JP3302138B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-type air conditioner having a plurality of outdoor units, and connecting a plurality of indoor units to each of the outdoor units by piping and signal lines.

[0002]

2. Description of the Related Art There is a multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit. By using this air conditioner, many rooms such as a building can be air-conditioned at once.

In this air conditioner, a compressor and an outdoor heat exchanger are provided in an outdoor unit, an indoor heat exchanger is provided in each indoor unit, and a refrigerant pipe is connected to the compressor, the outdoor heat exchanger, and each indoor heat exchanger. The refrigeration cycle is configured by connecting them, and each unit is connected to a signal line to construct an operation control system.

[0004] Recently, a large-sized air-conditioning system in which a plurality of indoor units are connected to one outdoor unit to constitute a single refrigeration cycle unit and a plurality of such refrigeration cycle units are provided has appeared.

[0005]

The pipe connection and signal line connection between the outdoor unit and each indoor unit are performed manually by an operator at the time of installation in a building. However, since the number of connected units is large, carelessness is required. There is a fear that errors may occur in pipe connection and signal line connection. If such erroneous connection remains, proper operation is naturally difficult.

Therefore, after installation, it is necessary to check one by one whether the connection state of each part is correct. However, this inspection work is troublesome for the operator and takes a long time. In particular, when the number of outdoor units and indoor units is considerably large, such as a large model having a plurality of refrigeration cycle units, inspection is often omitted, and incorrect connection may be missed.

[0007] The present invention has been made in view of the above circumstances,
The purpose is to check whether the connection between the outdoor unit and each indoor unit is correct, even if the number of units is large, quickly and reliably without burdening the workers. It is an object of the present invention to provide an air conditioner that can improve work efficiency at the time of installation and can operate properly.

[0008]

[0009]

SUMMARY OF THE INVENTION The air conditioner of the first invention, an operation unit for setting the number and capacity of the indoor units to be connected to the outdoor unit, provided in the indoor unit, the indoor means for transmitting the capacity data of the unit by a signal line to the outdoor unit of the destination, provided to each outdoor unit, means for detecting the transmission signal of the number and capacity of the indoor units connected to the outdoor unit from the indoor unit Means for judging the presence or absence of a connection abnormality by comparing the detected number and capacity with the set number and the set capacity, and judging the connection abnormality when receiving signals from a plurality of outdoor units provided in each indoor unit. Means, and when all of the above determination results are without connection abnormality,
Means for sequentially operating each outdoor unit one by one, means for detecting a change in the state of each indoor unit during operation of each outdoor unit, and means for determining the presence or absence of a connection abnormality according to the detection result. Prepare.

The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect of the invention, further comprising a plurality of remote control type operation devices connected to each indoor unit, and a central control device commonly connected to each outdoor unit. It is provided with one remote control type operation device and means for displaying each determination result provided in these operation devices.

[0011]

[0012]

In the air conditioner of the first invention, in each outdoor unit, the number and capacity of the connected indoor units are detected, and the detected number and capacity are compared with the predetermined set number and set capacity to determine the connection abnormality. Is determined. In each indoor unit, when a signal is input from a plurality of outdoor units, it is determined that there is a connection abnormality. When all the determination results show no connection abnormality, each outdoor unit is sequentially operated one by one. During the operation of each outdoor unit, a state change of each indoor unit is detected, and the presence or absence of a connection abnormality is determined according to the detection result.

[0013] In the air conditioner of the second invention, in addition to the operation of the first invention, each determination result is commonly connected to a plurality of remote control type operation devices connected to each indoor unit and each outdoor unit. The display is performed by one remote control type operation device for centralized control.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, two outdoor units A ₁ and A ₂ are prepared. Of these, outdoor unit A
_{A first} refrigeration cycle unit is configured by connecting _three indoor units B ₁ , B ₂ , and B ₃ to a refrigerant pipe. Also,
The outdoor unit A ₂ has three indoor units B ₄ , B ₅ and B
₆ is connected to a refrigerant pipe to constitute a second refrigeration cycle unit.

The outdoor unit A ₁ has compressors 1 and 2 housed in a common closed case. The compressor 1 is an inverter-driven variable capacity compressor. The compressor 2 is a fixed power compressor driven by a commercial power supply.

The high pressure side pipe 4a is connected to the discharge port of the compressor 1. The high pressure side pipe 4b is connected to the discharge port of the compressor 2, and the check valve 3 is provided in the high pressure side pipe 4b. The high pressure side pipe 4 a and the high pressure side pipe 4 b are connected to the high pressure side pipe 4. The low pressure side pipe 5 is connected to the suction ports of the compressors 1 and 2.

An outdoor heat exchanger 8 is connected to the high-pressure side pipe 4 via an oil separator 6 and a four-way valve 7. A dryer 11 is connected to the outdoor heat exchanger 8 via a check valve 9 and a liquid tank 10. A heating expansion valve 12 is connected in parallel with the check valve 9 by piping. An outdoor fan 13 is provided near the outdoor heat exchanger 8.

A strainer 15 is connected to the low-pressure side pipe 5 via an accumulator 14 and a four-way valve 7. The oil separator 6 extracts lubricating oil contained in the refrigerant discharged from the compressors 1 and 2. An oil return pipe 16 is connected from the oil separator 6 to the low-pressure side pipe 5.

One end of a cooling bypass 17 is connected to a liquid-side pipe between the check valve 9 and the liquid tank 10.
The other end of the cooling bypass 17 is connected to a low-pressure side pipe between the four-way valve 7 and the accumulator 14. The cooling bypass 17 is provided with a flow regulating valve 18.

A high pressure switch 21 and a refrigerant temperature sensor 25 are mounted on the high pressure side pipe 4a. In the high pressure side pipe 4b,
The high pressure switch 22 and the refrigerant temperature sensor 26 are mounted. The high-pressure switches 21 and 22 operate when the pressure of the refrigerant abnormally increases and reaches a predetermined value.

A refrigerant pressure sensor 23 is mounted on the high pressure side pipe 4, and a refrigerant pressure sensor 24 and a refrigerant temperature sensor 27 are mounted on the low pressure side pipe 5. The heat exchanger temperature sensor 28 is attached to the outdoor heat exchanger 8. Attaching the outside air temperature sensor 29 at a predetermined position of the outdoor unit A _1.

[0022] which is the other of the same configuration applies to the outdoor unit A _2. Between the dryer 11 and the strainer 15, to the pipe connecting the indoor heat exchanger 33 via a strainer 31 and a flow regulating valve 32 of the indoor unit B _1. An indoor fan 34 is provided near the indoor heat exchanger 33. Then, a refrigerant pressure sensor 35 and a refrigerant temperature sensor 37 are attached to the liquid side pipe between the PMV 32 and the indoor heat exchanger 33. A refrigerant pressure sensor 36 and a refrigerant temperature sensor 38 are mounted on a gas side pipe connected to the indoor heat exchanger 33. An indoor temperature sensor 39 is provided in the passage of the intake air of the indoor fan 34.

Other indoor units B ₂ , B ₃ , B ₄ , B
_5, it is also the same configuration and the same refrigerant pipe connecting the B _6. That is, at the time of cooling, the four-way valve 7 is set to the neutral state, whereby the refrigerant discharged from the compressors 1 and 2 flows in the direction of the solid line arrows in the drawing to form a cooling cycle,
The outdoor heat exchanger 8 functions as a condenser, and each indoor heat exchanger 33 functions as an evaporator. Further, at the time of heating, the four-way valve 7 is switched, whereby the refrigerant discharged from the compressors 1 and 2 is caused to flow in the direction of the dashed arrow in the drawing to form a heating cycle, and the indoor heat exchangers 33 are connected to the condenser and the outdoor. The heat exchanger 8 functions as an evaporator.

The flow control valve 18 and each flow control valve 3
Reference numeral 2 denotes a pulse motor valve whose opening continuously changes according to the number of input driving pulses. Hereinafter, the flow control valve is abbreviated as PMV.

Further, as shown in FIG.
₁ and the indoor units B ₁ , B ₂ , B ₃ are connected by a signal line (= bus communication line) C to construct a first operation control system, and the outdoor unit A ₂ and the indoor units B ₃ , B
_4, B ₅ are connected by a signal line C to have built the second operation control system.

These operation control systems perform time-division data transmission and reception between the outdoor unit and each indoor unit. That is, first data request command from the outdoor unit A ₁ to the indoor unit B _1, B _2, B ₃ is sent, in the form of response, sequentially from the indoor unit B _1, B _2, B ₃ to the outdoor unit A ₁ Data is transferred. The same is true for data transmission and reception with the outdoor unit A ₂ and the indoor unit _{B 3, B 4, B 5} .

Each outdoor unit has an outdoor control unit 50. The outdoor control unit 50 includes a microcomputer and its peripheral circuits. The outdoor control unit 50 includes a four-way valve 7, an outdoor fan motor 13M, a PMV 18, high-pressure switches 21, 22, refrigerant pressure sensors 23, 24, refrigerant temperature sensors 25, 26, 27, a heat exchanger temperature sensor 28, and an outside air temperature sensor 29. , An outdoor commercial AC power supply 51, an inverter 52, and a switch 53 are connected.

The inverter 52 is connected to the power supply 51 via a power supply line in the outdoor control unit 50, rectifies the power supply voltage, and converts the rectified voltage into a voltage of a predetermined frequency by switching according to a command from the outdoor control unit 50. And output. This output is the driving power of the compressor motor 1M.

The switch 53 is, for example, a contact of an electromagnetic contactor. Switch 5 on the power line in the outdoor control unit 50
3, the compressor motor 2M is connected. Then, a remote control type operation device (hereinafter, abbreviated as a centralized remote controller) 54 is commonly connected to the outdoor control unit 50 of each of the outdoor units A ₁ and B ₁ .

The centralized remote controller 54 has a display 54a and a test run switch 54b in addition to key buttons (not shown) for setting operating conditions, and is provided in a management room or the like in a building. Further, the centralized remote controller 54 also serves as operating means for setting the number Ns and capacity Vs of the indoor units to be connected to the outdoor units A ₁ and A ₂ , respectively.

The indoor control unit 60 comprises a microcomputer and its peripheral circuits. In this indoor control unit 60,
The PMV 32, the indoor fan motor 34M, the refrigerant pressure sensors 35 and 36, the refrigerant temperature sensors 37 and 38, the indoor temperature sensor 39, the indoor commercial AC power supply 61, and a remote control type operation device (hereinafter abbreviated as a remote control) 62 are connected. I do. The remote controller 62 has a display 62a in addition to key buttons (not shown) for setting operating conditions.

The indoor control section 60 has the following functional means. [1] Means for transmitting to the outdoor unit A data of operating conditions set by operating the key buttons of the remote controller 62.

[2] The difference ΔT between the detected temperature (intake air temperature) Ta of the indoor temperature sensor 39 and the set temperature Ts of the remote controller 62 is obtained, and the required capacity data corresponding to the temperature difference ΔT is sent to the outdoor unit A. Means to send.

[3] Means for controlling the opening of the PMV 32 according to the required capacity of the indoor unit. [4] During cooling, the degree of superheat of the refrigerant in the indoor heat exchanger 33 is determined from the detected temperature Te ₂ of the refrigerant temperature sensor 38 on the outlet side of the indoor heat exchanger 33 and the detected pressure (evaporation pressure) Pe _{2 of the} refrigerant pressure sensor 36. Means to detect.

[5] During heating, the refrigerant in the cold room heat exchanger 33 is determined based on the detected temperature Te ₁ of the refrigerant temperature sensor 37 at the outlet side of the indoor heat exchanger 33 and the detected pressure (condensation pressure) Pe _{1 of the} refrigerant pressure sensor 35. Means for detecting the degree of supercooling of the vehicle.

[6] Means for correcting the opening of the PMV 32 so that the detected degree of superheat and degree of supercooling become set values respectively set. [7] When nothing receive signals from the outdoor unit at a predetermined time after turning on the power 61 t _1, means for character display of the indoor side abnormal indicator 62a of the remote controller 62.

[8] Means for transmitting the data of the capacity of the indoor unit to the connected outdoor unit when the trial operation mode is notified from the outdoor unit. [9] Means for fully opening the PMV 32 when receiving the second step start command from the outdoor unit in the test operation mode.

[10] Means for detecting a state change (change in at least one of the refrigerant temperature and pressure) when the PMV 32 is fully opened. [11] Means for informing the outdoor unit of the detected state change.

[12] Means for detecting erroneous connection between the indoor unit and a plurality of outdoor units by communication of a bus communication line. That is, when signals are received redundantly from a plurality of outdoor units, it is detected that the number of connected outdoor units is plural, it is determined that there is an indoor abnormality, the fact is notified to the outdoor units, and the display of the remote control 62 is displayed. 62a
To display characters.

The outdoor controller 50 has the following functional means. [1] Means for controlling the operating capacity of the compressors 1 and 2 (the number of operating compressors 1 and 2 and the operating frequency F of the compressor 1) in accordance with the total required capacity of each indoor unit B.

[2] The four-way valve 7 is set to the neutral state, and the refrigerant discharged from the compressors 1 and 2 is supplied to the four-way valve 7, the outdoor heat exchanger 8, each flow regulating valve 32, each indoor heat exchanger 33, and the four-way valve. 7
Means for returning to the compressors 1 and 2 to perform a cooling operation.

[3] The four-way valve 7 is switched, and the refrigerant discharged from the compressors 1 and 2 is passed through the four-way valve 7, each indoor heat exchanger 33, each flow control valve 32, the outdoor heat exchanger 8, and the four-way valve 7. Compressor 1,
Means for returning to 2 and performing a heating operation.

[4] Means for executing a defrosting operation on the outdoor heat exchanger 8 in accordance with the detected temperature Te of the heat exchanger temperature sensor 28 during heating. [5] Detected pressure Pd of refrigerant pressure sensor 23 abnormally rises and set value (lower than operating point of high pressure switches 21 and 22)
, A first high-pressure protection means for reducing the capacity (operating frequency F) of the compressor 1 by a predetermined value.

[6] Second high-pressure protection means for stopping the operation of the compressor 1 when the high-pressure switch 21 is activated and stopping the operation of the compressor 2 when the high-pressure switch 22 is activated. [7] Detection temperature of refrigerant temperature sensor 25 (discharge refrigerant temperature)
When _one of Td ₁ and the detection temperature (discharge refrigerant temperature) Td ₂ of the refrigerant temperature sensor 26 rises to the set value Tdx, the PMV 18 of the cooling bypass 17 is opened, and the opening degree is increased to the higher of Td ₁ and Td _2. Means to control accordingly.

[8] A means for setting a test operation mode when receiving a test operation mode command from the centralized remote controller 54 and sending a test operation command to the indoor unit. [9] In the test operation mode, the number N and the capacity V of the indoor units connected to the outdoor unit are detected by a transmission signal from the indoor unit.

[10] The total value Vm of the detected capacities V and the total value Vsm of the set capacities Vs of the central remote controller 54
Means to find each. [11] First determining means for determining the presence or absence of a connection abnormality by comparing the detected number of connected devices N with the set number of devices Ns in the central remote controller 54.

[12] Total value Vm and total value Vsm obtained above
A second determining means for determining the presence or absence of a connection abnormality by comparing with. [13] Means for notifying the centralized remote controller 54 of the judgment results of the first and second judgment means together with the presence / absence of an indoor side abnormality.

[14] In the trial operation mode, the centralized remote controller 54
Means for operating the compressors 1 and 2 and receiving a second step start command to all the connected indoor units when receiving a start command from the unit.

[15] After transmitting the second step start command, the number of connected signals N sent from the indoor unit to the effect of state change detection is compared with the number of connected devices N to determine whether there is a connection abnormality. 3 determination means.

[16] Means for informing the centralized remote controller 54 of the judgment result of the third judgment means. On the other hand, the centralized remote controller 54 has the following functional means. [1] Means for sending a test operation mode command to each outdoor unit when the test operation switch 54b is turned on.

[2] When the judgment results of the first and second judgment means, which are notified from each outdoor unit, are normal and there is no abnormality on the indoor side, a start command is sequentially sent to each outdoor unit with a time difference. Means to send.

[3] Means for displaying each determination result notified from each outdoor unit in characters on the display 54a. Next, the operation of the above configuration will be described. Figure 3 shows the operation of the outdoor unit
4, the operation of the indoor unit is shown in the flowchart of FIG. 5, and the operation of the centralized remote controller 54 is shown in the flowchart of FIG.

At the time of installation, a worker manually connects refrigerant pipes and signal lines between each outdoor unit and each indoor unit. The number Ns and the capacity Vs of the indoor units to be connected to each outdoor unit are determined by the central remote controller 54.
Set with.

When the connection work is completed and the setting of the number Ns and the capacity Vs is completed, the operator turns on the power supply 51 of each outdoor unit and the power supply 61 of each indoor unit, and sets the test operation switch 54b of the central remote controller 54. Turn on.

When the trial run switch 54b is turned on, the trial run mode is set, and a trial run mode command is sent from the outdoor unit to each indoor unit. In each indoor unit is started simultaneously time count t and power-on, if receiving a test operation mode instruction from the outdoor unit to the predetermined time t _1, the determination that the signal line connection between the outdoor unit has not been Below, the indoor side abnormality is displayed in characters on the display 62a of the remote controller 62.

When the test operation mode command is input from the outdoor unit to the indoor unit within the predetermined time t ₁ , the indoor unit reads the capacity data of the indoor unit from the internal memory,
Send it to the outdoor unit.

When an indoor unit receives a signal from two outdoor units in an overlapping manner (when two outdoor units are erroneously connected to the indoor unit), the indoor unit notifies the outdoor unit that there is an abnormality on the indoor side, and This is indicated by characters on the display 62a of the remote controller 62.

The outdoor unit detects the number of signals (capacity data) transmitted and received from the indoor unit as the number N of connected indoor units. In addition, the outdoor unit detects the capacity V of the indoor unit connected to the outdoor unit based on the content (capacity data) of the received signal, the total value Vm of the detected capacities V, and the A total value Vsm of each set capacitance Vs is obtained.

The detected number N of connected units and the number Ns set by the central remote controller 54 are the same, and the total value Vm and the total value V
If sm is the same and there is no abnormality on the indoor side, the outdoor unit determines that the first step is normal (no abnormal connection),
This is notified to the central remote controller 54.

However, if the number of connected units N is different from the set number of units Ns, the number of connected units N is displayed on the display 54a of the central remote controller 54.
Is displayed, and it is determined that the first step is abnormal (there is a connection abnormality). If the total value Vm is different from the total value Vsm, or if there is an indoor side abnormality, it is determined that the first step is abnormal. Then, when the first step abnormality is determined, the fact is notified to the central remote controller 54.

The central remote controller 54 operates normally in the first step,
The number of connected units N and the first step abnormality are displayed in characters on the display 54a. Here, FIG. 7 shows an example where the pipe connection and the signal line connection are normal, and FIG. 8 shows an example where it is abnormal.

That is, in the example of FIG. 8, the pipe connection is normal, but the indoor unit B _{3 of the} outdoor unit A ₁ system is used.
There is connected a signal line to the outdoor unit A ₂ is another system,
Moreover the signal line connected between the outdoor unit A ₂ and the indoor unit B ₄ is forgotten.

In this case, no test operation mode command is input from any of the outdoor units A ₁ and A ₂ to the indoor unit B ₄ . Therefore, the indoor unit B ₄ determines that there is an abnormality on the indoor side, and displays it on the attached remote controller 62.

The number of units to be connected to the outdoor unit A ₁ (=
Despite setting number Ns) is three, the actual connection number N of the outdoor unit A ₁ is detected is two, both the number does not match. Moreover, compared with the total value Vsm of the capacity of the indoor units to be connected to the outdoor unit A ₁ (= setting capacity Vs), the sum Vm of the actual volume V of the outdoor unit A ₁ is detected is reduced. Therefore, the outdoor unit A
₁ judges the connection abnormality and displays it on the central remote controller 54.

[0065] workers, by viewing the remote display, and perceive that there is a connection abnormality relates indoor unit B ₄ and the outdoor unit A _1, will be re-work. Then, after this work is completed, the test operation is performed again.

Here, it is sufficient that the proper connection is completed.
There is a possibility that the erroneous connection of the indoor unit B ₄ and the outdoor unit A ₁ is made. In this case, the set number Ns matches the connected number N. Moreover, the capacity of the indoor unit B ₄ are given the same as the capacity of the indoor unit B _3, so that the detected capacitance sum Vm and setting the total capacity value Vsm in the outdoor unit A ₁ coincides. In this case, the first step is determined to be normal even though the connection is incorrect.

Therefore, when the first step is normal, the centralized remote controller 54 sequentially sends a start command to each outdoor unit with a time difference. Each outdoor unit has a centralized remote control 54
, The compressors 1 and 2 are operated and a second step start command is sent to all the indoor units.

When the indoor unit receives the second step command, it opens the PMV 32 fully and sets the refrigerant pressure sensor 3
6 monitoring the detected temperature Te ₁ of sensed pressure Pe ₂ and the coolant temperature sensor 37.

When the PMV 32 is fully opened, the refrigerant flows through the indoor heat exchanger 33. Due to the circulation of the refrigerant, the detected pressure Pe ₂ of the refrigerant pressure sensor 36 and the detected temperature Te ₁ of the refrigerant temperature sensor 37 change. The indoor unit that has detected the change in at least one of the pressure and the temperature sends a change detection signal to the outdoor unit.

As in the above example, when there is an erroneous connection between the indoor unit B ₄ and the outdoor unit A ₁ ,
Upon operation of the A _1, the indoor unit B ₁ is a connection target,
A state change is detected only in B ₁ and B ₂ among B ₂ and B _{3, and} no state change is detected in B ₃ .

The outdoor unit counts the number of received change detection signals L sent from each indoor unit and compares it with the set number Ns. In the above example, since L and Ns do not match, the outdoor unit determines that the second step is abnormal and displays it on the central remote control 54.

The worker who has noticed the second step abnormality senses that the outdoor unit and the indoor unit are erroneously connected by different systems, and restarts the work. In this way, just by setting the test operation mode, the connection between the outdoor unit and each indoor unit can be checked quickly and reliably without burdening the workers, even if the number of connected units is large. Can be. Therefore, work efficiency at the time of installation can be improved, and proper operation can be performed.

[0073]

As described above , according to the present invention,
Even if the number of units is large, it is possible to quickly and reliably check whether the connection between the outdoor unit and each indoor unit is correct, even if the number of units is large, thereby improving work efficiency during installation. And an air conditioner that can operate properly.

[0074]

[0075]

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control circuit of the embodiment.

FIG. 3 is a flowchart for explaining the operation of each outdoor unit of the embodiment.

FIG. 4 is a flowchart following FIG. 3;

FIG. 5 is a flowchart for explaining the operation of each indoor unit in the embodiment.

FIG. 6 is a flowchart for explaining the operation of the centralized remote controller in the embodiment.

FIG. 7 is an exemplary diagram showing a normal connection example according to the embodiment;

FIG. 8 is a diagram showing an example of an abnormal connection according to the embodiment.

[Explanation of symbols]

A ₁ , A ₂ ... outdoor unit, B _{1 to} B ₆ ... indoor unit, 1 ... variable capacity compressor, 2 ... fixed capacity compressor, 8 ... outdoor heat exchanger, PMV (flow control valve), 33 ... indoor heat Exchanger, 50 outdoor control unit, 54 centralized remote controller, 54a
Display, 54b Test run switch, 60 Indoor control unit, 62 Remote controller, 62a Display.

Claims (2)

(57) [Claims] 1. An air conditioner having a plurality of outdoor units, each of which has a plurality of indoor units connected by piping and signal lines, sets the number and capacity of indoor units to be connected to each outdoor unit. Operating means for transmitting the capacity data of the indoor unit provided to each indoor unit to the connected outdoor unit via the signal line; and an indoor unit provided for each outdoor unit and connected to the outdoor unit. Means for detecting the number and capacity of the indoor units by a transmission signal from the indoor unit; means for determining the presence or absence of a connection abnormality by comparing the detected number and capacity with the set number and the set capacity; and provided in each indoor unit. Means for judging that there is a connection abnormality when signals are received from a plurality of outdoor units; Means for sequentially operating each outdoor unit one by one when there is no connection abnormality; means for detecting a state change of each indoor unit during operation of each outdoor unit; and presence or absence of a connection abnormality according to the detection result. An air conditioner comprising: means for determining 2. The air conditioner according to claim 1, wherein a plurality of remote control type operation devices connected to each indoor unit and one remote control type operation device for central control commonly connected to each outdoor unit. An air conditioner, comprising: a device, and means for displaying each of the determination results provided on the operation device.