Haier 1U68REMFRA User manual

SERVICE MANUAL
Wall Mounted Type
DC Inverter
1U68REMFRAModel No.
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 product or products dealt with in this service information by anyone else could result in serious injury or death
WARNING
2018 (Qingdao Haier Air Conditioner General corp. , Ltd)
All rights reserved. Unauthorized copying and distribution is a violation of law
Haier Group
Version V1 Date 2018-12-07

Contents
Domestic air conditioner
Contents
1. Introduction ............................................................................................1
2. Specifications.........................................................................................7
3. Sensors list ............................................................................................8
4. Piping diagrams .....................................................................................9
5. Operation range....................................................................................10
6. Printed circuit board connector wiring diagram ....................................11
7. Functions and control..............................................................................
8. Dimensional drawings...........................................................................
9. Center of gravity ...................................................................................
10. Service diagnosis ...............................................................................
11. Performance and curves diagrams.....................................................
12. Circuit diagrams..................................................................................
15
48
30
29
29
56

Introduction
Domestic air conditioner
1. Introduction
1.1 Model name explanation
1 U 6 8 R E M F AR
The maximum combination number
Type of outdoor unit : U (normal type)
Nominal cooling capacity (24000BTU/h)
Platform of outdoor units: 2p (2p platform)
Europe
Version number
Heat pump & R32 refrigerant
DC inverter
Apply toT1; 220~240V50HZ/1ph
1

 Introduction
 Domestic air conditioner
1.2 Safety Cautions
Be sure to read the following safety cautions before conducting repair work.
The caution items are classified into “Warning” and “Caution”. The “Warning” items are especially important
since they can lead to death or serious injury if they are not followed closely. The “Caution” items can also
lead
to serious accidents under some conditions if they are not followed. Therefore, be sure to observe all the
safety
caution items described below.
About the pictograms
Ƹ This symbol indicates an item for which caution must be exercised.
The pictogram shows the item to which attention must be paid.
żThis symbol indicates a prohibited action.
The prohibited item or action is shown inside or near the symbol.
ƔThis symbol indicates an action that must be taken, or an instruction.
The instruction is shown inside or near the symbol.
After the repair work is complete, be sure to conduct a test operation to ensure that the equipment operates
Normally, and explain the cautions for operating the product to the customer.
1.2.1 Caution in Repair
Warning
Be sure to disconnect the power cable plug from the plug socket before disassembling the equipment for
a repair.
Working on the equipment that is connected to a power supply can cause an electrical shook.
If it is necessary to supply power to the equipment to conduct the repair or inspecting the circuits, do not
touch any electrically charged sections of the equipment.
If the refrigerant gas discharges during the repair work, do not touch the discharging refrigerant gas .The
refrigerant gas can cause frostbite.
When disconnecting the suction or discharge pipe of the compressor at the welded section, release the
refrigerant gas completely at a well-ventilated place first.
If there is a gas remaining inside the compressor , the refrigerant gas or cooling machine oil discharges
when the pipe is disconnected, and it can cause injury.
If the refrigerant gas leaks during the repair work, ventilate the area. The refrigerant gas can generate
toxic gases when it contacts flames.
The step-up capacitor supplies high-voltage electricity to the electrical components of the outdoor unit.
Be sure to discharge the capacitor completely before conducting repair work . A charged capacitor can
cause an electrical shock.
Do not start or stop the air conditioner operation by plugging or unplugging the power cable plug.
Plugging or unplugging the power cable plug to operate the equipment can cause an electrical shock or
fire.
2

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 Domestic air conditioner
Warning
Do not repair the electrical components with wet hands . Working on the equipment with wet hands can
cause an electrical shock
Do not clean the air conditioner by splashing water. Washing the unit with water can cause an electrical
shock.
Be sure to provide the grounding when repairing the equipment in a humid or wet place, to avoid
electrical
shock.
Be sure to turn off the power switch and unplug the power cable when cleaning the equipment. The
internal fan rotates at a high speed, and cause injury.
Do not tilt the unit when removing it. The water inside the unit can spill and wet the furniture and floor.
Be sure to check that the cooling cycle section has cooled down sufficiently before conducting repair
work. Working on the unit when the cooling cycle section is hot can cause burns.
Use the welder in a well-ventilated place. Using the welder in an enclosed room can cause oxygen
deficiency.
1.2.2 Cautions Regarding Products after Repair
Warning
Be sure to use parts listed in the service parts list of the applicable model and appropriate tools to
conduct repair work. Never attempt to modify the equipment. The use of inappropriate parts or tools can
cause an electrical shock, excessive heat generation or fire.
When relocating the equipment, make sure that the new installation site has sufficient strength to
withstand the weight of the equipment.
If the installation site does not have sufficient strength and if the installation work is not conducted
securely, the equipment can fall and cause injury.
Be sure to install the product correctly by using the provided standard installation frame.
Incorrect use of the installation frame and improper installation can cause the equipment to fall, resulting
in injury.
For
integral
units only
Be sure to install the product securely in the installation frame mounted on a window frame.
If the unit is not securely mounted, it can fall and cause injury.
For
integral
units only
3

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 Domestic air conditioner
Warning
Be sure to use an exclusive power circuit for the equipment, and follow the technical standards related to
the electrical equipment, the internal wiring regulations and the instruction manual for installation when
conducting electrical work.
Insufficient power circuit capacity and improper electrical work can cause an electrical shock or fire.
Be sure to use the specified cable to connect between the indoor and outdoor units. Make the
connections securely and route the cable properly so that there is no force pulling the cable at the
connection terminals.
Improper connections can cause excessive heat generation or fire.
When connecting the cable between the indoor and outdoor units, make sure that the terminal cover
does
not lift off or dismount because of the cable.
If the cover is not mounted properly, the terminal connection section can cause an electrical shock,
excessive heat generation or fire.
Do not damage or modify the power cable.
Damaged or modified power cable can cause an electrical shock or fire. Placing heavy items on the
power cable, and heating or pulling the power cable can damage the cable.
Do not mix air or gas other than the specified refrigerant (R-410A / R22) in the refrigerant system.
If air enters the cooling system, an excessively high pressure results, causing equipment damage
and injury.
If the refrigerant gas leaks, be sure to locate the leak and repair it before charging the refrigerant. After
charging refrigerant, make sure that there is no refrigerant leak.
If the leak cannot be located and the repair work must be stopped, be sure to perform pump-down and
close the service valve, to prevent the refrigerant gas from leaking into the room. The refrigerant gas
itself
is harmless, but it can generate toxic gases when it contacts flames, such as fan and other heaters,
stoves and ranges.
.
When replacing the coin battery in the remote controller, be sure to disposed of the old battery to prevent
children from swallowing it.
If a child swallows the coin battery, see a doctor immediately.
Caution
Installation of a leakage breaker is necessary in some cases depending on the conditions of the
installation site, to prevent electrical shocks.
Do not install the equipment in a place where there is a possibility of combustible gas leaks.
If a combustible gas leaks and remains around the unit, it can cause a fire.
Be sure to install the packing and seal on the installation frame properly. If the packing and seal are not
installed properly, water can enter the room and wet the furniture and floor.
4

 Introduction
 Domestic air conditioner
1.2.3 Inspection after Repair
Warning
Check to make sure that the power cable plug is not dirty or loose, then insert the plug into a power outlet
all the way.
If the plug has dust or loose connection, it can cause an electrical shock or fire.
If the power cable and lead wires have scratches or deteriorated, be sure to replace them.
Damaged cable and wires can cause an electrical shock, excessive heat generation or fire.
Warning
Do not use a joined power cable or extension cable, or share the same power outlet with other electrical
appliances since it can cause an electrical shock, excessive heat generation or fire.
Caution
Check to see if the parts and wires are mounted and connected properly, and if the connections at the
soldered or crimped terminals are secure. Improper installation and connections can cause excessive
heat generation, fire or an electrical shock.
If the installation platform or frame has corroded, replace it. Corroded installation platform or frame can
cause the unit to fall, resulting in injury.
Check the grounding, and repair it if the equipment is not properly grounded. Improper grounding can
cause an electrical shock.
Be sure to measure the insulation resistance after the repair, and make sure that the resistance is 1 M
ohm or higher.
Faulty insulation can cause an electrical shock.
Be sure to check the drainage of the indoor unit after the repair.
Faulty drainage can cause the water to enter the room and wet the furniture and floor.
1.2.4 Using Icons
Icons are used to attract the attention of the reader to specific information. The meaning of each icon is described in
the table below:
5

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 Domestic air conditioner
1.2.5 Using Icons List
Icon Type of Information Description
Note Note
A “note” provides information that is not indispensable, but may
nevertheless be valuable to the reader, such as tips and tricks.
Caution Caution
A “caution” is used when there is danger that the reader, through
incorrect manipulation, may damage equipment, loose data, get
an
unexpected result or has to restart (part of) a procedure.
Warning Warning
A “warning” is used when there is danger of personal injury.
Reference
A “reference” guides the reader to other places in this binder or in
this manual, where he/she will find additional information on a
specific topic.
6

Specification
Domestic air conditioner
2 .Specifications
NOMINAL DISTRIBUTION SYSTEM VOLTAGE
1/esahP
05zHycneuqerF
032VegatloV
NOMINAL CAPACITY and NOMINAL INPUT
cooling heating
Capacity rated KW
7.0(2.2-8.5)
Btu/h
Power Consumption(Rated) KW 2.16 2.18
.4.0.7.0W/WPOCS/REES
350hWKnoitpmusnocygrenelaunnA
h/³mlavomeRerutsioM
TECHNICAL SPECIFICATIONS-UNIT
Dimensions H*W*D mm 890×353x697
Packaged
Dimensions H*W*D mm 1046x460x780
51GK/thgieW
.56GK/thgiewssorG
Sound level 52erusseepdnuoS
65BdrewopdnuoS
ELECTRICAL SPECIFICATIONS
gnitaehgnilooc
9.39.4
AtnerrucgninnurlanimoN
Maximum running current A 12.5 13.5
0.1.1.0AtnerrucgnitratS
TECHNICAL SPECIFICATIONS-PARTS
gnitaehgnilooc
Compressor
rosserpmoCyratoRepyT
TVB220FAEMCledoM
1370WtuptuorotoM
epytliO
52.0LemulovegrahcliO
Fan
naflaixAepyT
05WtuptuorotoM
.2900h/³m)hgih(etarwolfriA
800/300mpr)wol/hgih(deepS
Heat
exchanger
Type ML fin-¶7
.HI-HX tube
4.1*51*2hctif*egats*woR
7
2.8*10 ³
1963
52
65
dB(A)
(A)
8.1(2.4-10.0)
23880(7500-29000) 27640(8190-34120)
Fw68S

Specification
Domestic air conditioner
TECHNICAL SPECIFICATIONS-OTHERS
Refrigerant
circuit
Refrigerant type R32
Refrigerant charge KG 1.2
Maximum allowable distance
between indoor an outdoor m 25
Maximum allowable level difference m 15
Refrigerant control EEV
Piping connections
(external diameter)
liquid mm 6.35
gas mm 12.7
drain mm 16
Heat insulation type Both liquid and Gas pipes
Max. piping Length m 25
Max. vertical Difference m 15
Chargeless m 10
Amount of Additional Charge of Refrigerant g/m 20
Intemational Protection degree IP 24
Note: the data are based on the conditions shown in the table below
cooling heating Piping length
Indoor: 27 DB/19 WB
Outdoor: 35 DB/24 WB
Indoor:20 DB
Outdoor: 7 DB/6 WB 5m
3 Sensors list
type Description Qty
Ambient sensor Its used for detecting temperature of outdoor side
1
●Defrosting sensor Its used for controlling outdoor defrosting at heating mode
Discharging sensor Its used for compressor in case of over
●-heat
Suction sensor Its used for detecting suction pipe temperature of compressor to
adjust gas flowing 1
Conversation formulae
Kcal/h= KW×860
Btu/h= KW×3414
cfm=m³/min×35.3
8

Pinping diagrams
Domestic air conditioner
4ˊPiping diagrams
9
EEV
EEV

Operation range
10 Domestic air conditioner
5.Operation range
-10
0
21
27
35
20
40
60
43
-20
-40

Printed circuit board connector wiring diagram
11 Domestic air conditioner
6. Printed circuit board connector wiring diagram
Connectors
PCB (1) (Control PCB) For 1U18JEFFRA/1U24REFFRA/1U24REBFRA
1) CN1, CN2 Connector for power N and L
2) CN3 Connector for ground
3) CN23 Connector for DC POWER 15V and 5V to the module board
4) CN9, CN10 Connector for CN2,CN1 on the module board
5) CN22 Connector for fan motor
6) CN11 Connector for four way valve coil
7) CN17,CN47 Connector for thermistors
8) CN24 Connector for communicate between the control board and the module board
9) CN25, CN28 Connector to N and P of the module board
10) CN36 Connector for communicate between indoor and outdoor unit
11) CN15 Connector for electric expansion valves
PCB (2) (Module PCB) For 1U18JEFFRA/1U24REFFRA/1U24REBFRA
CN10 Connector for the DC power 5V and 15V form the control PCB
CN11 Connector for communicating between the control board and the module board
P (CN8), N (CN9) Connector for capacitance board
LI (CN3), LO (CN4) Connector for reactor
CN5, CN6, CN7 Connector for the U, V, W wire of the compressor
Notes: Other Designations
PCB (1) (Control PCB)
1) FUSE 1, (25A, 250VAC); FUSE 2(3.15A, 250VAC)
2) LED 1 Keep light representative normal, if keep flash interval representative trouble Alarm
3) RV1, RV2, RV3 Varistor

Printed circuit board connector wiring diagram
12 Domestic air conditioner
PCB (1)

CN6
CN7 CN1 CN2 CN25 CN28CN23 CN24
CN9 CN10 CN36
CN3
CN11 CN15 CN47 CN17 CN22

Printed circuit board connector wiring diagram
13 Domestic air conditioner
PCB(2)
CN4 CN3 CN10
CN6
CN5
CN8
CN11
CN9
CN7
CN1 CN2

Functions and control
13 Domestic air conditioner
Wiring diagrams
INDOOR UNIT
0010534175
AC-N OUT
CN9
CN10
AC-L OUT
CN11
4-WAY VALVE
M
CN22
CN15
VALVE A
CN3
PE
POWER
BL(OR W)
Y/G
CN36
COMB
COMA
N
R
CN1
CN2
AC-N
AC-L
FUSE1
T25A 250VAC
CN24
CN23
MODULE COM
MODULE POWER
TO INDOOR UNIT
CN3
CN10
B
BL
BL
OR
CN5
CN1 CN4
CN8 CN9
CN2
CN11
CN6 CN7
REACTOR
B
M
R(U)
S(V)
C(W)
BWR
DC FAN
OUTDOOR PCB
MOUDLE PCB
ELECTRIC
EXPANSION
Y/G
Y/G
123(C)
BL(OR W)
BL
UVWP N
AC-L
LI AC-N L0
CN25
N
P
CN28
2
1
GR GR
BR(OR B)
CAP
M
VALVE MOTOR
WARNING
CAUTION
OUTDOOR UNIT WIRING DIAGRAM
CAP
COMPRESSOR
DON'T TOUCH CAPACITOR, EVEN AFTER PLUG-OFF ( DANGER OF ELECTRIC SHOCK)!
CN7
CN6
AC-N OUT
AC-L OUT BR(OR B)
BL(OR W)
BL(OR W)
BR(OR B)
Note:The dotted parts are optional.
The@1andthe@2cannotexistatthetime,
but must keep one of them.
B: Black W: White
R: Red Y/G: Yellow/Green
BR:Brown OR:Orange
BL: Blue GR:Gray
THE CAPACITOR RETAINS HIGH VOLTAGE EVEN AFTER THE PLUG-OFF. FOR YOUR
SAFETY, BE SURE TO WAIT AT LEAST 5 MINUTES.AFTER PLUG OFF AND USE A
TESTER TO CONFIRM THE VOLTAGE BETWEEN CONNECTOR CN25 AND CN28(ON
MAIN PCB BOARD) IS LESS THAN DC 10V BEFORE START SERVICING OR LED2
EXTINGUISHED.
CN50 DRED LINE
AMBIENT TEMP.SENSOR
DEFROST TEMP.SENSOR
COMP.TEMP.SENSOR
TC
CS
HW
CN17
CN18
CN19
@1
AMBIENT TEMP.SENSOR
TEMP.SENSOR
DEFROST
COMP.TEMP.SENSOR
CN17
HW
CS
TC
@2
XQ
CN47
TEMP.SENSOR
SUCTION
M
AC FAN
MOTOR
~
CN43
AC FAN

Functions and control
15 Domestic air conditioner
7. Functions and control
7.1 Main functions and control specification
7.1.1 The operation frequency of outdoor unit and its control
7.1.1.1 The operation frequency control of compressor
The operation frequency scope of compressor˖
Mode Minimum operation frequency Maximum operation frequency
Heating˄18K/24K˅24 Hz /20Hz 103 Hz /100Hz
Refrigeration˄18K/24K˅20 Hz /20Hz 85 Hz /85Hz
7.1.1.2 The starting of compressor
When the compressor is started for the first time, it must be kept under the conditions of
38Hz,58Hz,88Hz for 30second,one minute, one minute (the overheating protection of the outdoor unit
air-blowing temperature, immediately decrease the frequency when the compressor is overflowing and
releasing the pressure)ˈthen it can be operated towards the target frequency. When the machine runs
normally, there’s no such process. After starting the compressor for operation, the compressor should
run according to the calculated frequency, and every determined frequency for protection should be
prior to the calculated frequency.
7.1.1.3 The speeds of increasing or decreasing the frequency of the compressor
The speed of increasing or decreasing the frequency rapidly 1 -----------1HZ/second
The speed of increasing or decreasing the frequency slowly 2 -----------1HZ/10seconds
7.1.1.4 The calculation of the compressor’s frequency
Refrigeration/dehumidification mode:
Pn=(Nh_c- S_c)*10ı50 outdoor environment control
Pn=(Nh_c- S_c) *10˘50 PIDcontrol
Heating mode:
Pn=(S_c -Nh_c) *10ı60 outdoor environment control
Pn=(S_c -Nh_c) *10˘60 PIDcontrol
(Nh_c=indoor environment temperature S_c=setting temperature)
1˅The minimum/maximum frequency limitation
AˊWhile refrigerating: F-MAX-r is the maximum operation frequency of the compressor; F-MIN-r is the
minimum operation frequency of the compressor.
BˊWhile heating: F-MAX-d is the maximum operation frequency of the compressor; F-MIN-d is the
minimum operation frequency of the compressor.
2˅The frequency limitation which is affected by the environment temperature.
(Wh_c= environment temperature)
Heating mode:
Serial No. Temperature scope Frequency limitation˄18K/24K˅
1 Wh_c<-12 Max_hz1 103HZ/87 HZ
2 Wh_c<-8 Max_hz2 103HZ/87 HZ

Functions and control
16 Domestic air conditioner
3 Wh_c<-2 Max_hz3 103HZ/87 HZ
4 Wh_c<5 Max_hz4 90HZ/76 HZ
5 Wh_c<10 Max_hz5 78HZ/67 HZ
6 Wh_c<17 Max_hz6 67HZ/62 HZ
7 Wh_c<20 Max_hz7 56HZ/44 HZ
8Wh_c>˙20 Max_hz8 52HZ/39 HZ
Remarks: The above are the maximum frequency limitations of the complete appliance which are
affected by the environment, and they have nothing to do with the ability of the indoor unit.
Refrigeration/dehumidification mode:
Serial No. Temperature scope Frequency limitation˄18K/24K˅
1 Wh_c<16 Max_hz1 33HZ/30HZ
2 Wh_c<22 Max_hz2 43HZ/35 HZ
3 Wh_c<29 Max_hz3 55HZ/51 HZ
4 Wh_c<32 Max_hz4 63HZ/62 HZ
5 Wh_c<40 Max_hz5 75HZ/75 HZ
6 Wh_c<48 Max_hz6 63HZ/66 HZ
7 Wh_c>=48 Max_hz7 53HZ/49 HZ
Remarks: the above are not only the maximum frequency limitations of the complete appliance
which are affected by the environment, but also the maximum ability limitation of the system. When the
starting ability is not the maximum, its maximum frequency limitation is calculated by the following
equations:
The frequency limitation which is affected by the temperature and under the condition of actual
ability˙the actual running system ability*the maximum frequency which is limited by the temperature
and under the condition of maximum ability/the maximum designing ability of the system
Refrigeration/dehumidification mode:
Heating mode:
The calculation of the actual output frequency:
F= F-ED-*(rated frequency)hK
F-ED-*(rated frequency)= The frequency which is limited by the outdoor environment temperature
Notes:
The indoor setting
airflow speed Low Medium Quiet
The percentage of the
rated frequency K
(18K/24K)
70%/700% 85%/85% 42%/60%
The indoor setting
airflow speed Low Medium Quiet
The percentage of the
rated frequency K
(18K/24K)
80%/80% 90%/90% 51%/60%

Functions and control
17 Domestic air conditioner
When refrigerating, it is needed to satisfy
F-MIN-d(compressor’s Min_hz)< F<F-MAX-d(compressor’s Max_hz)
When heating, it is needed to satisfy
F-MIN-r (compressor’s Min_hz)< F<F-MAX-r (compressor’s Max_hz)
PID control :
The innital frequency Sn is determined by Pn . We can calculate Hzoutf according to the value of Kp ,Ki ,Kd,
Out_gain,Pn.Then , Fn = Sn + Hzoutf. The value of Fn is calculated in each sample time (60 seconds),and Fn is
adujusted according to previous frequency of Sn and filtered output of Hzoutf.
7.1.2 The outdoor fan control (Exchange fan)
When the fan is changed among every airflow speed (including stop blowing), in order to avoid the
airflow speed from skipping frequently, it must be kept under each mode for over 30 seconds, and then
it can be changed to another mode (when refrigerating, the time is changed to 15 seconds).
7.1.2.1 The outdoor fan control
Within three minutes of compressor starting, the compressor is controled according to the ambient temperature.
Tao˄ć˅ Tao <22ć22ć< Tao <28ćTaoı29ć
Refrigeration/dehumidification
(18K/24K)
2ndlevel /2ndlevel 3rdlevel /4thlevel 5thlevel /6thlevel
Tao˄ć˅ Tao <<10ć10ć< Tao <17ćTao ı17ć
Heating 5th level /6thlevel 3th level /5thlevel 3rdlevel /2ndlevel
After 3 minutes, the compressor is controled according to the ambient temperature and the frequency of the
compressor.
Refrigeration/dehumidification
frequency˄Hz˅18K˄24K)
<40 Hz 40 Hz-60 Hz ı60 Hz
Tao˄ć˅
İ22 2nd level 3rd level 5 th level(6 th)
22-28 3rd level 5 th level 7 th level(6 th)
ı28 7 th level
Heating frequency˄Hz˅
(18K/24K)
<51 Hz 51-70 Hz ı70 Hz
Tao˄ć˅
İ10 5nd level(3rd) 6rd level 7 th level
10-17 3rd level(2nd) 4 th level 5 th level(6 th)
ı17 2nd level
7.1.3 The control of the outdoor Electronic expansion valve (EEV)
In cooling mode, the EEV opening range is 90~480 steps. The EEV opening is 90 steps when unit is
off.
In heating mode, the EEV opening range is 60~480 steps. The EEV opening is 60 steps when unit is
off.
After outdoor unit is off, the EEV opening keep the current on for 5 s, then open the EEV completely for
2 minutes, then become 90 steps (cooling) or 60 steps (heating).

Functions and control
18 Domestic air conditioner
The EEV opening will increase if SH (superheat degree) >0 while decrease if SH<0.
Adjust frequency:
If |SH|=0, 60s/ 1 step
If |SH|ı3,and ƸSH=0, 10s/ 1 step.
If 3ı|SH|ı0, 30s/ 1 step.
ƸSH= current SH- last SH
SH= Ts (suction temp)-Tc1 (indoor coil temp)-Tsh (fixed data, depend on different models, -1~2)
7.1.4 Four way control
For the details of defrosting four-way valve control, see the defrosting process.
Four way working in other ways:
Under the mode of heating, open the four-way valve, when the compressor is not started or
changed to non-heating mode, make sure the compressor is stoped for 2 minutes, and then close the
four-way valve.
7.1.5 Protection function
7.1.5.1 TTC high temperature-preventing protection
Once the machine is started, it can run TTC(air-blowing temp) overheating protection of
air-blowing, but air-blowing sensor malfunction must alarm after 4 minutes during which the
compressor is started (during the course of self-detection, there’s no such limitation)
Sensor detection methods: 100 times (one cycle of procedure run is one time, and about 5ms,
detection method for each time: continuously sampling for 8 times, then order them and take the mean
value of the middle 2 values), take the mean value.
TTC˄ć˅
18K˄24K˅Abnormal stop
110˄110˅
Decreasing the frequency rapidly˄1HZ/second˅
107(105)
Decreasing the frequency slowly (1HZ/10seconds)
102(100)
The frequency doesn’t change.
98(98)
Increasing the frequency (1HZ/10second)
93(93)
Increasing the frequency˄1HZ/1second˅
TTC>=110ćlasts for 20 seconds. Overheating protection of air-blowing, alarm malfunction to the
indoor, others don’t last.
7.1.5.2 TC high temperature-preventing control of the indoor heating unit˖
Tpg_indoor is the highest value of the effective indoor unit (start it and it is in accord with the
running state). TC=indoor coil temp.
The indoor heat exchanger sensor tests the temperature of the indoor heat exchanger. If the
temperature is higher than 63ć, decrease the rotate speed of the compressor and do the high
temperature-preventing protection of the indoor heat exchanger; if the temperature of the indoor heat
exchanger is lower than 45ć, recover to the normal control.