JP7051355B2 - Air conditioner - Google Patents

Description

The present invention relates to an air conditioner in which an indoor unit and an outdoor unit are connected so as to perform serial communication.

In a separate type air conditioner composed of an indoor unit and an outdoor unit, serial communication is usually used for control between the indoor unit and the outdoor unit. In addition, the operating power of the air conditioner is supplied from the commercial power supply, but only the indoor unit is connected to the commercial power supply, and the operating power of the outdoor unit is indoors by the AC power supply line connecting the indoor unit and the outdoor unit. Supplied from the machine.

In the above configuration, it is necessary to connect the indoor unit and the outdoor unit by a serial communication line and an AC power supply line. Therefore, when installing the air conditioner, wiring work is performed by the installation worker. When the wiring connection between the indoor unit and the outdoor unit is made by a person in this way, the possibility of erroneous wiring cannot be completely eliminated. When such erroneous wiring occurs, a high-voltage commercial power source is applied to the communication circuit, which is a low-voltage circuit, and there is a risk that heat generation or burning of circuit components may occur.

Patent Document 1 discloses an air conditioner having an erroneous wiring detection function. The air conditioner of Patent Document 1 is provided with an overvoltage detector at the terminal portion of the communication circuit, and detects erroneous wiring by detecting that an overvoltage is applied to the communication circuit by the overvoltage detector. Further, Patent Document 1 discloses that when an erroneous wiring is detected, the communication circuit is separated from the communication circuit terminal to prevent the communication circuit from being destroyed by the erroneous wiring.

Japanese Unexamined Patent Publication No. 7-217972

In Patent Document 1, since an overvoltage detector is provided for detecting erroneous wiring, there is a problem that the number of parts increases and the cost increases accordingly. Further, even in a normal connection state without erroneous wiring, an overvoltage may be temporarily generated due to noise. In such a case, it is not particularly necessary to disconnect the communication circuit, but Patent Document 1 describes erroneous wiring. No consideration is given to distinguishing between overvoltage due to noise and temporary overvoltage due to noise.

The present invention has been made in view of the above problems, and provides an air conditioner capable of detecting erroneous wiring between an indoor unit and an outdoor unit without providing a special component for detecting erroneous wiring. The purpose.

In order to solve the above problems, the present invention is an air conditioner in which an indoor unit and an outdoor unit are connected via a communication line and a power supply line, and the indoor unit-outdoor via the communication line. It has a control unit that controls communication between machines and power supply between the indoor unit and the outdoor unit via the power supply line, and the control unit detects an abnormal signal in the communication line. It is characterized in that an erroneous wiring of the communication line and the power supply line is detected and the power supply in the power supply line is stopped.

According to the above configuration, an abnormal signal generated when erroneous wiring of a communication line and a power supply line occurs can be detected by a control unit (for example, a microcomputer), and erroneous wiring can be detected by input determination of the control unit. .. As a result, it is not necessary to provide a special component (for example, an overvoltage detector) for detecting erroneous wiring in the control circuit, the control circuit can be simplified, and the cost can be reduced.

Further, in the air conditioner, the control unit may be configured to detect as the abnormal signal when a High signal or a Low signal that continues for a first predetermined time or longer is input.

According to the above configuration, when miswiring of the communication line and the power supply line occurs, the input signal at the time of communication reception of the control unit becomes a high signal or a low signal without change, so that the miswiring can be reliably detected. Can be done. Further, since the high signal or the low signal is detected as an abnormal signal only when the high signal or the low signal continues for the first predetermined time or more, it is possible to reliably distinguish the abnormal signal from the high signal or the low signal generated in normal communication. can.

Further, in the air conditioner, the air conditioner is operated by a commercial power source, and the control unit receives the abnormal signal only at the time of the first serial communication after the power plug is plugged into the outlet. It can be configured to determine incorrect wiring by detection.

According to the above configuration, the miswiring is determined only in the first serial communication after plugging, which needs to detect miswiring, and is erroneous in situations where self-noise of the air conditioner during compressor operation occurs. Since the wiring is not determined, it is possible to avoid erroneous determination due to self-noise.

Further, in the air conditioner, the control unit is a High signal that continues for a second predetermined time longer than the first predetermined time, except for the first serial communication after the power plug is plugged into the outlet. Alternatively, when a Low signal is input, it is determined that there is an abnormality, and the power supply in the power supply line can be stopped.

According to the above configuration, in the first serial communication after plugging in which it is necessary to detect erroneous wiring, the first predetermined time for determination can be shortened, and the energization can be promptly stopped when erroneous wiring is detected. can. On the other hand, in serial communication when it is not necessary to detect erroneous wiring (when it is not the first serial communication after plugging in), the second predetermined time for judgment should be lengthened to avoid erroneous judgment due to self-noise. Can be done.

In the air conditioner of the present invention, an abnormal signal generated when an erroneous wiring of a communication line and a power supply line occurs is detected by a control unit (for example, a microcomputer), and the erroneous wiring is detected by an input determination of the control unit. It is not necessary to provide a special component (for example, an overvoltage detector) for detecting erroneous wiring in the control circuit, and the control circuit can be simplified and the cost can be reduced.

It is a circuit diagram which shows the schematic structure of the control circuit of the air conditioner which concerns on Embodiment 1. FIG. It is a circuit diagram which shows the example of the case where erroneous wiring occurs in the control circuit of FIG. It is a circuit diagram which shows the other example when the miswiring occurs in the control circuit of FIG. It is a circuit diagram which shows the other example when the miswiring occurs in the control circuit of FIG. It is a flowchart which shows the miswiring detection method in Embodiment 3. FIG.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a circuit diagram showing a schematic configuration of a control circuit of an air conditioner according to the first embodiment. The circuit diagram in FIG. 1 is a simplified diagram in which parts that are not directly related to the characteristic parts of the present invention are appropriately omitted.

The control circuit shown in FIG. 1 is composed of an indoor side circuit 100 provided in an indoor unit of an air conditioner and an outdoor circuit 200 provided in an outdoor unit. The indoor side circuit 100 includes an indoor microcomputer M1 and a first serial communication circuit 110, and the outdoor circuit 200 includes an outdoor microcomputer M2 and a second serial communication circuit 210. That is, in the air conditioner according to the first embodiment, serial communication is used for control between the indoor unit and the outdoor unit. Further, the operating power of this control circuit is supplied to the indoor circuit 100 from the power plug P connected to the commercial power supply, and is supplied to the outdoor circuit 200 from the indoor circuit 100 via the AC power supply line (power supply line). Will be done.

The indoor circuit 100 and the outdoor circuit 200 are connected by three wires 301 to 303. The wiring connection of the indoor circuit 100 and the outdoor circuit 200 requires two wirings as a serial communication line (communication line) and two wirings as an AC power supply line. In the control circuit of FIG. 1, by sharing one wiring with the serial communication line and the AC power supply line, it is possible to connect by three wirings 301 to 303. Specifically, the AC power supply line is configured by the wirings 301 and 302, the serial communication line is configured by the wirings 302 and 303, and the wiring 302 is shared by both lines. In this case, although the AC power supply line is composed of the wirings 301 and 302, the AC current flows only in the wiring 301, and the DC current also flows in the wiring 302.

The indoor circuit 100 has three connection terminals T11, T21, and T31, and the outdoor circuit 200 has three connection terminals T12, T22, and T32. The wiring 301 connects between the connection terminal T11 and the connection terminal T12. The wiring 302 connects between the connection terminal T21 and the connection terminal T22. The wiring 303 connects between the connection terminal T31 and the connection terminal T32. Further, the indoor circuit 100 and the outdoor circuit 200 each include a capacitor C1 and a capacitor C2 for noise prevention in an AC power supply line. Further, the relay RY1 provided in the indoor circuit 100 is a power supply relay, and when the relay RY1 is turned on, operating power is supplied to the outdoor circuit 200, and when the relay RY1 is turned off, the relay RY1 is supplied to the outdoor circuit 200. The operating power is cut off.

The first serial communication circuit 110 includes a first photocoupler 111 for signal reception and a second photocoupler 112 for signal transmission. Further, the first serial communication circuit 110 includes a DC power supply Vs for the serial circuit, a reverse current prevention diode D1, a Zener diode ZD1 for protecting the second photocoupler 112, and resistors R1 to R3 for current limiting. are doing.

The second serial communication circuit 210 has a third photocoupler 211 for signal reception and a fourth photocoupler 212 for signal transmission. Further, the second serial communication circuit 210 includes a reverse current prevention diode D2, a noise prevention capacitor C3 in the serial communication line, a Zener diode ZD2 for protecting the fourth photocoupler 212, and current limiting resistors R4 to R6. And have.

In the control circuit of FIG. 1, when a signal is transmitted from the indoor circuit 100 to the outdoor circuit 200, the second photocoupler 112 transmits a signal (pulse signal) according to the output of the indoor microcomputer M1. The signal transmitted by the second photocoupler 112 is received by the third photocoupler 211 of the outdoor circuit 200 and input to the outdoor microcomputer M2. Specifically, when the output of the outdoor microcomputer M2 is Low and the fourth photocoupler 212 is ON, when the output of the indoor microcomputer M1 is Low, the second photocoupler 112 is ON and the input of the outdoor microcomputer M2 is High. Become. When the output of the outdoor microcomputer M2 is Low and the fourth photocoupler 212 is ON, when the output of the indoor microcomputer M1 is High, the second photocoupler 112 is OFF and the input of the outdoor microcomputer M2 is Low.

When a signal is transmitted from the outdoor circuit 200 to the indoor circuit 100, the fourth photocoupler 212 transmits a signal (pulse signal) according to the output of the outdoor microcomputer M2. The signal transmitted by the fourth photocoupler 212 is received by the first photocoupler 111 of the indoor circuit 100 and input to the indoor microcomputer M1. Specifically, when the output of the indoor microcomputer M1 is Low and the second photocoupler 112 is ON, when the output of the outdoor microcomputer M2 is Low, the fourth photocoupler 212 is ON and the input of the indoor microcomputer M1 is High. Become. When the output of the indoor microcomputer M1 is Low and the second photocoupler 112 is ON, and when the output of the outdoor microcomputer M2 is High, the fourth photocoupler 212 is OFF and the input of the indoor microcomputer M1 is Low.

FIG. 1 shows a case where the indoor circuit 100 and the outdoor circuit 200 are normally connected by wiring, but in reality, erroneous wiring may occur between the indoor circuit 100 and the outdoor circuit 200. be. FIG. 2 is a circuit diagram showing an example of a case where erroneous wiring occurs in the control circuit of FIG.

In the erroneous wiring shown in FIG. 2, the connection terminal T32 is connected to the connection terminal T11, the connection terminal T12 is connected to the connection terminal T31, and the connection terminal T22 is connected to the connection terminal T21. That is, the wiring connection between the connection terminal T21 and the connection terminal T22 is correct, but the remaining two wiring connections are reversed.

When the erroneous wiring as shown in FIG. 2 occurs, in this control circuit, an AC power supply (commercial power supply) is applied between the connection terminal T22 and the connection terminal T32 on the outdoor circuit 200 side. As a result, the Zener diode ZD2 and the resistor R4 of the outdoor circuit 200 generate heat. At this time, an abnormal signal that is always High is input to the indoor microcomputer M1 at the time of reception.

Specifically, when an erroneous wiring occurs as shown in FIG. 2 or when an indoor signal is received, a current continues to flow through the connection terminal T31 of the indoor circuit 100, and the first photocoupler 111 is always ON. 2 When the photocoupler 112 is ON, the input of the indoor microcomputer M1 is always High. Therefore, when the indoor microcomputer M1 detects a high input for a predetermined time t1 (first predetermined time: for example, 5 seconds) or more, the indoor microcomputer M1 indicates a short-circuit determination and sets the relay RY1 in order to avoid heat generation of circuit components. Turn it off and stop energizing the outdoor circuit 200. That is, in the present embodiment, the indoor microcomputer M1 corresponds to the control unit described in the claims.

Therefore, if there is a High input of t1 or more for a predetermined time, a short-circuit determination is made, so that erroneous wiring can be reliably detected. It is desirable that the predetermined time t1 is set to a time of 1 second or longer so that the abnormal signal at the time of incorrect wiring can be reliably distinguished from the normal communication signal. Further, when erroneous wiring is detected, it is preferable that the relay RY1 is turned off in as short a time as possible in order to suppress heat generation of circuit components. Therefore, it is not preferable to set the predetermined time t1 to an unnecessarily long time, and it is desirable that the predetermined time t1 is set to a time of 10 seconds or less.

FIG. 2 shows an example in which erroneous wiring is detected by a short-circuit determination, but the erroneous wiring in which a short-circuit determination is made is not limited to the example of FIG. For example, as shown in FIG. 3, even if the wiring is erroneous, the connection terminal T22 is connected to the connection terminal T11, the connection terminal T22 is connected to the connection terminal T21, and the connection terminal T12 is connected to the connection terminal T31. Incorrect wiring can be detected by short-circuit determination of the indoor microcomputer M1. Of course, in addition to this, there are erroneous wirings detected by the short-circuit determination of the indoor microcomputer M1.

[Embodiment 2]
In the first embodiment, an example of erroneous wiring detected by the short-circuit determination of the indoor microcomputer M1 has been described. In the second embodiment, an example of erroneous wiring detected by the open determination of the indoor microcomputer M1 will be described.

FIG. 4 is a circuit diagram showing an example of a case where erroneous wiring occurs in the control circuit of FIG. In the erroneous wiring shown in FIG. 4, the connection terminal T12 is connected to the connection terminal T11, the connection terminal T22 is connected to the connection terminal T31, and the connection terminal T21 and the connection terminal T32 are not connected.

When the erroneous wiring as shown in FIG. 4 occurs, in this control circuit, an AC power supply (commercial power supply) is applied between the connection terminal T22 and the connection terminal T32 on the outdoor circuit 200 side. As a result, the Zener diode ZD2 and the resistor R4 of the outdoor circuit 200 generate heat. At this time, an abnormal signal that is always Low is always input to the indoor microcomputer M1.

Specifically, when an erroneous wiring as shown in FIG. 4 occurs, no current flows through the connection terminal T31 of the indoor circuit 100, and the first photocoupler 111 is always OFF, so that the input of the indoor microcomputer M1 is input. It is always Low. Therefore, when the indoor microcomputer M1 detects a Low input for a predetermined time t1 (for example, 5 seconds) or more, the indoor microcomputer M1 indicates an open determination, the relay RY1 is turned off to avoid heat generation of circuit components, and the outdoor circuit. Stop energizing the 200.

When the indoor circuit 100 and the outdoor circuit 200 are normally connected and the operating power is supplied to the outdoor circuit 200, the input of the indoor microcomputer M1 is for a long time (predetermined time t1 or more). ) It doesn't stay low. This is because when the operating power is supplied to the outdoor circuit 200, communication is always performed between the indoor circuit 100 and the outdoor circuit 200, and the input of the indoor microcomputer M1 frequently switches between High / Low. Is. Therefore, it is possible to reliably detect erroneous wiring by making an open determination when there is a Low input of t1 or more for a predetermined time.

Note that FIG. 4 is only an example of erroneous wiring that can be detected by the open determination of the indoor microcomputer M1, and there are other erroneous wirings that can be detected by the open determination of the indoor microcomputer M1.

When erroneous wiring occurs between the indoor side circuit 100 and the outdoor circuit 200, regardless of the erroneous wiring, in the indoor microcomputer M1, the short-circuit determination shown in the first embodiment or the second embodiment is performed. It is one of the open determinations shown in the above, and it is possible to reliably detect erroneous wiring. Further, by detecting the miswiring by the input determination of the indoor microcomputer M1, it is not necessary to provide a special component (for example, an overvoltage detector) for detecting the miswiring, so that the control circuit can be simplified and the cost can be reduced. It will contribute. The logical relationship between the microcomputer and the photocoupler in the above description is merely an example, and the present invention is not limited thereto. For example, a transistor may be interposed between the microcomputer and the photocoupler, but in this case, the logical relationship between the microcomputer and the photocoupler is reversed.

[Embodiment 3]
In the first and second embodiments, when an abnormal signal (serial error) at a predetermined time t1 is detected at the input of the indoor microcomputer M1, it is detected as an erroneous wiring and the energization to the outdoor circuit 200 is stopped. However, in this case, in the air conditioner during actual operation, an error such as erroneous wiring is erroneously determined even during normal operation without erroneous wiring due to self-noise generated from the compressor during operation. It is possible that the case will end up.

In order to avoid such erroneous determination due to self-noise, it is conceivable to take a predetermined time t1 until erroneous wiring is detected. However, when the predetermined time t1 is lengthened, the time until the miswiring is detected and the operation is stopped becomes long, and the time for applying the high voltage commercial power supply to the serial communication circuit which is a low voltage circuit is also long. become longer. Therefore, heat generation of circuit parts due to energization until the operation is stopped cannot be ignored.

In the third embodiment, an erroneous wiring detection method capable of avoiding erroneous determination due to self-noise and promptly detecting the erroneous wiring and stopping the operation will be described. FIG. 5 is a flowchart showing the erroneous wiring detection method in the third embodiment.

First, when the relay RY1 is turned on and the operation of the air conditioner is started (ST1), the first serial communication after the start of operation is the first serial communication after the power plug P is plugged into the indoor outlet. Whether or not it is determined (ST2). Then, when it is the first serial communication after the plug is inserted (YES in ST2), it shifts to ST3, and when it is not the first serial communication after the plug is inserted (NO in ST2), it shifts to ST4. Since the indoor microcomputer M1 is reset when the power plug P is inserted into the indoor outlet, it is possible to determine ST2 depending on the presence or absence of this reset.

In ST3, when a serial error of t1 or more for a predetermined time is detected (YES in ST2), a stop operation is performed by error detection (ST7), and when such a serial error is not detected (NO in ST2), operation is performed. (ST5).

That is, in ST3, the miswiring determination described in the first and second embodiments is performed. This is because the load of the compressor etc. is not operating in the serial communication immediately after the start of operation, so there is little self-noise (the possibility of erroneous judgment due to self-noise is low), and erroneous wiring is only during the installation work of the air conditioner. This is because if the miswiring is not detected in the first serial communication after the plug is inserted, there is no problem with the miswiring after that.

On the other hand, in ST4, when a serial error for a predetermined time t2 (second predetermined time) or longer is detected (YES in ST4), a stop operation is performed by error detection (ST7), and no such serial error is detected. In the case (NO in ST4), the operation is continued (ST6). Here, the predetermined time t2 is set to be a longer time (for example, 30 seconds) than the predetermined time t1 in ST3. If the operation is continued in ST5 or ST6, the operation shifts to ST4, and the determination of ST4 is repeatedly executed during the operation of the air conditioner.

In the determination of ST4, since it is not the first serial communication after the plug is inserted, it is not necessary to detect the incorrect wiring, and a serial error due to a factor other than the incorrect wiring such as a failure of a circuit component is detected. However, in this determination, since self-noise is generated by the operation of a load such as a compressor, the predetermined time t2 is set longer than the predetermined time t1 so as to avoid erroneous determination due to self-noise. Even if an error is detected in the determination of ST4, since this is not an error due to incorrect wiring, a high voltage is not applied to the serial communication circuit which is a low voltage circuit. Therefore, even if the predetermined time t2 required for the determination of ST4 is lengthened, the problem of heat generation of the circuit component does not occur.

In the miswiring detection method according to the third embodiment, the time required for determination differs depending on whether or not it is the first serial communication after the plug is inserted. Therefore, in the first serial communication after plugging in which it is necessary to detect erroneous wiring, the predetermined time t1 for determination can be shortened, and the energization can be quickly stopped when erroneous wiring is detected. On the other hand, in serial communication when it is not necessary to detect erroneous wiring (when it is not the first serial communication after plugging in), the predetermined time t2 for determination can be lengthened to avoid erroneous determination due to self-noise. ..

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

Indoor circuit 100
Outdoor circuit 200
First serial communication circuit 110
2nd serial communication circuit 210
Indoor microcomputer M1 (control unit)
Outdoor microcomputer M2
Power plug P
Connection terminals T11 to T31
Connection terminals T12 to T32
Relay RY1

Claims (3)

It is powered by commercial power and is powered by
An indoor unit equipped with a first connection terminal, a second connection terminal, and a third connection terminal,
An outdoor unit equipped with a fourth connection terminal, a fifth connection terminal, and a sixth connection terminal,
The first wiring that connects the first connection terminal and the fourth connection terminal,
The second wiring that connects the second connection terminal and the fifth connection terminal,
A third wiring that connects the third connection terminal and the sixth connection terminal,
A communication circuit provided in the indoor unit and connected to the third connection terminal,
It has an indoor microcomputer provided in the indoor unit and having an input unit connected to the communication circuit.
The first connection terminal and the fourth connection terminal are connected by the first wiring, the second connection terminal and the fifth connection terminal are connected by the second wiring, and the above. When the third connection terminal and the sixth connection terminal are connected by the wiring of the third wiring, the power supply line is formed by the first wiring and the second wiring, and the second wiring is formed. A communication line is formed by the wiring and the third wiring.
The communication circuit outputs a High signal when the third connection terminal and the fourth connection terminal are connected, and when the third connection terminal and the fifth connection terminal are connected. It is configured to output a Low signal to
The indoor microcomputer detects as an abnormal signal when the High signal or the Low signal is continuously input to the input unit for a first predetermined time or longer.
The indoor microcomputer determines miswiring by detecting the abnormal signal only at the time of the first communication after the indoor unit is connected to the power supply.
The indoor microcomputer is an air conditioner that detects as an abnormal signal when a High signal or a Low signal is continuously input for a second predetermined time longer than the first predetermined time, except during the first communication. .. The air conditioner according to claim 1.
The indoor unit is provided between the first connection terminal or the second connection terminal and a power source, and supplies or cuts off power to the first connection terminal or the second connection terminal. Equipped with a control unit
The indoor microcomputer is an air conditioner that controls the power supply control unit to cut off the supply of electric power when the abnormal signal is detected. The air conditioner according to claim 1 or 2 .
Has a compressor,
The indoor microcomputer is an air conditioner that executes the first communication before the compressor operates.

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