JP5452972B2 - Wiring connection inspection method and inspection device for integrated watt-hour meter - Google Patents

Description

  Whether or not the wiring connection between the main circuit of the integrating watt-hour meter and the measuring instrument current transformer and the load for measuring the amount of power used by the load connected to the main circuit supplying power is correct. The present invention relates to a wiring connection inspection method and an inspection apparatus for an integrated watt-hour meter.

Conventionally, whether the wiring connection of an integrating watt-hour meter using such an instrument current transformer is detected is as follows, for example. FIG. 1 is an example of wiring connection in the case where an integrating watt hour meter WH is connected to a main circuit of a three-phase three-wire distribution system using instrument current transformers CT1 and CT3 to measure the power consumption of a load. In this case, for example, in order to inspect the correctness of the connection between the current transformer CT1 for the meter and the integrating watt hour meter WH, in general, both of them are as follows from the small impedance of the current input part of the integrating watt hour meter. One end of the wire connected to the terminal is removed from the terminal, and a work for confirming the continuity between the one end of the removed wire and the terminal to which the other end of the wire is connected is required. The actual work procedure is as follows.
(1) Remove one end of the electric wire 1 connecting the power supply side terminal S1 of the current transformer CT1 and the power supply side current terminal 1S of the integrated watt hour meter WH from the terminal 1S of the integrated watt hour meter WH.
(2) Remove one end of the electric wire 2 connecting the load side terminal L1 of the current transformer CT1 and the load side current terminal 1L of the integrating watt hour meter WH from the terminal L1 of the current transformer CT1.
(3) Inspect and confirm the continuity between one end of the electric wire 1 removed in (1) above and the terminal S1 of the current transformer CT1.
(4) Conduct continuity between one end of the electric wire 2 removed in (2) above and the terminal 1L of the integrated watt hour meter WH by checking with a tester or the like.
(5) Return one end of the removed electric wire 1 to the terminal 1S of the connecting watt-hour meter WH.
(6) Return one end of the removed electric wire 2 to the terminal L1 of the connecting current transformer CT1.
In particular, in the case of a through-type instrument current transformer, the direction in which the output current of the instrument current transformer flows may not be inspected by visual inspection or continuity inspection. It is necessary to connect and input predetermined power and check whether or not the integrated watt hour meter shows a predetermined power amount value within a unit time.

Furthermore, as a device devised to prevent an adverse effect due to incorrect wiring on the main circuit of the watt-hour meter, a determination unit for determining the correctness of the wiring based on the voltage value detected in the watt-hour meter is provided ( Patent Document 1), and another example in which a voltage comparison unit and a phase comparison unit are provided in the watt hour meter to determine whether the wiring is correct (Patent Document 2).
JP 2006-71600 A JP 2006-300729 A

  However, in the conventional method and apparatus as described above, it takes time and labor to remove the wire connected by wiring, and there is a possibility that incorrect wiring may occur when the wire is returned to the original connection. In order to check the movement of the watt-hour meter by connecting the power supply and load of the unit and checking the operation of the watt hour meter, it is necessary to have a corresponding power supply facility and load device. There was also a risk that could lead to an electric shock accident, which was a problem.

  Moreover, in the thing of the said patent document 1 thru | or patent document 2, since the detection means which detects the correctness of wiring connection is incorporated in the watt-hour meter, at the time of wiring connection work which attaches a watt-hour meter newly Although it can prevent miswiring, it does not help detect miswiring of wiring connections already made with a watt hour meter that does not incorporate such detection means, leading to higher watt hour meter costs, etc. There was also a problem.

  Therefore, the present invention has been made in view of the various circumstances of the prior art, and in order to perform the inspection, the wiring connection of the integrated watt-hour meter already made to the main circuit and the measuring instrument current transformer and the load is removed one by one. To check the correct and incorrect wiring connection of the integrated watt-hour meter safely, quickly, easily, and reliably, without leaving it necessary and without requiring large-scale power supply equipment and load devices to be connected. It is an object of the present invention to provide an inspection method and an inspection apparatus that can perform the above-described process.

In order to achieve the above-mentioned object, the present invention is mainly configured as follows: “Main circuit in metering circuit and measuring current transformer without changing wiring connection of integrating watt-hour meter to load and circuit for measuring In a state in which the normal power supply to the main circuit is cut off, a predetermined voltage as an inspection reference is applied to the circuit to be measured from the inspection apparatus main body, and an inspection reference current is caused to flow. Inspect the wiring connection of the integrated watt-hour meter by comparing the voltage waveform and current waveform detected from the current terminal with the reference waveform created by the main body of the inspection device in terms of the phase difference and size. It is characterized by adopting the means of “determining and displaying by the control unit of the apparatus main body”.

In the inventions according to claim 1 and claim 3, unlike the prior art, there is no need for time and troublesome to remove the measurement target circuit of the integrating watt hour meter, the current transformer for the instrument, and the wiring connection to the load one by one. In this state, it is possible to safely and quickly, easily, and surely check the wiring connection of the integrating watt-hour meter correctly without requiring connection of a large-scale power supply facility or load device.
In addition, since erroneous wiring can be easily and reliably identified, the wiring can be quickly, easily, and reliably corrected at the time of erroneous wiring.

  In the inventions according to claim 2 and claim 4, whether the wiring connection of the integrating watt hour meter in each distribution system of the circuit to be measured over the single-phase two-wire, single-phase three-wire, three-phase three-wire, three-phase four-wire Inspection can be performed safely, quickly, easily and reliably.

This is a wiring connection example of a conventional integrated watt-hour meter connected to a main circuit of a three-phase three-wire distribution system using an instrument current transformer. It is a block block diagram of the integrated watt-hour meter wiring connection inspection apparatus which concerns on an example of implementation of this invention. It is explanatory drawing which shows the operation switch and test result display part in an integrated electricity meter wiring connection test | inspection apparatus same as the above. It is explanatory drawing which shows the voltage waveform of each phase at the time of normal of a three-phase four-wire power distribution system. It is explanatory drawing which shows a voltage waveform at the time of producing the connection difference of R phase and S phase of a three-phase four-wire distribution system. It is explanatory drawing which shows a voltage waveform at the time of producing the connection difference of R phase and N phase of a three-phase four-wire distribution system. It is explanatory drawing which shows the current waveform of each phase at the time of normal of the distribution system of a three-phase four-wire and a three-phase three-wire. It is explanatory drawing which shows the electric current waveform at the time of reversely connecting the R-phase current transformer for a three-phase four-wire and a three-phase three-wire distribution system. It is explanatory drawing which shows the electric current waveform at the time of connecting the R-phase and S-phase current transformer of a three-phase four-wire and a three-phase three-wire distribution system differently. It is explanatory drawing which shows each line voltage waveform at the time of normal of a three-phase three-wire power distribution system. It is explanatory drawing which shows the voltage waveform between R-S line | wires when the connection difference of R phase and S phase of a three-phase three-wire distribution system arises. It is explanatory drawing which shows the voltage waveform of each phase at the time of normal of a single phase three-wire power distribution system. It is explanatory drawing which shows the voltage waveform at the time of producing the connection difference of R phase and N phase of a single phase three-wire power distribution system. It is explanatory drawing which shows the voltage waveform at the time of producing the connection difference of R phase and T phase of a single phase three-wire power distribution system. It is explanatory drawing which shows the current waveform of each phase at the time of normal of a single phase three-wire power distribution system. It is explanatory drawing which shows the voltage waveform of each phase at the time of the normal of a single phase two wire power distribution system. It is explanatory drawing which shows the current waveform of each phase at the time of normal of a single phase two-wire power distribution system.

  Embodiments of the present invention will be described below with reference to the drawings (FIGS. 2 to 17).

  FIG. 2 is a block diagram of a wiring connection inspection device for an integrating watt-hour meter according to an embodiment of the present invention. The illustrated example is a current transformer for an instrument with respect to a main circuit and a load of a three-phase four-wire distribution system. When the integrated watt hour meter 6 (WH) is attached using (CT1, CT2, CT3), it shows the state inspected by the inspection device body 3 to which the wiring connection of the integrated watt hour meter 6 is attached is there.

In other words, this inspection device is mainly in the state without removing the main circuit of the three-phase four-wire distribution system and the measuring current transformer (CT1, CT2, CT3) and the integrated watt-hour meter 6 to the load. And in the state where the normal power supply to the main circuit is cut off (with the switch MB cut off), the built-in power supply circuit 17 and three load resistors (1Ω) are connected to this measurement target circuit (main circuit). Then, a predetermined voltage (2V AC voltage) serving as an inspection standard is applied from the inspection device main body 3 to supply an inspection reference current 2A, and the voltage terminal and the current terminal of the integrated watt-hour meter 6 are connected to the inspection device main body 3. In addition, the voltage waveform and the current waveform flowing in the voltage terminal and the current terminal are detected by the inspection apparatus body 3, and the detected voltage waveform and current waveform are respectively compared with the reference waveform created by the inspection apparatus body 3 and the phase difference thereof. And the magnitude of The control unit of the testing device body correctness of the amount six wiring connections is obtained without such to be displayed determined by (microcomputer) 14.
The power-side current terminal of the integrating watt-hour meter 6 is connected to the power-side current terminals of instrument current transformers CT1, CT2, and CT3 that are connected to the R, S, and T phases on the power supply side of the main circuit, respectively. Yes. Further, the main circuit R, S, T, and N phase are connected to each voltage terminal of the integrating watt-hour meter 6.

The inspection device main body 3 has a built-in power supply circuit (power circuit) 17 and three load resistors that apply a voltage as a predetermined inspection standard to the circuit to be measured (main circuit) and flow a reference current, and analog-digital conversion A control unit (microcomputer) 14 that has a built-in voltage detector (A / D converter) and judges the correctness of the wiring connection of the integrated watt-hour meter 6 through the voltage waveform and current waveform detected by the integrated watt-hour meter 6. I have. The control unit (microcomputer) 14 is connected to a current amplifier circuit 10, a CT ratio changeover switch 11, a circuit selection switch (selection of the distribution method of the main circuit) 12, and a voltage detection circuit 13. Further, an inspection start switch 19 and an inspection result display unit 18 are connected to the control unit (microcomputer) 14, and a sine wave generation circuit 15 and a phase control circuit 16 are further connected. The phase control circuit 16 is connected to a control unit (microcomputer) 14 and is connected to a sine wave generation circuit 15 and a power supply circuit (power circuit) 17.
The power supply circuit (power circuit) 17 is connected to the R, S, T, and N phases on the power supply side of the main circuit via clips 7a, 7b, 7c, and 7d extending from here. Clips 9a, 9b, 9c, and 9d extend from the three load resistors built in the inspection device body 3, and each of these clips 9a to 9d has R, S, T, and N phases on the load side of the main circuit. Connected to.
Clamp-type current sensors 5a, 5b, and 5c extend from the current amplification circuit 10 of the inspection apparatus body 3, and these current sensors 5a, 5b, and 5c are the power supply side currents of the current transformers CT1, CT2, and CT3 for the instrument. Each terminal is connected to each electric wire connecting the power supply side current terminal of the integrated watt-hour meter 6. Further, clips 8a, 8b, 8c, 8d extend from the voltage detection circuit 13 of the inspection apparatus body 3, and these 8a to 8d are integrated electric energy connected to the R, S, T, and N phases of the main circuit. A total of 6 voltage terminals are connected.
The instrument current transformers CT1, CT2, and CT3 are connected to the power supply side current terminal of the integrating watt-hour meter 6, and are used for measuring the R-phase, S-phase, and T-phase currents of the main circuit, respectively.
The inspection method will be described in detail below.

  The sine wave generation circuit 15 of the inspection device main body 3 generates a sine wave with a frequency of 50 Hz, which is the fundamental wave of the inspection, and one of the waveforms is an A / D converter built in the control unit (microcomputer) 14 And the other is sent to the phase control circuit 16. The phase control circuit 16 generates single-phase two-wire, single-phase three-wire, three-phase three-wire, and three-phase four-wire waveforms in accordance with instructions from the microcomputer 14 and sends them to the power circuit 17. As described above, the power circuit 17 functions as a power source having an AC voltage of 2V, and supplies a load current 2A by being connected to a load resistance 1Ω built in the inspection apparatus body 3. Whether the waveform is sent from the phase control circuit 16 to the power circuit 17 depends on an instruction from the control unit (microcomputer) 14.

  When power is supplied to the inspection apparatus main body 3 and the microcomputer 14 is in the initial state, the power circuit 17 is not outputting a waveform. Here, when the inspection start switch 19 of the inspection apparatus body 3 is pressed, the control unit (microcomputer) 14 instructs the phase control circuit 16 to output a waveform corresponding to the position of the circuit selection switch 12. The waveform from the phase control circuit 16 is output from the power circuit 17, and from the clips 7a to 7d connected to the main circuit, passes through the current transformers CT1 to CT3 for instruments, passes through the clips 9a to 9d, and 3 of the inspection apparatus main body 3 Flows into each load resistance 1Ω. At this time, if the integrating watt-hour meter 6 is in a normal connection, a current waveform proportional to the current transformation ratio of the measuring current transformer is added to the current terminal of the integrating watt-hour meter 6 and the voltage terminal to The voltage output from the power circuit 17 of the inspection apparatus body 3 is applied. The current flowing through the current terminal is detected by the current sensors 5a to 5c, amplified by the current amplification circuit 10 of the inspection apparatus body 3 according to the ratio corresponding to the CT ratio changeover switch 11, and the A / Input to D converter. The voltage waveform at the voltage terminal of the integrating watt-hour meter 6 is detected by the voltage detection circuit 13 of the inspection apparatus main body 3 via the clips 8a to 8d and input to the A / D converter of the microcomputer 14. The microcomputer 14 compares the detected current waveform and voltage waveform with the reference waveform of the sine wave generation circuit 15 to determine whether the wiring is correct. If normal, a normal display is displayed on the inspection result display unit 18. If the wiring is incorrect, the cause of the error is determined from the waveform, and the cause is displayed on the inspection result display unit 18.

Next, a method for determining correctness of wiring and display of determination results will be described. FIG. 4 shows a reference waveform generated by the sine wave generation circuit 15 of the inspection apparatus main body 3 and a voltage waveform detected by the voltage detection circuit 13 in the case of normal wiring in the three-phase four-wire distribution system. The R, S, and T phases have the same voltage value, and the reference phase and the R phase voltage RN based on the N phase are in phase.The S phase is 120 ° from the reference wave, and the T phase is 240 ° from the reference wave. There is a phase difference.
Here, it is assumed that the R phase and the S phase of the wiring of the voltage terminal of the integrating watt-hour meter 6 are connected in reverse. The waveform of each phase in this case is as shown in FIG. Compared to the normal case, the phase difference between the R phase and the S phase is reversed, and the connection difference between the R phase and the S phase is determined. Similarly, the connection difference between R phase and T phase, S phase and T phase is judged from the difference in phase difference, and the result is shown in LED indicator 20a in Fig. 3 for RS, to 20b in ST, and in TR In case, it lights up to 20c.

  Next, it is assumed that the R phase and the N phase of the wiring of the voltage terminal of the integrating watt hour meter 6 are connected in reverse by the same distribution method. The waveform of each phase in this case is as shown in FIG. Compared to the normal case, the phase difference between the reference wave and the R phase is 180 °, and the connection difference between the R phase and the N phase is determined. Similarly, the connection difference between the S phase and the N phase, the T phase and the N phase is determined from the difference in the phase difference, and the result is the LED indicator 21a in FIG. 3 in the case of RN, 21b in the case of SN, In case, it lights up to 21c.

  Next, it is assumed that the R-phase connection of the voltage terminal wiring of the integrated watt-hour meter 6 is disconnected in the same distribution method. In this case, since no voltage appears in the R phase, it is determined from the magnitude of the voltage, and the result is turned on to the LED indicator lamp 22a in FIG. From the same determination method for the S phase and the T phase, the result is lit to 22b for the S phase and to 22c for the T phase. When judging whether the N-phase connection is disconnected, apply a voltage only to the R-phase and not output to the S- and T-phases. When normal, an appropriate voltage appears in the R-phase, but the N-phase is disconnected. If the voltage is divided by the load resistance of the S and T phases and the impedance of the power circuit 17, it is determined that the voltage is ½ or less of the normal value, and the result is lit to 22d.

Next, FIG. 7 shows a reference wave in the case of normal wiring in the same distribution system and a waveform that is appropriately amplified by the current amplifier circuit 10 by detecting the current flowing through the current transformers CT1 to CT3 for the current with the current sensors 5a to 5c. It is. The R, S, and T phases have the same current value, and the reference wave and the R phase current are in phase, the S phase is 120 ° from the reference wave, and the T phase is 240 ° from the reference wave.
Here, it is assumed that the wiring from the meter current transformer CT1 is connected in a crossing manner such that the current direction is reversed at the current terminal of the integrating watt-hour meter 6. In this case, the R-phase waveform is as shown in FIG. Compared to the normal case, the phase difference between the reference wave and the R phase is 180 °, and the reverse connection in the current direction of the R phase is determined. Similarly, the S phase and the T phase are also determined from the difference in phase difference, and the result lights up to the LED indicator 23a in FIG. 3 for the R phase, to 23b for the S phase, and to 23c for the T phase. .

  Next, it is assumed that the R phase and the S phase of the wiring of the current terminal of the integrating watt hour meter 6 are connected in reverse by the same distribution method. The waveform of each phase in this case is as shown in FIG. Compared to the normal case, the phase difference between the R phase and the S phase is reversed, and the difference between the R phase and the S phase is determined. Similarly, the difference in T phase is determined from the difference in phase difference, and the result is lit to LED indicator 25a in Fig. 3 for R phase, 25b for S phase, and 25c for T phase. .

  Next, it is assumed that the R-phase connection of the current terminal wiring of the integrating watt-hour meter 6 is disconnected in the same distribution method. In this case, since no current appears in the R phase, it is determined from the magnitude of the current, and the result is lit on the LED indicator lamp 24a in FIG. From the same determination method for the S phase and the T phase, the result is lit to 24b for the S phase and 24c for the T phase.

In the case of the three-phase three-wire distribution system, the current transformers for the instrument are CT1 and CT3 in FIG. 2, there is no main phase N, and the voltage detected by the voltage detection circuit 13 of the inspection device body 3 is as shown in FIG. In addition, the line voltage of RS, ST, and TR is normal, and the waveform of each line voltage in normal wiring is 30 ° for the RS line, 150 ° for the ST line, and 270 ° for the TR line. There is a phase difference.
Here, it is assumed that the R phase and the S phase of the wiring of the voltage terminal of the integrating watt-hour meter 6 are connected in reverse. The waveforms of the reference wave and the line voltage RS in this case are as shown in FIG. Compared to the normal case, the 180 ° phase difference is widened, and the connection difference between the R phase and the S phase is determined. Similarly, the connection difference between the S phase and the T phase, the T phase and the R phase is determined from the difference in the phase difference, and the result is the LED indicator 20a in Fig. 3 for RS, 20b for ST, and TR In case, it lights up to 20c.

  Next, it is assumed that the R-phase connection of the voltage terminal wiring of the integrated watt-hour meter 6 is disconnected in the same distribution method. In this case, since no voltage appears in the R phase, it is determined from the magnitude of the voltage, and the result is turned on to the LED indicator lamp 22a in FIG. From the same determination method for the S phase and the T phase, the result is lit to 22b for the S phase and to 22c for the T phase.

  Next, the reference wave and the R, S, and T current waveforms for normal wiring in the same distribution method are the same as those in FIG. 7 for the three-phase four-wire distribution method. The wiring judgment and display between CT1 and CT3 and the integrated watt hour meter 6 are the same for the R phase and T phase of the three-phase four-wire distribution system, but the S phase current is not directly detected. The current value and the phase difference are calculated by calculation of the control unit (microcomputer) 14 based on the detected values of the R phase and the T phase.

In the case of the single-phase three-wire distribution system, the current transformers for the instrument are CT1 and CT3 in FIG. 2, there is no S phase of the main circuit, and the voltage detected by the voltage detection circuit 13 of the inspection device body 3 is as shown in FIG. In addition, the line voltages of RN and TN are the same, and the waveform of each line voltage during normal wiring has the same phase as the reference wave and the line voltage RN, and the line voltage TN has a phase difference of 180 °.
Here, it is assumed that the R phase and the N phase of the wiring of the voltage terminal of the integrating watt-hour meter 6 are connected in reverse. The waveforms of the reference wave and the line voltages RN and TN in this case are as shown in FIG. Compared to the normal case, RN has a 180 ° phase difference, TN has a double peak value, and determines the connection difference between the R phase and the N phase. Similarly, when T phase and N phase are connected in reverse, TN has a 180 ° phase difference compared to normal, RN has a double peak value, and there is a difference in connection between T phase and N phase. In the case of RN, the result is lit to the LED indicator 21a in FIG. 3, and in the case of TN, it is lit to 21c.

Next, it is assumed that the R phase and T phase of the voltage terminal wiring are connected in reverse. The waveforms of the reference wave and the line voltages RN and TN in this case are as shown in FIG. Compared to the normal case, RN has a 180 ° phase difference, TN has the same phase, and the connection difference between the R phase and the T phase is determined, and the result is lit on the LED indicator 20c in FIG.
Next, it is assumed that the R-phase connection of the voltage terminal wiring of the integrated watt-hour meter 6 is disconnected in the same distribution method. In this case, since no voltage appears in the R phase, it is determined from the magnitude of the voltage, and the result is turned on to the LED indicator lamp 22a in FIG. For the T phase, the same determination method is used. When judging whether the N-phase connection is disconnected, apply a voltage only to the R-phase and not output it to the T-phase. Under normal conditions, an appropriate voltage appears in the R-phase, but the N-phase is disconnected. In this case, the voltage is divided by the load resistance of the T phase and the impedance of the power circuit 17, and is determined to be a voltage that is 1/2 or less of the normal value, and the result is lit to 22d.

Next, FIG. 15 shows a reference wave in the case of normal wiring in the same distribution system and a waveform that is detected by the current sensors 5a and 5c and the current amplifying circuit 10 appropriately amplifying the current flowing through the current transformers CT1 and CT3. It is. The R and T phases have the same current value, the reference wave and the R phase current are in phase, and the T phase has a 180 ° phase difference from the reference wave.
Here, it is assumed that the wiring from the meter current transformer CT1 is connected in a crossing manner such that the current direction is reversed at the current terminal of the integrating watt-hour meter 6. In this case, compared with a normal case, the phase difference between the reference wave and the R phase is 180 °, and reverse connection in the current direction of the R phase is determined. Similarly, the T phase is also judged from the difference in phase difference, and if both the R and T phases are connected in the reverse direction, the same judgment result will be obtained as when the R phase and the T phase are mistakenly wired. Judgment is made by applying voltage to the main circuit separately for the R and T phases. When a normal current appears in the phase to which the voltage is applied and the phase difference is 180 ° different, the connection is reversed, and when current appears in the other phase, the current is different. When the result of reverse connection is R phase, the LED indicator lamp 23a in FIG. The result of the difference is lit to the LED indicator 25a in FIG. 3 for the R phase and to 25c for the T phase.

  Next, it is assumed that the R-phase connection of the current terminal wiring of the integrating watt-hour meter 6 is disconnected in the same distribution method. In this case, since no current appears in the R phase, it is determined from the magnitude of the current, and the result is lit on the LED indicator lamp 24a in FIG. For the T phase, the same determination method is used.

In the single-phase two-wire distribution system, the current transformer for instrumentation is CT1 in Fig. 2, and only the R phase and N phase of the main circuit, the voltage detected by the voltage detection circuit 13 of the inspection device body 3 is as shown in Fig. 16 Furthermore, RN is a line voltage, and the waveform of each line voltage during normal wiring is in phase with the reference wave and the line voltage RN.
Here, it is assumed that the R phase and the N phase of the wiring of the voltage terminal of the integrating watt-hour meter 6 are connected in reverse. In this case, the reference wave and the waveform of the line voltage RN have a 180 ° phase difference wider than that in the normal case, and a connection difference is determined. The result is turned on to the LED indicator lamp 21a in FIG.

  Next, it is assumed that the R-phase connection of the voltage terminal wiring of the integrated watt-hour meter 6 is disconnected in the same distribution method. Since no voltage appears in the R phase in this case, the determination is made based on the magnitude of the voltage, and even when the N phase is disconnected, the same result is obtained and the determination cannot be made. Accordingly, the result is lit on both the LED indicator lights 22a and 22d in FIG.

Next, FIG. 17 is a waveform obtained by detecting the reference wave and the current flowing through the instrument current transformer CT1 in the case of normal wiring in the same distribution system with the current sensor 5a and appropriately amplifying them with the current amplifier circuit 10. The reference wave and the R phase current are in phase.
Here, it is assumed that the wiring from the meter current transformer CT1 is connected in a crossing manner such that the current direction is reversed at the current terminal of the integrating watt-hour meter 6. Compared to the normal case, the phase difference between the reference wave and the R phase is 180 °, and the reverse connection in the current direction of the R phase is determined. The result of the reverse connection is turned on to the LED indicator lamp 23a in FIG.

Next, it is assumed that the R-phase connection of the current terminal wiring of the integrating watt-hour meter 6 is disconnected in the same distribution method. In this case, since no current appears in the R phase, it is determined from the magnitude of the current, and the result is lit on the LED indicator lamp 24a in FIG.
In each power distribution method, when the voltage waveform detected by the voltage detection circuit 13 of the inspection device body 3 and the current waveform detected by the current amplification circuit 10 are normal, the LED indicator lamp 27 indicating normality in FIG. 3 is lit. To do.
If it is not in a normal state and does not satisfy the condition indicating the erroneous wiring, the LED indicator lamp 26 indicating other abnormality in FIG. 3 is turned on.

CT1, CT2, CT3 Current transformer for instrument
WH energy meter
MB Switch (breaker)
S1, S3 Power supply terminal of current transformer for instrument
L1, L3 Load side terminal of current transformer for instrument
P1, P2, P3 Integrated watt-hour meter voltage terminal
1S, 3S Energy meter power supply side current terminal
Load side current terminal of 1L, 3L energy meter
R, S, T, N AC power supply phases
1, 2 wire
3 Inspection equipment
5a to 5c Clamp current sensor
6 Energy meter
7a to 7d Power supply side clip
8a to 8d Voltage detection clip
9a to 9d Load side clip
10 Current amplifier circuit
11 CT ratio selector switch
12 Circuit selection switch
13 Voltage detection circuit
14 Control unit (microcomputer)
15 Sine wave generator
16 Phase control circuit
17 Power circuit
18 Inspection result display
19 Inspection start switch
20a-20c, 21a-21c, 22a-22d, 23a-23c, 24a-24c, 25a-25c, 26, 27
led

Claims (4)

A state in which the main wattmeter in the measurement target circuit and the measuring current transformer and the integrated watt-hour meter are not disconnected from the load, and the normal power supply to the main circuit in the measurement target circuit is cut off. In this case, a predetermined reference voltage is applied to the circuit to be measured from the main body of the inspection device via the built-in power supply circuit and the load resistance to cause the inspection reference current to flow, and the voltage terminal and current terminal of the integrated watt-hour meter Is connected to the inspection device main body, the voltage waveform and the current waveform flowing through the voltage terminal and current terminal are detected by the inspection device main body, and the detected voltage waveform and current waveform are created by the inspection device main body. The product is characterized in that the correctness / incorrectness of the wiring connection of the integrating watt-hour meter is determined and displayed by the control unit of the inspection apparatus main body by comparing the phase difference and the magnitude of each. Wiring connection inspection method of the power meter. In the wiring connection inspection method of the integrated watt-hour meter according to claim 1, any one of a single-phase two-wire, a single-phase three-wire, a three-phase three-wire, and a three-phase four-wire as a main circuit in the measurement target circuit A circuit selection switch for selecting a power distribution method is provided, and a reference waveform corresponding to the main circuit in the measurement target circuit selected by the circuit selection switch is created in the inspection apparatus main body, and the reference waveform and the detected integrated watt-hour meter By comparing the voltage waveform and current waveform flowing in the voltage terminal and current terminal in terms of phase difference and magnitude, respectively, the correct and incorrect wiring connection of the integrated watt hour meter according to the distribution method of the main circuit in the circuit to be measured A wiring connection inspection method for an integrated watt-hour meter, characterized in that the control unit of the inspection apparatus main body determines and displays this. A state in which the main wattmeter in the measurement target circuit and the measuring current transformer and the integrated watt-hour meter are not disconnected from the load, and the normal power supply to the main circuit in the measurement target circuit is cut off. In this case, a predetermined reference voltage is applied to the circuit to be measured from the main body of the inspection device via the built-in power supply circuit and the load resistance to cause the inspection reference current to flow, and the voltage terminal and current terminal of the integrated watt-hour meter Is connected to the inspection device main body, the voltage waveform and the current waveform flowing through the voltage terminal and current terminal are detected by the inspection device main body, and the detected voltage waveform and current waveform are created by the inspection device main body. The product is characterized in that the correctness / incorrectness of the wiring connection of the integrating watt-hour meter is determined and displayed by the control unit of the inspection apparatus main body by comparing the phase difference and the magnitude of each. Wiring connection inspection device for a power meter. 4. The integrated watt-hour meter wiring connection inspection device according to claim 3, wherein the inspection device main body further includes any one of a single-phase two-wire, a single-phase three-wire, a three-phase three-wire, and a three-phase four-wire as a main circuit in the measurement target circuit. A circuit selection switch for selecting a power distribution method is provided, and a reference waveform corresponding to the main circuit in the measurement target circuit selected by the circuit selection switch is created in the inspection apparatus main body, and the reference waveform and the detected integrated watt-hour meter By comparing the voltage waveform and current waveform flowing in the voltage terminal and current terminal in terms of phase difference and magnitude, respectively, the correct and incorrect wiring connection of the integrated watt hour meter according to the distribution method of the main circuit in the circuit to be measured A wiring connection inspection device for an integrated watt-hour meter, characterized in that the control unit of the inspection device main body determines and displays this.