JPS61286901A - Protecting device for electrical equipment - Google Patents

Abstract

PURPOSE:To clarify a driven protecting device by inputting the operation of each protecting device individually in a microcomputer, stopping the driving of a contactor in accordance with said input and displaying the driven protecting device on a display unit corresponding to the device. CONSTITUTION:When any one of the protecting devices 4a, 4b is driven, any one of contacts 21a, 21b is closed and a protecting device operation signal is inputted to an input circuit 16 in the microcomputer 8. Subsequently, a de- energizing signal is outputted from an output circuit 17 of the microcomputer 8 to a contactor driving relay 22 through a buffer 26, so that a contact 22a is opened, the contactor 3 is de-energized and a contact 3a is opened to stop the operation of a compressor 2. Simultaneously, A lighting signal to a display unit 15a or 15b corresponding to the protecting device 4a or 4b is outputted from the output circuit 17 through the buffer 26 to light up the display unit 15a or 15b. Thus, the driven protecting device can be precisely displayed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for detecting abnormalities in electrical equipment such as air conditioners.
De-energize the contactor for energizing electrical equipment! ! This invention relates to a protection device for electrical equipment that stops the operation of electrical equipment.

[Prior Art] Figure 4 is an electrical circuit diagram showing a conventional air conditioner protection device described in Section 270 of the ``Cooling and Heating Handbook IJ'' published by Mitsubishi Electric in 1984. In Figure 5, (1) is a three-phase AC power supply, (2) is an electric compressor, (3) is this compressor (
2) In the energizing contactor, (3a) is its make contact, (
4a and 4b are two protective devices connected in series, which are break contacts that operate and open when the air conditioner is abnormal. (5) is a self-holding relay, (5a) (5
b) is the transfer contact of the self-holding relay (5), (
6) is a driving command signal input terminal, (7) is a relay energized by the driving command signal to the connecting terminal, and (7a) is its make contact.

Next, its operation will be explained. When the driving command signal voltage is applied from the terminal (6) to the relay (7), it is energized and the make contact (7a) is closed. This allows the contactor (
3) is the make contact (7a) between the power supply (1) lines.

It is connected in series with the protective bag [1 (4a) (4b) and the transfer contact (5a) of the relay (5), and is excited by applying the power supply voltage. This excitation causes it to make contact (
3a) is closed and power supply voltage is applied to the compressor (2).

Start driving. In this state, the protective device (4a) (
4b) operates and opens the contact, the self-holding relay (5) is momentarily connected in series with the contactor (3) and the power supply voltage is applied. However, due to the impedance difference between the self-holding relay (5) and the contactor (3), most of the power supply voltage is applied to the self-holding relay (5) and energizes it, and the contactor (3) is deenergized and the contact (3a) ) is opened and the operation of the compressor (2) is stopped. Also, due to the energization of the self-holding relay (5), its transfer contacts (5a) and (5b) are switched, and the power supply voltage is completely applied to the self-holding relay (5), and the contactor is short-circuited and becomes de-energized, completing self-holding of operation stop in the event of air conditioner abnormality.

[Problems to be solved by the invention] Conventional protection devices for electrical equipment are configured as described above, so even if a protection device operates, it is unclear which protection device has operated, and Since re-operation is easily possible by resetting the command, during service 1. For example, if the operation command has been canceled by the customer, the service person will need to check the operation of the protective device again and find the cause, which will reduce the service time. There were drawbacks such as this.

This invention was made to solve the above-mentioned problems, and aims to provide a protection device for electrical equipment that makes it clear which protection device has operated among a plurality of protection devices.

Another object of the present invention is to obtain a protection device for electrical equipment that can select whether or not it can be restarted by resetting the operation command in addition to the above-mentioned object.

[Means for Solving the Problems] A protection device for electrical equipment according to the present invention includes a microcomputer that outputs a contactor drive signal in response to an input operation command, and the microcomputer individually controls the operation of a plurality of protection devices. means for inputting information into the computer; means for outputting a signal to stop the contactor drive in response to any of the protection device operation input; and means for outputting a display signal for individually displaying the protection device operation in response to the protection operation input; It is equipped with the following.

Further, in the above-described protection device for electrical equipment according to another aspect of the present invention, an on/off signal is input to the microcomputer to turn it on.

An operation prohibition switch is provided to determine whether or not re-operation is possible upon resetting the operation command in response to an off signal.

[Function] In this invention, even if the microcomputer receives an operation command input and a contactor drive signal is output, if any of the protective devices operates and the operation input is input to the microcomputer, the contactor is activated. The drive signal output is stopped and the contactor is deenergized.

Lights up the indicator corresponding to the activated protective device.

In another aspect of the present invention, when the display turns on due to the operation of the protection device, the operation prohibition switch is turned on, and when the ON signal is input to the microcomputer, restarting the operation upon resetting the operation command is prohibited. In this way, the operation of the electrical equipment is determined by the presence or absence of an operation command, the presence or absence of a protective device operation, and whether the operation prohibition switch is on or off.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 2 is an electric circuit diagram thereof.

In the figure (1) (2) (3) (3a) (/la
) (4b) and (6) are an AC power source, a compressor, and a contactor similar to the conventional example shown in FIG.

It is a make contact, a protection device, and an operation command signal input terminal. (8) is a microcomputer (hereinafter referred to as microcomputer); (9) is an operation prohibition switch; (10) is a driving command input means for inputting a driving command signal from the driving command signal input terminal (6) to the microcomputer (8); (11) is a drive prohibition switch input means for inputting ON/OFF of the drive prohibition switch (9) to the microcomputer (8); (12a) (12)
b) The microcomputer (
(8) is a protective device operation input means for inputting the input; (13) is a contactor drive/stop signal output means for outputting a drive signal and a drive stop signal from the microcomputer (8) to the contactor (3);
(14) is an indicator (such as an LED) when the protective device (4a) is activated.
15a), the protective device (4b) and the operating indicator (15b)
This is a display signal output means for lighting up. In Figure 2, (16) is the input circuit of the microcomputer (8), (17) is the output circuit, (18) is the central processing unit (hereinafter referred to as CPU), (19) is memory, (20a) and (20b) are An abnormality capture relay that is deenergized according to the operation of the protective devices (4a) and (4b), (21a) and (21b) are their break contacts, (22) is a relay for driving the contactor (3),
(22a) is its make contact, (23) is a photocoupler for operation command input, and (24) is a current limiting resistor.

(25) is a pull-up resistor, and (26) is a buffer.

Next, the operation will be explained with reference to the flowchart of FIG. 3 showing a program stored in the memory (19) of the microcomputer (8) and executed by the CPU (18). To start the program, in step (30), the terminal (6) is connected to the microcomputer (8) via the photocoupler (23).
) receives a driving command signal input to the CPU (18
) and output circuit (17) based on the result.
contactor drive relay (2) via the buffer (26).
2) An energizing signal is output, the contact (22a) closes, the contactor (3) is driven, the contact (3a) closes, and the air conditioner (2) enters the operating state.0th step (31) Check whether the protective bag [(4a) or (4b) is operating. When either of the protective devices F (4a) (4b) operates, that is, the abnormality capture relay (20a) (
20b) is deenergized and the contact (21a) (21b
) is closed, the input circuit (16) of the microcontroller (8)
When the protective device operation signal is input to the step (32)
Proceed to.

From the output circuit (17) of the microcomputer (8) to the buffer (26
), a de-energizing signal is output to the contactor drive relay (22χ), which opens the contact (22a) to de-energize the contactor (3), and opens the contact (3a) to operate the compressor (2). In the next step (33), the indicator (15a) or (15b) corresponding to the protective device (4a) or (4b) is
A lighting signal is outputted from the output circuit (17) of the microcomputer (8) via the buffer (26), and the indicator (15a) or (15b) lights up.

Next, the process advances to step (34) to check whether the driving command has been reset. If the operation command is not reset, the protective device self-holding loop (32) (33) (3
Repeat 4). Compressor (2) operation stop and indicator (
15a) When (15b) lights up, the user knows that an abnormality has occurred, and if the cause is easily identified and removed immediately,
If you reset the operation command without turning on the operation prohibition switch (9), it will proceed to steps (34) and (35) and go to step (
36) outputs an energizing signal to the contactor drive relay (22) to start operation, and in step (37) the display (15a) (
15b) is turned off. When the cause of the abnormality is unknown, the user turns on the operation prohibition switch (9). If the ON signal is input to the input circuit of the microcomputer (8), for example, even if the operation command is reset by mistake, the process returns from step (35) to step (32) and restarting the operation is prevented.

In the above embodiments, the protection device for a compressor was explained as an example, but it goes without saying that the present invention can be applied to electrical equipment other than compressors.

[Effects of the Invention] As described above, according to the present invention, the operation of the protection device is individually input to the microcomputer, the drive of the contactor is stopped according to the input, and the display corresponding to the protection device is displayed. Because of this, it is possible to confirm which protective device has been activated, which has the effect of making it easier to discover the cause and enable prompt service.

According to another invention of the present invention, an operation prohibition switch is provided, and the ON/OFF signal of this switch is inputted to the microcomputer to determine whether or not to restart the operation when the operation command is reset. It has the effect of preventing the restart of operation of electrical equipment before removal.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an embodiment of the present invention, Fig. 2 is an electric circuit diagram thereof, Fig. 3 is a flowchart showing its operation, and Fig. 4 is a diagram of a conventional protection device for an air conditioner. It is an electrical circuit diagram. In the figure, (2) is a compressor that is an electrical device, (3) is a contactor, (4a) and (4b) are protective devices, (6) is an operation command signal input terminal, (8) is a microcomputer, and (9) is a
) is a drive prohibition switch, (10) is a drive command input means,
(11) is an operation prohibition switch input means, (12a) (
12b) is a protective device operation input means, (13) is a contactor drive/stop output means, (14) is a display signal output means, (
15a) and (15b) are indicators. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (2)

[Claims] (1) In a protection device for electrical equipment that has a plurality of protection devices that operate in the event of an individual abnormality and deenergize the contactor for energizing the electrical equipment, a microcomputer outputs the contactor drive signal in response to the input of an operation command. means for individually inputting the operations of the plurality of protection devices to the microcomputer, and outputting a signal from the microcomputer to stop the driving of the contactor in response to input of the operation of any of the protection devices by the means; and means for outputting a display signal from the microcomputer that individually displays the protection device operation in response to the protection device operation input. (2) In a protection device for electrical equipment having a plurality of protection devices that operate in the event of an individual abnormality and deenergize the electrical equipment energizing contactor, a microcomputer outputs the contactor driving signal in response to the input of an operation command. means for individually inputting the operations of the plurality of protection devices to the microcomputer, and outputting a signal from the microcomputer to stop the driving of the contactor in response to input of the operation of any of the protection devices by the means; means for outputting a display signal from the microcomputer that individually displays the protective device operation in response to the protective device operation input, and inputting an on/off signal to the microcomputer and responding to the on/off signal. A protection device for electrical equipment characterized by comprising an operation prohibition switch for determining whether or not to restart the operation when the operation command is reset.