JP2006194804A - Ground leakage location probing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solely, easily and quickly allow a worker to identify a location at which a ground leakage occurs. <P>SOLUTION: A ground leakage probing apparatus is provided with: a ground leakage checking current carrying section for sequentially carrying a current to an output device connected to an output section of a PLC for controlling a sequence in a freshly-mixed concrete manufacturing plant, a motor connected to a power outputting section controlled by an output from the output section and an input device connected to an input section for 0.3 second so as to prevent their operations; a storage section for storing the device to which the current is carried when an input is detected at a ground leakage contact while the current is carried to the device; and a display section for identifying and displaying the devices stored in the storage section. The current is sequentially carried to all the devices in the plant for 0.3 second at the same voltage as a voltage during a normal operation. The device whose leakage current is detected by a ground leakage relay is identified as the ground leakage location when the current is carried. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an earth leakage location exploration method and apparatus used to enable quick identification of an earth leakage location when an earth leakage occurs in various plants such as a ready-mixed concrete manufacturing plant.

  In general, a plant is composed of a large number of devices, and in order to operate such a plant efficiently, it is necessary to integrate and manage a large number of devices constituting the plant. A control system that performs control is important.

  That is, as an example of a plant, for example, in a ready-mixed concrete manufacturing plant, when aggregates such as sand and gravel, which are materials of ready-mixed concrete, are carried by a truck and put into a receiving hopper, they are put into the receiving hopper. By appropriately operating the conveyor for transporting the aggregate connected to the lower end of the receiving hopper and the shuttle conveyor, the aggregate can be further subdivided into sand or gravel, and further with respect to sand and gravel. Each type is transferred to a corresponding aggregate storage tank and stored once. Aggregate in each aggregate storage tank is cut out sequentially from the gate at the lower end of each aggregate storage tank, and then a conveyor for transportation and a turn chute provided on the downstream side thereof are operated appropriately. The mixture is transferred to an aggregate storage bin provided for each type of aggregate above the mixer for mixing fresh concrete.

  Further, when cement, which is a raw concrete material, is carried by a tank truck, the carried cement is pumped to a corresponding cement silo according to the type of the cement and stored temporarily. The cement in the silo is cut out from the cement silo by operating the cut gate and rotary feeder at the bottom of the silo, and put on the air flow fed from the Roots blower and placed above the mixer for ready-mixed concrete. Each cement type is transferred by air to a cement storage bin provided for each type of cement.

  After that, when the kind and amount of ready-mixed concrete to be manufactured on the weighing operation panel are set in order to knead and manufacture ready-mixed concrete in the batcher plant, the composition and amount of ready-mixed concrete to be manufactured After the usage amount for each type of sand and gravel as the aggregate and the usage amount for each type of cement are calculated, the aggregate is transferred to the aggregate measuring hopper comprising the load cell from each aggregate storage bin. Are sequentially cut out for each type so as to coincide with the calculated usage amount for each type of aggregate. Similarly, the cement is cut out from each cement storage bin to a cement weighing hopper equipped with a load cell in order to match the amount used for each type of cement. After that, each type of aggregate measured by the aggregate weighing hopper and each type of cement measured by the cement weighing hopper are provided below each hopper. A desired type of ready-mixed concrete can be manufactured by adding the required amount of water and a required additive and kneading them.

  Therefore, the above-mentioned ready-mixed concrete production plant includes aggregate-related facilities including a large number of devices such as an aggregate receiving hopper, a conveyor and shuttle conveyor, an aggregate storage tank, a conveyor and turn chute, and an aggregate storage bin. Cement silo, cement-related equipment with a lot of equipment such as cut gates and rotary feeders, roots blowers, cement storage bins, etc. It consists of a batcher plant equipped with equipment and other various facilities. Furthermore, a motor as a power source for operating various machines provided in each of the above facilities, and the machine itself Various limit switches and various sensors, such as detecting the movements of materials and detecting the amount and state of aggregates and cement. UNA input device is also provided. Therefore, in the whole said ready-mixed concrete manufacturing plant, the apparatus relevant to control has reached several hundred, and has become very large. For example, the number of motors alone has reached several tens.

  As one of methods for controlling the entire plant having a lot of equipment related to control like the above-mentioned ready-mixed concrete manufacturing plant, it is conceivable to perform relay sequence control by combining elements such as a relay and a timer. However, when relay sequence control is performed, there is a problem that wiring for connecting devices related to control becomes complicated and the number of parts increases. Further, the relay sequence control has a problem that when the control content is changed, the circuit configuration itself must be changed.

  Therefore, in recent years, a control system using a PLC, which is a programmable controller, is common as a method for controlling the entire plant having many devices related to control.

  The PLC has a configuration including a CPU, a memory, a register, an input / output unit (input / output interface), etc., stores an externally created program, and responds to an input signal based on the program. An output signal is created, and the output device can be controlled by the output signal.

  Therefore, in the above-mentioned ready-mixed concrete production plant, for example, as shown in FIG. 3, equipment related to control is collectively blocked for each equipment such as aggregate related equipment 1, cement related equipment 2, batcher plant 3, etc. A PLC 4 is provided for each block, and the PLC 4 outputs an output unit (output interface) 7 according to an input from an input device 6 such as a sensor in each block connected to the input unit (input interface) 5 of the PLC 4. It is possible to control the output to the output device 8 connected to the power supply or to control the power supply to the motor 10 that is the power device by the power unit 9 controlled by the output from the output unit 7. It is like that.

  Furthermore, a central control panel 11 for controlling all the PLCs 4 provided for each of the blocks is provided.

  The central control panel 11 includes a main control unit 11a for centrally managing and controlling devices to be controlled (metering, kneading, loading, cement supply, aggregate supply, aggregate reception) of each plant facility, The main control unit 11a stores data necessary for plant control, and can input, change, and delete various data, and controls peripheral devices (display device, print record, etc.), PLC4 Then, data that cannot be processed is calculated and stored, and data that requires high-definition calculation control processing is processed without going through the PLC 4 by analog value comparison calculation or the like. Further, in the central control panel 11, on the basis of an operation command signal received from the main control unit 11a, each PLC 4 provided for each block is connected to the output unit 7 of each PLC 4. A signal (command) for appropriately turning on / off the output to each output device 8 is transmitted, or an input is received from each input device 6 connected to each input unit 5 to the PLC 4 for each block. If there is, the PLC (programmable controller) 11b for centralized management control of each of the PLCs 4 is configured to receive the signal from each PLC 4, compare the contents thereof, and determine whether the next process can be performed. When the external PLC 4 for each block is a slave unit, the PLC 4 functions as a so-called master unit for centrally managing and controlling these PLCs 4. A configuration equipped with C11b. The PLC 11b transmits necessary signals to the main controller 11a as needed. As a result, the PLC 11b receives the operation command signal from the main control unit 11a in the central control panel 11, and the PLC 11b starts controlling all the PLCs 4 provided for each of the blocks. The whole thing can be integrated and managed. In FIG. 3, for convenience of illustration, power is supplied to the input device 6 connected to the input unit 5 of each PLC 4, the output device 8 connected to the output unit 7, and the power unit 9. The number of motors 10 as equipment is omitted. Therefore, the actual number of input devices 6, output devices 8, and motors 10 is not reflected.

  Note that the input unit 5 of the PLC 4 corresponds to noise from the outside as shown in FIG. 4 as an example of a circuit configuration of an AC 100V input unit. Most types are designed to be insulated. On the other hand, as the output unit 7, a unit that performs relay contact 15 output as shown in FIG. 5 as an example of a circuit configuration is generally used, and further, although not shown, performs transistor output and triac output. An output unit of the type is also used, and in any type, the internal circuit 13 of the PLC 4 is insulated and guarded from the external circuit 16 on the output side.

  By the way, in a plant such as the above-mentioned ready-mixed concrete manufacturing plant, as countermeasures against electric leakage, various input devices 6 connected to the input unit 5 of the PLC 4 and various types connected to the output unit 7 as shown in FIG. A leakage relay 17a as a leakage detector is provided at the upstream portion (power supply side) position of the power unit 9 for controlling the power supply to the power device by the output from the output device 8 and the output unit 7, As shown in FIG. 6 (b), if a leakage relay 17b as a leakage detector is provided at the upstream part (power supply side) position of the power supply circuit to the motor 10, and if a leakage occurs in a certain device, Since the earth leakage relays 17a and 17b provided on the upstream side of the device in which the earth leakage occurs can be operated, the central control panel 11 (see FIG. 3) is operated based on the operation of the earth leakage relays 17a and 17b. ) It is common to allow emitted a warning such as lighting a distribution ramp. Further, when the sensitivity current exceeds 200 mA, it is considered that the operation of the entire plant is stopped together with the alarm by the central control panel 11.

  When the occurrence of leakage is detected by the alarm as described above, for example, when the leakage occurs in a certain device, the device is repaired or replaced, or the leakage is detected. If it is caused by deterioration of the sheath of a cable connected to a certain device, it is necessary to repair or replace the place where the leakage has occurred, such as replacing the cable, and configure the plant for that purpose. It is necessary to identify the location where the electrical leakage occurred from the large number of devices.

  As described above, as a method conventionally used for specifying a leakage point, a method in which an operator measures an insulation resistance for each cable by using an insulation resistance meter is generally used.

  As shown in FIG. 7, a plurality of electrical parts 21 that are supplied with power from the connection 18 to the commercial power supply via the earth leakage breaker 19 and the energization controller 20 are connected in parallel to the connection 18. As a method for confirming a leakage location in an electrical device having the above-described configuration, the plurality of electrical parts 21 are energized one by one in a state where the leakage breaker 19 is started up. The electrical parts 21 that are in the energized state when the breaker 19 is cut off are stored in the storage device (EPROM) 23 using the microcomputer 22 immediately before the energization is cut off. When the earth leakage breaker 19 is started in the energized state, the electrical part 21 that has caused the earth leakage is read from the storage device 23 and displayed. Leakage location confirmation method of such display on the unit 24 has been conventionally proposed (e.g., see Patent Document 1).

Japanese Patent Laid-Open No. 5-312883

  However, the conventional method for searching for a leakage point using an insulation resistance meter requires a specialist engineer to carry out the search work, so that the number of workers who can perform the work is limited. . In addition, there are instruments that can be measured in the live line state. However, for safety reasons, it is usually necessary to measure the insulation resistance value for each cable after the exploration site is in a power failure state. There is a problem that it takes time and labor to search for the earth leakage point as a whole. In particular, if the system configuration of the equipment to be searched for the earth leakage location is not well understood, there is a risk that a great deal of time and labor may be required. Therefore, it may take half a day or more to search for this earth leakage location, during which time the plant will be suspended.

  Further, as shown in the above-mentioned ready-mixed concrete manufacturing plant, as shown in FIG. 3, the equipment related to the control is divided into blocks for each facility 1, 2, and 3, and sequencer control by the PLC 4 is performed for each block. Since the electronic devices are used for the input / output parts (input / output interfaces) 5 and 7 of the PLC 4, the mega check performed by applying a high voltage with an insulation resistance meter can be easily performed. In this case, the external line is disconnected from the input / output units 5 and 7 of the PLC 4 each time when the leakage of the device connected to the place where the electronic device is used as described above is checked. Since the inspection with an insulation resistance meter must be performed after that, there is a problem that time and labor are further increased. In order to proceed with the work, one worker performs the removal work of the external line from the input / output parts 5 and 7 of the PLC 4, and another worker confirms the equipment connected to the removed external line. There is also a problem that manpower is required because two people work in principle, such as an inspection with an insulation resistance meter.

  The leak location confirmation method described in Patent Document 1 has a problem that when the leak breaker 19 is activated, the leak breaker 19 must be restored manually thereafter. In addition, Patent Document 1 discloses the idea of automatically and sequentially energizing each electrical part 21 and de-energizing, but energizing only some of the electrical parts 21 is performed. In this way, the energized electrical part 21 is in the same state as the normal operating state. Therefore, in the method for confirming the leakage location of Patent Document 1, the individual electrical parts 21 are connected in parallel to the connection 18 to the commercial power source, and the electrical parts 21 are switched between energization and deenergization with respect to each other. Although it is possible to identify a leakage point in a relatively simple device in which each of the operation state (operation state) and the operation stop state (operation stop state) can be switched independently, it is shown in FIG. Like a ready-mixed concrete production plant, a plurality of PLCs 4 controlled by the central control panel 11 allow a plurality of input devices 6, output devices 8, and motors 10 as power devices to be associated with each other to perform sequence control. It is not applicable to the investigation of the leakage point in a certain plant. That is, in the plant as described above, for example, a gate at the lower end of the aggregate storage tank in the aggregate-related equipment 1 and a conveyor for transporting the aggregate discharged from the aggregate storage tank by the operation of the gate In many cases, a plurality of machines are operated while being linked. However, if only one of these machines is energized to perform a normal operation, for example, the conveyor is not in operation. Nonetheless, there is a risk that inconvenience may occur because it is impossible to link with other machines that should be operated in conjunction with each other, such as the gate only being operated and the aggregate being discharged from the aggregate storage tank. Therefore, it is not possible to energize only a part of the equipment in the plant as described above to perform the same operation as during normal operation.

  Accordingly, the present invention provides an earth leakage that can be easily conducted in a short time and without requiring labor by a single worker while the equipment is in a live line state when an earth leakage occurs in the plant. An object of the present invention is to provide a location exploration method and apparatus.

  In order to solve the above-mentioned problem, the present invention, corresponding to the invention according to claim 1, causes each device in the plant to be sequentially energized for a short time, and when the each device is energized, an electric leakage is caused. A method for detecting a fault location by monitoring the presence or absence of the detector operation and identifying the device that was energized when the leak detector was activated as a fault location. Sequence control, and further related to control by the programmable controller from the central control panel in a plant equipped with a control system capable of comprehensively controlling the programmable controller and the main control unit in the central control panel A command to sequentially energize each device for a short time is given, and when each device is energized, the presence or absence of the operation of the leakage detector is monitored to detect the leakage Corresponding to the leak location investigation method for identifying the device that was energized as the leak location when the device is operated, and the invention according to claim 4, a number of devices are sequence-controlled by a programmable controller, and , Equipped with a control system that can control the programmable controller and the main control unit in a central control panel, having a leakage detector on the upstream side of each device, and further, from the central control panel, A leakage detecting energization unit configured to allow each device related to control by the programmable controller to be sequentially energized in a short time, and operation of the leakage detector when energizing each device The storage unit for storing the device that was energized when the leakage detector was activated and the device stored in the storage unit The leakage point locator having provided comprising the display portion for displaying to cut.

  In addition, the energization time for energizing each device in the above is set to be a short time during which the leakage detector can operate but the operation of the power device is not started.

According to the earth leakage location exploration method and apparatus of the present invention, the following excellent effects are exhibited.
(1) Energize each device in the plant sequentially for a short time, monitor the presence / absence of the leakage detector when energizing each device, and energize when the leakage detector is activated To identify the equipment that was performing the leakage as a leakage point, specifically, the sequence control of a large number of devices using a programmable controller, and the programmable controller and the main control unit can be comprehensively controlled by a central control panel When a command to sequentially energize each device related to the control by the programmable controller is given from the central control panel in the plant having the control system configured as described above, and the devices are energized. There is a method and device for monitoring the presence or absence of the operation of the leakage detector and identifying the device that was energized when the leakage detector was activated as the leakage point. In the occurrence location of the leakage can be easily identified. In addition, since the operation to be performed by the operator can be greatly simplified during the work for searching for the leakage point, it is possible to eliminate the need for manpower and increase labor.
(2) Since it takes a very short time to inspect the presence or absence of electric leakage for one device, it is possible to inspect the presence or absence of electric leakage in a short time for a large number of devices constituting the plant. Compared with the prior art, the time required for the search for the leakage point can be greatly reduced. For this reason, it becomes possible to significantly shorten the operation stop period of the plant when the electric leakage occurs.
(3) Since the energization performed for each device controlled by the programmable controller for the leakage check is the same as the voltage during normal operation, an electronic device such as an output unit or an input unit of the programmable controller There is no risk of high voltage acting on the location where it is used. Therefore, it is possible to carry out a search operation for a leakage point without removing the external line from the output unit or the input unit, and it is possible to perform a search operation for a leakage point while keeping each device in a live line state.
(4) Even when a leakage occurs in any of the input unit, the output unit, and the power unit of the programmable controller, the leakage point can be identified.
(5) In order to inspect each device for current leakage, a device for sequentially energizing each device for a short time is installed in the central control panel and programmable controller in the existing control system. It is possible to build by just doing.
(6) By conducting the energization time for energizing each device so that the leakage detector can be operated but the operation of the power device is not started, the operation for searching for the leakage point is set. At this time, there is no risk that only some of the machines will actually operate. For this reason, even in a plant in which a plurality of devices are operated in relation to each other, the devices cannot be linked. It is possible to prevent the possibility of inconvenience.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 and FIG. 2 show an embodiment of a method and apparatus for detecting a leakage location according to the present invention. FIG. 1 shows an outline of the flow of the method for searching for a leakage location according to the present invention, and FIG. The outline of the earth leakage location exploration device of the present invention used in the present invention is shown.

  That is, for example, as shown in FIG. 3, an input device 6, an output device 8, and a power device related to a series of sequence control, such as aggregate-related equipment 1, cement-related equipment 2, batcher plant 3, and other equipment. The devices such as the motor 10 for driving the predetermined machine are collectively formed into blocks, and PLC 4-1 to PLC 4-n are provided for each of the blocks so that sequence control can be performed. -1 to PLC4-n can be collectively controlled by a central control panel (control computer) 11 having a main control unit 11a and a PLC 11b for centralized control of each of the PLCs 4-1 to 4-n. And an input device 6 connected to the input section (input interface) 5 of each of the PCL4-1 to PLC4-n, and an output (Output interface) The output device 8 connected to 7, the upstream position of the power unit 9 controlled by the output from the output unit 7, and the upstream of the power supply circuit that supplies power to the motor 10 as the power device As shown in FIGS. 6 (a) and 6 (b), each PLC4- in the ready-mixed concrete production plant provided with the earth leakage relays 17a and 17b as the earth leakage detector for detecting the presence or absence of earth leakage is shown in the respective positions. 1 to PLC 4 -n, as shown in FIG. 2, a plurality of PLCs 4-1, 4-2, 4-3,... A plurality of motors 10 as power devices to which power is supplied from an output device 8, a power unit 9 controlled based on an output from the output unit 7, and the one PLC 4-1, 4-2, 4- 3, ... An energization operation is provided in the plant control system so that a plurality of input devices 6 connected to the 4-n input unit (input interface) 5 are energized one by one in order. The leakage check energization unit 25 is provided so that all the PLCs 4-1 to PLC4-n can be sequentially performed. Further, the current leakage check energization unit 25 sequentially requires each output device 8, each motor 10, and each input device 6 for each PLC 4-1, 4-2, 4-3,..., 4-n. When the occurrence of electric leakage is detected by the operation of the electric leakage relays 17a and 17b when the electric current is supplied for a short period of time, the storage unit 26 is configured to store the device that is the electric current target at that time. The earth leakage location exploration device I of the present invention is provided with a display unit 27 for displaying the device stored in the storage unit 26 so as to be specified.

More specifically, the earth leakage location exploration device I of the present invention is preliminarily set to, for example, a PLC 4-1 for performing sequence control in the aggregate-related equipment 1 in the ready-mixed concrete production plant, and the cement-related equipment 2. The PLC for performing the sequence control is set as PLC4-2, the PLC for performing the sequence control in the batcher plant 3 is set as PLC4-3, etc., and the PLCs of the control system are set as PLC4-1 to PLC4-n, Individual identification can be made by setting an identification number by a serial number. In addition, although not shown, each terminal of the output unit (output interface) 7 in each PLC 4-1 to PLC 4-n is set to an identification number by a serial number, such as OUT _{1 to} OUT _p , respectively. Although not shown in the figure, each power unit 9 is configured to be individually identifiable and to control the power supplied to each motor 10 based on the output from the output unit 7. In order to correspond to the motor 10, for example, as P _{1 to} P _q , identification numbers by serial numbers are set so that they can be individually identified. Further, although not shown, each terminal of the input unit (input interface) 5 is set to an identification number by a serial number such as IN _{1 to} IN _r , respectively, so that it can be individually identified. As a result, all input devices 6, output devices 8, and motors 10 related to control in the ready-mixed concrete production plant are connected to the input terminals 5 of the PLCs 4-1 to PLC4-n to which these devices are connected. The combination of the identification number assigned to the output terminal of the output unit 7 or the power unit 9 and the identification number assigned to the PLC 4-1 to PLC 4-n itself allows the identification number to be individually identified. is there.

  Furthermore, the earth leakage location exploration device I according to the present invention has a configuration in which a start button (start switch) 28 is provided on a console (not shown).

Specifically, when the start button 28 is pressed, the leakage check energization unit 25 first outputs the PLC 4-1 provided in the aggregate-related equipment 1 via the central control panel 11, for example. For each output device 8 connected to each output terminal to which the identification numbers OUT ₁ to OUT _p of the unit 7 are attached, output is performed in a short time in the order of the identification numbers assigned to the output terminals. ), And the power supply is controlled by the power unit 9 that is controlled based on the output from the output unit 7 of the PLC 4-1. On the other hand, power supply (energization) can be performed in a short time sequentially in the order of the identification numbers P _{1 to} P _r attached to the power unit 9.

As described above, when short-time energization is completed for all the output devices 8 connected to the output unit 7 of the PLC 4-1 and all the motors 10 connected to the power unit 9, the above leakage The inspection energization unit 25 is attached to each input terminal with respect to each input device 6 connected to each input terminal to which the identification number of IN _{1 to} IN _r of the input unit 5 of the PLC 4-1 is attached. In order of the identification numbers, the power can be supplied for a short time sequentially. The input device 6 connected to the input unit 5 of the PLC 4-1 is input (energized) to the input terminal of the PLC 4-1 in a normal operation state. By simply energizing the device 6 to make it active, the type in which the corresponding input terminal in the input section 5 of the PLC 4-1 can be energized, conversely, for example, a limit switch or the like As described above, there is no input (energization) to the input unit 5 of the PLC 4-1 in the normal operation state, and input (energization) to the input unit of the PLC 4-1 starts when the target machine is in a specific state. There is a form of being. Among these, in the case where the input device 6 of the type in which input (energization) to the input unit 5 is started by the operation of the target machine is used for short-time energization for detecting the presence or absence of leakage, Until the short-time input from the input device 6 can be forcibly performed, the machine that is the target of the input device 6 can be operated under the same conditions as in normal operation. It is like that.

  Thereafter, the electric leakage inspection energization unit 25 is connected to each output device 8 connected to the output terminal of the output unit 7 that is sequence-controlled by the PLC 4-2 in the cement-related equipment 2, and each motor connected to the power unit 9. 10. For each input device 6 connected to the input terminal of the input unit 5, the output terminal of the output unit 7, the power unit 9, and the input unit 5 in the same manner as performed for the PLC 4-1. PLCs provided in the remaining batcher plant 3 and other equipments can be energized in a short time in order of the identification numbers assigned to the input terminals. In the same manner as described above for each output device 6, each motor 10 as a power device, and each input device 6 related to the control of each of the 3-PLC 4-n, respectively, corresponding input / output terminals and power units In the order of attached are in which identification number, are to be able to perform sequential short energization.

  Connected to the output unit 8 connected to the output unit 7 in each PLC 4-1 to PLC 4-n and the motor 10 whose power supply is controlled by the power unit 9 and the input unit 5. Further, the energization time when energizing each input device 6 is such that the leakage relays 17a and 17b operate by utilizing a large difference between the machine operation and the electric transmission speed, but the actual machine operation does not occur. It is set to a short time. That is, the leakage relays 17a and 17b can detect the presence or absence of leakage within 0.1 seconds from energization, while the motor 10 used as a power source for a required machine is actually used after energization (power supply) is started. Since it takes 0.5 seconds or more before the operation is started, the current leakage check energization unit 25 uses the time difference between the input unit 5, the output unit 7, The devices 6, 8, and 10 connected to the power unit 9 can be energized, for example, every 0.3 seconds. It should be noted that the voltages when energizing the devices 6, 8, and 10 connected to the input unit 5, the output unit 7, and the power unit 9 are all equal to the voltages during normal operation. It is set to.

  In the ready-mixed concrete manufacturing plant provided with the earth leakage location exploration device I according to the present invention having the above-described configuration, when the occurrence of earth leakage is detected by the operation of the earth leakage relays 17a and 17b during operation of the plant, the operation of the plant is Suspend once.

  In this state, as shown in the flow of FIG. 1, when the start button 28 of the above-described leakage location searching apparatus I of the present invention is pressed (step 1), the search for the leakage location is started (step 2: S2). = 1 (step 3: S3), the leakage check energization unit 25 firstly outputs each output device 8 connected to the x (= 1) -th PLC, that is, the output unit 7 of the PLC 4-1. In addition, each motor 10 as a power device that receives power supply from the power unit 9 controlled by the output from the output unit 7 is sequentially energized for 0.3 seconds. .

  That is, first, it is determined whether the energization target device to be energized is the output or power device by the leakage check energization unit 25 (step 4: S4), and is determined to be the output or power device. In step 5 (S5), the PLC 4-1 energizes (outputs) the output device 8 from the output unit 7 to the motor 10 as the power device via the power unit 9 from the output unit 7. A signal for causing energization (power supply) to be performed is transmitted. Thereafter, monitoring is performed until the energization time reaches 0.3 seconds set in advance (step 6: S6). When the energization time reaches 0.3 seconds, the signal from the PLC 4-1 is stopped, The energization to the output device 8 or the motor 10 as the power device is stopped (step 7: S7). In parallel with the steps 5 (S5) to 7 (S7), the leakage relays 17a and 17b are energized for 0.3 seconds to the required devices in the respective steps 5 (S5) to 7 (S7). It is determined whether or not an earth leakage contact input has occurred (step 8: S8). When it is determined in step 8 (S8) that the leakage contact inputs of the leakage relays 17a and 17b are not generated, the process proceeds to step 9 (S9), and all the connections connected to the output unit 7 in the PLC 4-1 are performed. It is determined whether or not the energization process for 0.3 seconds has been performed on all the motors 10 connected to the output device 8 and the power unit 9, and the above energization to all the output devices 8 and the motors 10 is performed. When the processing is not performed, the energization process is performed on the output device 8 or the motor 10 to which the next identification number is assigned, or on all the output devices 8 and the motor 10. In the case where it is interrupted, the input device 6 is caused to return to step 4 (S4) to start processing.

  On the other hand, if it is determined in step 8 (S8) that a leakage contact input has occurred in the leakage relays 17a and 17b, the target device that is energized when the leakage contact input is generated is then powered. It is determined whether or not it is a device (step 10: S10). When the device to be energized at the time of the leakage contact input is the motor 10, since it is determined in step 10 (S10) that it is a power device, the process proceeds to step 11 (S11). After storing the identification number given to the connected power unit 9 and the identification number of the PLC 4-1 that has transmitted a signal for performing energization processing to the motor 10 in the storage unit 26, As in the case where the leakage contact input is not generated, the process proceeds to step 9 (S9).

  If it is determined in step 8 (S8) that the leakage contact input is generated in the leakage relays 17a and 17b, the energization target device is the output device 8, the power in step 10 (S10). Since it is determined that the device is not a device, in this case, the process proceeds to step 12 (S12) to determine whether or not the device to be energized is an output device. In step 12 (S12), the output device is determined. If it is determined that the output device 8 is present, the process proceeds to step 13 (S13) in order to perform the identification number of the corresponding output terminal of the output unit 7 connected to the output device 8 and the energization process for the output device 8. The identification number of the PLC 4-1 that has transmitted the above signal is stored in the storage unit 26, and thereafter, the process proceeds to step 9 (S 9) in the same manner as when the earth leakage contact input has not occurred.

  Next, as described above, by repeating the process of step 4 (S4) to step 13 (S13) while sequentially changing the energization target, in step 9 (S9), all output devices 8 and motors 10 are transferred. When it is determined that each of the energization processes for 0.3 seconds has been performed, the leakage check energization unit 25 connects the corresponding input terminal to each input device 6 connected to the input unit 5 of the PLC 4-1. The energization process is sequentially started in the order of the identification numbers attached to the.

  When the energization target device is the input device 6, since it is determined in step 4 (S4) that it is not an output or power device, the process proceeds to step 14 (S14), and in step 14 (S14), It is determined whether or not the input device 6 to be energized is of a type that must force the input to the input section of the PLC 4-1, and the energized device forcibly inputs the input. If the input device 6 has a format that does not need to be performed, the process returns to step 5 (S5), and the input is performed by the PLC 4-1, as in the case where the output device 8 and the motor 10 are energized devices. A signal for starting energization (input) is transmitted from the device 6 to the input unit 5, and then in step 6 (S6), it is determined whether or not the energization time has reached 0.3 seconds. When the energization time reaches 0.3 seconds, Proceed step 7 to (S7), to stop the signal from PLC4-1, so that energization of the input device 6 is stopped. At the same time, in parallel with Step 5 (S5) to Step 7 (S7), in Step 8 (S8), the leakage relay 17a (FIG. ))), It is determined whether or not the leakage contact input has occurred, and if it is determined that the leakage contact input of the leakage relay 17a has not occurred, the process proceeds to step 9 (S9) as it is, and the PLC 4-1 When it is determined whether or not all the input devices 6 connected to the input unit 5 have been energized for 0.3 seconds, and all the input devices 6 have not been energized. In step S4, the input device 6 connected to the input terminal with the next identification number is returned to step 4 (S4) to start processing.

  When it is determined in step 14 (S14) that the input device 6 to be energized is in a format that must force the input to the input unit 5 of the PLC 4-1. Then, the process proceeds to step 15 (S15), and an operation command is given to a required device for enabling the input device 6 to input to the PLC 4-1. Thereafter, monitoring is performed until an input from the input device 6 to the PLC 4-1 occurs due to the operation of the required device (step 16: S16). When an input from the input device 6 to the PLC 4-1 occurs, A stop command is given to the required equipment (step 17: S17). In parallel with the processing of step 17 (S17), the process proceeds to step 8 (S8), and when input from the input device 6 to the input unit 5 of the PLC 4-1, that is, energization occurs, It is determined whether or not an earth leakage contact input of the earth leakage relay 17a has occurred.

  In step 8 (S8), when it is determined that the leakage contact input of the leakage relay 17a has occurred during the energization (input) from the input device 6 to the input unit 5 of the PLC 4-1, the energization target device is the output device. Similarly to the case of 8 or the motor 10, the process proceeds to step 10 (S10). In this case, since the device to be energized is the input device 6, it is determined in step 10 that it is not a power device, and the process proceeds to step 12 (S12). In step 12 (S12), it is also determined that it is not an output device. Therefore, the process proceeds to step 18 (S18) to identify the identification number assigned to the input terminal of the input unit 5 to which the input device 6 is connected and to cause the input device 6 to perform energization processing. After storing the identification number of the PLC 4-1 that has transmitted the above signal in the storage unit 26, the process proceeds to step 9 (S <b> 9) in the same manner as when no leakage contact input occurred.

  Thereafter, when energization processing for 0.3 seconds is performed on all the input devices 6 connected to the input unit 5 of the PLC 4-1, whether or not x = n, that is, the assigned identification number. It is determined whether or not the energization process is performed for 0.3 seconds for each output device 8, each motor 10 as the power device, and each input device 6 related to the sequence control by the PLC 4-n that maximizes the power consumption. (Step 19: S19). If x = n is not satisfied, x = x + 1 is set (step 20: S20), and then the process returns to step 4 (S4), so that the identification numbers are assigned. Each PLC4-2 to PLC4-n is sequentially energized every 0.3 seconds in the same manner as performed for each output device 8, each motor 10, and input device 6 related to the control of the PLC 4-1, This energizing place When, if the earth leakage relay 17a, the electric leakage contact input 17b arises, the current target device at that time, so as to be stored in the storage unit 26 in step 11, 13 or 18.

  After that, when x = n in Step 19 and it is confirmed that all the PLCs 4-1 to 4-n have been processed, the process proceeds to Step 21 (S21) to search for a leakage point. Stop. In addition, the display unit 27 is configured so that the device that has been energized when the leakage contact input of the leakage relays 17a and 17b, which has been stored in the storage unit 26 in step 11, 13, or 18 is generated, can be specified. (Step 22: S22), and the operation is terminated. In addition, as a method for displaying on the display unit 27 so that the device to be energized when the leakage contact input is generated can be specified, for example, whether the device is the output device 8, the motor 10, or the input device 6 Is displayed together with the identification number given to the output terminal, power unit 9 or input terminal to which the device is connected, and PLC 4-1 to PLC 4-n performing control related to the device. If the above equipment can be specified, such as displaying the serial number attached to, or displaying the equipment in a circuit configuration diagram of the ready-mixed concrete plant so that it can be distinguished from other equipment. The method may be appropriately selected.

  Therefore, as described above, according to the leak location investigation method and apparatus of the present invention, a short-time energization process for each output device 8, motor 10, and input device 6 along the flow shown in FIG. 1. After sequentially performing the above, it is possible to easily identify the location where the leakage occurs by simply monitoring the display on the display unit 27. In addition, since the operator only needs to press the start button 28 provided in the earth leakage location exploration device I of the present invention at the time of the earth leakage location exploration work, no manpower is required. In addition to eliminating the possibility of increasing labor, it is possible to detect a leakage point easily and in a short time by a single operation without the need for an insulation resistance meter. Furthermore, since it is an automatic exploration, it does not require specialized technology, so anyone can conduct an exploration of the leakage point. In addition, the time required to inspect the presence or absence of electric leakage for one device is as short as 0.3 seconds, in which the electric current is supplied to the device by the electric leakage inspection energization unit 25. Even if an interval of 0.7 seconds is taken until the energization process for detecting the presence or absence of leakage is performed on the device, it is possible to inspect the presence or absence of leakage for one device per second. Therefore, even for hundreds of devices in a ready-mixed concrete manufacturing plant, it is possible to inspect whether or not there is a leak in all the devices in several hundred seconds. That is, according to the leakage location investigation method of the present invention, the location where the leakage occurs is identified by whether or not the leakage current is generated when energization is performed instead of measuring the insulation resistance value of the conductor. Therefore, it is possible to significantly reduce the time required to search for a leakage point as compared with the conventional case. For this reason, it becomes possible to greatly shorten the plant stoppage period when the electric leakage occurs.

  In addition, the current-carrying time for a leakage check performed on each output device 8, each motor 10 as a power device, and each input device 6 is set to 0.3 seconds so that the leakage relays 17a and 17b can be operated. Because it is set so that energization is stopped before the actual operation of various machines is started, there is no risk that only some machines will actually operate. There is no risk of inconvenience even if the earth leakage exploration method and apparatus of the present invention are applied to a plant that is operated in connection with the above.

  Further, in the PLC 4-1 to PLC 4-n, the internal circuit 13, the output-side external circuit 16, and the input-side external circuit 14 are separated (see FIGS. 4 and 5), and the leakage point is searched. As a power device that receives power supply from each output device 8 connected to the output unit 7 of the PLC 4-1 to PLC 4-n for processing, and a power unit 9 controlled by the output from the output unit 7 Since the energization performed to each motor 10 and each input device 6 connected to the input unit 5 is not changed from the voltage during normal operation, the electronic device is connected to the output unit 7 or the input unit 5 of the PLC. Even if these are used, there is no risk of high voltage acting on these electronic devices, so there is no need to remove the external line from the output unit 7 or the input unit 5, and each device remains in a live state. Exploration work for earth leakage points It can be carried out.

  Moreover, even if a leakage occurs in the equipment connected to any of the input unit 5, the output unit 7, and the power unit 9 of the PLC 4-1 to PLC 4-n, the leakage point can be specified.

  The leakage check energization unit 25, the storage unit 26, the display unit 27, and the start button 28 in the leakage location exploration device of the present invention control a plurality of PLCs in a conventional plant control system. Although it may be provided separately from the central control panel 11 provided for performing, it is preferable to equip the central control panel 11 together from the viewpoint of equipment cost and the like. Further, when searching for the leakage point along the flow shown in FIG. 1 as described above, the operation for inspecting the presence or absence of leakage by sequentially energizing each device for a short time is performed by the central control panel 11. Therefore, the earth leakage location exploration device I of the present invention includes the PLC and the central control panel 11 provided in the plant. It can be easily constructed using an existing control system.

  After the leakage occurrence location is identified by using the leakage location exploration method and apparatus of the present invention, the required equipment identified as the leakage occurrence location may be appropriately replaced or repaired, for example, The leakage location specified by the present invention may be further narrowed down by further scrutinizing it using an insulation resistance meter.

  In addition, this invention is not limited only to the said embodiment, In description of the flow of FIG. 1, in the electrical leakage location search method of this invention, the apparatus in connection with the sequence control by each PLC4-1 to PLC4-n. As for each output device 8, each motor 10 as a power device, and each input device 6 are inspected for the presence or absence of electric leakage, and this inspection is shown to be performed sequentially for each PLC 4-1 to PLC 4-n. However, it is possible to sequentially energize all the equipment related to the plant control system for a short time, and when the occurrence of leakage is detected by this energization, the equipment that was energized at that time is later If it can be stored in the storage unit 26 so that it can be identified, the order of the devices for conducting the short-term energization for the leakage check may be changed as appropriate. It may not be as to perform in sequence for each ~PLC4-n. The energization time for each device to detect the presence or absence of leakage is the time when the leakage relays 17a and 17b can be operated when leakage occurs after the start of energization, and the actual operation of various machines is started. It can be set to 0.2 seconds, 0.4 seconds, or any other time as long as it is shorter than the required time. If energization is performed, it is possible to use an earth leakage detector other than the earth leakage relays 17a and 17b as long as it can quickly detect the presence of an earth leakage and emit a signal. If a control system of the type in which PLC is controlled using PLC is provided, it can be applied to the search for the location where leakage occurs in plants other than the ready-mixed concrete manufacturing plant. It is of course that various changes and modifications may be made within the scope not.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an outline of a processing flow for searching for a leak location, showing an embodiment of a leak location search method and apparatus according to the present invention. It is a figure which shows the outline | summary of the apparatus used for the earth-leakage location search method of FIG. It is a figure which shows the outline | summary of the control system of a ready-mixed concrete manufacturing plant. It is this schematic which shows the circuit structure of the input part of PLC. It is this schematic which shows the circuit structure of the output part of PLC. (A) and (B) are diagrams showing an outline of equipment for detecting electric leakage in a plant such as a ready-mixed concrete manufacturing plant. It is a figure which shows the outline | summary of the leak location confirmation method conventionally proposed in order to confirm the leak location in an electric equipment.

Explanation of symbols

4,4-1,4-2,4-3,4-n PLC (programmable controller)
6 Input equipment 8 Output equipment 10 Motor (power equipment)
11 Central control panel 11a Main controller 11b PLC
17a, 17b Earth leakage relay (earth leakage detector)
25 Current-carrying section for detecting leakage 26 Storage section 27 Display section

Claims (5)

  Each plant device is energized in a short time in sequence, and when each device is energized, the presence or absence of the leakage detector is monitored, and when the leakage detector is activated, it is energized. A method for exploring an electric leakage location, characterized by identifying the device as an electric leakage location.   From the central control panel in the plant equipped with a control system in which a large number of devices are sequence-controlled by a programmable controller, and the programmable controller and the main control unit can be comprehensively controlled by the central control panel. A command for sequentially energizing each device related to the control by the programmable controller is given, and when energizing each device, the presence or absence of the operation of the earth leakage detector is monitored. An electrical leakage location exploration method characterized in that a device that has been energized when activated is identified as an electrical leakage location.   3. The method for searching for a leakage point according to claim 1 or 2, wherein an energization time for energizing each device is set to be a short time during which the leakage detector can operate but the operation of the power device is not started.   A large number of devices are sequence-controlled by a programmable controller, and further equipped with a control system that makes it possible to control the programmable controller and the main controller in a central control panel. And a leakage detecting energization unit configured to allow the devices related to the control by the programmable controller to be sequentially energized in a short time from the central control panel, A storage unit for monitoring the presence or absence of the operation of the leakage detector when energizing the device and storing the device that was energized when the leakage detector was activated, and stored in the storage unit An earth leakage location exploration device having a configuration including a display unit for displaying so as to be able to identify a connected device.   5. The leakage detecting energization unit has a function of sequentially energizing a short period of time when the operation of the power device is not started, although the leakage detector can be activated for each device by the central control panel. The earth leakage location survey device described.

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