JPH08121850A - Transmission equipment for air-conditioning system - Google Patents

Abstract

PURPOSE: To ensure the reliability of a system while avoiding stoppage of the whole system, even when communication fails in parts of communication signal lines. CONSTITUTION: In regard to an air-conditioning system provided with outdoor- indoor communication signal lines 7 for transmission and reception of control signals between outdoor control units 5 and indoor control units 6 and equipped with a centralized controller 9 connected to the outdoor-indoor communication signal lines 7 by a centralized control signal line 10 so as to control outdoor and indoor unit 3, 4,... in a centralized manner, the communication signal lines 7 and 10 falling in a communication failure are cut off from a system when the communication failure occurs in parts of the communication signal lines 7 and 10, while the state of communication in normal communication channels is maintained and operations in these parts are continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission device for an air conditioner, and more particularly, it is provided with a plurality of refrigerant circulation units each having an outdoor unit and an indoor unit connected by refrigerant pipes. The present invention relates to an improvement of a transmission system capable of centralized control of operation control by transmitting and receiving signals between an outdoor unit and an indoor unit and a centralized controller.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 59-210249 as an example of an air conditioner, an outdoor unit and an indoor unit are connected by a refrigerant pipe and the outdoor unit is controlled. An outdoor control unit and an indoor control unit for controlling the indoor unit are connected by an internal / external communication signal line, whereby a refrigerant circulation unit configured to exchange various control signals such as an operation signal and a mode signal between the units. It is known that a plurality is provided. In addition, each control unit is connected to the centralized controller via the centralized control signal line and the internal / external communication signal line, and the control signal from this centralized controller is controlled by the centralized control signal line and the internal / external communication signal line. It is sent to the unit and the whole system is controlled centrally.

Further, for the purpose of simplifying the configuration by shortening the wiring length of each signal line connecting between the control units and between the control unit and the centralized controller, FIG.
As shown in Fig. 2, the control units (c, c, ...) Provided to the outdoor unit (a, a, ...) And the indoor unit (b, b, ...) respectively.
, D, d, ...) and the centralized controller (e) are also connected in series by the signal line (f).

[0004]

However, in the structure disclosed in the above-mentioned Japanese Patent Laid-Open No. 59-210249 and the structure shown in FIG. 5, a short circuit or a disconnection occurs at one position of the signal line (f). Occurs, the communication is disabled in that part, which causes each control unit (c, c,
Communication between the centralized controller (e) and the central controller (e) is disabled and the entire system does not function.

The present invention has been made in view of this point, and when the communication is disabled in a part of a signal line, the function of the entire system is prevented from being stopped and the reliability of the system is improved. The purpose is to ensure sex.

[0006]

In order to achieve the above object, the invention according to claim 1 concentrates on the internal and external communication signal lines when communication is disabled on at least one of the internal and external communication signal lines. Disconnected from the control unit so that transmission can be performed only with normal signal lines. Specifically, as shown in FIG. 1, a refrigerant circulation unit (2A, 2B, 2C) formed by connecting a heat source side unit (3) and a use side unit (4) with a refrigerant pipe.
Is provided in plural, each refrigerant circulation unit (2A, 2B, 2C),
Heat source side control unit (5) that controls the heat source side unit (3)
And a user-side control unit that controls the user-side unit (4)
An own system communication path (7) for transmitting and receiving control signals to and from (6) is provided to centrally control the above heat source side units (3, 3, ...) and use side units (4, 4, ...). Central control unit
Between the (9) and its own system communication path (7, 7, ...), the centralized communication path (10) that enables communication by the centralized control signal between them is provided It is assumed to be a transmission device. Then, a communication path disconnecting means (28) capable of disconnecting the centralized communication path (10) between each of the own system communication paths (7) and the central control unit (9), and the plurality of own system communication paths (7). , 7,
...), the communication status judging means (31) for judging the communication status and the output of the communication status judging means (31), and when at least one own system communication path (7) is incommunicable, this communication is impossible. A communication path disconnection instruction means (32) for disconnecting the centralized communication path (10) between the local system communication path (7) and the centralized control unit (9) by the communication path disconnection means (28) I am trying.

According to the second aspect of the present invention, when communication is disabled in the central control signal line, all the internal and external communication signal lines and the central control unit are disconnected so that transmission can be performed only by the internal and external communication signal lines. did. Specifically, in the transmission device of the air conditioner having the same premise as that of the invention described in claim 1, the centralized communication path (10) between each own system communication path (7) and the centralized control unit (9) is provided. Communication path disconnection means (2
8), a communication state determination means (31) for determining the communication state of the centralized communication path (10), and an output of the communication state determination means (31),
When the centralized communication path (10) cannot communicate, the centralized communication path (10) between all the local system communication paths (7, 7, ...) and the central control unit (9) is disconnected by the communication path disconnecting means (28 ), The communication path disconnection instruction means (32) is provided.

According to the third aspect of the present invention, when communication is disabled on at least one of the internal and external communication signal lines or when communication is disabled on the centralized control signal line, communication can be performed using only normal signal lines. I did it. Specifically, in the transmission device of the air conditioner having the same premise as that of the invention described in claim 1, the centralized communication path (10) between each own system communication path (7) and the centralized control unit (9) is provided. Communication path disconnecting means (28) that can be disconnected, and the plurality of own system communication paths (7,
7, ...) and a communication status judging means (31) for judging the communication status of the centralized communication path (10), and at least one own system communication path (7) receiving the output of the communication status judging means (31). When communication is not possible, the centralized communication path (10) between the local system communication path (7) and the centralized control unit (9), which is incapable of communication, is disconnected by the communication path disconnecting means (28) and the centralized communication is performed. When the communication path (10) is incommunicable, the centralized communication path (10) between all the local system communication paths (7, 7, ...) and the central control unit (9) is disconnected by the communication path disconnecting means (28). The communication path disconnection instruction means (32) for disconnecting is provided.

The invention according to claim 4 is the above-mentioned claim 1, 2
Alternatively, in the transmission device of the air conditioner described in 3,
As shown in, the communication path opening / closing means (28) is relayed (28a, 28b).
It is composed by.

According to a fifth aspect of the present invention, in the air conditioner transmission device according to the fourth aspect, the centralized communication path (10) is provided.
, Two transmission lines (10a, 10b) for transmitting control signals respectively
The relay (28a, 28b) consists of two transmission lines (10a, 1b
0b) is configured to be opened and closed in synchronization with each other.

[0011]

With the above construction, the present invention provides the following actions. During operation of the air conditioner, control signals are transmitted and received between the heat source side control unit (5) and the user side control unit (6) by the own system communication path (7), and the communication path disconnecting means (28) is connected. State of each heat source side unit
(3,3, ...) And each of the use side units (4,4, ...) Are centrally controlled by a centralized control signal transmitted from the centralized control unit (9) through the centralized communication path (10). In the invention according to claim 1, when at least one own system communication path (7) is incommunicable, the communication path disconnection instructing means (32) and the own system communication path (7) incapable of communication. Centralized control unit (9)
The centralized communication path (10) between and is disconnected by the communication path disconnecting means (28). In the invention according to claim 2, the centralized communication path is provided.
When (10) is unable to communicate, communication path disconnection instruction means (32)
However, all local system communication channels (7,7, ...) and central control unit
The centralized communication path (10) with (9) is disconnected by the communication path disconnecting means (28). Further, in the invention according to claim 3, when the communication is impossible on either the own system communication path (7) or the centralized communication path (10), the communication path disconnection instruction means (32) is the communication path disconnection means (28). To disconnect. By these operations, the communication on the normal communication path is maintained, and the operation by the communication in that portion can be continued.

According to a fourth aspect of the invention, the communication path disconnecting means.
By using the relays (28a, 28b) for (28), only one set of interfaces, which is a connecting portion to the centralized communication path (10) in the heat source side control unit (5), is required, and the configuration is simplified. In addition, there is little power loss when the switch is connected, and it is unlikely to be affected by disturbance due to noise.

In the invention according to claim 5, the centralized communication path (10)
Is transmitted by the control signal transmitted from each of the two transmission lines (10a, 10b). When the centralized communication path (10) is disconnected by the communication path disconnecting means (28), the relays (28a, 28b) are synchronously opened. Therefore, the balance between both transmission lines (10a, 10b) is maintained and the reliability of the system is secured.

[0014]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 2 shows a control system of the air conditioner (1) according to this example. The air conditioner (1) is provided with a plurality of refrigerant circulation units (2A, 2B, 2C).
(2A, 2B, 2C) is configured into three systems in FIG. 2, and two refrigerant circulation units (2A, 2B) among the three system refrigerant circulation units (2A, 2B, 2C) are One indoor unit (4) is connected to the outdoor unit (3), and the remaining one refrigerant circulation unit (2C) is two indoor units (4) for one outdoor unit (3). , 4) are connected in parallel with each other.

The outdoor unit (3) is a heat source side unit according to the present invention, which includes an outdoor heat exchanger having a compressor, a four-way switching valve, a fan (not shown), and an outdoor electric expansion valve. The unit (4) is a use side unit in the present invention provided with an indoor electric expansion valve and an indoor heat exchanger having a fan, and each refrigerant circulation unit (2A, 2B, 2C) has a cooling operation mode and a heating mode. The refrigerant flow direction is variable depending on the operation mode.

The outdoor unit (3) is provided with an outdoor control unit (5) as a heat source side control unit of the present invention, while the indoor unit (4) is used as a use side control unit of the present invention. It is equipped with an indoor control unit (6). And each control unit (5, 6) in the same refrigerant circulation unit (2A, 2B, 2C), the internal and external communication signal line that constitutes the own system communication path in the present invention to be able to exchange control signals with each other.
(7) connected by refrigerant circulation unit (2A, 2B, 2C)
It composes three control systems (8A, 8B, 8C) corresponding to. As a result, the air conditioning operation is controlled for each control system (8A, 8B, 8C).

Further, each outdoor control unit (5, 5, ...) Is a centralized controller as a centralized control unit in the present invention.
The central control signal line (10) forming a central communication path is connected to (9), and the control signal from the central controller (9) is transmitted to this central control signal line (10) and each internal and external communication signal line.
(7,7, ...) is transmitted to each outdoor control unit (5,5, ...) and each indoor control unit (6,6, ...), and each unit (3,3, ..., 4,4, ...) ) Is controlled comprehensively (centralized control).

Further, in each of the indoor units (4),
A remote control (11) is connected, and control signals such as set temperature are exchanged between this remote control (11) and the indoor control unit (6) to individually control each indoor unit (4, 4, ...).
It is controlled by (11).

Next, as a characteristic configuration of this example, a control unit for transmitting and receiving a control signal will be described. Outdoor control unit (5), indoor control unit (6)
And the transmission method between the centralized controller (9) is AMI
A balanced communication system is adopted as the communication system, and is configured to perform half-duplex signal transmission with a preset polarity.

As shown in FIG. 3, the outdoor control unit (5) includes a transmitter circuit (20), a receiver circuit (21), and a polarity judgment circuit (2).
2) and the transmission circuit (20), the reception circuit (21) and the polarity determination circuit (22) are connected to the microcomputer (30). Further, the indoor control unit (6) and the centralized controller (9) are
The transmission circuit (2
0), a receiving circuit (21) and a polarity determining circuit (22) are provided. Here, in particular, the circuit configuration will be described taking the outdoor control unit (5) as an example. In addition, the internal and external communication signal line (7)
The centralized control signal line (10) is composed of a positive signal line (7a, 10a) and a negative signal line (7b, 10b) as transmission lines, respectively.

The transmission circuit (20) transmits an information signal to the internal / external communication signal line (7) and the centralized control signal line (10) according to the output signal from the microcomputer (30). 20a, 20b), and the positive side signal line (7a, 10a) and negative side signal line of the above-mentioned internal and external communication signal line (7) and centralized control signal line (10)
Connect each driver (2) to the common wiring (23, 24) connected to (7b, 10b).
0a, 20b) are connected via coupling wiring (20c, 20d). Further, capacitors (20e, 20f) for removing a direct current component are connected to the coupling wirings (20c, 20d).

Further, the receiving circuit (21) has a common wiring (23,
24) via coupling wiring (21a, 21b) and is configured to receive the information signal on the internal / external communication signal line (7) and the centralized control signal line (10) and output it to the microcomputer (30). ing.

The polarity determination circuit (22) is a common wiring.
It is connected to the positive side signal line (7a, 10a) and the negative side signal line (7b, 10b) of the internal and external communication signal line (7) and the centralized control signal line (10) via (23, 24), and The polarity of the internal / external communication signal line (7) and the centralized control signal line (10) is judged, and the polarity judgment circuit (22)
The driver (20) of the transmitter circuit (20)
a, 20b) makes it possible to invert the information signal to be transmitted.

Further, the internal / external communication signal line (7) and the centralized control signal line (10) are connected to a DC superimposing circuit (25) through an opening / closing circuit (26). This DC superimposing circuit (25)
(25a, 25b) via the positive signal line (7a, 10b) of each communication line (7, 10)
a) and a negative side signal line (7b, 10b) is provided with a direct current power supply (27) connected, the direct current power supply (27), a predetermined direct current voltage on both signal lines (7, 10), for example, , + 15V DC voltage is applied.

Further, the switching circuit (26) includes the power supply lines (25
a, 25b) two relay switches (26a, 26b)
The relay switch (26a, 26b) is opened and closed to electrically connect and disconnect the DC superimposing circuit (25) and each communication line (7, 10).

Both of the relay switches (26a, 26b) are opened and closed under the control of the microcomputer (30). In the preset outdoor control unit (5), the relay switches (26a, 26b) are opened and closed. Is closed and the DC superposition circuit (2
When 5) and each communication line (7, 10) are conducted, this DC voltage is superimposed. That is, for example, the DC superimposing circuit (25) of the outdoor control unit (5) set to the address [0] is set to apply a DC voltage to each signal line (7, 10), and the other outdoor control unit (5) In 5), the relay switches (26a, 26b) are opened (OFF).

The power supply lines (25a, 25b) are provided with discharge resistors (25c, 25d), and both power supply lines (25a, 25b)
Between them, connect a capacitor so that it is in parallel with the DC power supply (27).
(25e) is connected.

The discharge resistors (25c, 25d) are connected to the signal lines (7, 1
The residual charge of 0) is discharged to suppress the generation of signal waveform distortion. The capacitor (25e) holds the impedance of each signal line (7, 10) at a predetermined low value.

The feature of this example is that the centralized control signal line (10) is provided with an opening / closing circuit as a communication path disconnecting means.
(28) is provided. This switching circuit (28)
Is equipped with two relay switches (28a, 28b) provided on the central control signal line (10), and each circuit (20a, 28b) is opened and closed by the control of the microcomputer (30). , 2
1, 22) and each signal line (10a, 10b) are configured to conduct and cut off. And both relay switches (2
8a, 28b) are normally closed, and are opened only when a short circuit occurs in the internal / external communication signal line (7) or the central control signal line (10).

Next, the communication operation of the information signal of the air conditioner (1) will be described with reference to the flowchart of FIG. When the power is turned on, in step ST1, each relay switch in the switching circuit (28) of the centralized control signal line (10)
Turn on (28a, 28b). This allows the centralized controller
Transmission and reception are possible between (9) and each control unit (5, 6). In this state, move to step ST2, where each outdoor unit
(3,3, ...) and the indoor units (4,4, ...) are numbered. Then, in step ST3, the relay switches (28a, 28b) are turned off to disable the transmission and reception between the central controller (9) and the control units (5, 6), that is,
Only the transmission and reception between the outdoor control unit (5) and the indoor control unit (6) can be performed by the internal and external communication signal line (7). Next, in this state, in step ST4, transmission / reception between the outdoor control unit (5) and the indoor control unit (6) is performed by the indoor / outdoor communication signal line (7), and each control unit (5, 5, ...,
6,6, ...) to recognize its own system. In other words, the other unit that you are connected to by the internal / external communication signal line (7)
Recognize the number (3,4). Then, in step ST5, each relay switch (28a, 28b) is turned on to enable transmission / reception between the centralized controller (9) and each control unit (5, 6), so that each signal line ( Communication by 7, 10) is enabled.

Next, in step ST6, it is detected whether or not a communication abnormality has occurred, and if the communication is normal, NO, then normal communication is started in step ST7. On the contrary, in the case of YES in which the occurrence of the communication abnormality is detected due to the short circuit of the internal / external communication signal line (7) or the centralized control signal line (10), the relay switches (28a, 28b) are turned on again in step ST8. O
The central controller (9) and each control unit (5, 5,
, 6,6, ...) is disabled, and only the outdoor control unit (5) and the indoor control unit (6) can be transmitted and received by the internal and external communication signal line (7). In this state, in step ST9, transmission / reception via the internal / external communication signal line (7) is performed to judge whether or not the transmission / reception state of the own system is normal. When the transmission / reception state of the own system is determined to be abnormal, NO, the process proceeds to step ST10 and the abnormality is displayed on the abnormality display lamp of the indoor unit (4). Further, in this case, the transmission / reception state may be temporarily abnormal, so in consideration of this, step ST11
In this case, after this abnormal display is delayed for a predetermined time (for example, several minutes), the process returns to the step ST1 again and the same communication starting operation as described above is performed. If an error continues to be detected even during this communication start operation, it is confirmed that a communication error such as a short circuit in the internal / external communication signal line (7) has occurred, and the error display is continued. .

On the other hand, if it is determined in step ST9 that the transmission / reception state of the own system is normal, the process proceeds to step ST12 to turn on each relay switch (28a, 28b) to turn on the central controller (9). Each control unit (5,5, ...,
6,6, ...) Can be sent and received. In other words, by the operation of steps ST8 to ST12, each relay switch (28a, 28b) is kept in the OFF state only when the transmission / reception state of the own system is abnormal, and conversely, the transmission / reception state of the own system is normal. Relay switch (28
a, 28b) will be returned to the ON state.

Thereafter, in step ST13, it is detected whether or not the communication is normal, and when the communication is normal, the operation is switched to the normal communication operation to determine the operation of each unit (3, 4). On the other hand, when the control is started and the communication error is NO, the internal / external communication signal line (7) is
It is judged that a communication error such as a short circuit has occurred in the centralized control signal line (10), and in step ST14, the relay switches (28a, 28b) are turned off and the centralized controller (9)
To and from each control unit (5, 6) is disabled, that is, only the outdoor control unit (5) and the indoor control unit (6) can be transmitted and received by the internal and external communication signal line (7). And transmit and receive only within its own system (3,
4) is controlled. By such operation, step ST
The communication state determining means (3
1) is configured, and steps ST8, 12, and 14 configure the communication path disconnecting instruction means (32) in the present invention.

Such a control operation is performed by each refrigerant circulation unit.
It will be sequentially performed in each of (2A, 2B, 2C). For this reason, in the refrigerant circulation unit (2A, 2B, 2C) where communication error occurs in the internal / external communication signal line (7), each relay switch (28a, 28b) remains in the OFF state, and the system reliability is high. You can secure the sex. If a communication error occurs in the centralized control signal line (10), each relay switch (2
In this case, the reliability of the system is also ensured by turning off (8a, 28b) and making transmission / reception between the centralized controller (9) and the outdoor control unit (5) impossible. Can be secured.

Also, since the connection state between the centralized controller (9) and the outdoor control unit (5) is switched by the relay switches (28a, 28b), the outdoor control unit (5)
In this case, only one set of interfaces, which is a connecting portion to the centralized control signal line (10), is required, and the configuration can be simplified. Further, it is possible to obtain a configuration in which the loss is small at the time of switching the connection state and is less likely to be affected by the disturbance due to noise.

[0036]

As described above, according to the present invention, the following effects are exhibited. According to the invention described in claim 1, when at least one own system communication path is incommunicable, the centralized communication path between the own system communication path and the centralized control unit is cut off. According to the invention described in claim 2, when the centralized communication path is incommunicable, all the centralized communication paths between the own system communication path and the centralized control unit are cut off. According to this configuration, since both the configurations of the above-described inventions of claims 1 and 2 are provided, when the communication is disabled in a part of the communication path, the communication can be performed only by the normal signal line, It is possible to maintain the communication state on the normal communication path and continue the operation in that portion, and it is possible to secure a large reliability of the system.

According to the invention as set forth in claim 4, since the communication path disconnecting means is constituted by a relay, one set of interfaces, which is a connecting portion to the centralized communication path in the heat source side control unit, is sufficient, and the structure is simplified. Can be planned.
Further, it is possible to obtain a configuration in which power loss is small when the switches are connected and is less likely to be affected by disturbance due to noise.

According to the fifth aspect of the present invention, the centralized communication path is composed of two transmission lines each for transmitting a control signal,
Since the relays are provided so as to be synchronously opened and closed for each of the two transmission lines, when the centralized communication path is disconnected by the communication path disconnecting means, the relays are synchronously opened. The balance of each transmission line is maintained, and the reliability of the system can be secured.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

FIG. 2 is a control system diagram of the air conditioner according to the embodiment.

FIG. 3 is a block circuit diagram of an outdoor control unit.

FIG. 4 is a flowchart showing a communication start operation and an operation at the time of communication abnormality.

FIG. 5 is a view corresponding to FIG. 2 in a conventional example.

[Explanation of symbols]

 (1) Air conditioner (2A) to (2B) Refrigerant circulation unit (3) Outdoor unit (heat source side unit) (4) Indoor unit (use side unit) (5) Outdoor control unit (heat source side control unit) (6 ) Indoor control unit (use side control unit) (7) Internal / external communication signal line (local system communication path) (9) Centralized controller (centralized control unit) (10) Centralized control signal line (centralized communication path) (10a) Positive side Signal line (transmission line) (10b) Negative side signal line (transmission line) (28) Switching circuit (communication path disconnection means) (28a, 28b) Relay switch (31) Communication status determination means (32) Communication path disconnection instruction means

Claims (5)

[Claims] 1. A heat source side unit (3) and a use side unit
(4) Refrigerant circulation unit (2A,
2B, 2C), each refrigerant circulation unit (2A, 2B, 2C) has a heat source side unit.
A heat source side control unit (5) that controls (3) and a user side control unit (6) that controls the user side unit (4) are provided with their own system communication path (7) that sends and receives control signals. , The heat source side unit (3, 3, ...) and the use side unit
The centralized control unit (9) for centrally controlling (4,4, ...) And each own system communication path (7,7, ...) Allows communication by a centralized control signal between them. In an air conditioner transmission device provided with a centralized communication path (10), a communication path that enables disconnection of the centralized communication path (10) between the respective system communication path (7) and the centralized control unit (9). Cutting means (28)
And a communication status judging means (31) for judging the communication status of the plurality of own system communication paths (7, 7, ...) And at least one own system communication receiving the output of the communication status judging means (31). When the communication path (7) is incommunicable, the communication path disconnecting means (28) disconnects the communication path disconnecting means (28) between the communication path (7) and the central control unit (9) that cannot communicate. A transmission device for an air conditioner, which is provided with a communication path disconnection instruction means (32). 2. A heat source side unit (3) and a use side unit
(4) Refrigerant circulation unit (2A,
2B, 2C), each refrigerant circulation unit (2A, 2B, 2C) has a heat source side unit.
A heat source side control unit (5) that controls (3) and a user side control unit (6) that controls the user side unit (4) are provided with their own system communication path (7) that sends and receives control signals. , The heat source side unit (3, 3, ...) and the use side unit
The centralized control unit (9) for centrally controlling (4,4, ...) And each own system communication path (7,7, ...) Allows communication by a centralized control signal between them. In an air conditioner transmission device provided with a centralized communication path (10), a communication path that enables disconnection of the centralized communication path (10) between the respective system communication path (7) and the centralized control unit (9). Cutting means (28)
And a communication state judging means (31) for judging the communication state of the centralized communication path (10), and an output of the communication state judging means (31) for receiving the centralized communication path (10)
Is unable to communicate, all local communication channels (7,7, ...)
Communication path disconnecting means (3) for disconnecting the centralized communication path (10) between the central control unit (9) and the central control unit (9) by the communication path disconnecting means (28).
2) A transmission device for an air conditioner, which is provided with and. 3. A heat source side unit (3) and a use side unit
(4) Refrigerant circulation unit (2A,
2B, 2C), each refrigerant circulation unit (2A, 2B, 2C) has a heat source side unit.
A heat source side control unit (5) that controls (3) and a user side control unit (6) that controls the user side unit (4) are provided with their own system communication path (7) that sends and receives control signals. , The heat source side unit (3, 3, ...) and the use side unit
The centralized control unit (9) for centrally controlling (4,4, ...) And each own system communication path (7,7, ...) Allows communication by a centralized control signal between them. In an air conditioner transmission device provided with a centralized communication path (10), a communication path that enables disconnection of the centralized communication path (10) between the respective system communication path (7) and the centralized control unit (9). Cutting means (28)
And the above-mentioned multiple system communication channels (7, 7, ...) and centralized communication channel (10)
The communication status judging means (31) for judging the communication status of the communication system and the output of the communication status judging means (31), and when at least one own system communication path (7) is incommunicable, this communication is impossible. When the centralized communication path (10) between the own system communication path (7) and the centralized control unit (9) is disconnected by the communication path disconnecting means (28), and when the centralized communication path (10) cannot communicate, A communication path disconnection instruction means (32) for disconnecting the centralized communication path (10) between all the local system communication paths (7, 7, ...) and the centralized control unit (9) by the communication path disconnection means (28). A transmission device for an air conditioner, comprising: 4. The communication line disconnecting means (28) is a relay (28a, 28a).
b) according to claim 1,
2. The air conditioner transmission device according to 2 or 3. 5. The centralized communication path (10) is composed of two transmission lines (10a, 10b) each transmitting a control signal, and the relay (28a, 28b) is two transmission lines (10a, 10b). 5. The transmission device for an air conditioner according to claim 4, wherein the transmission device is provided so as to be opened and closed in synchronization with each of the above.