extracted from wipo:
formulas and tables are not copied:
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
OUTDOOR UNIT OF AIR CONDITIONER;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED
AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED
2
DESCRIPTION
Field
[0001] The present invention relates to an outdoor unit
of an air conditioner that sends outside 5 air to an outdoor
heat exchanger with a fan and performs heat exchange
between a refrigerant and the outside air.
Background
10 [0002] Suppose that in an air conditioner, two outdoor
fans that send outside air to an outdoor heat exchanger are
installed on an outdoor unit such that the two outdoor fans
are arranged one above the other. In the case where the
air conditioner performs cooling operation when the
15 temperature of the outside air is low, the amount of heat
exchange between the outside air and a refrigerant in the
outdoor heat exchanger reaches or exceeds operating
capacity required for an indoor unit, so that the inside of
a room is excessively cooled.
20 [0003] There is a technique for preventing heat exchange
from exceeding the operating capacity required for the
indoor unit in such a case, by stopping the lower outdoor
fan and rotating only the upper outdoor fan to reduce the
amount of heat exchange between the outside air and the
25 refrigerant in the outdoor heat exchanger. In this
technique, the upper outdoor fan is rotated. Therefore,
outside air does not stay in the vicinity of electrical
components including an outside air temperature sensor
provided in the upper part of a machine chamber, so that
30 the accuracy of a value to be detected by the outside air
temperature sensor and cooling efficiency of the electrical
components are maintained.
[0004] Meanwhile, a wire for supplying drive electric
3
power to a fan motor that rotates each of the two outdoor
fans may be connected to the wrong fan motor at the time of,
for example, assembling in a factory or replacement of the
fan motor during maintenance work. In this case, the lower
fan located away from the outside air 5 temperature sensor
and the electrical components will rotate. Therefore, the
temperature of outside air cannot be accurately detected,
and in addition, the electrical components cannot be cooled.
Thus, there is a possibility that the electrical components
10 are overheated and break down.
[0005] Patent Literature 1 proposes a method for
rotating an intended fan motor by providing a mode for
determining the connection states of two fan motors based
on a value detected by an outside air temperature sensor,
15 detecting an increase in the temperature of an outdoor heat
exchanger based on an increase in the value detected by the
outside air temperature sensor, and switching destinations
of drive electric power supply in the case where it is
determined that connections of the two fan motors have been
20 reversed.
Citation List
Patent Literature
[0006] Patent Literature 1: Japanese Patent No. 5516466
25
Summary
Technical Problem
[0007] However, there is a possibility that the method
disclosed in Patent Literature 1 does not enable improper
30 connection to be detected in the case of an outdoor unit of
a multi air conditioning system for buildings, capable of
being connected to a plurality of indoor units and
separately operating or stopping each indoor unit. The
4
multi air conditioning system for buildings is also
referred to as a variable refrigerant flow (VRF) system.
In the VRF system, an outdoor unit is generally selected
which has a heat exchange capacity sufficient to allow all
the connected indoor units to operate. In 5 the multi system
for buildings, when only a small number of indoor units are
operated for cooling, an outdoor heat exchanger will have a
sufficient heat exchange capacity with respect to the
operating capacity required for the indoor units.
10 Therefore, the temperature of the outdoor heat exchanger
hardly increases and the value detected by the outside air
temperature sensor does not increase either, so that
improper connection cannot be detected.
[0008] As described above, there has been a problem that
15 improper connections of fan motors may not be detected in
the method for detecting improper connections of fan motors
based on a value detected by an outside air temperature
sensor.
[0009] The present invention has been made in view of
20 the above, and an object of the present invention is to
obtain an outdoor unit of an air conditioner capable of
improving the probability of detecting improper connections
of fan motors.
25 Solution to Problem
[0010] To solve the above problems and achieve the
object an outdoor unit of an air conditioner according to
the present invention includes: a refrigerant circuit
including a compressor, a flow path switch, an outdoor heat
30 exchanger, a decompressor, and indoor heat exchangers
connected via refrigerant pipes; two outdoor fans to supply
air to the outdoor heat exchanger, the two outdoor fans
being arranged one above the other; two fan motors to drive
5
the respective two outdoor fans; a controller including two
fan motor connectors and a fan motor power supply, the two
fan motor connectors being capable of being connected to
the fan motors, the fan motor power supply being capable of
separately supplying power to each of 5 the two fan motors
connected to the fan motor connectors; and electrical
component temperature sensors to measure temperatures of
electrical components including at least components
included in the controller, the electrical component
10 temperature sensors being installed in an electrical
component box in which the controller is enclosed. The
controller includes a control circuitry, wherein at a time
of single-fan operation in which only upper one of the two
outdoor fans is operated, the control circuitry is
15 configured: to detect each of the two fan motors is
connected to which of the two fan motor connectors; and to
supply power in such a way to drive upper one of the
outdoor fans based on a result of the detection, wherein
the detection is performed based on comparison between
20 temperatures of the electrical components at a start of the
single-fan operation and temperatures of the electrical
components after a set time has elapsed since the start of
the single-fan operation.
25 Advantageous Effects of Invention
[0011] An outdoor unit of an air conditioner according
to the present invention has an effect of enabling the
probability of detecting improper connections of fan motors
to be improved.
30
Brief Description of Drawings
[0012] FIG. 1 is a diagram illustrating a refrigerant
circulation path of an air conditioner according to a first
6
embodiment of the present invention.
FIG. 2 is a perspective view of the inside of an
outdoor unit of the air conditioner according to the first
embodiment.
FIG. 3 is a block diagram of a control 5 system of the
outdoor unit of the air conditioner according to the first
embodiment.
FIG. 4 is a flowchart illustrating an operation flow
of single-fan operation of the outdoor unit of the air
10 conditioner according to the first embodiment.
FIG. 5 is a block diagram of a control system of an
outdoor unit of an air conditioner according to a second
embodiment of the present invention.
FIG. 6 is a flowchart illustrating an operation flow
15 of single-fan operation of the outdoor unit of the air
conditioner according to the second embodiment.
FIG. 7 is a diagram illustrating a configuration in
which the function of a control circuitry of the outdoor
unit of the air conditioner according to the first
20 embodiment or the second embodiment is implemented by
hardware.
FIG. 8 is a diagram illustrating a configuration in
which the function of the control circuitry of the outdoor
unit of the air conditioner according to the first
25 embodiment or the second embodiment is implemented by
software.
Description of Embodiments
[0013] Outdoor units of air conditioners according to
30 embodiments of the present invention will be described
below in detail with reference to the drawings. Note that
the present invention is not limited to the embodiments.
[0014] First Embodiment.
7
FIG. 1 is a diagram illustrating a refrigerant
circulation path of an air conditioner according to a first
embodiment of the present invention. In an air conditioner
100 according to the first embodiment, a plurality of
indoor units 80a and 80b is connected to 5 an outdoor unit 90
to form a VRF system.
[0015] The outdoor unit 90 includes a compressor 1, a
flow path switch 3, an outdoor heat exchanger 4, a first
stationary valve 5, and a second stationary valve 6. The
10 compressor 1, the flow path switch 3, the outdoor heat
exchanger 4, the first stationary valve 5, and the second
stationary valve 6 are connected by refrigerant pipes to
form a refrigerant circuit 30. The compressor 1 sucks a
refrigerant, compresses the sucked refrigerant to put the
15 refrigerant into a high-temperature and high-pressure state,
and conveys the refrigerant to the refrigerant circuit 30.
The flow path switch 3 is provided on the downstream side
of the compressor 1, and switches between the flow of the
refrigerant for heating operation and the flow of the
20 refrigerant for cooling operation. The outdoor heat
exchanger 4 performs heat exchange between air and the
refrigerant. The outdoor heat exchanger 4 acts as a
condenser during the cooling operation and as an evaporator
during the heating operation.
25 [0016] Furthermore, the outdoor unit 90 includes:
various sensors, such as pressure sensors and temperature
sensors; and a controller 16 including a substrate and a
control circuitry 19. The controller 16 is electrically
connected to the various sensors and the flow path switch 3.
30 Examples of the sensors included in the controller 16
include an outside air temperature sensor 9, an electrical
component temperature sensor 17, a high-pressure side
pressure sensor 2, and a low-pressure side pressure sensor
8
14. The outside air temperature sensor 9 detects the
temperature of outside air. The electrical component
temperature sensor 17 detects the temperature of the
substrate of the controller 16. Furthermore, the highpressure
side pressure sensor 2 5 is provided on the
discharge side of the compressor 1, and detects the highpressure
side pressure of the refrigerant. The highpressure
side output of the refrigerant is also referred to
as condenser pressure. Furthermore, the low-pressure side
10 pressure sensor 14 is provided on the intake side of the
compressor 1, and detects the low-pressure side pressure of
the refrigerant. The low-pressure side pressure of the
refrigerant is also referred to as evaporator pressure.
[0017] Furthermore, the outdoor unit 90 includes outdoor
15 fans 7a and 7b and fan motors 8a and 8b. The outdoor fans
7a and 7b supply air to the outdoor heat exchanger 4. The
fan motors 8a and 8b drive the outdoor fans 7a and 7b,
respectively. A propeller fan can be applied to the
outdoor fans 7a and 7b. FIG. 2 is a perspective view of
20 the inside of the outdoor unit of the air conditioner
according to the first embodiment. As illustrated in FIG.
2, the fan motors 8a and 8b are fixed to a fan motor
mounting part 50. FIG. 3 is a block diagram of a control
system of the outdoor unit of the air conditioner according
25 to the first embodiment. As illustrated in FIG. 3, the fan
motors 8a and 8b are driven by the control circuitry 19
included in the controller 16 via a fan motor power supply
20, fan motor connectors 15a and 15b, and fan motor wirings
18a and 18b. The outdoor fans 7a and 7b blow air into the
30 controller 16 to cool the substrate. As illustrated in FIG.
2, the controller 16 is enclosed in an electrical component
box 40. The electrical component box 40 is attached to the
upper part of a separator 51. Electrical components to be
9
housed in the electrical component box 40 include at least
components that constitute the controller 16. The
components included in the controller 16 are exemplified by
a terminal block for connection to a power source, and
various sensors as well as a circuit board 5 and electronic
components. Furthermore, slits (not illustrated) are
provided in the separator 51. The slits enable the
controller 16 to be cooled with air blown by the outdoor
fans 7a and 7b.
10 [0018] The indoor units 80a and 80b include
decompressors 10a and 10b and indoor heat exchangers 11a
and 11b, respectively. The decompressors 10a and 10b
decompress and expand the refrigerant. The decompressors
10a and 10b are connected to the indoor heat exchangers 11a
15 and 11b, respectively, by refrigerant pipes. The indoor
heat exchangers 11a and 11b perform heat exchange between
air blown by a fan (not illustrated) and the refrigerant.
The indoor heat exchangers 11a and 11b act as evaporators
during the cooling operation and as condensers during the
20 heating operation. An expansion valve can be applied to
the decompressors 10a and 10b.
[0019] Furthermore, the indoor units 80a and 80b include
various temperature sensors. The various sensors of the
indoor units 80a and 80b and the decompressors 10a and 10b
25 are electrically connected to the controller 16 similarly
to the various sensors of the outdoor unit 90. The
temperature sensors of the indoor units 80a and 80b can be
exemplified by evaporator temperature sensors that detect
the evaporator temperatures of the indoor heat exchangers
30 11a and 11b. As illustrated in FIG. 1, the evaporator
temperature sensors include indoor liquid pipe temperature
sensors 12a and 12b provided on liquid pipes and indoor gas
pipe temperature sensors 13a and 13b provided on gas pipes.
10
[0020] As illustrated in FIG. 1, the air conditioner 100
includes a plurality of the indoor units 80a and 80b. The
indoor units 80a and 80b are connected in parallel between
the first stationary valve 5 and the second stationary
valve 6 by refrigerant pipes. The indoor 5 heat exchanger
11a and the decompressor 10a are connected in the indoor
unit 80a. The indoor heat exchanger 11b and the
decompressor 10b are connected in the indoor unit 80b. The
indoor heat exchanger 11a is provided with the indoor
10 liquid pipe temperature sensor 12a and the indoor gas pipe
temperature sensor 13a. The indoor heat exchanger 11b is
provided with the indoor liquid pipe temperature sensor 12b
and the indoor gas pipe temperature sensor 13b.
[0021] The compressor 1, the flow path switch 3, the
15 outdoor heat exchanger 4, the first stationary valve 5, the
decompressors 10a and 10b, the indoor heat exchangers 11a
and 11b, and the second stationary valve 6 are connected in
sequence by pipes to form the refrigerant circuit 30 that
circulates the refrigerant.
20 [0022] The controller 16 controls operation of the
refrigerant circuit 30 and the outdoor fans 7a and 7b.
Specifically, based on values detected by the various
sensors, the controller 16 controls: the capacity of the
compressor 1; the opening degrees of the decompressors 10a
25 and 10b; and the driving of the outdoor fans 7a and 7b.
[0023] Among the various sensors included in the outdoor
unit 90, the outside air temperature sensor 9 is attached
above the outdoor heat exchanger 4. Therefore, the outside
air temperature sensor 9 is easily affected by the state of
30 outside air in the vicinity of the outdoor heat exchanger 4.
When only one of the indoor units 80a and 80b is operated,
the outdoor heat exchanger 4 has a sufficient heat exchange
capacity with respect to the operating capacity required
11
for the indoor unit 80a or the indoor unit 80b. Therefore,
the temperature of the outdoor heat exchanger 4 hardly
rises, and a value detected by the outside air temperature
sensor 9 does not rise either. Furthermore, when it is
windy outside, the flow of outside air to 5 the outdoor heat
exchanger 4 is caused without the use of the rotation of
the outdoor fans 7a and 7b. Thus, the outside air does not
stay, and the value detected by the outside air temperature
sensor 9 does not rise. Furthermore, since the outdoor
10 heat exchanger 4 acts as an evaporator during the heating
operation, the temperature of the refrigerant decreases and
the value detected by the outside air temperature sensor 9
also decreases.
[0024] Meanwhile, the following can be said about the
15 electrical component temperature sensor 17 among the
various sensors included in the outdoor unit 90. A value
detected by the electrical component temperature sensor 17
rises even when only one of the indoor units 80a and 80b is
operated. This is because heat generation in the
20 electrical components is always caused by current flowing
through the electrical components and the resistance values
of the electrical components. Furthermore, even when it is
windy outside, a rise in electrical component temperature
can be detected without being affected by the outside wind.
25 This is because the electrical component temperature sensor
17 is installed in the electrical component box 40. The
electrical component temperature sensor 17 is installed in
the electrical component box 40, and is shielded from the
outdoor fans 7a and 7b except for the slit portion provided
30 in the separator 51. Therefore, the result of measurement
measured by the electrical component temperature sensor 17
is less likely to be affected by airflow generated by the
outdoor fans 7a and 7b than the result of measurement
12
measured by the outside air temperature sensor 9.
Furthermore, heat generation in the electrical components
is always caused by the current flowing through the
electrical components and the resistance values of the
electrical components even during the heating 5 operation, so
that a rise in electrical component temperature can be
detected.
[0025] FIG. 4 is a flowchart illustrating an operation
flow of single-fan operation of the outdoor unit of the air
10 conditioner according to the first embodiment. In step
S101, the control circuitry 19 determines whether a singlefan
operation start condition is satisfied. If the singlefan
operation start condition is satisfied, a determination
of “Yes” is made in step S101, and the process proceeds to
15 step S102. If the single-fan operation start condition is
not satisfied, a determination of “No” is made in step S101,
and step S101 is repeated.
[0026] In step S102, the control circuitry 19 outputs,
to the fan motor power supply 20, a command to supply power
20 only to the fan motor 8a, which is the upper fan motor, and
stop supply of power to the fan motor 8b, which is the
lower fan motor. Furthermore, the control circuitry 19
stores the temperatures of the electrical components
measured by the electrical component temperature sensor 17.
25 In this way, the control circuitry 19 performs the singlefan
operation.
[0027] In step S103, the control circuitry 19 determines
whether a set time has elapsed since the single-fan
operation was started. If the set time has elapsed since
30 the single-fan operation was started, a determination of
“Yes” is made in step S103, and the process proceeds to
step S104. If the set time has not elapsed, a
determination of “No” is made in step S103, and step S103
13
is repeated.
[0028] In step S104, the control circuitry 19 determines
whether differences between the current values of the
temperatures of the electrical components measured by the
electrical component temperature 5 sensor 17 and the
temperatures of the electrical components at the start of
the single-fan operation are less than a threshold value.
If the differences between the temperatures of the
electrical components at the start of the single-fan
10 operation and the current temperatures of the electrical
components are less than the threshold value, a
determination of “Yes” is made in step S104, and the
process proceeds to step S105. If the differences between
the temperatures of the electrical components at the start
15 of the single-fan operation and the current temperatures of
the electrical components are equal to or greater than the
threshold value, a determination of “No” is made in step
S104, and the process proceeds to step S106.
[0029] In step S105, the control circuitry 19 determines
20 that connections of the outdoor fans 7a and 7b are normal,
and the process proceeds to step S108.
[0030] In step S106, the control circuitry 19 determines
that the connections of the outdoor fans 7a and 7b have
been reversed, and the process proceeds to step S107. In
25 step S107, the control circuitry 19 stops supply of power
to the fan motor connector 15a, and starts supply of power
to the fan motor connector 15b. That is, the control
circuitry 19 switches power supply for the fan motor
connectors 15a and 15b. Therefore, supply of power to the
30 fan motor 8b connected to the fan motor connector 15a in a
manner opposite to a normal state is stopped, and supply of
power to the fan motor 8a connected to the fan motor
connector 15b is started. When step S107 is completed, the
14
process proceeds to step S108.
[0031] In step S108, the controlcircuitry 19 determines
whether a single-fan operation end condition is satisfied.
If the single-fan operation end condition is satisfied, a
determination of “Yes” is made in 5 step S108, and the
process ends. If the single-fan operation end condition is
not satisfied, a determination of “No” is made in step S108,
and step S108 is repeated.
[0032] The outdoor unit 90 of the air conditioner 100
10 according to the first embodiment detects improper
connections of the fan motors 8a and 8b based on the values
detected by the electrical component temperature sensor 17.
Therefore, improper connections of the fan motors 8a and 8b
can be detected even when the cooling operation is
15 performed by only a small number of the indoor units, that
is, the cooling operation is performed by only one of the
indoor units 80a and 80b.
[0033] Furthermore, in the outdoor unit 90 of the air
conditioner 100 according to the first embodiment, the
20 electrical component temperature sensor 17 is installed in
the electrical component box 40. Thus, false detection of
the fan motors 8a and 8b can be detected even under the
condition that the value detected by the outside air
temperature sensor 9 does not rise since it is windy
25 outside and air is not stagnant around the outside air
temperature sensor 9.
[0034] Note that the amount of heat exchange between the
outside air and the refrigerant in the outdoor heat
exchanger may also reach or exceed the operating capacity
30 required for the indoor units during the heating operation
in an environment with high outside air temperature as well
as the above-described cooling operation in an environment
with low outside air temperature. In this case, even if
15
only the upper one of the outdoor fans 7a and 7b is rotated
so as to reduce the amount of heat exchange between the
outside air and the refrigerant and secure the operating
capacity required in the room, the temperature of the
outside air measured by the outside air 5 temperature sensor
9 decreases. This is because the outdoor heat exchanger 4
acts as an evaporator during the heating operation.
Therefore, improper connection cannot be detected during
the heating operation by use of the method for detecting
10 improper connection based on an increase in the value
detected by the outside air temperature sensor 9. However,
the outdoor unit 90 of the air conditioner 100 according to
the first embodiment detects improper connections of the
fan motors 8a and 8b based on the values detected by the
15 electrical component temperature sensor 17. Thus, the
improper connections of the fan motors 8a and 8b can be
detected even in the case where the heating operation is
performed in the environment with high outside air
temperature.
20 [0035] Second Embodiment.
FIG. 5 is a block diagram of a control system of an
outdoor unit of an air conditioner according to a second
embodiment of the present invention. The outdoor unit 90
of the air conditioner 100 according to the second
25 embodiment is different from the outdoor unit 90 of the air
conditioner 100 according to the first embodiment in that
the controller 16 includes a connection state memory 21.
The connection state memory 21 stores connection state
information indicating which of the fan motor connectors
30 15a and 15b each of the fan motors 8a and 8b is connected
to.
[0036] FIG. 6 is a flowchart illustrating an operation
flow of single-fan operation of the outdoor unit of the air
16
conditioner according to the second embodiment. This
operation flow differs from the operation flow of the
single-fan operation of the outdoor unit 90 according to
the first embodiment in that the processes of steps S109
and S110 have been added between steps 5 S101 and S102.
[0037] When the single-fan operation start condition is
satisfied, the control circuitry 19 determines, in step
S109, whether the connection state information is stored in
the connection state memory 21. If the connection state
10 information is stored in the connection state memory 21, a
determination of “Yes” is made in step S109, and the
process proceeds to step S110. In step S110, the
connection state information is read out from the
connection state memory 21, and the process proceeds to
15 step S102. If the connection state information is not
stored, a determination of “No” is made in step S109, and
the process proceeds to step S102.
[0038] In step S102, the control circuitry 19 outputs,
to the fan motor power supply 20, a command to supply power
20 only to the fan motor 8a, which is the upper fan motor, and
to stop supply of power to the fan motor 8b, which is the
lower fan motor. At this time, in the case where the
connection state information has been read in step S110,
power is supplied to one of the fan motor connectors 15a
25 and 15b, connected to the fan motor 8a so that power is
supplied to the fan motor 8a.
[0039] Subsequent operation is the same as the operation
of the outdoor unit according to the first embodiment,
except that the connection state information is stored in
30 the connection state memory 21 in step S105 or step S106.
[0040] The outdoor unit 90 of the air conditioner 100
according to the second embodiment can start the single-fan
operation so that only the outdoor fan 7a is driven in the
17
case where the connection state information is stored in
the connection state memory 21. Therefore, the cooling of
the controller 16 can be started immediately after the
start of the single-fan operation, and it is thus possible
to reduce the possibility that the electrical 5 components
may break down due to an increase in temperature.
[0041] The function of the control circuitry 19 of the
outdoor unit 90 of the air conditioner 100 according to the
first embodiment or second embodiment described above is
10 implemented by processing circuitry. The processing
circuitry may be dedicated hardware, or may be a processing
device that executes a program stored in a storage device.
[0042] In the case where the processing circuitry is
dedicated hardware, the processing circuitry corresponds to
15 a single circuit, a composite circuit, a programmed
processor, a parallel-programmed processor, an application
specific integrated circuit, a field programmable gate
array, or a combination thereof. FIG. 7 is a diagram
illustrating a configuration in which the function of the
20 control circuitry of the outdoor unit of the air
conditioner according to the first embodiment or the second
embodiment is implemented by hardware. A logic circuit 29a
that implements the function of the control circuitry 19 is
incorporated in processing circuitry 29.
25 [0043] In the case where the processing circuitry 29 is
a processing device, the function of the control circuitry
19 is implemented by software, firmware, or a combination
of software and firmware.
[0044] FIG. 8 is a diagram illustrating a configuration
30 in which the function of the control circuitry of the
outdoor unit of the air conditioner according to the first
embodiment or the second embodiment is implemented by
software. The processing circuitry 29 includes a processor
18
291, a random access memory 292, and a storage device 293.
The processor 291 executes a program 29b. The random
access memory 292 is used as a work area by the processor
291. The program 29b is stored in the storage device 293.
The processor 291 deploys the program 5 29b stored in the
storage device 293 on the random access memory 292, and
executes the program 29b. As a result, the function of the
control circuitry 19 is implemented. The software or
firmware is described in a programming language, and stored
10 in the storage device 293. The processor 291 can be
exemplified by, but is not limited to, a central processing
unit. It is possible to apply, to the storage device 293,
a semiconductor memory such as a random access memory (RAM),
a read only memory (ROM), a flash memory, an erasable
15 programmable read only memory (EPROM), or an electrically
erasable programmable read only memory (EEPROM) (registered
trademark). The semiconductor memory may be a non-volatile
memory or a volatile memory. Furthermore, in addition to
the semiconductor memory, a magnetic disk, a flexible disk,
20 an optical disk, a compact disk, a mini disk, or a Digital
Versatile Disc (DVD) can be applied to the storage device
293. Note that the processor 291 may output data such as a
calculation result to the storage device 293 to store the
data in the storage device 293, or may store the data in an
25 auxiliary storage device (not illustrated) via the random
access memory 292.
[0045] The processing circuitry 29 implements the
function of the control circuitry 19 by reading out and
executing the program 29b stored in the storage device 293.
30 It can also be said that the program 29b causes a computer
to execute a procedure and method for implementing the
function of the control circuitry 19.
[0046] Note that the processing circuitry 29 may be
19
partially implemented by dedicated hardware and partially
implemented by software or firmware.
[0047] Thus, the processing circuitry 29 can implement
each of the above-described functions by means of hardware,
software, firmware, or a combination 5 thereof.
[0048] The configurations set forth in the above
embodiments show examples of the subject matter of the
present invention, and it is possible to combine the
configurations with another technique that is publicly
10 known, and is also possible to make omissions and changes
to part of the configurations without departing from the
gist of the present invention.
Reference Signs List
15 [0049] 1 compressor; 2 high-pressure side pressure
sensor; 3 flow path switch; 4 outdoor heat exchanger; 5
first stationary valve; 6 second stationary valve; 7a, 7b
outdoor fan; 8a, 8b fan motor; 9 outside air temperature
sensor; 10a, 10b decompressor; 11a, 11b indoor heat
20 exchanger; 12a, 12b indoor liquid pipe temperature sensor;
13a, 13b indoor gas pipe temperature sensor; 14 lowpressure
side pressure sensor; 15a, 15b fan motor
connector; 16 controller; 17 electrical component
temperature sensor; 18a, 18b fan motor wirings; 19
25 control circuitry; 20 fan motor power supply; 21
connection state memory; 29 processing circuitry; 29a
logic circuit; 29b program; 30 refrigerant circuit; 40
electrical component box; 50 fan motor mounting part; 51
separator; 80a, 80b indoor unit; 90 outdoor unit; 100 air
30 conditioner; 291 processor; 292 random access memory; 293
storage device.
20
We Claim:
1. An outdoor unit of an air conditioner, comprising:
a refrigerant circuit including a compressor, a flow
path switch, an outdoor heat exchanger, a 5 decompressor, and
indoor heat exchangers connected via refrigerant pipes;
two outdoor fans to supply air to the outdoor heat
exchanger, the two outdoor fans being arranged one above
another;
10 two fan motors to drive the respective two outdoor
fans;
a controller including two fan motor connectors and a
fan motor power supply, the two fan motor connectors being
capable of being connected to the fan motors, the fan motor
15 power supply being capable of separately supplying power to
each of the two fan motors connected to the fan motor
connectors; and
electrical component temperature sensors to measure
temperatures of electrical components including at least
20 components included in the controller, the electrical
component temperature sensors being installed in an
electrical component box in which the controller is
enclosed, wherein
the controller includes a control circuitry, wherein
25 at a time of single-fan operation in which only
upper one of the two outdoor fans is operated, the control
circuitry is configured:
to detect each of the two fan motors is connected
to which of the two fan motor connectors; and
30 to supply power in such a way to drive upper one
of the outdoor fans based on a result of the detection,
wherein
the detection is performed based on comparison
21
between temperatures of the electrical components at a
start of the single-fan operation and temperatures of the
electrical components after a set time has elapsed since
the start of the single-fan operation.
5
2. The outdoor unit of the air conditioner according to
claim 1, further comprising:
a connection state memory to store connection state
information indicating each of the two fan motors is
10 connected to which of the two fan motor connectors, wherein
the control circuitry is configured:
to read out the connection state information from
the connection state memory at the start of the single-fan
operation; and
15 to determine the fan motor to be supplied with
power through the fan motor power supply.