Fault diagnostic apparatus for electric appliance

A fault diagnostic apparatus for a device subject to a plurality of predetermined fault conditions. The apparatus includes a fault detector for automatically detecting the occurrence of any of the plurality of fault conditions and an indicating circuit for indicating the occurence of only specific one of the plurality of fault conditions manually designated by an operator.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a fault diagnostic apparatus and, more 
particularly, to a fault diagnostic apparatus for an electric appliance 
such as an air conditioning system. 
2. Description of the Prior Art 
A presently known heat pump type air conditioning system has the ability to 
determine when the air conditioning system is operating improperly and has 
provisions for indicating to the owner of the system when service is 
required and also for indicating to the serviceman the general nature of 
the fault or faults involved in the improper operation. 
Such a fault diagnostic apparatus for a serviceman is disclosed, for 
example, in U.S. Pat. No. 4,381,549. The fault diagnostic apparatus of 
this patent can indicate a plurality of fault items in a fixed specified 
order in a fault diagnostic operation mode. The fault items are displayed 
by code numbers corresponding to each possible fault item on a light 
emitting diode (LED) matrix display for visual readout of information 
data. The fault diagnostic apparatus of the patent, however, has a 
drawback in that a plurality of LEDs is required for the LED matrix 
display. The fault diagnostic apparatus of this patent also has another 
drawback in that the serviceman cannot immediately inquire about specific 
fault item, or examine the fault items in any desired order. Further, the 
fault diagnostic apparatus of this patent has an important drawback in 
that the serviceman easily may misread the code number because many 
numbers are displayed for short intervals. 
SUMMARY OF THE INVENTION 
Accordingly, an object of the present invention is to provide a fault 
diagnostic apparatus for an air conditioning system which has an indicator 
with a more simple construction. 
Another object of the present invention is to provide a fault diagnostic 
apparatus for an air conditioning system in which the serviceman can 
immediately examine for the occurence of a specific fault item. 
A further object of the present invention is to provide a fault diagnostic 
apparatus for an air conditioning system in which the serviceman can 
examine a plurality of fault items in any desired order. 
In order to achieve the above objects, the fault diagnostic apparatus for 
air conditioning system according to the present invention includes a 
fault detector for automatically detecting the occurence of any of the 
plurality of fault conditions and an indicating circuit for indicating, in 
response to an inquiry about a specific potential fault condition. 
Manually designated by the operator, whether that fault condition exists.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will be described in detail with reference to the 
accompanying drawings, namely, FIGS. 1 to 9. Throughout the drawings, like 
reference numerals and letters are used to designate like or equivalent 
elements for the sake of simplicity of explanation. 
Referring now to FIG. 1, a typical air conditioning system will be briefly 
described. The air conditioning system of FIG. 1 comprises an outdoor unit 
100, an indoor unit 102, a pair of refrigerant pipes 104 and 106 and a 
cable 108 for signal and power transmissions between the indoor unit 102 
and the outdoor unit 100. The outdoor unit 100 includes a compressor 110, 
an outdoor unit heat exchanger 112, a fluid change over switch 114 and an 
outdoor unit fan 116. The indoor unit 102 includes an indoor unit heat 
exchanger 118 and an indoor unit fan 120. The indoor unit heat exchanger 
118 is coupled to the compressor 110 and the outdoor unit heat exchanger 
112 of the outdoor unit 100 through the pair of refrigerant pipes 104 and 
106 so that a refrigerant circulates through the compressor 110, the 
outdoor unit heat exchanger 112 and the indoor unit heat exchanger 118. 
The fluid change-over switch 114 changes directions of the refrigerant 
compressed by the compressor 110 to the outdoor unit heat exchanger 112 or 
the indoor unit heat exchanger 118 in accordance with a cooling operation 
or a heating operation. In the heating operation, the compressed 
refrigerant flows into the indoor unit heat exchanger 118 of the indoor 
unit 102 through the fluid change-over switch 114 and condenses therein. 
The condensed refrigerant is transmitted into the outdoor unit heat 
exchanger 112 of the outdoor unit 100 and evaporates therein. In the 
cooling operation, the compressed refrigerant flows into the outdoor unit 
heat exchanger 112 of the outdoor unit 100 through the fluid change-over 
switch 114 and condenses therein. The condensed refrigerant is transmitted 
into the indoor unit heat exchanger 118 of the indoor unit 102 and 
evaporates therein. The evaporated refrigerant returns into the compressor 
110 and is compressed therein. The compressor 110 is driven by an inverter 
type motor 122 while the outdoor unit fan 116 and the indoor unit fan 120 
promote the evaporation or the condensation of the refrigerant in the 
indoor unit heat exchanger 118 and outdoor unit heat exchanger 112. 
The operation of the air conditioning system is controlled by a remote 
controller, as described later. The controller wirelessly transmits 
command data to an indoor unit control circuit 124 in the indoor unit 102. 
The indoor unit control circuit 124 directly controls the indoor unit fan 
120 in response to the command data and also transmits the command data to 
an outdoor unit control circuit 126 in the outdoor unit 100. The outdoor 
unit control circuit 126 controls the outdoor unit fan 116 and the 
inverter type motor 122 in response to the command data. 
The indoor unit control circuit 124 and the outdoor unit control circuit 
126 are connected to a plurality of detectors for detecting faults or 
sensors for receiving control signals therefrom. The indoor unit control 
circuit 124, for example, is connected to an indoor unit fan fault 
detector 128 for the indoor unit fan 120, an atmospheric temperature 
sensor 130 for an indoor environment, a humidity sensor 132 for the indoor 
environment, a heat exchanger temperature sensor 134 for the indoor unit 
heat exchanger 118 and a voltage sensor 136 for a power supply source. The 
outdoor unit control circuit 126, for example, is connected to an outdoor 
unit fan fault detector 138 for the outdoor unit fan 116, a temperature 
sensor 140 for the compressed refrigerant and a current sensor 142 for the 
power supply source. One of the control circuit, e.g., the indoor unit 
control circuit 124 has a function to detect a miscoupling of the cable 
108 to the outdoor unit 100 or indoor unit 102. The indoor unit control 
circuit 124 or the outdoor unit control circuit 126 discriminates the 
miscoupling of the cable 108 by examining whether the indoor unit control 
circuit 124 or the outdoor unit control circuit 126 fails to transmit a 
predetermined signal. 
Referring now to FIG. 2, a first embodiment of the fault diagnostic 
apparatus for the air conditioning system will be described. The first 
embodiment of the fault diagnostic apparatus comprises the indoor unit 
control circuit 124, the outdoor unit control circuit 126 and the wireless 
remote controller now designated with a reference 144. 
The wireless remote controller 144 is the primary manual input device that 
interfaces with the user and includes various desired input keys, and 
associated logic circuits for manual entry of user-selected control data 
to the air conditioning system. The wireless remote controller 144 
includes a code generator 146 for generating identification codes 
specified to fault items and converting them to corresponding code 
signals, a code signal transmission circuit 148 for wirelessly 
transmitting the identification code signals and a transmission start 
button 150 for the code signal transmission circuit 148. The 
identification codes are previously stored in memories, e.g., ROMs (read 
only memory) provided in the code generator 146. The code generator 146 is 
activated by a fault diagnostic mode switch (not shown) which is located, 
for example, at a hidden part of an enclosure of the wireless remote 
controller 144 and is intended to be accessed by the serviceman. The code 
generator 146 reads out a suitable identification code in accordance with 
operations of the input keys and converts it to the corresponding code 
signal. The identification code signal is wirelessly transmitted from the 
code signal transmission circuit 148 when the transmission start button 
150 is operated by the serviceman. The code generator 146 and the code 
signal transmission circuit 148 may constitute a microprocessor. Table I 
below shows examples of fault items and corresponding identification codes 
stored in the ROMs of the code generator 146. 
TABLE I 
______________________________________ 
Identification 
code Fault Item 
______________________________________ 
00 Miscoupling of Cable 
01 Fault in Indoor Unit Fan 
02 Abnormal State of 
Atmospheric Temperature 
03 Overflow of Drain Water 
04 Overcurrent in Power 
Supply System 
______________________________________ 
The above explanation will be applied to remote controllers of other 
embodiments as described later. 
The indoor unit 102 has a code signal receiving circuit 152, the indoor 
unit control circuit 124, an indoor unit fan control circuit 154, the 
indoor unit fan fault detector 128, the atmospheric temperature sensor 
130, the humidity sensor 132, a drain water overflow sensor 156, the 
voltage sensor 136, an indicator lamp control circuit 158, an indicator 
lamp 160, which is used with a lamp such as an operating state indicator 
lamp, and an indoor unit receiver/transmitter circuit 162. The code signal 
receiving circuit 152 receives the identification code signal transmitted 
from the wireless remote controller 144. The indoor unit control circuit 
124 examines a signal obtained in a suitable detector or sensor in the 
indoor unit 102 in response to the corresponding identification code 
signal applied from the code signal receiving circuit 152. The indoor unit 
control circuit 124 also transmits identification code signal to the 
outdoor unit 100 through the cable 108. The indoor unit control circuit 
124 drives the indicator lamp control circuit 158 when the selected 
detector on the outdoor unit 102 detects a fault. 
The outdoor unit 100 includes an outdoor unit receiver/transmitter circuit 
164, the outdoor unit control circuit 126, an outdoor unit fan control 
circuit 166, the outdoor fan fault detector 138, an inverter type motor 
drive circuit 168, the current sensor 142 and the refrigerant temperature 
sensor 140. The outdoor unit receiver/transmitter circuit 164 receives the 
identification code signal transmitted from the indoor unit 
receiver/transmitter circuit 162 in the indoor unit 102. The outdoor unit 
control circuit 126 examines a signal obtained in a suitable detector or 
sensor in the outdoor unit 100 in response to the corresponding 
identification code signal applied from the outdoor unit 
receiver/transmitter circuit 164. The outdoor unit control circuit 126 
also drives the indicator lamp control circuit 158 of the indoor unit 102 
through the indoor unit control circuit 124 in response to when the 
selected detector detects a fault. 
The indoor unit control circuit 124 and/or the outdoor unit control circuit 
126 further have the function to examine the miscoupling condition of the 
cable 108 by itself, as described above. 
Referring now to FIG. 3, an operation flow chart is shown for the fault 
diagnostic routine of the first embodiment of the present invention. In 
the flow chart, diamond shaped boxes represent program inquiries, while 
rectangular shaped boxes represent program instructions. This is the same 
as operation flow charts of other embodiments described later. 
The routine starts when the serviceman operates the fault diagnostic mode 
switch of the wireless remote controller 144. The code generator 146 then 
reads out any one of the identification codes stored in the memories in 
STEP 1. However, the identification code is easily able to be replaced by 
a desired one by operating a suitable key, e.g., an UP key or a DOWN key 
of the input keys. A code signal corresponding to the desired 
identification code is transmitted to the indoor unit control circuit 124 
of the indoor unit 102. The routine forwards to a suitable flow branch in 
response to the identification code, in STEP 2. The code signals 
corresponding to the identification codes "00", "01" and "02" are 
processed in the indoor unit control circuit 124 of the indoor unit 102, 
while the code signals corresponding to the identification codes "03", 
"04" and others are processed in the outdoor unit control circuit 126 of 
the outdoor unit 100. 
When the identification code "00" is designated in the code generator 146 
of the wireless remote controller 144, the indoor unit control circuit 124 
examines whether signals transmitted through the cable 108 agree with 
expected signals or not, in STEP 2 of a "00"-branch. Thus, the miscoupling 
condition of the cable 108 to the outdoor unit 100 and indoor unit 102 is 
examined. In accordance with the detection of the cable miscoupling 
condition, the indoor unit control circuit 124 drives the indicator lamp 
control circuit 158 so that the indicator lamp 160 connected to the 
indicator lamp control circuit 158 flickers, in STEP 3a of the "00" 
branch. When the indoor unit control circuit 124 does not detect a 
miscoupling condition of the cable 108, the indicator lamp 160 goes out, 
in STEP 3b of the "00" branch. The indicator lamp 160 is able to be 
provided only for indicating the result of the fault diagnostic, or the 
indicator lamp 160 also may be used as a lamp for indicating the operating 
state of the air conditioning system. The operating state indicator lamp 
160 is mounted on a front panel of the indoor unit 102, as shown in FIG. 
4. When the identification code "01" is designated in the code generator 
146 of the wireless remote controller 144, the indoor unit control circuit 
124 performs an inspection for a detection signal from the indoor unit fan 
fault detector 128, in STEP 2 of a "01"-branch. When the indoor unit fan 
fault detector 128 detects some fault of the indoor unit fan 120, the 
indoor unit control circuit 124 drives the indicator lamp control circuit 
158 so that the indicator lamp 160 flickers, in STEP 3a of the 
"01"-branch. When the indoor unit fan fault detector 128 does not detect 
any fault of the indoor unit fan 120, the indoor unit control circuit 124 
drives the indicator lamp control circuit 158 so that the indicator lamp 
160 goes out, in STEP 3b of the "01"-branch. When the identification code 
"02" is designated in the code generator 146 of the wireless remote 
controller 144, the indoor unit control circuit 124 performs an inspection 
on a detection signal from the atmospheric temperature sensor 130, in STEP 
2 of a "02"-branch. When the detection signal of the atmospheric 
temperature sensor 130 is out of a predetermined level range, the indoor 
unit control circuit 124 drives the indicator lamp control circuit 158 so 
that the indicator lamp 160 flickers, in STEP 3a of the "02"-branch. When 
the detection signal of the atmospheric temperature sensor 130 is in the 
predetermined level range, the indoor unit control circuit 124 drives the 
indicator lamp control circuit 158 so that the indicator lamp 160 goes 
out, in STEP 3b of the "02"-branch. When the identification code "03" is 
designated in the code generator 146 of the wireless remote controller 
144, the indoor unit control circuit 124 performs an inspection on a 
detection signal from the drain water overflow sensor 156, in STEP 2 of a 
"03"-branch. When the drain water overflow sensor 156 detects an overflow 
of drain water in the indoor unit 102, the indoor unit control circuit 124 
drives the indicator lamp control circuit 158 so that the indicator lamp 
160 flickers, in STEP 3a of the "03"-branch. When the drain water overflow 
sensor 156 does not detect an overflow of drain water, the indoor unit 
control circuit 124 drives the indicator lamp control circuit 158 so that 
the indicator lamp 160 goes out, in STEP 3b of the "03"-branch. 
When the identification code "04" is designated in the code generator 146 
of the wireless remote controller 144, the indoor unit control circuit 124 
or the outdoor unit control circuit 126 performs an inspection for a 
detection signal from the current sensor 142, in STEP 2 of a "04"-branch. 
When the detection signal of the current sensor 142 is out of a 
predetermined amount range, the indoor unit control circuit 124 drives the 
indicator lamp control circuit 158 so that the indicator lamp 160 
flickers, in STEP 3a of the "04"-branch. When the detection signal of the 
current sensor 142 is in the predetermined amount range, the indoor unit 
control circuit 124 drives the indicator lamp control circuit 158 so that 
the indicator lamp 160 goes out, in STEP 3b of the "04"-branch. 
The same or equivalent routines are also performed for inspections on 
detected signals of the humidity sensor 132, the voltage sensor 136 and 
the refrigerant temperature sensor 140. 
The first embodiment of the fault diagnostic apparatus is able to be 
modified as follows. In the modification, some identification codes are 
designated for a plurality of fault items, e.g., two fault items, as shown 
in Table II in below. 
TABLE II 
______________________________________ 
Identification 
Fault Item Fault Item 
code for Lamp 170a 
for Lamp 170b 
______________________________________ 
00 Miscoupling of 
Overflow of Drain 
Cable Water 
01 Fault in Indoor 
Overcurrent in 
Unit Fan Power Supply System 
02 Abnormal State 
of Atmospheric 
Temperature 
______________________________________ 
In the modification according to the Table II, the indoor unit control 
circuit 124 simultaneously or continuously performs two inspection 
routines in response to the designation of one identification code to the 
code generator 146 of the wireless remote controller 144. When one routine 
detects a fault, the indoor unit control circuit 124 drives the indicator 
lamp control circuit 158 so that one operation mode indicator lamp 170a, 
e.g., a heating mode indicator lamp connected to the indicator lamp 
control circuit 158 flickers. When the other routine detects a fault, the 
indoor unit control circuit 124 drives the indicator lamp control circuit 
158 so that another operation mode indicator lamp 170b, e.g., a cooling 
mode indicator lamp connected to the indicator lamp control circuit 158 
flickers. Therefore, the serviceman is easily able to discriminate between 
the fault items. The heating mode indicator lamp 170a and the cooling mode 
indicator lamp 170b also are mounted on a front panel of the indoor unit 
indoor unit 102, as shown in FIG. 4. 
Referring now to FIG. 5, a second embodiment of the fault diagnostic 
apparatus for the air conditioning system will be described. The second 
embodiment of the fault diagnostic apparatus comprises the indoor unit 
control circuit 124 and the wireless remote controller 144. The wireless 
remote controller 144 has a construction the same or similar to the 
controller in the first embodiment. Therefore, the identification code 
signal is transmitted from the code signal transmission circuit 148 when 
the transmission start button 150 is operated by the serviceman. 
The indoor unit control circuit 124 includes a code signal receiving 
circuit 152, a code discriminating section 172, an indoor unit bloc fault 
discriminating section 174, an outdoor unit bloc fault discriminating 
section 176, a cable bloc fault discriminating section 178, a whole bloc 
fault discriminating section 180, an indication selecting section 
indicator lamp control circuit 158a and an indication switching section 
indicator lamp control circuit 158b. The indoor unit bloc fault 
discriminating section 174 receives detection signals outputted from the 
indoor unit fan fault detector 128, the atmospheric temperature sensor 
130, the humidity sensor 132, etc. in the indoor unit 102. The outdoor 
unit bloc fault discriminating section 176 receives detection signals 
outputted from the outdoor unit fan fault detector 138, the current sensor 
142 and the refrigerant temperature sensor 140 in the outdoor unit 100. 
The detection signals of the outdoor unit fan fault detector 138, the 
current sensor 142 and the refrigerant temperature sensor 140 in the 
outdoor unit 100 are transmitted from the outdoor unit 100 to the indoor 
unit 102 through a cable 108 (see FIG. 1). The cable bloc fault 
discriminating section 178 receives detection signals outputted from cable 
miscoupling detectors 182, 184 and 186. The cable miscoupling detectors 
182, 184 and 186 can be formed by a software system in the indoor unit 
control circuit 124 in which the software system performs a function to 
detect miscoupling conditions of signal wirings or power supply wirings in 
the cable 108 to the outdoor unit 100 or the indoor unit 102. That is, the 
indoor unit control circuit 124 detects the miscoupling conditions of the 
signal wirings or the power supply wirings in the cable 108 by examining 
whether the indoor unit control circuit 124 fails to transmit a 
predetermined signal between the outdoor unit 100 and the indoor unit 102. 
All of the detection signals are further applied to the indication 
selecting section indicator lamp control circuit 158a. 
The indoor unit bloc fault discriminating section 174 supplies a first unit 
bloc fault discrimination signal S1 to a first indicator lamp. The first 
indicator lamp also can be used with the heating mode indicator lamp 170a 
(see FIG. 4). The outdoor unit bloc fault discriminating section 176 
supplies a second unit bloc fault discrimination signal S2 to a second 
indicator lamp, when any one of the indoor unit fan fault detector 128, 
the atmospheric temperature sensor 130, the humidity sensor 132, etc. 
detects a fault condition corresponding to the detector or the sensor. The 
second indicator lamp also can be used with the cooling mode indicator 
lamp 170b (see FIG. 4). The cable bloc fault discriminating section 178 
supplies a third unit bloc fault discrimination signal S3 to a third 
indicator lamp, when any one of the cable miscoupling detectors 182, 184 
and 186 detects a fault condition corresponding to the specified detector 
51, 52 or 53. The third indicator lamp can be used with a drying mode 
indicator lamp 170c. The drying mode indicator lamp 170c is mounted on the 
front panel of the indoor unit indoor unit 102 together with the heating 
mode indicator lamp 170a and the cooling mode indicator lamp 170b (see 
FIG. 4). 
The unit bloc fault discrimination signals S1, S2 and S3 are further 
applied to a whole bloc fault discriminating section 180. The whole bloc 
fault discriminating section 180 supplies a whole bloc fault 
discrimination signal S4 to the indicator lamp control circuit 158b, when 
any one of the indoor unit bloc fault discriminating section 174, the 
outdoor unit bloc fault discriminating section 176 and the cable bloc 
fault discriminating section 178 outputs the unit bloc fault 
discrimination signal S1, S2 or S3. The indicator lamp control circuit 
158b further receives output signals of the indicator lamp control circuit 
158a and the code discriminating section 172. An output signal of the 
indicator lamp control circuit 158b is applied to a fourth indicator lamp 
160. The fourth indicator lamp 160 can be used with an operating state 
indicator lamp 160, as described before in the first embodiment. 
Referring now to FIG. 6, an operation flow chart is shown for the fault 
diagnostic routine of the indoor unit control circuit 124 of the second 
embodiment according to the present invention. 
In the routine, the indoor unit bloc fault discriminating section 174, the 
outdoor unit bloc fault discriminating section 176 or the cable bloc fault 
discriminating section 178 discriminates whether any fault detection 
signal is outputted from the detectors or signals outputted from the 
sensors are out of a predetermined range, in STEP 1. The indoor unit bloc 
fault discriminating section 174 outputs a first bloc fault discrimination 
signal S1 and supplies the first bloc fault discrimination signal S1 to 
the heating mode indicator lamp 170a, in STEP 2. Similarly, the outdoor 
unit bloc fault discriminating section 176 outputs a second bloc fault 
discrimination signal S2 and applies the second bloc fault discrimination 
signal S2 to the cooling mode indicator lamp 170b. Also, the cable bloc 
fault discriminating section 178 outputs a third bloc fault discrimination 
signal S3 and applies the third bloc fault discrimination signal S3 to the 
drying mode indicator lamp 170c. The bloc fault discrimination signals S1, 
S2 and S3 are further applied to the whole bloc fault discriminating 
section 180. The whole bloc fault discriminating section 180 then outputs 
a whole bloc fault discrimination signal S4 and applies the whole bloc 
fault discrimination signal S4 to the indicator lamp control circuit 158b. 
The indicator lamp control circuit 158b drives the operation state 
indicator lamp 160 so that the operation state indicator lamp 160 
flickers. 
Therefore, the user of the air conditioning system can know that any fault 
has happened in the system from the flickering of the operation state 
indicator lamp 160 or the flickerings of the operation state indicator 
lamp 160 and any lamp of the heating mode indicator lamp 170a, the cooling 
mode indicator lamp 170b and the drying mode indicator lamp 170c, and can 
make a phone call to the serviceman for services. In the phone call, the 
serviceman can obtain from the user information about which lamp or lamps 
of the heating mode indicator lamp 170a, the cooling mode indicator lamp 
170b and the drying mode indicator lamp 170c are flickering. The heating 
mode indicator lamp 170a, the cooling mode indicator lamp 170b and the 
drying mode indicator lamp 170c typically have letter indications, e.g., 
of "HEATING", "COOLING" and "DRYING", respectively. The serviceman can 
determine what bloc or unit has a fault according to the information of 
the letter indications through the phone call. Thus, the serviceman can 
bring service parts necessary for the unit. 
A service or a diagnostic routine for the air conditioning system starts 
when the serviceman operates the fault diagnostic mode switch of the 
wireless remote controller 144 (see FIG. 2). At the start of the routine, 
the serviceman can immediately input identification codes corresponding to 
the fault items of the faulted unit, in response to the flickering lamp of 
the heating mode indicator lamp 170a, the cooling mode indicator lamp 170b 
and the drying mode indicator lamp 170c, in STEP 3 of FIG. 6. That is, the 
serviceman can neglect inspections for other blocs or units to which 
corresponding indicator lamps fail to indicate fault conditions. The code 
generator 146 then reads out any one of the identification codes stored in 
the memories in STEP 3. However, the identification code is easily able to 
be replaced by a desired one of the identification codes corresponding to 
the fault items of the faulted unit by operating a suitable key, e.g., an 
UP key or a DOWN key of the input keys. An identification code "00" is 
designated when the drying mode indicator lamp 170c has flickered in STEP 
2. Identification codes "01", "02" and "03" are designated when the 
heating mode indicator lamp 170a has flickered in STEP 2. Identification 
codes "04" and others are designated when the heating mode indicator lamp 
170b has flickered in STEP 2. 
A code signal corresponding to the desired identification code is 
transmitted to the code signal receiving circuit 152 of the indoor unit 
control circuit 124. The routine forwards to a suitable flow branch in 
response to the identification code, in STEP 4. The code signals 
corresponding to the identification codes "00", "01", "03" and "03" are 
directly processed in the indoor unit control circuit 124 of the indoor 
unit 102, while the code signals corresponding to the identification codes 
"04" and others are transmitted from the outdoor unit 100 through the 
outdoor unit control circuit 126 and the cable 108 (see FIG. 2) and 
processed in the indoor unit control circuit 124. When the identification 
code "00" is designated in the code generator 146 of the wireless remote 
controller 144 for the inspection of any miscoupling of the cable 108, the 
indoor unit control circuit 124 examines whether signals transmitted 
through the cable 108 agree with expected signals or not, in STEP 4 of a 
"00"-branch. Thus, the miscoupling condition of the cable 108 to the 
outdoor unit 100 and indoor unit 102 is examined. In accordance with the 
detection of the cable miscoupling condition, the indication selection 
section 158a and the indication switching section 158b in the indoor unit 
control circuit 124 drive the indicator lamp 160 connected to the 
indication switching section 158b so that the indicator lamp 160 flickers, 
in STEP 5a of the "00" branch. When the indoor unit control circuit 124 
fails to detect the miscoupling condition of the cable 108, the indicator 
lamp 160 goes out, in STEP 5b of the "00" branch. The indicator lamp 160 
is able to be provided only for indicating the result of the fault 
diagnostic, or the indicator lamp 160 also may be used as a lamp for 
indicating the operating state of the air conditioning system. The 
operating state indicator lamp 160 is mounted on a front panel of the 
indoor unit 102, as shown in FIG. 4. 
When any one of the identification codes "01" and etc. is designated in the 
code generator 146 of the wireless remote controller 144, the indoor unit 
control circuit 124 performs an inspection for the indoor unit 102. For 
example, when the identification code "01" is designated, the indoor unit 
control circuit 124 performs an inspection for the indoor unit fan fault 
detector 128, in STEP 4 of a "01"-branch. When the indoor unit fan fault 
detector 128 detects some fault of the indoor unit fan 120, the indoor 
unit control circuit 124 drives the indicator lamp control circuit 158 so 
that the indicator lamp 160 flickers, in STEP 5a of the "01"-branch. While 
the indoor unit fan fault detector 128 fails to detect any fault of the 
indoor unit fan 120, the indication selection section 158a and the 
indication switching section 158b in the indoor unit control circuit 124 
drive the indicator lamp 160 so that the indicator lamp 160 goes out, in 
STEP 5b of the "01"-branch. The same or equivalent routines can be also 
performed for the inspection of the detected signals of the atmospheric 
temperature sensor 130, the humidity sensor 132, the voltage sensor 136 
and the drain water overflow sensor 156. 
When any one of the identification codes "04" and others is designated in 
the code generator 146 of the wireless remote controller 144, the indoor 
unit control circuit 124 performs an inspection for the outdoor unit 100. 
For example, when the identification code "04" is designated, the indoor 
unit control circuit 124 performs an inspection for the current sensor 
142, in STEP 4 of a "04"-branch. When the detection signal of the current 
sensor 142 is out of a predetermined amount range, the indication 
selection section 158a and the indication switching section 158b in the 
indoor unit control circuit 124 drive the indicator lamp 160 so that the 
indicator lamp 160 goes out, in STEP 5b of the "04"-branch. The same or 
equivalent routines can be also performed for the inspection of the 
detected signals of the outdoor unit fan fault detector 138 and the 
refrigerant temperature sensor 140. 
In operations of the the above diagnostic routines, the code signal 
receiving circuit 152 of the indoor unit control circuit 124 receives the 
identification code signal transmitted from the wireless remote controller 
144. The code discriminating section 172 discriminates the identification 
code from the code signal and provides the code to the indicator lamp 
control circuit 158a. The code signal further is applied to the indicator 
lamp control circuit 158b so that the indicator lamp control circuit 158b 
is changed to the fault diagnostic operation mode. In the fault diagnostic 
operation mode, the indicator lamp control circuit 158b first turns off 
the operation state indicator lamp 160. The indicator lamp control circuit 
158a selects a suitable fault detector or sensor in response to the 
corresponding identification code. The indoor unit control circuit 124 
itself examines a signal obtained in the suitable detector or sensor. The 
indoor unit control circuit 124 drives the indicator lamp control circuit 
158a in response to whether the selected detector or sensor detects a 
fault. For example, when an identification code for inspecting the indoor 
unit fan 120 (see FIG. 1) is inputted and the indoor unit fan fault 
detector 128 detects a fault, the indicator lamp control circuit 158a 
drives the operation state indicator lamp 160 so that the operation state 
indicator lamp 160 again flickers, in STEP 5a. Accordingly, the serviceman 
easily can determine the faulted section, i.e., the indoor unit fan 120, 
according to the prescribed inputted identification code corresponding to 
the indoor unit fan 120. 
Referring now to FIG. 7, a third embodiment of the fault diagnostic 
apparatus for the air conditioning system will be described. The third 
embodiment of the fault diagnostic apparatus also comprises the indoor 
unit control circuit 124 and the wireless remote controller 144, in 
similar to the second embodiment. However, detected fault conditions are 
indicated by only one indicator lamp. The wireless remote controller 144 
also has a construction the same or similar to the controller in the first 
embodiment. Therefore, the identification code signal is transmitted from 
the code signal transmission circuit 148 when the transmission start 
button 150 is operated by the serviceman. 
The indoor unit control circuit 124 has a construction similar to the 
indoor unit control circuit 124 of the second embodiment. That is, the 
indoor unit control circuit 124 includes the code signal receiving circuit 
152, the code discriminating section 172, the indoor unit bloc fault 
discriminating section 174, the outdoor unit bloc fault discriminating 
section 176, the cable bloc fault discriminating section 178, the whole 
bloc fault discriminating section 180, the indicator lamp control circuit 
158a and the indicator lamp control circuit 158b. The indoor unit bloc 
fault discriminating section 174 receives detection signals outputted from 
the indoor unit fan fault detector 128, the atmospheric temperature sensor 
130, the humidity sensor 132, etc. in the indoor unit 102 and outputs a 
first unit bloc fault discrimination signal S1, when any one of the indoor 
unit fan fault detector 128, the atmospheric temperature sensor 130, the 
humidity sensor 132 etc. detects a fault condition. The outdoor unit bloc 
fault discriminating section 176 receives detection signals outputted from 
the outdoor unit fan fault detector 138, the current sensor 142 and the 
refrigerant temperature sensor 140 in the outdoor unit 100 and outputs a 
second unit bloc fault discrimination signal S2, when any one of the 
outdoor unit fan fault detector 138, the current sensor 142 and the 
refrigerant temperature sensor 140 detects a fault condition. The 
detection signals of the outdoor unit fan fault detector 138, the current 
sensor 142 and the refrigerant temperature sensor 140 in the outdoor unit 
100 are transmitted from the outdoor unit 100 to the indoor unit 102 
through a cable 108 (see FIG. 1). The cable bloc fault discriminating 
section 178 receives detection signals outputted from the cable 
miscoupling condition detectors 182, 184 and 186 and outputs a third unit 
bloc fault discrimination signal S3, when any one of the cable miscoupling 
condition detectors 182, 184 and 186 detects a fault condition. The cable 
miscoupling condition detectors 182, 184 and 186 also can be formed by 
software systems in the indoor unit control circuit 124 that performs a 
function to detect a miscoupling of the 14 to the outdoor unit 100 or the 
indoor unit 102, in similar to the second embodiment. 
The indoor unit bloc fault discriminating section 174, the outdoor unit 
bloc fault discriminating section 176 and the cable bloc fault 
discriminating section 178 supply the unit bloc fault discrimination 
signals S1, S2 and S3 to the indicator lamp control circuit 158a, 
respectively. The unit bloc fault discrimination signals are further 
applied to the whole bloc fault discriminating section 180. The whole bloc 
fault discriminating section 180 outputs a whole bloc fault discrimination 
signal S4 to the indicator lamp control circuit 158b, when any one of the 
indoor unit bloc fault discriminating section 174, the outdoor unit bloc 
fault discriminating section 176 and the cable bloc fault discriminating 
section 178 outputs the unit bloc fault discrimination signal S1, S2 or 
S3. The indicator lamp control circuit 158b further receives output 
signals of the indicator lamp control circuit 158a and the code 
discriminating section 172. An output signal of the indicator lamp control 
circuit 158b is applied to an indicator lamp 160, e.g., the operating 
state indicator lamp, as described in the first embodiment. 
Referring now to FIG. 8, an operation flow chart is shown for the fault 
diagnostic routine of the indoor unit control circuit 124 of the third 
embodiment according to the present invention. 
The routine starts when the serviceman operates the fault diagnostic mode 
switch of the wireless remote controller 144. The code generator 146 then 
reads out any one of the identification codes stored in the memories, in 
STEP 1. The identification code is easily able to be replaced by a desired 
one by operating a suitable key, e.g., an UP key or a DOWN key of the 
input keys. Bloc identification codes, e.g., codes "10", "20" and "30" are 
allotted to the indoor unit bloc fault discriminating section 174, the 
outdoor unit bloc fault discriminating section 176 and the cable bloc 
fault discriminating section 178, respectively. While a first group of 
individual identification codes "11", "12", "13" etc. are allotted to the 
indoor unit fan fault detector 128, the atmospheric temperature sensor 
130, the humidity sensor 132 etc., respectively. A second group of 
individual identification codes "21", "22", "23" etc. are allotted to the 
outdoor unit fan fault detector 138, the refrigerant temperature sensor 
140, the current sensor 142 etc., respectively. And a third group of 
individual identification codes "31", "32", "33" etc. are allotted to the 
cable miscoupling detectors 182, 184, 186 etc., respectively. 
A prescribed bloc code signal corresponding to the desired identification 
code for one of the bloc fault discriminating sections is transmitted to 
the indoor unit control circuit 124 of the indoor unit 102. The routine 
forwards to a suitable flow branch in response to the bloc identification 
code, in STEP 2. In STEP 2, the serviceman can inspect whether any fault 
condition presents in a predetermined unit, i.e., the indoor unit 102, the 
outdoor unit 100 or the coupling state of the cable 108, according to the 
bloc identification code "10", "20" or "30". If the operation state 
indicator lamp 160 flickers (STEP 3a) as described later, the serviceman 
can forward to the inspection for the individual detector or sensors in 
the unit corresponding to the bloc identification code. If the operation 
state indicator lamp 160 fails to flicker (STEP 3b), the serviceman can 
return to the other inspection for the other unit in STEP 2. In the 
operations in STEP 2, the indoor unit control circuit 124 inspects 
automatically whether a prescribed bloc fault discriminating section, 
e.g., the indoor unit bloc fault discriminating section 174 produces the 
unit bloc fault discrimination signal S1 in response to the corresponding 
bloc identification code "10". When the prescribed bloc fault 
discriminating section, e.g., the indoor unit bloc fault discriminating 
section 174 is generating the unit bloc fault discrimination signal S1 at 
the time that the corresponding bloc identification code "10" is applied 
to the indoor unit control circuit 124, the indicator lamp control circuit 
158b receives the unit bloc fault discrimination signal S1 through the 
indicator lamp control circuit 158a and drives the operation state 
indicator lamp 160 to flicker (STEP 3a). Thus, the serviceman can notice 
that there occures some fault in the prescribed unit, e.g., the indoor 
unit 102. Then the serviceman forwards to the inspection for the 
individual detector or the sensors in the prescribed unit (STEP 4). 
The routines in STEP 4 and thereafter are performed in similar to the 
routines of the first embodiment (see STEP 2 in FIG. 3) or the second 
embodiment (see STEP 3 in FIG. 6). That is, the serviceman can 
discriminate the detector or the sensor in which the fault condition 
presents, in response to the individual identification code. A prescribed 
code signal corresponding to the desired individual identification code is 
transmitted to the indoor unit control circuit 124 of the indoor unit 102. 
The routine forwards to a suitable flow branch in response to the 
individual identification code (STEP 5). In the operations in STEP 5, the 
indoor unit control circuit 124 inspects automatically whether a 
prescribed detector or sensor, e.g., the indoor unit fan fault detector 
128 produces the detection signal in response to the corresponding 
individual identification code "11". When the prescribed detector, e.g., 
the indoor unit fan fault detector 128 is generating the detection signal 
at the time that the corresponding individual identification code "11" is 
applied to the indoor unit control circuit 124, the indicator lamp control 
circuit 158b receives the detection signal through the indicator lamp 
control circuit 158a and drives the operation state indicator lamp 160 to 
flicker (STEP 6a). Thus, the serviceman can notice that there occures some 
fault in the prescribed element, e.g., the indoor unit fan 120 (see FIG. 
1) corresponding to the indoor unit fan fault detector 128. If the 
operation state indicator lamp 160 fails to flicker (STEP 6b), the 
serviceman can return to the inspection of STEP 5 for the other detector 
or sensor in the same unit.