JPH0244264A - Apparatus for inspecting phase of motor power circuit - Google Patents

Abstract

PURPOSE:To accurately inspect the phase of the power circuit of a motor by providing a current transformer capable of gripping an electric wire from the outside to supply or cut off the DC between the phases of a three-phase circuit and judging the order of induced spike like currents. CONSTITUTION:The switches A, B of a current applying device 11 are operated to supply and cut off the DC between the phases of a three-phase circuit consisting of lead wires 12, terminal stands 6, cables 7, connection parts 10, draw-out wires 9 and a motor 8. The grips CT 17 of a judge device 15 can catch the change of the DC allowed to flow by an applying device 11 to induce spike like currents at the times of the supply and cut-off of the DC. The electric signals detected by the grips CT 17 are inputted to an input order judge part through lead wires 16 and the order thereof is judged. The judge result is displayed on an input order display part 20 at every phase and a phase correct- or-not judge part judges whether a phase is correct or not and, therefore, accurate inspection can be performed.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to cable installation for a power circuit of an electric motor.

The present invention relates to a motor power circuit assembly inspection device that inspects whether or not cable phases are correctly connected when connection work is performed.

(Conventional technology) In construction work for plants such as power plants, cable work for motor power circuits includes cable installation, terminal treatment, cable continuity check, motor side cable connection, motor side cable connection insulation treatment, and power supply side cable connection. It is done in the order of. In this sequence of operations, the phases of the installed cable are inspected at the cable continuity check.

The inspection method is to place people at both ends of the installed cable, prepare one telephone equipment, and have the person placed at one end of the cable connect the core wires of the cable to the earth (ground) one by one. This is done by having a person stationed at one end receive a call through the telephone equipment and use a tester to confirm continuity between the cable and the ground.

(Problem to be Solved by the Invention) In the conventional method, between the work of cable terminal processing, which can be carried out by one set of workers, and the work of insulation processing of cable connection parts, as work after cable installation due to the procedure of cable construction, There is a job called a cable continuity check that requires two sets of workers. Therefore, work was interrupted and inefficient.

Additionally, the construction period was lengthened because a cape was required.

Since the cable connection is performed after the cable continuity check, even if the cable phases are correct in the cable continuity check, there is a possibility that the cables may be connected in the wrong phase when connecting the cables.

It was not possible to perform a phase inspection of the cable after the cable connection was taped.

If you neglect to check the continuity of the cable and insulate the cable connection, or if the results of the cable continuity check are not clearly recorded, you may continue to operate the motor, and if the cable is in the wrong phase. If it is connected, there is a risk of damaging the motor, so it is necessary to perform a cable phase inspection again using a cable continuity check. However, at this time, it is necessary to peel off the insulation treatment of the cable connection part, and if the impedance of the motor winding is low, the cable connection part must be removed immediately, resulting in extra work.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor power circuit assembly inspection device that can shorten the construction period and perform efficient phase inspection of a motor power circuit.

[Structure of the invention]

(Means for Solving Problem Il!) In order to achieve the above object, in the present invention, a DC current is connected to each phase of the terminal on the power distribution board side of the cable that connects the power distribution board and the electric motor for each phase. a current applier that applies the DC current to the cable; a current transformer that is connected to each phase of the cable near the motor to detect the DC current; and a current transformer that detects the DC current from the current transformer. Provided is a motor power circuit assembly testing device characterized by comprising a determining device for determining whether each phase is correctly connected to the motor.

(Function) In the device configured in this way, a current signal is input to the determination device via the current transformer by passing a direct current from the current applicator to the cable and cutting it off. Depending on the input order of the current signals, it is possible to determine whether each phase of the cable is correctly connected to the motor.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a schematic diagram of an embodiment of a motor power circuit assembly inspection device according to the present invention. A power supply bus 2 is housed in the switchboard 1, and a breaker 3, a load switch 4, a thermal relay 5, and a terminal block 6 are connected in this order. A cable 7 is connected to this terminal block 6. The electric motor 8 is connected to the switchboard 1
It is installed at a location away from the cable 7 and is connected to the cable 7 via a connecting portion 10 by a lead wire 9.

The current applicator 11 is connected to each terminal block 6 of each phase by a clip I3 provided at the tip of the lead wire 12. On the front panel 14 of the current applicator 11, a switch A and a switch B are arranged.

A lead wire 16 is connected to the determiner 15 .

A current transformer (hereinafter referred to as grasping CT) 17 is connected to the tip of this lead mu;, which is configured so that the cable 7 and the lead wire 9 can be grasped from the outer ring. This grasping CT 17 is provided with an input order display panel 20 on the front panel 18 of the 0 determiner 15 connected to each phase of the lead line 9, and includes input order display lamps 20a, 20b, 20c, 20d.

20e, 2Of, 20g, 20h, and 20j are arranged. A judgment display panel 21 is provided below the input order display panel 20, and a judgment result display lamp 21a.

21b is arranged. Above the input order display panel 20, a reset switch 24, a measurement ready display lamp 26, a power supply display lamp 27, and a power switch 28 are arranged.

FIG. 2 is a configuration diagram of the current applicator 11. The current applicator 11 has a built-in DC fig. switch A
consists of two contacts, and is configured such that when switch A is turned on, a + current is applied to the clip 13a and a - current is applied to the clip 1.3b. The switch B consists of two contacts, and is configured such that by turning on the switch B, a negative current is applied to the clip 13b and a positive current is applied to the clip 13c.

The clips 13a, 13b, and 13c each have an R
,S.

A T is displayed.

FIG. 3 is a block diagram of the 1-judger 15. The inside of the 6-judger I5 includes a power supply section 40. It is composed of an input order determining section 41, a compatibility determining section 42, and a measurement preparation possible determining section 43. The power source section 40 sends its electrical output 44 to the input order determining section 41, the power indicator lamp 27, and the measurement preparation possible determining section 43 via the power switch 28. The input order determining section 41 inputs the current signal 45 from the 1-grasp CT 17, and transmits the measurement signals 46.47 to the input order display panel 20 and the compatibility determining section 4.
It is output to 2. The compatibility determining unit 42 receives a determination signal 47
is input, and a compatibility signal 48 is output to the determination result display panel 21. The reset switch 24 is configured so that the input order determining section 41 and the compatibility determining section 42 can be returned to their initial states by turning on this switch. The measurement preparation possibility determination unit 43 determines whether the N air output 44. Status signal 49 from input order determining section 41. Inputting the status signal 50 from the correct/incorrect determining section 42, the first determining unit 15 determines whether or not it is in a testable state, and outputs the determination result to the measurement ready display lamp 26. In addition, grasping CT
1.7 is engraved with an arrow 51 and R, S, T markings.

Next, the operation of this embodiment will be explained. As shown in FIG. 1, the clip 13 attached to the tip of the lead wire 12 of the current applicator 11 is connected to the end piece 6 of the switchboard. As shown in FIG. 2, the clips 13 are as follows: a clip 13a marked with R is connected to the R phase of the terminal block 6, a clip 13b marked with S is connected to the S phase of the terminal block 6, and a clip 13c marked with T is connected to the R phase of the terminal block 6. The terminal block 6
Connect to the T phase of The gripping CT 17 is connected to the cable lead-out line 9 of FIG. 1 according to the direction of the arrow 51 shown in FIG. That is, they are connected so that the arrow points in the direction of the electric motor 8. Also, R, S, which seems to be correct at this stage,
Connect to each phase of T, matching the R, S, and T indications of C and T17.

Operate switches A and B of the current applicator 11 in FIG. Terminal block6. Cable 7, connection part 10, lead wire 9. Direct current is passed between the phases of a three-phase circuit consisting of the electric motor 8 and cut off. The grasp CT 17 of the determiner 15 can detect changes in the DC current applied by the current applicator 11, and induces spike-like currents when the DC current is applied and when it is cut off. The current signal 45 detected by the grasping CT 17 is led to the input order determining section 41 shown in FIG. 3 via the lead wire 16. The input order determining unit 41 determines the order of the spike-like currents detected by the three-phase grasping CT 17.

In other words, which phase receives the spike-like signal first, which phase receives the spike-like signal second, and which phase receives the spike-like signal thirdly? Determine and memorize which phase it is. Input order determination unit 4I
The results determined are displayed on the display lamps 20a to 20 of the input order display panel 20. Input order display lamp 2
The display of 0a to 20j is 20a.

20b, 20c are the first input R phase, S phase, T
The display corresponds to the phase, 20d, 20e, 20f
are the displays corresponding to the R phase, S phase, and T phase input second, and 20g, 20h, and 20j are the R phase input third.

This is a display corresponding to S phase and T phase. Input order determination unit 41
The determination result is also sent to the compatibility determination unit 42 as a determination signal 47.
The signal is also transmitted to the terminal to determine whether the phase connection is correct or not, and one of the display lamps 21a and 21b of the determination result display panel 21 is turned on. If the judgment result is good, 21a lights up, and if the judgment result is negative, 21b lights up. Reset switch 2
Step 4 resets the memory of the internal circuits of the input order determining section 41 and the compatibility determining section 42, and makes it possible to start measurement. The measurement preparation possibility determination unit 43 is.

The internal reset states of the input order determining section 41 and the compatibility determining section 42 are determined, and the normality of the power supply section 40 is determined.

The measurable indicator lamp 26 is turned on. Power for driving the input order determining section 41, phase correctness determining section 42, and measurement ready determination section 43 is supplied from the power supply section 40 via the power switch 28. Further, the status of the power supply unit is displayed on a power display lamp 27.

The relationship between the current of each phase and the current waveform of each phase detected by the grasp CT 17 when the switch A of the current applicator 11 is turned on → off, and then the switch B is turned on → off is 4, reference numerals 50a, 50b, and 50c in FIG. 4 indicate R and S of the cable 7 to which the current is applied by the current applicator 11.

T shows the current waveform of each phase, and symbols 51a, 51b, 5
1c shows the current waveforms of the R, S, and T phases detected by the grasping CT 11. If the phases of cable 7 are connected normally, pulses in the positive direction are generated in the order of current waveforms 51a, 51b, and 51c, as indicated by the dotted circle in Figure 4.If the phases of 6 cables are connected incorrectly, Current waveform 51a.

The order in which the waveforms 51, b, and 51c appear changes.

The input order determination unit 41 in FIG.
b.

The order in which the positive direction pulse waveforms shown in 51c are generated is determined, and the phase determination section 42 determines the determination result to determine whether the connection of the phases of the cable 7 is correct or not. If there is an error in the phase of the cable 7, it is possible to know which phase has been inserted incorrectly by looking at the display on the input order display panel 20 that displays the judgment result of the input order judgment section 41.

According to this embodiment, after installing the judgment device, the judgment can be made by operating the current applicator, and the judgment results can be stored, so that even one set of inspection personnel can carry out the inspection. 6. Since the inspection can be performed, it is possible to prevent the motor 1 from reversing due to a construction error after the cable continuity check.

In addition, in terms of work efficiency, cable terminal processing, connection, and insulation processing can be carried out without interruption, allowing for efficient work progress. Furthermore, since there is no need to prepare telephone equipment for checking cable continuity, the construction period can be shortened.

Note that the configuration of the present invention is not limited to this embodiment. For example, if you install three switches for the current applicator,
Currents may be applied to each of the R, S, and T phases by operating the respective switches, and the input order determining section may be configured accordingly.

〔Effect of the invention〕

According to the present invention, the phase inspection of the power circuit of the electric motor can be reliably performed, so that the cable construction work can be carried out efficiently and the construction period can be shortened.

An embodiment of the circuit phase inspection device is shown, where Figure 1 is a schematic diagram of the switchboard, current applicator 1 determiner, and electric motor, Figure 2 is a configuration diagram of the current applicator, and Figure 3 is a configuration diagram of the determiner. FIG. 4 is a diagram showing the current waveform applied by the current applicator and the current waveform detected by the determiner.

1...Switchboard 4...Load switch 6...
・Terminal block 7...Cable 8...Motor 9...Leader line lO...Connection part
11... Current applicator 15... Judgment device
17...Grasp CT agent Patent attorney Nori Chika
Yudo Ken Daishimaru Figure 1 Figure Figure 1

Claims (1)

[Claims] A current applicator connected to each phase of the distribution board side terminal of a cable that connects the distribution board and the electric motor for each phase and applies a direct current to the cable, and a current applicator connected to each phase of the cable near the electric motor. It is characterized by comprising a current transformer that detects the direct current, and a determination device that determines whether each phase of the cable is correctly connected to the motor based on the input order of current signals from the current transformer. Motor power circuit phase inspection device.