAUTION OF LOW TEMPERATURE
In order to avoid frostbite, be assured of no refrigerant leakage during the installation or repairing of refrigerant circuit.
OPERATION MANUAL

30
12. Operation Control
12.1 Basic Function
Inverter control, which equipped with a microcomputer in determining the most suitable operating mode as time
passes, automatically adjusts output power for maximum comfort always. In order to achieve the suitable operating
mode, the microcomputer maintains the set temperature by measuring the temperature of the environment and
performing temperature shifting. The compressor at outdoor unit is operating following the frequency instructed by
the microcomputer at indoor unit that judging the condition according to internal setting temperature and intake air
temperature.
12.1.1 Internal Setting Temperature
Once the operation starts, remote control setting temperature will be taken as base value for temperature shifting
processes. These shifting processes are depending on the air conditioner settings and the operation environment.
The final shifted value will be used as internal setting temperature and it is updated continuously whenever the
electrical power is supplied to the unit.
12.1.2 Cooling Operation
12.1.2.1 Thermostat control
Compressor is OFF when Intake Air Temperature - Internal Setting Temperature < -2.7°F (-1.5°C) continue for
3 minutes.
When compressor is OFF (Thermostat OFF) and AUTO FAN is set, the fan will stop periodically.
Compressor is ON after waiting for 3 minutes, if the Intake Air Temperature - Internal Setting Temperature >
Compressor OFF point.
12.1.3 Soft Dry Operation
12.1.3.1 Thermostat control
Compressor is OFF when Intake Air Temperature - Internal Setting Temperature < -3.6°F (-2.0°C) continue for
3 minutes.
When compressor is OFF (Thermostat OFF) and AUTO FAN is set, the fan will stop periodically.
Compressor is ON after waiting for 3 minutes, if the Intake Air Temperature - Internal Setting Temperature >
Compressor OFF point.
12.1.4 Heating Operation
12.1.4.1 Thermostat control
Compressor is OFF when Intake Air Temperature - Internal Setting Temperature > +3.6°F (+2.0°C) continue for
3 minutes.
Compressor is ON after waiting for 3 minutes, if the Intake Air Temperature - Internal Setting Temperature <
Compressor OFF point.
60.8F~86F(16C~30C)
Remote Control Setting Temperature
(Min: 60.8F(16C) ~ 91.4F(33C)
Auto Operation Mode Shifting
Indoor Air Temperature Shifting
Outdoor Air Temperature Shifting
Powerful Mode Shifting
Setting Temperature Limit Checking
Internal Setting Temperature

31
12.1.5 Automatic Operation
This mode can be set using remote control and the operation is decided by remote control setting temperature,
remote control operation mode and indoor intake air temperature.
During operation mode judgment, indoor fan motor (with speed of Lo-) is running for 30 seconds to detect the
indoor intake air temperature.
Every 10 minutes, the indoor temperature is judged.
For the 1st judgment
oIf indoor intake temperature - remote control setting temperature 3.6°F (2°C), COOL mode is decided.
oIf -3.6°F (-2°C) indoor intake temperature - remote control setting temperature < 3.6°F(2°C), DRY mode is
decided.
oIf indoor intake temperature - remote control setting temperature < -3.6°F (-2°C), HEAT mode is decided.
For the 2nd judgment onwards
oIf indoor intake temperature - remote control setting temperature 5.4°F (3°C), if previous operate in DRY
mode, then continue in DRY mode. otherwise COOL mode is decided.
oIf -3.6°F (-2°C) indoor intake temperature - remote control setting temperature < 5.4°F (3°C), maintain with
previous mode.
oIf indoor intake temperature - remote control setting temperature < -3.6°F (-2°C), HEAT mode is decided.
12.1.6 Fan Operation
Fan Operation is used to circulate air in a room.
During operation, indoor fan run continuously but outdoor fan and compressor stop.
Temperature setting is not applicable.
12.2 Indoor Fan Motor Operation
12.2.1 Basic Rotation Speed (rpm)
A. Basic Rotation Speed (rpm)
i. Manual Fan Speed
[Cooling, Dry]
Fan motor’s number of rotation is determined according to remote control setting.
Remote control żżżżż
Tab Hi Me+ Me Me- Lo
[Heating]
Fan motor’s number of rotation is determined according to remote control setting.
Remote control żżżżż
Tab SHi Me+ Me Me- Lo
-10.8
(-6)
-9.0
(-5)
-7.2
(-4)
-5.4
(-3)
-3.6
(-2)
-1.8
(-1)
0
(0)
1.8
(1)
3.6
(2)
5.4
(3)
7.2
(4)
9.0
(5)
10.8
(6)
Unit: F(C)
Heat Dr
y
Cool
-
Heat
Maintain
current mode
Cool
/Dry
-10.8
(-6)
-9.0
(-5)
-7.2
(-4)
-5.4
(-3)
-3.6
(-2)
-1.8
(-1)
0
(0)
1.8
(1)
3.6
(2)
5.4
(3)
7.2
(4)
9.0
(5)
10.8
(6) Unit: F(C)

32
ii. Auto Fan Speed
[Cooling, Dry]
According to room temperature and setting temperature, indoor fan speed is determined automatically.
When set temperature is not achieved, the indoor fan will operate according to pattern below.
When set temperature achieved, the indoor fan speed will be fixed. When thermostat off, the fan stop periodically.
[Heating]
According to indoor pipe temperature, automatic heating fan speed is determined as follows.
B. Feedback control
Immediately after the fan motor started, feedback control is performed once every second.
During fan motor on, if fan motor feedback 2550 rpm or < 50 rpm continue for 10 seconds, then fan motor error
counter increase, fan motor is then stop and restart. If the fan motor counter becomes 7 times, then H19 - fan
motor error is detected. Operation stops and cannot on back.
12.3 Outdoor Fan Motor Operation
It starts when compressor starts operation and it stops 30 seconds after compressor stops operation.
During cooling operation, and outdoor ambient temperature is below 46.4°F (8°C), outdoor fan speed will be
controlled according to outdoor piping temperature as following:
abc def gh
[1 pattern : 10 s]
ab
Higher
F
a
n
Speed
Medium
L
ower
RPM Increased
RPM Maintain
RPM Reduced
OFF
Indoor Pipe Temp.
95
o
F(35
o
C)
102.2
o
F(39
o
C)
60.8
o
F(16
o
C)
66.2
o
F(19
o
C)
ON
Compressor:
Outdoor Fan:
ON
ON
OFF
OFF
Fan Speed
30 sec
ON
OD Pipe Te
m
p.
Outdoor fan
speed increased
Outdoor fan
speed reduce
Outdoor fan
speed maintain
B
A
A -5.4°F (A -3°C)
B -5.4°F (B -3°C)

33
OD Pipe Temperature
A 78.8°F (26°C)
B 91.4°F (33°C)
During above condition, when indoor heat exchanger temperature is below 41°F (5°C), the outdoor fan will stop
according to outdoor piping temperature as following:
12.4 Airflow Direction
There are two types of airflow, vertical airflow (directed by horizontal vane) and horizontal airflow (directed by
vertical vanes).
Control of airflow direction can be automatic (angles of direction is determined by operation mode, heat
exchanger temperature and intake air temperature) and manual (angles of direction can be adjusted using
remote control).
12.4.1 Vertical Airflow
Operation Mode Airflow Direction Upper Vane Angle (°) Lower Vane Angle (°)
1 2 3 4 5 1 2 3 4 5
Heating
Auto with Heat
Exchanger
Temperature
A 25 17
B 55 37
C 25 17
Summer House 55 37
Manual 20 45 55 65 70 17 27 37 47 56
Cooling Auto 45 ~ 70 2 ~ 39
Manual 20 25 50 55 70 2 7 17 27 39
Soft Dry Auto 45 ~ 70 2 ~ 39
Manual 20 25 50 55 70 2 7 17 27 39
1. Automatic vertical airflow direction can be set using remote control; the vane swings up and down within the
angles as stated above. For heating mode operation, the angle of the vane depends on the indoor heat
exchanger temperature as Figure 1 below. It does not swing during fan motor stop. When the air conditioner is
stopped using remote control, the vane will shift to close position.
2. Manual vertical airflow direction can be set using remote control; the angles of the vane are as stated above and
the positions of the vane are as Figure 2 below. When the air conditioner is stopped using remote control, the
vane will shift to close position.
OD Pipe Temp.
Outdoor
fan OFF
Outdoor
fan ON 86°F (30°C)
122.0°F (50°C)
Upper vane: 60°
Lower vane: 58°
86.0°F (30°C)
C
B
A
Indoor Heat
Exchanger Temperature
Closed Position
Figure 1
96.8°F (36°C)
136.4°F (58°C)
Figure 2
Step 3
Step 2
Step 1
Reference point
Step 4
Step 5

34
12.4.2 Horizontal Airflow
Automatic horizontal airflow direction can be set using remote control; the vane swings left and right within the
angles as stated below. For heating mode operation, the angle of the vane depends on the indoor heat
exchanger temperature as Figure 1 below. It does not swing during fan motor stop.
Operation Mode Vane Angle (°)
Heating, with heat exchanger temperature A 65 ~115
B 90
Cooling and soft dry 65 ~115
Manual horizontal airflow direction can be set using remote control; the angles of the vane are as stated below
and the positions of the vane are as Figure 2 above.
Pattern 1 2 3 4 5
Airflow Direction Patterns at
Remote Control
Vane Angle (°) 90 65 77.5 102.5 115
12.5 Quiet operation (Cooling Mode/Cooling area of Dry Mode)
Purpose
oTo provide quiet cooling operation compare to normal operation.
Control condition
oQuiet operation start condition
When “POWERFUL/QUIET” button at remote control is pressed twice.
POWERFUL/QUIET LED illuminates.
oQuiet operation stop condition
When one of the following conditions is satisfied, quiet operation stops:
POWERFUL/QUIET button is pressed again.
Stop by OFF/ON switch.
Timer “off” activates.
AUTO COMFORT button is pressed.
ECONAVI button is pressed.
When quiet operation is stopped, operation is shifted to normal operation with previous setting.
When fan speed is changed, quiet operation is shifted to quiet operation of the new fan speed.
When operation mode is changed, quiet operation is shifted to quiet operation of the new mode.
During quiet operation, if timer “on” activates, quiet operation maintains.
After off, when on back, quiet operation is not memorised.
Control contents
oFan speed is changed from normal setting to quiet setting of respective fan speed.
Fan speed for quiet operation is reduced from setting fan speed.
12.6 Quiet Operation (Heating)
Purpose
oTo provide quiet heating operation compare to normal operation.
Control condition
oQuiet operation start condition
When “POWERFUL/QUIET” button at remote control is pressed.
POWERFUL/QUIET LED illuminates.
109.4°F (43°C)
104°F (40°C)
0° Top View
2
314
5
B: fix front
A: swing
Indoor Heat Exchanger
Temperature
Figure 1 Figure 2

35
oQuiet operation stop condition
When one of the following conditions is satisfied, quiet operation stops:
POWERFUL/QUIET button is pressed again.
Stop by OFF/ON switch.
Timer “off” activates.
AUTO COMFORT button is pressed.
ECONAVI button is pressed.
When quiet operation is stopped, operation is shifted to normal operation with previous setting.
When fan speed is changed, quiet operation is shifted to quiet operation of the new fan speed.
When operation mode is changed, quiet operation is shifted to quiet operation of the new mode, except
fan mode only.
During quiet operation, if timer “on” activates, quiet operation maintains.
After off, when on back, quiet operation is not memorised.
Control contents
oFan speed manual
Fan speed is changed from normal setting to quiet setting of respective fan speed.
Fan speed for quiet operation is reduced from setting fan speed.
oFan Speed Auto
Indoor FM RPM depends on pipe temp sensor of indoor heat exchanger.
12.7 Powerful Mode Operation
When the powerful mode is selected, the internal setting temperature will shift lower up to 3.6°F (2°C) (for
Cooling/Soft Dry) or higher up to 6.3°F (3.5°C) (for Heating) than remote control setting temperature for
20 minutes to achieve the setting temperature quickly.
12.8 Timer Control
There are 2 sets of ON and OFF timer available to turn the unit ON or OFF at different preset time.
If more than one timer had been set, the upcoming timer will be displayed and will activate in sequence.
12.8.1 ON Timer Control
ON timer 1 and ON timer 2 can be set using remote control, the unit with timer set will start operate earlier than
the setting time.
This is to provide a comfortable environment when reaching the set ON time.
60 minutes before the set time, indoor (at fan speed of Lo-) and outdoor fan motor start operate for 30 seconds to
determine the indoor intake air temperature and outdoor air temperature in order to judge the operation starting
time.
From the above judgment, the decided operation will start operate earlier than the set time as shown below.
12.8.2 OFF Timer Control
OFF timer 1 and OFF timer 2 can be set using remote control, the unit with timer set will stop operate at set time.
12.9 Auto Restart Control
When the power supply is cut off during the operation of air conditioner, the compressor will re-operate within
three to four minutes (there are 10 patterns between 2 minutes 58 seconds and 3 minutes 52 seconds to be
selected randomly) after power supply resumes.
This type of control is not applicable during ON/OFF Timer setting.
This control can be omitted by open the circuit of JP1 at indoor unit printed circuit board.
Indoo
r
intak
e
ai
r
temperature
o
F(
o
C)
Outdoor air
temperature
o
F(
o
C)
86 (30)
86 (30) 95 (35)
Cooling/Soft Dry
10 min
15 min
5min
77 (25)
Indoo
r
intak
e
ai
r
temperature
o
F(
o
C)
Outdoor air
temperature
o
F(
o
C)
59 (15)
32 (0) 41 (5)
Heating
30 min
25 min
35 min
41 (5)

36
12.10 Indication Panel
LED POWER TIMER POWERFUL/QUIET RFP ECONAVI AUTO COMFORT
Color Green Orange Orange Green Green Green
Light ON Operation ON Timer Setting ON POWERFUL/QUIET
Mode ON RFP ON ECONAVI ON AUTO COMFORT
ON
Light OFF Operation OFF Timer Setting OFF POWERFUL/QUIET
Mode OFF RFP OFF ECONAVI OFF AUTO COMFORT
OFF
Note:
If POWER LED is blinking, the possible operation of the unit are Hot Start, during Deice operation, operation
mode judgment, or ON timer sampling.
If Timer LED is blinking, there is an abnormality operation occurs.
12.11 Room Freeze Protection Function (RFP) Operation
When the RFP is selected, the unit will operate the fan at high speed for proper room temperature monitoring.
When the sensor detects that the room temperature has dropped below 46°F / 8°C, the compressor/heat pump
operation begins.
When the room temperature reaches 50°F / 10°C, the unit shuts off, then will repeat continuously if the
temperature drops below 46°F / 8°C again.
<Disclaimer>
This function may not be performed if the unit is not energized, or under a certain condition that unit is unable to
operate such as in protection mode. Please consult with the HVAC installers or professional for details.
The Room Freeze Protection function (RFP) cannot be used unless the unit is energized and set into the RFP
mode.
In the advent of a power failure this mode will not function. During the RFP mode, POWERFUL OPERATION,
QUIET OPERATION and FAN SPEED selection are all disabled. Please consult with your HVAC installer or
professional for more details.
12.12 AUTO COMFORT and ECONAVI Operation
Area of human availability, activity level and absent is judged based on pulses by using 2 infrared sensors. The
internal setting temperature shift, fan speed and horizontal airflow direction are adjusted in order to provide
comfort environment while maintain the energy saving level.
AUTO COMFORT start condition:
oWhen AUTO COMFORT button is pressed.
AUTO COMFORT stop conditions:
oWhen AUTO COMFORT button is pressed again.
oWhen unit is OFF by OFF/ON button.
oWhen unit is OFF when OFF TIMER activates.
oWhen unit is OFF by AUTO OFF/ON button at indoor unit.
oWhen POWERFUL, QUIET operation activates.
oWhen AIR SWING ŻŹ button is pressed.
ECONAVI start condition:
oWhen ECONAVI button is pressed.
ECONAVI stop conditions:
oWhen ECONAVI button is pressed again.
oWhen unit is OFF by OFF/ON button.
oWhen unit is OFF when OFF TIMER activates.
oWhen unit is OFF by AUTO OFF/ON button at indoor unit.
oWhen POWERFUL, QUIET operation activates.
oWhen AIR SWING ŻŹ button is pressed.

37
12.12.1 Human Activity Sensor
Area of human availability, activity level and absent is judged based on pulses by using infrared sensor. The
internal setting temperature shift, fan speed and horizontal airflow direction are adjusted in order to provide
comfort environment while maintain the energy saving level.
Human activity judgment is as following:
12.12.1.1 Signal Detection
Presumption flow of human position.
oDetection outline.
12.12.1.2 Information Log
The signal from Infrared sensors will be log to human activity database for further analysis.
12.12.1.3 Human Activity Level Judgment
Human Activity Level is judged based on the frequency of pulses detected by the infrared sensors within a
timeframe. The activity level will be categorized into High, Normal, Low level.
When a pulse is detected within this timeframe, the status of human presence is judged.
When there is no signal detection continues for 40 minutes or more, the status of human absence is judged.
Signal Detection
Information Log
Human Activity Level Judgment
Determination of Presence or Absence
C
B
A
120°
23 ft (7m)
6.6ft (2m)
23ft (7m)
Human Sensor Motion Check Sensor move to left and
right and detection area
(A, B, C) output frequency
is detected
Check Installation Position and Detection Area
Human Sensor STM move
Fixed Detection
Process Detection Result
Determination of fixed
detection area and its order
(Fixed detection i
s
continued until it
measures all the
detection area)

38
12.12.1.4 Determination of Presence or Absence
Human presence status shall be determined based on the human presence status of each area.
When all area has been detected absent for more than 40 minutes then it will judge as absence.
12.12.1.5 Setting Temperature and Fan Speed Shift
* During low activity, fan speed 1 tap up for first 15 minutes or until set temperature is reached.
** During human absence, maximum fan speed for COOL/DRY mode is medium fan.
12.12.1.6 ECONAVI and AUTO COMFORT Demo Mode
To enable ECO DEMO mode:
To disable ECO Demo MODE:
oTransmit ECO Demo signal again.
Low activity Normal activity
Human
Mode
Set
temperature
High activity Absent
ECONA
V
I; Detecting human presence and activity, the unit controls room temperature to save energy.
Low activity Normal activity
Human
Mode
Set
temperature
High activity Absent
Set
Fan Speed
A
UTO COMFORT ; Detecting human presence and activity, the unit controls room temperature to keep human
comfortable consistently.
HEAT
COOL/DRY
HEAT
COOL/DRY
+1 tap
+1 tap*
+2°F / +1°C
+2°F / +1°C
+0.5°F / +0.3°C
-2°F / -1°C
-4°F / -2°C
+4°F / +2°C
-4°F / -2°C
-4°F / -2°C
+4°F / +2°C
-4°F / -2°C
SET
Transmit ECO demo code and
after 30 seconds return to normal
mode.
Press continously for 5s
Transmit check code
and after 30 seconds return to normal
mode.
Transmit sunlight sensor check code
and after 30 seconds return to normal
mode.
Remote control normal mode

39
12.12.1.7 Human Activity Sensor Abnormality
Abnormality detection:
Connector disconnection / Wire cut abnormality
oSensor judge Hi level continuously for 25 seconds
Circuit abnormality
o70 seconds after power ON, if human activity sensor judge Lo level continuously for 25 seconds
Error Code judgment
When abnormality happened, internal counter increase by 1 time.
Human activity sensor power OFF, retry after 5 seconds.
When the human activity sensor maintains normal condition for 120 seconds, the counter reset or AC reset.
When abnormality counter reached 4 times, H59 occurred – No TIMER indicator blinking.
When error code happened, the unit is able to operate without AUTO COMFORT / ECONAVI.
12.12.1.8 Human Activity Sensor Check Mode
To enable human activity sensor abnormality check mode:
During ECONAVI is ON, when CHECK signal received, if either sensors has abnormality, the 4 times abnormality
counter is ignored, ECONAVI Indicator will blink immediately and error code is memorized.
The unit could operate without ECONAVI or AUTO COMFORT.
The ECONAVI indicator blinking could be cancelled by pressing ECONAVI button again.
If the human activity sensor has no abnormality, the CHECK process will end and continue with normal operation.
SET
Transmit ECO demo code and
after 30 seconds return to normal
mode.
Press continously for 5s
Transmit check code
and after 30 seconds return to normal
mode.
Transmit sunlight sensor check code
and after 30 seconds return to normal
mode.
Remote control normal mode

40
12.13 Electric Heater Control 1
Starting condition
oWhen all condition (1+2+3+4+5+6+7) are fulfilled.
Operation ON
Indoor Heating mode
Thermostat ON
Temperature different control
Example:
a. When air conditioning is switch ON,
Remote controller setting = 82.4°F (28°C)
Intake air temperature = 78.8°F (26°C)
Temp difference = 82.4°F (28°C) - 78.8°F (26°C) = 3.6°F (2°C)
Heater ON
b. After a while when
Remote controller setting = 82.4°F (28°C)
Intake air temperature = 80.6°F (27°C)
Temp difference = 82.4°F (28°C) - 80.6°F (27°C) = 1.8°F (1°C)
Heater OFF
c. After a while when
Temp difference 7.2°F (4°C)
Heater ON
Intake air temperature control
Evaporator pipe sensor control
Indoor Fan speed Lo Fan
Control content
oElectric heater will be switch ON when all condition for starting condition fulfilled.
oOnce Electric heater switched ON, It will operate at least 3 minutes.
When air conditioning is
switched ON
Heater ON
Temp difference
(Remote controller setting -
Intake air temperature)
7.2 (4)
1.8 (1)
Heater OFF
ON by
Temp difference 7.2°F (4°C)
OFF by
Temp difference 1.8°F (1°C)
°F (°C)
When air conditioning is
switched ON
Heater ON
Heater OFF
84.2 (29)
Intake air temperature [°F (°C)]
78.8 (26)
When air conditioning is
switched ON
Heater ON
Heater OFF
140.0 (60) (ȕ)
Evaporator pipe sensor
[°F (°C)]
132.8 (56) (Į)

41
12.14 Electric Heater Control 2
During Error happened, air conditioning unit will stop operation, TIMER LED will blink and indoor vane closed.
Electric heater can be switch ON when fullfill the starting condition as follow except 2 errors.
oH14 (Indoor intake air temperature sensor abnormality)
oH19 (Indoor fan motor mechanism lock)
Starting condition
When all condition (1+2+3+4) are fulfilled.
oOperation ON
oIndoor Heating mode
oError happened Except error H14 and H19
oTemperature different control
Control content
oIndoor unit will start operate when receive operation ON signal from remote controller.
oIndoor fan speed
For error
Other errors
minimum fan speed = Lo Fan
oOnce Electric heater switched ON, It will operate at least 3 minutes.
12.15 Base Pan Heater Control
Specification:
oPower: 100 W
oVoltage: 230 V
Purpose:
oTo control base pan heater cable operation to melt ice on base pan during heating operation
Starting conditions:
oWhen outdoor air temperature less than or same 41.0°F (5°C) and A/C operation is heating
Control contents:
oPower supply to base pan heater is ON
Cancel conditions:
oWhen outdoor air temperature exceeds entry condition by 35.6°F (2°C) after deice OR
oWhen operation is not at heating mode
When air conditioning is
switched ON
Heater ON
Temp difference
(Remote controller setting -
Intake air temperature)
3.6 (2)
1.8 (1)
Heater OFF
ON by
Temp difference 3.6°F (2°C)
OFF by
Temp difference 1.8°F (1°C)
°F (°C)
H23 - Indoor heat exchange sensor 1 abnormality
H24 - Indoor heat exchange sensor 2 abnormality
H27 - Outdoor air temperature sensor abnormality
H28 - Outdoor heat exchange sensor abnormality
Me Fan
(Fan speed higher than other error because the
outdoor unit compressor will still run at preset
frequency about 27Hz (H23, H24) and
40Hz (H27, H28)

42
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 minutes.
Model XE15SKUA
Operation Mode X (A) Y (A)
Cooling / Soft Dry (A) 10.98 14.74
Cooling / Soft Dry (B) 8.77 14.74
Heating 11.95 14.74
Cooling / Soft Dry (C) 8.77 14.74
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 248°F (120°C), compressor operation will stop immediately.
2 Compressor operation restarts after 3 minutes the temperature decreases to 230°F (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 1 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).
102.2°F (39.0°C)
100.4°F (38.0°C)
109.4°F (43.0°C)
107.6°F (42.0°C)
(B)
(C)
(A)
Outdoor air temperature

43
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 224.6°F (107°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
oFor 5 minutes, the compressor continuously operates and outdoor total current is between 0.75A and 0.95A.
oDuring Cooling and Soft Dry operations:
Indoor suction temperature - indoor piping temperature is below 7.2°F (4°C).
oDuring Heating operations :
Indoor piping temperature - indoor suction is under 9°F (5°C).
Control contents
oCompressor stops (and restart after 3 minutes).
oIf 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
Temperature, T, for: Cooling/Soft Dry Heating
Indoor intake air (°F) T < 57.2 or T 86.0 T < 57.2 or T 82.4
Outdoor air (°F) T < 55.4 or T 100.4 T < 39.2 or T 75.2
Indoor heat exchanger (°F) T < 86.0 T 32.0
Compressor = OFF
Compressor Frequency
Reduce
Compressor Frequency
Maintain
Free
2
24.6°F (107°C)
2
17.4°F (103°C)
(221°F (105°C))
212°F (100°C)
(203°F (95°C))
197.6°F (92°C)
195.8°F (91°C)
194°F (90°C)
(185°F (85°C))
Comp. temperature
(Comp. Discharge temperature)

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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.
The compressor will be stopped to avoid compressor overloading.
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 141.8°F (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 32°F (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 41°F (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 41°F (5°C) for 5 minutes, the fan speed will return to its
normal operation.
13.2.4 Freeze Prevention Control 2
Control start conditions
oDuring Cooling operation and soft dry operation
During thermo OFF condition, indoor intake temperature is less than 50°F (10°C) or
Compressor stops for freeze prevention control
oEither one of the conditions above occurs 5 times in 60 minutes.
Control contents
oOperation stops
oTimer LED blinks and “H99” indicated
Limited Frequency
Free
77°F (25°C)
71.6°F (22°C)
Outdoor
Air
Temperature
Comp. OFF
Comp. ON
0°F (-17.8°C)
-4.0°F (-20°C)
Outdoor
Air Temperature

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13.2.5 Dew Prevention Control 1
To prevent dew formation at indoor unit discharge area.
This control will be activated if:
oOutdoor air temperature and Indoor pipe temperature judgment by microcontroller is fulfilled.
oWhen Cooling or Dry mode is operated more than 20 minutes or more.
This control stopped if:
oCompressor stopped.
oRemote control setting changed (fan speed / temperature).
oOutdoor air temperature and indoor intake temperature changed.
Fan speed will be adjusted accordingly in this control.
13.2.6 Odor Cut Control
To reduce the odor released from the unit.
oStart Condition
AUTO FAN Speed is selected during COOL or DRY operation.
During freeze prevention control and timer preliminary operation, this control is not applicable.
oControl content
Depends on compressor conditions:
1. Compressor OFF ШCompressor ON.
The indoor unit fan stops temporarily and then starts to blow at minimum airflow for 30 seconds.
2. Compressor ON ШCompressor 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 86°F (30°C) or above.
13.3.2 Outdoor Air Temperature Control
The Max current value is regulated when the outdoor air temperature rise above 57.2°F (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 140°F (60°C), compressor will stop.
13.3.4 Low Temperature Compressor Oil Return Control
In heating operation, if the outdoor temperature falls below 14°F (-10°C) when compressor starts, the
compressor frequency will be regulated up to 600 seconds.
Current Regulated
Free Within Max Limit 53.6°F (12°C)
Outdoor air temperature
57.2°F (14°C)
OFF
Frequency Reduce
Frequency Limited
Free
Indoor Heat
Exchanger Temp.
140°F (60°C)
125.6°F (52°C)
114.8°F (46°C)
131°F (55°C)
120.2°F (49°C)

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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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14. Servicing Mode
14.1 Auto OFF/ON Button
1 AUTO OPERATION MODE
The Auto operation will be activated immediately once the Auto OFF/ON button is pressed. This operation
can be used to operate air conditioner with limited function if remote control is misplaced or malfunction.
2 TEST RUN OPERATION (FOR PUMP DOWN/SERVICING PURPOSE)
The Test Run operation will be activated if the Auto OFF/ON button is pressed continuously for more than
5 seconds. A “beep” sound will heard at the fifth seconds, in order to identify the starting of Test Run
operation (Forced cooling operation). Within 5 minutes after Forced cooling operation start, the Auto OFF/ON
button is pressed for more than 5 seconds. A 2 “beep” sounds will heard at the fifth seconds, in order to
identify the starting of Normal cooling operation.
Within 5 minutes after Normal cooling operation start, the Auto OFF/ON button is pressed for more than
5 seconds. A 3 “beep” sounds will be heard at the fifth seconds, in order to identify the starting of Forced
heating operation.
The Auto OFF/ON button may be used together with remote control to set / change the advance setting of air
conditioner operation.
3 REMOTE CONTROL NUMBER SWITCH MODE
The Remote Control Number Switch Mode will be activated if the Auto OFF/ON button is pressed
continuously for more than 11 seconds (3 “beep” sounds will occur at 11th seconds to identify the Remote
Control Number Switch Mode is in standby condition) and press “AC RESET” button and then press any
button at remote control to transmit and store the desired transmission code to the EEPROM.
There are 4 types of remote control transmission code could be selected and stored in EEPROM of indoor
unit. The indoor unit will only operate when received signal with same transmission code from remote control.
This could prevent signal interference when there are 2 or more indoor units installed nearby together.
To change remote control transmission code, short or open jumpers at the remote control printed circuit
board.
Remote Control Printed Circuit Board
Jumper A (JA) Jumper B (JB) Remote Control No.
Short Open A (Default)
Open Open B
Short Short C
Open Short D
During Remote Control Number Switch Mode, press any button at remote control to transmit and store
the transmission code to the EEPROM.
Auto OFF/ON
Button pressed
5sec
Beep Beep x 2 Beep x 3
5sec 5sec
Auto Operation Test Run Operation
(Forced cooling operation)
Test Run Operation
(Forced heating operation)
Stop Normal Cooling Operation Stop Stop
Auto OFF/ON
Button pressed
Auto OFF/ON
Button pressed
Auto OFF
/
ON
Button pressed
Auto OFF/ON button
pressed
Auto Operation
5 sec 8 sec 11 sec 16 sec
Test Run Operation
(Forced Cooling Operation)
Test Run Operation
(Forced Heating Operation)
Main unit always continue Test Run (forced cooling) operation
Beep Beep x 2
Press “AC RESET”, then any
key at remote control
Press “AC RESET”, then any
key at remote control
Press “AC RESET”
at remote control
Beep x 3 Beep x 4
Remote Control Number
Switch Mode
Remote Control Receiving
Sound OFF/ON
JA
JB