LG Electronics General Wall Mounted-Inverter Type User Manual
Room Air Conditioner
SVC MANUAL(General)
MODEL : General Wall Mounted-Inverter Type
CAUTION
Before Servicing the unit, read the safety precautions in this SVC manual.
Only for authorized service personnel.
http://biz.lgservice.com
CONTENTS
Part 1 General Information
1. Safety Precautions........................................................................................................4
2. Nomenclature ...............................................................................................................7
Part 2 Functions & Controls
1. List of Functions & Controls........................................................................................9
2. Basic Mode Controls .................................................................................................10
3. Special Mode Controls ...............................................................................................12
4. Utility Functions .........................................................................................................13
5. Protection Functions & Controls...............................................................................16
Air Conditioner Service Manual
Part 3 Test Run
1. Check before Test Run ...............................................................................................31
2. Test Run Flow chart ....................................................................................................32
3. Test Run Detail ............................................................................................................33
Part 4 Trouble Shooting Guide
1. 2-Way, 3-Way Valve ....................................................................................................35
2. Pumping Down ...........................................................................................................36
3. Evacuation (All amount of refrigerant leaked) ........................................................37
4. Gas Charging (After Evacuation) ..............................................................................38
5. Cycle Troubleshooting Guide ....................................................................................39
6. Electric Parts Troubleshooting Guide.......................................................................41
7. Self-diagnosis Function .............................................................................................46
2 Room Air Conditioner
Part 1 General Information
1. Safety Precautions ............................................................................................................4
2. Nomenclature......................................................................................................................7
Service Manual 3
Part 1 General Information
1. Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must be followed.
■ Incorrect operation due to ignoring instruction will cause harm or damage. The seriousness is classified by the following indications.
This symbol indicates the possibility of death or serious injury.
This symbol indicates the possibility of injury or damage to properties only.
■ Meanings of symbols used in this manual are as shown below.
Be sure not to do.
Be sure to follow the instruction.
Dangerous Voltage
1.1 Cautions in Repair
Be sure to disconnect the power cable plug from the plug socket before disassembling the equipment for a repair.Internal components and circuit boards are at
main potential when the equipment is connected to the power cables. This high
voltage is extremely dangerous and may cause death or severe injury if come in
contact with it.
Do not touch the discharging refrigerant gas during the repair work.
The discharging refrigerant gas.The refrigerant gas can cause frostbite.
Release the refrigerant gas completely at a well-ventilated place first.
Otherwise, when the pipe is disconnected, refrigerant gas or refrigerating
machine oil discharges and it Can cause injury.
When the refrigerant gas leaks during work, perform ventilation. If the refrigerant
gas comes in contact with a fire, poisonous gas generates. A case of leakage of
the refrigerant and the closed room full with gas is dangerous because a shortage of oxygen occurs. Be sure to perform ventilation.
When removing the front panel or cabinet, execute short-circuit and discharge
between high voltage capacitor terminals. If discharge is not executed, an electric
shock is caused by high voltage resulting in a death or injury.
Do not turn the air-conditioner ON or OFF by plugging or unplugging the power
plug. There is risk of fire or electrical shock.
4 Room Air Conditioner
Part 1 General Information
Do not use a defective or underrated circuit breaker. Use the correctly rated
breaker and fuse. Otherwise there is a risk of fire or electric shock.
Install the panel and the cover of control box securely. Otherwise there is risk of
fire or electric shock due to dust, water etc.
Indoor/outdoor wiring connections must be secured tightly and the cable should
be routed properly so that there is no force pulling the cable from the connection
terminals. Improper or loose connections can cause heat generation or fire.
Do not touch, operate, or repaire the product with wet hands. Holding the plug by
hand when taking out. Otherwise there is risk of electric shock or fire.
Do not turn on the breaker when the front panel and cabinet are removed.
Be sure to ground the air conditioner with an earthing conductor connected to
the earthing terminal.
Conduct repair works after checking that the refrigerating cycle section has
cooled down sufficiently. Otherwise, working on the unit, the hot refrigerating
cycle section can cause burns.
Do not tilt the unit while removing panels. Otherwise, the water inside the unit
can spill and wet floor.
Do not use the welder in a well-ventilated place. Using the welder in an enclosed
room can cause oxygen deficiency.
Be sure to turn off power switch before connecting or disconnecting connector,
or parts damage may be occur.
Service Manual 5
Part 1 General Information
1.2 Inspections after Repair
Check to see if the power cable plug is not dirty or loose. If the plug is dusty or
loose it can cause an electrical shock or fire.
Do not use a joined power cable or extension cable, or share the same power
outlet with other electrical appliances. otherwise, it can cause an electrical shock,
excessive heat generation or fire.
Do not insert hands or other objects through the air inlet or outlet while the product is operating. There are sharp and moving parts that could cause personal
injury.
Do not block the inlet or outlet of air flow. It may cause product failure
Check to see if the parts are mounted correctly and wires are connected.
Improper installation and connections can cause an electric shock or an injury.
Check whether the installation platform or frame has corroded. Corroded installation platform or frame can cause the unit to fall, resulting in injury.
Be sure to check whether the earth wire is correctly connected.
After the work has finished, be sure to do an insulation test to check whether the
resistance is 2[Mohm] or more between the charge section and the non-charge
metal section (Earth position). If the resistance value is low, a disaster such as a
leak or electric shock is caused at user’s side.
Check the drainage of the indoor unit after the repair. If drainage is faulty the
water may enter the room and wet floor.
6 Room Air Conditioner
2. Nomenclature
2.1 Global Model Name
AS W1264GG1
12 - 345678910
Code Type Code of Model Meaning
1 Production Center, A~Z L: Chang-won R22
Refrigerant A: Chang-won R410A
2 Product Type A~Z S: Split Type Air Conditioner
3 Cooling/Heating/Inverter A~Z C: Cooling Only
H: Heat Pump
X: C/O + E/Heater
Z: H/P + E/Heater
V: AC Inverter C/O
N: AC Inverter H/P
Q: DC Inverter C/O
W: DC Inverter H/P
4, 5 Capacity 0~9 Cooling/Heating Capacity
Ex. "09" → 9,000 Btu/h
6 Electric Range 1~9 1: 115V/60Hz
A~Z 2: 220V/60Hz
3: 208-230V/60Hz
5: 200-220V/50Hz
6: 220-240V/50Hz
7: 110V, 50/60Hz
Part 1 General Information
7 Chassis A~Z Name of Chassis
8 Look A~Z Look,
Color (Artcool Model)
9, 10 Function A~Z
A Basic
B Basic+4Way
C Plasma Filter
D Plasma Filter+4 Way
E Tele+LCD
F Tele+LCD+Nano plasma+4Way
G NBF F+(A/changeove)+A/clean+Low A
H NBF F+(A/changeove)+A/clean+4way+Low A
I Tele+LED+4way
J Internet
K Plasma F+4Way+Oxygen generator
L NBF F+(A/changeove)+A/clean
M NBF F+(A/changeove)+A/clean+4way
N NBF F+(A/changeove)+A/clean+PTC
P NBF F+(A/changeove)+Autoclean+4way+PTC
Q NBF F+(A/changeove)+A/clean+4way+Low A+PTC
R Negative ion+A/Clean
S (Nano)Plasma+Negative ion+A/Clean
T 4way+(Nano)Plasma F+Negative ion+A/Clean
U
Nano Plasma F+4Way+(A/changeove)+A/clean+Oxygen generator
V
4way+(Nano)Plasma F+Negative ion+A/Clean+Oxygen generator
W Dry contact
Y Basic + Low A
11 Serial No. 1~9 LG Model Development Serial No.
Service Manual 7
Part 2 Functions & Controls
1. List of Controls & Functions ..........................................................................................9
2. Basic Mode Controls......................................................................................................10
3. Special Mode Controls...................................................................................................12
4. Utility Functions .............................................................................................................13
5. Protection Functions & Controls .................................................................................16
8 Room Air Conditioner
Part 2 Functions & Controls
1. List of Functions & Controls
Category Function Description Remark
Basic mode
controls
Special Mode
controls
Utility Functions
Protection
Controls &
Functions
Cooling Mode
Heating Mode
Healthy Dehumidification
Automatic operation
Auto Changeover
Jet Cool
Jet Heat
Energy saving
Forced operation
Auto Clean
Air volume control
Natural Air control
Chaos Swing
Sleep mode Auto control
Auto Restart Function
Five Second Delay (Fan)
Two Minutes Stand-by
(Comp.)
Hot Start
Freeze prevention
Automatic Defrost
Power Relay Control
Inverter (with inverter
power control)
Overheating Protection
(Power Module)
Total Current Control
(Over Current Protection)
DC Peak Control
Discharge Pipe Temp Control
Low Ambient Function
Oil Return Control
Oil Equalizing Control
Cooling operation
Heating operation
Dry operation
Automatic operation
Cooling mode is automatically changed to heating mode and
vice verse
Powerful cooling mode
Powerful heating mode
Air volume & set temp. are automatically selected for saving
energy in cooling mode
Operation without remote controller
After cooling operation, this function makes the evaporator
dry
Indoor Fan speed Control
Air volume control Program
Vertical Airflow Direction control
Air volume & set temp. are automatically changed for com-
fortable sleep
When power returns after a power failure, Unit restarts in the
previous operating mode
For noise prevention
For overload prevention
To prevent cold wind blow on heating mode start
Evaporator frost prevention
Condenser frost prevention
Over current prevention
Modulation of voltage & frequency
To protect power module
To protect power device
To protect power module
For overheating protection
For operation at low temp.
To protect compressor
To protect compressor
Cooling Mode Only
NOTE: The Exploded View SVC Manual has the particular Function table for each model.
Service Manual 9
Part 2 Functions & Controls
2. Basic Mode Controls
2.1 Cooling Mode
+0.5°C(1°F)
Setting
Temp.
-0.5°C(-1°F)
INV. Comp.
Frequency
High LowHigh
Low
Comp. OFF
Thermo ON
Thermo OFF
• Operating frequency of compressor depends on the load condition, like the difference between the room temp. and
the set temp., frequency restrictions.
• If the compressor operates at some frequency, the operating frequency of compressor cannot be changed within 30
seconds. ( not emergency conditions)
• Compressor turned off when
- intake air temperature is in between ±0.5°C(±1°F) of the setting temp. limit for three minutes continuously.
- intake air temperature reaches below 1.0°C(2°F) of the temperature of setting temp..
• Compressors two minutes time delay.
- After compressor off, the compressor can restart minimum 2 minutes later.
2.2 Heating Mode
T2°C(T4°F).
Thermo OFF
T1°C(T2°F).
Setting
Temp.
INV. Comp.
Frequency
High LowHigh Comp. OFF
Low
Comp. OFF
Thermo ON
• Operating frequency of compressor depend on the load condition, The difference between the room temp. and set
temp., frequency restrictions.
• If compressor operates at some frequency, the operating frequency of compressor cannot be changed within 30 seconds.
• Condition of compressor turned off
- When intake air temperature reaches +T2°C(T4°F) above the setting temperature.
• Condition of compressor turned on
- When intake air temperature reaches +T1°C(T2°F) above the setting temperature.
* Condition of indoor fan turned off
- While in compressor on : indoor pipe temp. < 20°C(68°F)
- While in compressor off : indoor pipe temp. < 30°C(86°F)
• While in defrost control, the indoor and outdoor fans are turned off.
• Compressor 2minutes delay
- After compressor off, the compressor can restart minimum 2 minutes later.
• T1 and T2 may be changed by models
10 Room Air Conditioner
Part 2 Functions & Controls
2.3 Healthy Dehumidification operation
• When the dehumidification operation is set by the remote controller, the intake air temperature is detected and the set-
ting temp. is automatically set according to the intake air temperature.
Intake air Temp. Setting Temp.
26°C(78.8
24°C(75.2
22°C(71.6
°F)
°F)
18°C(64.4°F) ≤ intake air temp. < 22°C(71.6
intake air temp. < 18°C(64.4
•
When intake air temp. is 1 C(2 F) above the setting temp., condition of compressor is same as in cooling mode operation.
°F)
≤ intake air temp. 25°C(77
≤ intake air temp.< 26°C(78.8
≤ intake air temp. < 24°C(75.2
°F)
°F)
°F)
°F)
°F)
intake air temp. -1°C(-2
intake air temp. -0.5°C(-1
intake air temp.
18°C(64.4
°F)
°F)
°F)
• When intake air temperature reaches 1 C(2 F) below the setting temp., compressor operates in step1~step3 and the
indoor fan speed again operates at low speed or comes to a stop.
2.4 Automatic operation
• When the Auto operation is set by the remote controller, the intake air temperature is detected and the setting temp. is
automatically set according to the intake air temperature and operation mode.
• The air volume is automatically set according to the intake air temperature.
2.5 Auto changeover operation
• The air conditioner changes the operation mode automatically to keep indoor temperature steady.
• When room temperature vary over ±2°C(±4°F) with respect to setting temperature, air conditioner keeps the room tem-
perature in ±2°C(±4°F) with respect to setting temperature by changing the mode from cooling to heating and vice
versa.
+4°C(+8°F)
+2°C(+4°F)
+0.5°C(+1°F)
Setting
Temp.
-0.5°C(-1°F)
-2°C(-4°F)
Mode
Cooling
operation
Heating operation
Cooling
operation
Switching point
Heating thermo off
Cooling thermo off
Switching point
Service Manual 11
Part 2 Functions & Controls
3. Special Mode Controls
3.1 Jet Cool operation
• In the heating mode or Fuzzy operation, the Jet cool function does not work.
When it is input while in other mode of operation (cooling, dehumidification, ventilation), the Jet cool operation takes
place.
• In the Jet cool mode, the indoor fan is operated at super-high speed for 30 min. at cooling mode operation.
• In the Jet cool mode, the room temperature is maintained at a setting temperature of 18°C(64.4°F).
• When the sleep timer mode is input during the Jet cool operation, the Jet cool mode has the priority.
• When the Jet cool button is pressed, the upper/lower vane of the unit is reset to those of the initial cooling mode and
then operate so that the air outflow could reach further.
3.2 Jet Heat operation
• While in cooling mode or Fuzzy operation, the Jet Heat function does not work.
When it is input while in the Heating mode operation (dehumidification), the Jet Heat mode operation takes place
• In the Jet Heat mode, the indoor fan operated at super-high speed for 60 min. at Heating mode operation.
• In the Jet Heat mode, the room temperature is maintained at a temperature of 30°C(86°F).
• When the sleep timer mode is input during the Jet Heat mode operation, the Jet Heat mode has the priority.
• When the Jet Heat button is pressed, the upper/lower vane of the unit is the unit reset to those of the initial Jet heating
mode and then operates so that the air outflow could reach under flow.
3.3 Energy saving operation in cooling mode
• During cooling and dehumidification mode of operation, the Energy saving button can be input.
• In this operation, before we feel cold the set temperature and air volume is set automatically to save energy.
• The operation time and the other thing was decided by experiment.
12 Room Air Conditioner
Part 2 Functions & Controls
4. Utility Functions
4.1 Forced operation
• To operate the appliance manually in case when the remote control is lost, the forced operation selection switch is on
the main unit of the appliance, and operate the appliance in the standard conditions.
• The operating condition is set according to the outdoor temp. and intake air temperature as follows.
Indoor temp.
over 24°C(75.2°F)
21~24°C(69.8~75.2°F)
below 21°C(69.8°F)
• The unit select the last operation mode in 3 hours.
• Operating procedures when the remote control can't be used is as follows :
- The operation will be started if the ON/OFF button is pressed.
- If you want to stop operation, re-press the button.
- The ON/OFF switch is on the display PCB or side of indoor unit
Operating Mode
Cooling
Healthy Dehumidification
Heating
Setting temp.
22°C(71.6°F)
23°C(73.4°F)
24°C(75.2°F)
Setting speed of
indoor fan
High speed
4.2 Auto cleaning operation
• Function used to perform Self Cleaning to prevent the Unit from Fungus and bad odor.
• Used after the Cooling Operation before turning the unit off, clean the Evaporator and keep it dry for the next opera-
tion.
• The function is easy to operate as it is accessed through the Remote controller.
Unit
Operation
Indoor
Fan
Comp.
Time
ON
OFF
ON
OFF
ON
OFF
Setting step
OFFL Low
13~14 minutes 1 minute 2~3 minutes
Service Manual 13
Mode2
Mode3
Mode4
Mode5
Mode6
Mode7
Mode8
Mode9
OPEN
CLOSED
8°
Cooling Operation
120°
Mode2
Mode3
Mode4
Mode5
Mode6
Mode7
Mode8
Mode9
OPEN
CLOSED
8°
Heating Operation
120°
Mode1
Mode1
Mode2
Mode3
Mode4
Mode5
Mode6
Mode7
Mode8
OPEN
CLOSED
8°
Cooling Operation
Mode1
Mode2
Mode3
Mode4
Mode5
Mode6
Mode7
Mode8
OPEN
CLOSED
8°
Heating Operation
110°110°
Start
(S4, SE) 9,12kBtu/h Model
Start
Start
Start
(S5) 18, 24kBtu/h Model
(SD) 30kBtu/h Model
Mode
1
Mode
2
Mode
3
Mode
4
Mode
5
Mode
6
Mode
7
Mode
8
OPEN
CLOSED
8¡
Heating Operation
110¡
Start
Mode
7
Mode
1
Mode
2
Mode
3
Mode
4
Mode
5
Mode
6
Mode
8
OPEN
CLOSED
8¡
Cooling Operation
110¡
Start
Part 2 Functions & Controls
4.3 Air volume control
• Indoor fan motor control have 6 steps.
• Air volume is controlled "SH", "H", "Med", "Low" by the remote con-
troller.
• "LL" step is selected automatically in Hot start operation.
4.4 Natural Air Control(Auto Wind)
• When the Auto Step is selected and then operated, the high, medi-
um, or low speed of the airflow mode is operated for 2~15 sec. randomly by the Chaos Simulation.
Step Description
LL Very low, In heating mode
L Low
M Med
H High
SH Super high
Auto Natural wind
4.5 Chaos Swing
• By the Chaos swing key input, the upper/lower vane automatically operates with the Chaos swing or it is fixed to the
desired direction.
NOTE: Some Models are different by swing width and swing pattern.
14 Room Air Conditioner
Part 2 Functions & Controls
Setting temp. (˚C)
1.0˚C(2˚F) up
1.0˚C(2˚F) up
Cooling ON temp.
(Setting temp. +0.5˚C(+1˚F))
Cooling OFF temp.
(Setting temp. -0.5˚C(-1˚F))
0.5 1 Sleep time (hour
)
4.6 Sleep mode Auto control
• When the set sleep time is reached set time of [1,2,3,4,5,6,7hour] input by the remote control during the operation, the
operation of the appliance stops.
• When the appliance is on pause, the sleep timer mode cannot be input.
4.6.1 Sleep timer operation for cooling cycle
• While in cooling mode , 30 min. after the start of the sleep timer, the setting temperature increases by 1 C(2 .
After another 30minutes lapse, it increases again by 1°C(2 .
4.6.2 Sleep timer operation for heating cycle
• While in heating mode, 60 min. after the start of the sleep timer, the setting temperature decreases by 1 C(2 .
After another 60minutes lapse, it decreases again by 1°C(2 .
Setting temp. (°C)
Heating ON temp.
(Setting temp)
Heating OFF temp.
(Setting temp. +4.0°C(+8°F))
1.0°C(2°F) down
1.0°C(2°F) down
1 2 Sleep time (hr
)
4.7 Auto restart
• When the power comes back after a sudden power failure during operation, the mode before the power failure is kept
on the memory of the appliance and it automatically operates in the saved mode on the memory.
• Operation mode that is kept on the memory
- State of operation ON/OFF
- Operation mode/setting temp./selected airflow speed
- Sleep timer mode/remaining time of sleep timer
- Chaos Swing
Service Manual 15
Part 2 Functions & Controls
Comp. free
Comp. Step 4
Comp. Step 2
Comp. off
T1
3˚C(37.4˚F)
6˚C(42.8˚F)
7˚C(44.6˚F)
Indoor pipe
temp.
5. Protection Functions & Controls
5.1 Five Seconds Stand-by (fan)
• The indoor unit fan rotates after 5 seconds when unit is turned on.
5.2 Two Minutes Stand-by (comp.)
• Compressor starts two minutes later, after it is turned off
5.3 Hot start
• When unit starts in the heating mode to prevent cold wind blowing, the indoor fan does not rotate until the temp. of
heat exchanger reaches 30°C(86°F)(model by model)
5.4 Freeze prevention (Protection of the evaporator pipe from frosting)
• If the indoor pipe temperaure is below 0°C(32°F) in 7 min. after the compressor operates without pause while in cooling cycle operation mode, ➔ compressor, outdoor fan are turned off.
• When indoor pipe temp. is 7°C(44.6°F) or higher after 2 min pause of compressor ➔ compressor, outdoor fan is turned
on according to the condition of the room temperature.
NOTE: Some Models are different by T1.
16 Room Air Conditioner
T1: 0 ~ 2°C(32~35.6°F)
Part 2 Functions & Controls
5.5 Automatic defrost
5.5.1 9,12kBtu/h Model
• While in heating mode operation in order to protect the evaporator pipe of the outdoor unit from freezing,
reversed to cooling cycle to defrost the evaporator pipe of the outdoor unit.
• Defrosting control is available 40 minutes later since heating cycle started and the difference of the pipe temperature of outdoor unit reaches above option 1.
• The defrosting control is available without reference to heating operation time only if the pipe temperature of
outdoor unit reaches below option 2.
The mean outdoor
temperature
The minimum Time of
Heating(sec)
Minimum Time
Of Heating
Operating
Setting Freq.
Freq. Of
Comp
(Comp off
Inapplicable.)
Operating
Setting Freq.
Freq. Of
Comp
(Comp off
Applicable.)
The Degree
of Superheat
EEV
Control
Open step
4-Way
Indoor
ON
Setting
Speed
FAN
Setting
Indoor
Speed
FAN
-10˚C(14˚F) less than
>4Option 1
And Heating operating time 40 minutes
5sec
5sec
Step 5 (Option)_(13)
Min (Option)_(12)
15 sec
off
Step 5 (Option)_(13)
Min (Option)_(12)
-5~0˚C(23~32˚F) between
Expected heating operating time
Main Deice time
10 sec
30 sec
300
OFF
(Option)_(14)
Min (Option)_(12)
off
Min (Option)_(12)
off
Starting Step
Hi Speed
Hot
OFF
Start
0˚C(32˚F) more than-10~-5˚C(14~23˚F) between
>5>5>5
-25-25-30-30Option 2
1min
Setting
Freq.
Step 3 (Option)_(15)
Step 3 (Option)_(15)
ON
Setting
Speed
Super low speed
° low speed
Pre-Heat
LED
OFF
ON
OFF
Deice STEP 0123456
Service Manual 17
Part 2 Functions & Controls
5.5.2 18,24,30kBtu/h Model
• Starting to the defrosting operation
1) Defrost operation will be start when the conditions below are matched
a) Accumulation time of operation and the period after completion of defrost = 35 min.
b) After 10 minutes from re-starting the compressor .In case of being over 35 minutes of accumulated operating
time, defrosting operation starts after 10 minutes.
c) Piping temperature of the outdoor heat exchanger maintain below defrost starting temperature for 4 minutes
after 35 minutes continuous operation.
d)In case of passing 10 minutes after oil recovery operation
2) Outdoor piping temperature is below than –6°C (21.2°F, Option) for starting defrosting operation.
18 Room Air Conditioner
Part 2 Functions & Controls
• Defrosting Control Algorithm
1) Lowering the compressor frequency when starts the defrosting operation.
Constant speed compressor is ON after 10 seconds from the arrival time of 30 Hz (Option) frequency and is
speed up its revolution till 100 Hz (Option)
2) Every EEV have 350 pulse (Option) of opening when starts defrosting operation.
3) Reversing valve is OFF after 5 seconds from arriving the compressor operating frequency of 30 Hz and then
fans of indoor units turn OFF.(including the indoor unit with being OFF except the remote controller is being
OFF)
4) After 5 seconds from the time arriving 30 Hz, fans of outdoor unit turn OFF and Hot Gas bypass/Oil separator
valve turn ON.
NOTE: Comp.frequency and EEV pulse is different each models.
• Control algorithm of defrost completion
1) Frequency of compressor lowering to 30 Hz and maintain constant speed operation with 30 Hz for 75 seconds
and then stating operation. If the constant speed compressor is OFF, it will be receive OFF signal after 5 seconds from the arrival time of 30 Hz.
2) The EEV will open with the standard previous pulse after 5 seconds from the time of 30 Hz.
3) Reversing valve is ON after 15 seconds from the time of 30 Hz of compressor frequency.
4) Fan of outdoor unit is ON with high speed and maintain it after 5 seconds from the time of 30Hz.
5) Hot Gas bypass valve/Oil separator bypass valve make OFF after 75 seconds from the time of 30Hz.
NOTE: Comp.frequency and EEV pulse is different each models.
Service Manual 19
Part 2 Functions & Controls
3Ø
Comp.
Motor
U
UV W
V
W
+
5.6 Power Relay Control
• Power relay turns on 1 second later after the power is supplied to the outdoor unit.
• Control sequence : power on → PTC operating → power relay on
5.7 Inverter
1. The single phase power AC is converted into DC.
2. The single phase power DC is converted into a three phase chopped DC voltage with a variable frequency.
3. When the frequency changes, the rotation speed of the compressor changes resulting in an changed refrigerant circulation. This leads to changeable amount of the heat exchange per unit.
20 Room Air Conditioner
Part 2 Functions & Controls
5.8 Overheating Protection (Power Module)
5.8.1 9,12kBtu/h Model
• If the temperature of the heat sink thermistor. reaches over Toff, the Compressor stop instantly.
• The compressor operating frequency is limited according to the heat sink thermistor. (refer to below FIG.)
• It will blink 4 times, when the thermistor is open or short, also when the temperature is over T off.
∆T = (T off - T on)/3
T1 = T on + ∆T
T off °C
T2 °C
T1 °C
T on °C
COMP
Freq.
T2 = T on + 2 * ∆T
Free OFF FreeFc-1 Fc-1Fc-2 Fc-2
T on : 85°C(185°F) (Model by Model)
T off : 95°C(203°F) (Model by Model)
NOTE: Some Models are different by Ton, and Toff.
Heat Sink Temp.
Service Manual 21
Loading...