JP2002271984A - Test method of accident automatic recovery equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a test method of accident automatic recovery equipment wherein test is performed by forming a data base for simulation of high speed and high reliability. SOLUTION: This test method performs test by using data for simulation of an accident case for estimating recovery function of the automatic recovery equipment performing recovery by switching to a normal bus from a sensor of a power transmission circuit as an object of the accident automatic recovery and change of a switch. An accident standardization list which displays operation of each sensor arranged in a power transmission circuit at every accident case to be estimated, and a position list which displays operation of each switch are formed (A step). Every accident case estimated on the basis of the lists, input is performed to a wiring diagram 1 of an electric circuit displayed on an image plane of a computer, a test case list 21 a result confirmation list 3 and a data base 4 for simulation are outputted, which are inputted in the automatic recovery equipment, and this response result is referred to the result confirmation list 3, thereby judging whether the response result is acceptable (C step).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test method for an automatic recovery system for recovering an electric circuit system immediately after an accident occurs.

[0002]

2. Description of the Related Art When a short circuit accident occurs due to a lightning strike, a ground fault, or the like in an electric circuit system, for example, a part of a power transmission circuit of a substation, an automatic recovery device is provided to recover power transmission as quickly as possible. . The power transmission circuit has a configuration shown in FIG. 6, for example. FIG. 6 is a circuit diagram showing a circuit system for transmitting power from a substation bus to a factory, a building, a customer, and the like.
There are a plurality of AC power bus systems, for example, a bus 51 of the first and second systems,
52 is installed. It is assumed that a line system for transmitting power to a factory, a building, a customer, or the like is mainly used in one of the insteps A and B, for example, in the instep 51.

In this state, if it is assumed that an accident has occurred in one of the instep buses 51, 52, for example, instep A, the automatic recovery device checks that the inversion bus 52 is in a normal circuit, and switches to the ingress bus 52. It has a recovery function to recover the power outage time to the shortest time. That is, a large number of line systems 53, 5
4 is an example of connection. These line systems 53 and 54 are connected to the instep bus 51 by a disconnector 55 and an accident sensor 5
6. The gas pressure sensor 57 and the circuit breaker 58 are connected in series. In a normal state, the disconnecting switch 55 is in a conductive state and the power is transmitted through the current path of the instep bus 51.

In addition, a series circuit such as a disconnector 59, a current meter 60 for an accident sensor, a gas pressure sensor 57, and the like is connected between the circuit breaker 58 and the maiden bus 52 in order to quickly and automatically recover from an accident. . Thus, the line systems 53, 54
Is configured. When an accident occurs, the automatic recovery device controls the disconnector 55 (or 59) and the circuit breaker 58 to switch the bus so that the power outage time becomes extremely short, and
54 are protected. That is, it is assumed that a short circuit accident has occurred in the portion of the instep bus 51 indicated by the arrow 65. As a result, a large current flows through the line system transmitted from the instep bus 51.

When this current is detected by the current transformer 56 and the relay circuit is operated, the gas pressure sensor 57 detects a decrease in gas pressure. Immediately after this detection, the circuit breaker 58 operates in a non-conductive state (OFF) to bring the lower circuit into a power failure state. The automatic recovery device operates based on the detection result of the relay circuit and the gas pressure sensor 57. After confirming the normality of the maiden bus 52, the automatic restoration device switches off the disconnector 55 and controls the switching to the maiden bus 52 (normal circuit).
That is, the automatic recovery device turns off the disconnector 55 and then controls the disconnector 59 to the conductive state (ON) to switch the power transmission from the maiden bus 52. After this switching, the circuit breaker 58 is turned on manually or automatically to operate so that the power failure time becomes short.

The configuration of the automatic recovery system having such a function is the circuit configuration shown in FIG. 6 will be described using the same reference numerals, and detailed description thereof will be omitted. At normal time, the disconnector 55 is turned ON, and the line system 53
When an accident occurs (at the time of an accident), the output of a gas pressure sensor 57 and a relay circuit for specifying which circuit caused the accident are input to the information control device 71.

The circuit information input to the information control device 71 is transmitted to the failure determination automatic recovery control circuit 72 via a LAN.
The signal processing for automatic restoration is executed by Ethernet (registered trademark) communication via 73. That is, the failure determination automatic recovery control circuit 72 detects a change between the stored pre-accident data and the data at the time of the accident, determines the location of the failure, and outputs a control signal for restoring the failure. The configuration for creating this control signal is the automatic recovery device 74. The control signal output from the automatic recovery device 74 is the information control device 7
1. Supply to the line unit control boards 76, 77, 78 of the respective line systems 53, 54 via the star coupler 75.

The line-based control boards 76 to 78 automatically recover in response to a command from the automatic recovery device 74. Thus, the automatic recovery system is configured. After the automatic recovery device 74 having such a function is manufactured at a factory, a highly reliable test is performed before shipment. In this test, a number of estimated accident cases are created and input to the information control device 71 as test data for each case to test (test) whether an operation that satisfies the design specifications is performed. That is, a test (test) of the automatic restoration device 74 by simulation.

Next, a procedure for creating the simulation database will be described with reference to a flowchart of FIG. FIG. 8 is a flowchart illustrating a procedure for creating a simulation database for testing the automatic recovery device.

First, the step A will be described. An operator manually creates on the paper a large number of estimated failure cases as described above on the paper as a “fault location list”. This fault location list is a table showing the state of each sensor connected to each circuit shown in FIG. 6 at the time of failure.
A large number of such tables are created for every estimated failure case.

Further, for each case described in the "fault location list", a "position table (transmission relation)" indicating the operating state of each circuit component connected to each circuit in FIG. 6 is manually entered. Create on paper. This table creates the status before the accident (normal) and after the accident (when the accident occurs).

Next, the B step will be described. A state change record (test case) of each circuit element is manually created on the paper for each case in the position table. This figure is of two types, a "system status confirmation diagram" and a "drawing data confirmation diagram".
In the former system status check diagram, a change in the status of each circuit in the power transmission circuit connection diagram shown in FIG. 6 is schematically illustrated on paper for each failure case. The following drawing data confirmation diagram shows a failure occurrence location for each failure case in the power transmission circuit connection diagram shown in FIG. Further, a state change message is created. The state change message lists the operation state of each circuit component of the power transmission circuit shown in FIG. 6 for each failure case.

Next, step C will be described. FIG.
The lighting state of the indicator lamp connected to the power transmission circuit is manually created on the paper as a result confirmation table for each failure case.

Next, the D step will be described. From the test case table, a simulation database is created by hand on paper. This database contains 32 words
Is a bit. A database in which the operations of each of the circuit components A and B are expressed as "1" and "0" for each word is listed before and after the accident. By comparing the tables before and after the accident, it is possible to determine where (in which circuit) the accident has occurred.

A test before shipment of the automatic recovery device has been performed using the database created in this manner.
In addition, since such an automatic restoration device has a different system configuration such as each power plant and each substation, there is no exactly the same device, and an appropriate device is designed each time. Therefore, it is necessary to change the test content to a content suitable for the design, and it is necessary to perform a highly reliable test.

[0016]

However, in the above-mentioned test work, since there are so many failure cases, manual creation requires an enormous amount of time by advanced engineers. Although such test methods are highly reliable,
The cost has increased. It is also affecting cheap electricity supply. Further, since there are no identical electric circuit configurations, all automatic recovery devices are different. Therefore, it is necessary to create a simulation database for each device. Since this database is created by an advanced engineer, high reliability can be obtained, but human-based manual input is extremely erroneous. Since the test based on the erroneous input deteriorates the reliability of the automatic recovery apparatus, a considerable loss time is generated in error detection and correction by the check. Furthermore, after the test was completed, it took an enormous amount of time to create a report of the automatic recovery device.

The present invention has been made in view of the above circumstances, and a human analyzes a technology having a higher reliability and a technology having a higher probability of occurrence of a human error to speed up a highly reliable test. It is an object of the present invention to provide a test method for such an automatic recovery system for accidents.

Further, the present invention improves manual operation on paper, and tests an automatic accident recovery system by simulation in which a test case table, a result confirmation table, and a simulation database are automatically created by manually inputting a position table to a personal computer. It is intended to provide a test method of the accident automatic recovery device which is made to perform the test.

[0019]

In order to achieve the above object, a test method for an automatic recovery system for accidents according to the present invention is based on a change in sensors and switches provided in an electric circuit to be automatically recovered in case of an accident. A method for testing the restoration function of an automatic restoration device for restoring by switching to a normal circuit using simulation data of an estimated accident case, wherein the operation of each sensor provided in the electric circuit is displayed for each estimated accident case. A fault circuit specifying step of creating a fault locating table, an operation displaying step of creating a position table for each accident case in which the operation of each switch provided in the electric circuit is estimated, and the fault locating table and the position. A test case in which the information in the table is input to a computer for each estimated accident case and the operation of each switch provided in the electric circuit is displayed for each accident case Table, a result confirmation table which is a lighting result of an indicator light provided in the automatic recovery device, a calculation step by a computer for calculating and outputting the simulation database, and the simulation database and the test case table as test signals to the automatic recovery device. It is characterized by comprising a test step for inputting, and a judging step of judging pass / fail by comparing a response result of the automatic restoration apparatus with the result confirmation table by this test step.

The test method of the automatic accident recovery system of the present invention is as follows.
This is a method to test the restoration function of an automatic restoration device that switches to a normal circuit from changes in the sensors and switches of the electric circuit that is the subject of automatic restoration in the event of an accident and restores it using the simulation data of the estimated accident case. A fault circuit specifying step of creating a fault location table displaying for each accident case in which the operation of each sensor provided in the electric circuit is estimated; and an accident in which the operation of each switch provided in the electric circuit is estimated. An operation display step of creating a position table displayed for each case, and inputting the information of the fault location table and the position table to a wiring diagram of the electric circuit displayed on a computer screen for each estimated accident case for testing A calculation step by a computer for calculating and outputting a case table, a result confirmation table, and a simulation database; A test step of inputting a database and a test case table to the automatic recovery device as a test signal, and a determination step of comparing the response result of the automatic recovery device with the result confirmation table to determine pass / fail by the test step. It is characterized by becoming.

The test method of the automatic accident recovery system of the present invention is as follows.
The recovery function of the automatic recovery device that recovers by switching to the normal bus from changes in the sensors and switches installed in the power transmission circuit subject to automatic recovery in the event of an accident is tested using the simulation data of the estimated accident case. So,
A fault circuit specifying step of creating a fault location table displaying for each accident case in which the operation of each sensor provided in the power transmission circuit is estimated; and an accident in which the operation of each switch provided in the power transmission circuit is estimated. An operation display step of creating a position table displayed for each case, and inputting the information of the fault location table and the position table to a wiring diagram of the electric circuit displayed on a computer screen for each estimated accident case for testing A calculation step by a computer for calculating and outputting a case table, a result confirmation table, and a simulation database; a test step of inputting the simulation database and the test case table to the automatic recovery apparatus as a test signal; And comparing the response result with the result confirmation table to judge pass / fail. And characterized by being Bei.

The sensor is a gas pressure sensor and a relay circuit. The switch is a circuit breaker or a disconnector.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a test method for an automatic accident recovery system according to the present invention will be described with reference to FIG. FIG. 1 is a flowchart for explaining a simulation database creation procedure for testing the automatic accident recovery system. Since the automatic recovery device has been described with reference to FIG. This test database creation procedure is configured by combining a technique that is more reliable for humans and a technique that has a higher probability of error occurrence by humans.

That is, the former technique, which is more reliable for humans, is the step of creating a “fault location list” and a “position table”. The latter technique having a high probability of human error occurrence is a step of creating a "test case table, a result confirmation table, a simulation database" created from the "fault location list, position table". The latter creation step is automatically created by a computer (computer). In this way, a large number of accurate and reliable accident cases are created at high speed. Next, these will be described specifically.

Step A A "fault location list" is manually created on the paper for each estimated failure case. One embodiment of the failure case will be described with reference to Table 1. The fault location list is a table that describes the operating states of the respective sensors that perform faults provided in the wiring diagram (system diagram) of the power transmission circuit to be automatically recovered as described in FIG. This table is created for each of a large number of estimated accidents (failures). Therefore, as shown in Table 1, it is a table indicating whether the operation of each component at the time of the occurrence of an accident is "normal" or "abnormal". Table 1 is a table for explaining an embodiment of the fault location list. Therefore, it is a table showing that an accident has occurred in the circuit of the component that is abnormally displayed. That is, a faulty circuit can be specified.

[0026]

[Table 1]

Further, a position table is created. This position table is a table showing an operation state of each switch constituting a wiring diagram (system diagram) of a power transmission circuit to be automatically restored for each failure case, and Table 2 shows an example. . Table 2 is a table for explaining an embodiment of the position table. That is, this is a table in which the operation states of the disconnectors 55 and 59 and the circuit breakers 58 of the lines 53 and 54 are displayed as “ON” and “OFF”.

[0028]

[Table 2]

The list of fault locations shown in Table 1 and Table 2
From the position table, which circuit in the system diagram caused the accident can be specified.

Step B Information of the fault location list and the position table created in the step A is input to a computer (computer). This computer input is input by, for example, a personal computer screen (C
Input from the screen as in the AD system). FIG. 1 shows a personal computer screen 1. In this personal computer, a wiring diagram (system diagram) of the power transmission circuit to be automatically restored described with reference to FIG. 6 is previously registered and stored. This power transmission circuit is an AC power transmission system shown in FIG.
Lines 53, 5 for factories, buildings, consumers, etc. from 1, 52
4 is a circuit showing a system for transmitting power to the power supply circuit 4.

This power transmission circuit can be called up and displayed on the personal computer screen 1 as needed. The system state diagram is a diagram that is input for each failure case based on the failure localization list and the position table shown in Tables 1 and 2 on the displayed personal computer screen. This system state diagram is input to the personal computer.

Step C As a result, the personal computer 1 automatically creates and displays the test case table 2, the result confirmation table 3, and the simulation database 4 using software previously input. Test case table 2
There are a system status confirmation diagram and a drawing data confirmation diagram. FIG. 2 shows an example of the former system status confirmation diagram. The latter drawing data confirmation diagram is shown, for example, in FIG. First, the former system status confirmation diagram will be described. FIG. 2 is a system status confirmation diagram showing one embodiment of the failure case. This case is a system state confirmation diagram of a failure case in which a ground fault occurs in the instep bus 1.

The wiring diagram of the power transmission circuit has a configuration in which the lines 53 and 54 are connected to the lines A and B shown in FIG. In this table, □ indicates a circuit breaker, ○ indicates a disconnector, and a black circle x indicates that the disconnector was switched ON before the accident and OFF after the accident. Single circle 7 indicates a disconnector that was OFF before the accident. , And the double circle 8 indicates the ON disconnector after the accident,
A cross mark 9 in a black square indicates a state in which the circuit breaker has been turned off due to an accident.

That is, before the accident, the line 53 from the Kou bus 51,
The disconnector 55 and the circuit breaker 58 are controlled to be ON so as to supply power to the
Is turned off to set a standby state. At one time, for example, a ground fault is suddenly generated at one location of the instep bus 51, and when this is detected, the circuit breaker 58 is turned off. After that, Otomo Line 5
Check that 2 is normal. Then, the instep bus 51 and the disconnector 55 of the line from the instep bus 51 are turned off. Next, the disconnector 5 connected to the line from the
9 is turned ON.

FIG. 2 shows a "system state confirmation diagram" of one such failure case.

Such a "system state confirmation diagram" is automatically created by a personal computer by calculating a large number of failure cases estimated in the power transmission circuit of FIG. The “drawing data confirmation diagram” corresponding to each of these “system status confirmation diagrams” is also automatically created by the personal computer. Figure 3 shows the drawing data confirmation diagram.
And shows the failed wiring location for each failure case.

FIG. 3 shows a configuration in which all the wires 11 are provided in a gas pipe 12 for setting the power transmission circuit of FIG. 2 in the insulating gas, and the insulating gas is supplied into the gas pipe 12. . The marking line 13 is indicated on the gas pipe 12 to indicate the sensing area of each gas pressure sensor. The drawings up to the point where the gas pipe 12 is provided in FIG. 3 are shown for explaining the sensing area where the gas pressure sensor 57 is provided.

In the gas pressure sensor 57, a large current flows through the circuit in which the accident has occurred, so that the pressure of the filled gas decreases. This change in gas pressure is detected by the gas pressure sensor 5.
7 and input to the automatic recovery device as information. Such a “drawing data confirmation diagram” is automatically created by calculation by a personal computer. FIG. 3 shows a state in which a drawing data confirmation diagram is displayed as one failure case on the personal computer screen.

Next, the result confirmation table 3 will be described. The result confirmation table 3 includes a state change message table and a result confirmation table. The former state change message table is shown in, for example, Table 3, and the latter result confirmation table is shown in, for example, Table 4.

[0040]

[Table 3]

[Table 4]

First, the former state change message table shows the operation state of each switch in each failure case. The operation state is displayed as “ON” and “OFF”. Such a state change message table is automatically created by calculation by a personal computer. The latter result check table is created automatically by a personal computer by calculating whether or not the indicator lights of the circuits provided on the panel of the switchboard of the power transmission circuit indicate whether or not the lights are on for each failure case. This lighting can be indicated by, for example, an LED light emitting element.

Next, the simulation database 4
Will be described. As shown in Tables 5 and 6, this simulation database 4 expresses one word by 32 bits, and each breaker (Circu) of the instep and the maiden bus system.
it Breaker = CB), disconnector (Line Sw)
This is a database in which the operation of “itch = LS) is expressed by“ 1 ”and“ 0 ”. This database is automatically created by a personal computer before and after the accident.

[0043]

[Table 5]

[Table 6]

The database created as described above is input as a test signal to the information control device 71 of the automatic recovery device 74 shown in FIG. 7 to execute a test. The response result of the automatic restoration device 74 is compared and collated with the result confirmation table to determine the quality. If the judgment is "good" for all the accident cases, it is shipped. In this way, by creating a process in which a human is likely to make a mistake by a personal computer, simulation data of the automatic recovery device 74 can be created quickly and accurately. Therefore, the number of advanced engineers can be tested with a smaller number and in a shorter time.

FIG. 4 shows a system for creating a simulation database by the computer in the C and D steps. FIG. 4 is a system configuration diagram for automatically creating a simulation database. The flow for automatically creating a simulation database by this system is as shown in FIG. The central processing unit (CPU) 21 reads out the power transmission circuit from the power transmission circuit data file 24 and displays it on the display device 25 according to a command of the control program in the main memory 23 via the bus 22.

Data is input to the power transmission circuit displayed on the display device 25 by the input device 26 based on the fault location list and the position table for each fault case. The input data is transmitted to the image processing device 27 and the test case table 2 via the bus 22 by a control program registered in advance.
8. Perform arithmetic processing on the data registered in the simulation data file 29 and the test result confirmation table 30. By this arithmetic processing, a system status confirmation diagram, a drawing data confirmation diagram, a simulation database, a result confirmation table, a state change message table, and the like are output to the output device 31 as a test case table.

FIG. 5 shows such a process flow. A simulation database creation process will be described with reference to FIG.

Process 35 On the personal computer screen, information on the fault location table and the position table shown in Tables 1 and 2 is input for each fault case.

Process 36 The system status confirmation diagram shown in FIG. 2 is created from the system status confirmation data file.

Process 37 The drawing data confirmation diagram shown in FIG. 3 is created from the drawing data confirmation file.

Process 38 A simulation database as shown in Tables 5 and 6 is created from the simulation data file.

Process 39 A state change message table for determining the quality of the automatic recovery apparatus as shown in Table 3 is created from the state change message data file.

Process 40 A test result confirmation table for judging pass / fail of the automatic recovery device as shown in Table 4 is created from the test result confirmation data file.

Process 41 Outputs the simulation database and ends.

In the above embodiment, the embodiment in which the power transmission circuit is applied to the line transmission circuit of a substation has been described. However, as long as the circuit is an electric circuit, the power transmission circuit of a power station or the transmission circuit of an electric room in a building may be used. Any other electric circuit may be used.

[0056]

According to the present invention, a human can analyze a technique having a higher reliability and a technique having a higher probability of occurrence of an error by a human, and can speed up a test of a highly reliable automatic recovery system for an accident.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a simulation database creation procedure for testing an automatic accident recovery system.

FIG. 2 is a system status confirmation diagram showing one embodiment of a failure case input to the screen of the computer in FIG. 1;

FIG. 3 is a drawing data confirmation diagram showing an embodiment of a failure case input to the screen of the computer in FIG. 1;

FIG. 4 is a circuit connection diagram showing a circuit system for transmitting power from a substation bus to a factory, a building, a customer, and the like.

FIG. 5 is a circuit configuration diagram for explaining the configuration of the automatic restoration system of FIG. 4;

FIG. 6 is a flowchart for explaining a procedure for creating a conventional simulation database for testing the automatic restoration apparatus of FIG. 5;

FIG. 7 is a circuit diagram for explaining a conventional automatic recovery system.

FIG. 8 is a flowchart for explaining a procedure for creating a simulation database for testing a conventional automatic recovery device.

[Explanation of symbols]

1 ... PC screen, 2 ... Test case table, 3 ... Result confirmation table, 4, ... Simulation database,
6 ... black circle, x ... 7 ... single circle, 8 ... double circle,
9: black square, 11: wiring, 12: gas pipe, 13: partition line, 21: CPU, 22: bus, 23: main memory, 24: power transmission circuit data file, 25: display device, 26 ... Input device, 27: Image processing device, 28: Test case table, 29: Simulation data file,
30: Test result confirmation table.

Claims (5)

[Claims] 1. A recovery function of an automatic recovery device for recovering by switching to a normal circuit from a change in a sensor and a switch provided in an electric circuit targeted for automatic recovery in the event of an accident based on simulation data of an accident case in which a recovery function is estimated. A method for testing, comprising: a failure circuit identification step of creating a failure locating table displayed for each accident case in which an operation of each sensor provided in the electric circuit is estimated; and an operation of each switch provided in the electric circuit. An operation displaying step of creating a position table displayed for each of the estimated accident cases, and inputting the information of the fault locating table and the position table to a computer for each of the estimated accident cases, and opening and closing each of the switches provided in the electric circuit. Calculates a test case table that shows the operation of the detector for each accident case, a result confirmation table that is the lighting result of the indicator lamp, and a simulation database. Calculation step by a computer to be input, a test step of inputting the simulation database and the test case table as a test signal to the automatic recovery apparatus, and comparing the response result of the automatic recovery apparatus with the result confirmation table by this test step. And a judging step of judging pass / fail. 2. A simulation system for an accident case in which a recovery function of an automatic recovery device that switches to a normal circuit and recovers from a change in a sensor and a switch provided in an electric circuit to be automatically recovered in the event of an accident is estimated. A method for testing, comprising: a failure circuit identification step of creating a failure locating table displayed for each accident case in which an operation of each sensor provided in the electric circuit is estimated; and an operation of each switch provided in the electric circuit. An operation display step of creating a position table displayed for each accident case in which a fault is estimated, and a wiring diagram of the electric circuit displayed on a computer screen for each fault case in which information of the fault location table and the position table are estimated. An operation step by a computer for inputting data into a test case table, a result confirmation table, and a simulation database; A test step of inputting a database for test and a test case table to the automatic recovery apparatus as a test signal, and a determination step of comparing the response result of the automatic recovery apparatus with the result confirmation table to determine pass / fail by the test step. A test method for an automatic accident recovery system, characterized in that: 3. Simulation data of an accident case in which a recovery function of an automatic recovery device for recovering by switching to a normal bus from a change in a sensor and a switch provided in a power transmission circuit to be automatically recovered in case of a fault is estimated. A fault circuit specifying step of creating a fault locating table displaying for each accident case in which the operation of each sensor provided in the power transmission circuit is estimated, and each switching provided in the power transmission circuit An operation displaying step of creating a position table for each accident case in which the operation of the device is estimated; and the power transmission displayed on a computer screen for each accident case in which information of the fault location table and the position table are estimated. Calculation step by computer to input to circuit diagram and output test case table, result confirmation table and simulation database And a test step of inputting the simulation database and the test case table to the automatic recovery apparatus as a test signal. The test step compares the response result of the automatic recovery apparatus with the result confirmation table to determine pass / fail. And a test method for an automatic accident recovery system. 4. The test method for an automatic accident recovery system according to claim 1, wherein said sensor is a gas pressure sensor and a relay circuit. 5. The test method for an automatic accident recovery system according to claim 1, wherein the switch is a circuit breaker or a disconnecting switch.