SI22024A - Device for testing the safety of electrical installations - Google Patents

Abstract

The invention describes a device for testing the safety of electric installations, which via a multiplex keyboard with centrally located multifunction button and keyboard enabling a direct entering of alphanumeric characters, provides the possibility of simple operation and entering of the required data as well as selection of measurement functions. The device enables measurements of the terminal impedance between the PE terminal on the socket and the other metal contact part without rewiring measurement cables during the performance of measurements. The clearly shown results on the performed measurements are displayed by the device on a special display. The device also includes a multifunction insulation measurement device with an integrated function for testing IMD devices, which is enabled by a special electronic circuit. The device also includes a memory, where the predefined series of tests and measurements are stored along with communication interfaces, which enable the communication with external devices like USB keys, PCs and via the RFID RW device also with memory cards and chips.

Description

FIELD OF THE INVENTION

The invention falls within the field of electrical safety testing devices.

The state of the art

Electrical safety testing devices are already known in the art. They usually consist of a suitable housing that has switches and buttons to select the measurement type on the upper part, and LEDs that indicate to us what types of measurements are being made, and usually also indicate whether the results fit or not or have a display on the upper part.

The devices are manually controlled. Typically, the type of measurement is selected using the toggle switch.

A technical problem

The disadvantage of all known devices is that they require a lot of user knowledge, since the measurement parameters must be adjusted manually, and during the measurement itself, depending on the results obtained, select new and new settings. This results in many steps that the user of the device must take, so there is a high possibility of subjective errors and the measurement time is quite long.

A disadvantage of the known devices is that they show us the results, but do not give us any comment. If such a device detects an error, it only reports that it detects an error, and only tells us in the form of a measurement result or a specific mark, e.g. the red light comes on, the warning triangle symbol, etc. lights up. It does not tell us the possible cause of the error, nor does it suggest possible steps to remedy the detected error.

Known devices do not allow the measurement of the coupling resistance between the PE clip on the socket and other touching metal parts without carrying the measuring cables while performing the necessary measurements to assess the safety of the socket, nor are they able to communicate directly with a PC via USB or with memory cards and badges via RFID Reader / Reader.

Description of the invention

The subject of the invention is an electrical safety testing device that solves all the disadvantages described.

The device comprises a housing containing measuring electronics and a circuit that are already known in the art, so we do not describe it in detail.

The apparatus of the present invention contains a memory that already stores certain sequences of measurements and tests that cannot be modified. In addition to the results of measurements, the user can store in addition to the measurement results pre-prepared measurement sequences, lists of functions or functions arranged in a specific order, by which the user prepares a measurement sequence, limit values by which he compares measurement results and fuse lists with their characteristics, which allows the device to suggest a suitable fuse. The device according to the present invention enables the preparation, storage and performance of any sequence of measurements and tests of electrical installations.

The process of performing a measurement that takes place on the device being the subject of the invention is automatic. The user just selects the desired preset sequence of measurements, connects the device to the mains and presses the "start" key. From here on, the device constantly checks all safety conditions and then performs the necessary measurements, evaluates the partial results, saves them up to date, and finally gives an assessment of the safety of the electrical network.

If the device detects a power failure, it displays messages in the display that contain a description of the detected fault, a possible cause, and suggestions for correcting the cause of the fault. The automatic process of performing the sequence of measurements, as well as the procedure for the automatic evaluation of the safety of electrical circuits, are the subject of our two separate patent applications filed at the same time as the subject application, so we do not describe them in more detail here.

The programming of the measurement sequence is simplified by the introduction of a multidirectional keypad with a center-mounted multifunction key to confirm the selected parameters or to initiate the measurement process and the like. Another advantage of the device of the present invention is the introduction of a keyboard that allows direct entry of alphanumeric characters. Such a keyboard is known on mobile phones.

Furthermore, the device includes a high-resolution display (1/4 VGA) that allows you to view the entered parameters, and during and after the measurement results are displayed on the display, arranged neatly into specific fields, for transparency.

The device further comprises four terminal blocks, which allow the measurement of the coupling resistance between the PE terminal at the socket and other touching metal part as part of a comprehensive electrical socket test.

The apparatus of the present invention further comprises a multifunction insulation meter with an integrated IMD (Insulation Monitoring Device) function. This option is provided with an electronic circuit, which is described in more detail below. Furthermore, with the introduction of communication connectors, the device enables connection to a PC, various memory media, printers, and the like, either through an appropriate cable or wirelessly.

Short description of the pictures

The apparatus of the present invention is described in more detail below with the aid of the accompanying figures showing:

Figure 1: First embodiment of the front panel of the device according to the present invention,

Figure 2: Another embodiment of the front panel of the device according to the present invention,

Figure 3a: The first typical result screen that appears on the display,

Figure 3b: Another typical result screen that appears on the display,

Figure 4: Circuit diagram for measuring the coupling resistance between PE terminals

Figure 5:

Figure 6:

Figure 7:

on the socket and other touching metal parts,

Circuit diagram for testing IMD devices,

Schematic representation of communication interfaces,

Schematic representation of device connectivity with other devices.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows the first embodiment of the front panel of a device comprising a multidirectional keypad with a center-mounted multifunction key to confirm the selected parameters or to initiate the measurement process and the like 1 and display 2.

Figure 2 shows a second embodiment of the front panel of the device comprising a multidirectional keypad with a center-mounted multifunction key to confirm the selected parameters or to initiate the measurement process, etc. 1, a display 2, and a keypad for direct alphanumeric characters 11.

The aforementioned keypad for direct alphanumeric characters can also be made by appearing on the display 2, and the keys can be controlled by means of a multidirectional keypad with a center-mounted multifunction key 1, and it is also possible to use the keypad as an external unit to be connected to the device. through an appropriate communication interface. These two designs are not shown in the pictures.

The benefits of using a multifunction keypad with a center-mounted multifunction key are numerous, as the user can control the cursor on the display with a single finger to select the desired fields and press the center key to confirm. The center key is also used to command the measurement process. The center button is metallized and also serves as a measuring probe - a touch point.

Figure 3a shows a typical result screen as it appears on the display after performing a single measurement.

The screen contains the following fields:

address field 21 with function and subfunction name, battery status, display of active keys on the multidirectional keyboard 1, result box, subscores and rating good / bad 22, function parameter field 23, where standard parameters related to each measurement are collected, message box with Information and Alerts 24, which provides alerts and information regarding measurements. A novelty is whether or not the TEST SST is fulfilled on the input terminals, a box showing the connected voltages 25, which shows the current voltage status of the input terminals and (during measurement) the active terminals. The terminals are named according to the selected voltage system. The field also displays alerts related to the input voltage state (eg SINGLE FAULT status detection, three-phase rotation field, incorrect voltage state according to the selected voltage system, etc.), function switching field 26.

The function switch box 26 replaces the switch, which is essentially a rotary switch, as used by known devices. The measuring functions in the instrument can be adjusted by using the Left / Right keys on the multidirectional keypad 1 (eg Voltage, VN Insulation, Continuity of connection with the protective conductor (Continuity) ....), etc., and sub-functions using the UP, DOWN keys on the multidirectional keyboard 1 (eg in RCD function: RCDt, RCD I, RCD Auto, Uc, Rs).

The selected function is highlighted, e.g. colored black, the selected subfunction is visible in the address field 21 and in the function parameter field 23.

The functions in box 26 are sorted in a meaningful order by which the user prepares a sequence of measurements.

The order of stored functions is from left to right as follows: voltage - insulation contacts - short circuit resistance - loop loop resistance - RCD test - ground resistance.

The order of functions is chosen to fit the commonly used sequence of performing a comprehensive test of the security of the measurement site, thus simplifying the preparation of the measurement sequence.

The usual comprehensive test of the safety of a measurement site (most commonly electrical sockets) consists of the following measurements:

Measurement of insulation resistance between L and N, L and PE and N and PE wires (at mains voltage off), change of resistance of connection between PE terminal and equalizer of potential (at off mains voltage), change of resistance or impedance of short circuit power short circuit (when switched on voltage, impedance or impedance measurement of loop failure (with mains voltage on), RCD switch test (with mains voltage on).

The order chosen is the most favorable because the measurements are sequentially distributed without and with the supply voltage and thus the final number of operations to perform the test is the smallest. The advantage of the sequence so selected is that when performing a comprehensive safety test, the meter always moves to the next function after the measurement has been completed, just one step to the right, using the corresponding key on the multidirectional keyboard.

Figure 3b shows another typical result screen as it appears on the display with a large number of results. The picture shows that due to the high resolution of the display, a greater number of measurement results and other information can be clearly and clearly identified.

The apparatus of the present invention comprises four input / output terminals. In addition to the known L, PE and N terminals, the device also includes an S terminal 37, which allows measuring the resistance of the connection 36 between the PE terminal at the socket 31 and other touching metal parts, such as the equalizer of potential 32 (Figure 4), when the measuring terminals of the L, N, PE instrument are connected to the electrical outlet 31. The advantage of such a connection is that the complete safety test on the electrical outlet, without bandaging, is significantly faster. The rest of measurement electronics 35 (generators, loads and procedures are already known in the art.

A feature of the circuit shown in Figure 4 is the expanded ability to schedule measurement signals for individual measurements, capture and display of results, procedures for storing and connecting internal generators and loads through various instrument input terminals, with many new combinations provided. The most typical new combinations are:

any combination of measurement of the resistance of connections between the LN, LPE and NPE and PE S terminals without bandaging.

any combination of insulation resistance measurement between terminals LN, LPE and NPE, without bandaging.

generating signals for tracing conductors in the network between any output terminals (i.e. functionality - tracing of conductors).

These new combinations, to the extent possible, supplement and support the sequential process of measuring electrical parameters in electrical installations, which is the subject of our patent application filed at the same time.

The circuit is realized by a combination of relay array 34 and specific coupling of the input voltage meters 33, as shown in Figure 4.

Another feature of the device of the present invention is a multifunctional isolation meter with an integrated Insulation Monitoring Device (IMD) function designed to control insulation resistance in IT systems. These are fixedly installed devices for continuous monitoring of insulation resistance in IT systems.

The device can simulate various fault resistances between the phase conductors (L1, L2) and the protective conductor in the IT system in such a size class that an IMD alarm of the device is triggered. The resistance at which the alarm occurs shall be in accordance with the technical specification of the IMD device. IMD device limit values, however, depend on the type of use. For example, in the medical environment, for example, the limit value is typically in the 50 kQ size range.

Enter the alarm limit in the device, display the measured result in the display and save (43).

The new functionality is implemented with an electronic circuit 42 that simulates a fault resistance between a phase (L1 or L2) and a PE conductor. The electronic circuit 44 ensures that the simulated resistance circuit 42 is properly connected to the IT power system.

The connection is made in such a way that the IMD device 41 feels the simulated resistance 42 in the same way as it would, for example, feel the actual resistance 45.

The user changes the simulated resistance 42 with the keys until an IMD alarm occurs

41.

The resistance value 42 and the current-to-voltage ratio 42 obtained are displayed in the display 43 and can be stored in the instrument memory.

Figure 6 is a schematic representation of modem communication interfaces, which is also a feature of the device of the present invention.

Sliding bar 51 separates the measuring terminals (52) and communication interfaces, while the device communicates with external devices via a USB interface 53, which can be a USB slave interface and can also serve as a USB host (but of course the device may have multiple USB interfaces) and RS232 interfaces 54. Communication through the aforementioned interfaces is facilitated by the appropriate software (drivers). Charging of the rechargeable batteries in the measuring instrument is ensured via the charger input 55.

The communication interfaces 53, 54 of the measuring device 61, which also includes the memory 62 and the operating system 63, enable two-way communication of the measuring instrument with a personal computer 66 (Figure 7) via USB slave 53 and via RS232 interface 54, with a USB key 65 via a USB host interface 53, with TAG memory cards and cards 68 via RS232 interface 54 and read-write RFID unit 67.

Typical information to exchange is:

- information on the structure (structures, trees) of the electrical installation, measurement results, including date information on the measuring device, information on the settings of the measuring device.

The present patent application describes a device for testing the safety of electrical installations, which by the above description is by no means limited and includes all the obvious derivatives of the described device. The scope of the protection required is defined in the claims.

for

Metrel d.d. Representative:

Janko Pučnik

Claims (10)

Patent claims 1. An electrical safety testing device comprising a housing and measuring electronics, characterized in that it comprises: multi-keypad with a center-mounted multi-function key that is metallized to serve as a probe at the same time - a touchpad (1), a high-resolution display (2). Apparatus according to claim 1, characterized in that it comprises a keyboard for direct input of alphanumeric characters (11), which may be integrated into the device, or appear on display 2, or be an external unit connected to the device via an appropriate communication interface . Apparatus according to any preceding claim, characterized in that said display (2) is divided into an address field (21), a result field sub-results and an estimate (22), a function parameter field (23), a message box with information and warnings ( 24), a box showing the connected voltages (25) and a function switching box (26). Apparatus according to any one of the preceding claims, characterized in that the display (2) in the result box mentioned below results and the estimate (22) allows the display of results in one line or in several lines. Apparatus according to any one of the preceding claims, comprising the input output terminals L, PE and N, characterized in that it also contains an S terminal (37) which allows measurement of the connecting resistance (36) between the PE terminal at the socket (31) and the other touchable metal parts, such as the potential equalizer (32), even when the measuring terminals of the L, N, PE instrument are connected to an electrical outlet (31). Device according to any one of the preceding claims, characterized in that it contains a circuit containing a combination of a relay array (34) and input voltage meters (33) and also enables the following combinations of measurements: any combination of measurement of the resistance of connections between the LN, LPE and NPE and PE S terminals without bandaging. any combination of insulation resistance measurement between terminals LN, LPE and NPE, without bandaging. generating signals to trace the conductors in the network between any output terminals. Device according to any of the preceding claims, characterized in that it contains a multifunction insulation meter with an integrated function for testing IMD devices in IT systems, which simulates the resistance between the phase conductor (L1, L2) and the PE conductor. Apparatus according to any one of the preceding claims, comprising four measuring terminals (52) and an input for the battery charger of the device (55) and a sliding bar (51), characterized in that it comprises memory (62) and an operating system (63) and communication USB slave / USB host (53) and RS232 (54) interfaces that allow communication with a PC (66), a USB stick (65), and via a read-write RFID unit (67), as well as memory tags (TAG) and cards (68). Apparatus according to any one of the preceding claims, characterized in that it enables the preparation, storage and performance of any series of measurements and tests of electrical installations. Apparatus according to any preceding claim, characterized in that said memory (62) contains one or more stored sequences of measurements and tests of electrical installations.