CN202886480U - Grounding resistance detector - Google Patents

Abstract

The utility model discloses a grounding resistance detector, which comprises a voltage coil, a current coil, a voltage generator, a current amplifier, and a magnet jaw. Connected to the current amplifier, the voltage coil and the current coil are wound on the jaws of the magnet, the voltage coil is covered by the first shielding layer, the current coil is covered by the second shielding layer, and a third shielding layer is set between the voltage coil and the current coil The shielding layer, the voltage coil, the current coil and the third shielding layer form a closed circle of equal size. The detection device can conveniently clamp various types of grounding wires and can accurately detect the grounding resistance of the hoisting machinery, and has the advantages of convenient operation and strong anti-interference ability.

Description

Ground Resistance Tester

technical field

The utility model relates to an electric quantity testing instrument, in particular to a hoisting machinery grounding resistance detector.

Background technique

In industrial production and social life, whether it is power transmission and transformation equipment or good grounding of earth buildings, it is an important guarantee for the normal operation of equipment and life safety. In addition to the inspection of the newly installed grounding device to determine whether it meets the design requirements, the regular inspection of the existing grounding device is also an important guarantee to ensure the reliability of the grounding of the equipment. In the actual inspection of hoisting machinery and equipment, various forms of grounding wires such as flat steel, round steel and angle steel will be encountered, and the methods of laying the grounding wires of each manufacturer are different. For laying against the wall, some manufacturers make the cross-sectional size of the grounding wire slightly larger for the sake of safety. When using the existing clamp-type grounding resistance measuring instrument for testing, the grounding wires of different shapes and sizes will bring great harm to the testing personnel. The inconvenience limits the effective detection of conventional grounding resistance measuring instruments.

At present, the most commonly used hoisting machinery grounding resistance tester is ETCR2000 series. When the cross-sectional size of the grounding wire is small and far away from the wall, it is more convenient to use it to test the grounding resistance. However, when the cross-sectional size of the grounding wire is slightly larger or the grounding wire is laid against the wall, the jaws cannot smoothly surround the grounding wire under test, resulting in failure to detect normally.

It can be seen that the development of a measuring instrument that can conveniently clamp various types of grounding wires (flat steel, round steel, angle steel, etc.) and can accurately detect the grounding resistance of lifting machinery to ensure the intrinsic safety of lifting machinery and equipment has important practical significance.

Contents of the invention

The purpose of the utility model is to provide a grounding resistance detector, which can conveniently clamp various types of grounding wires and can accurately detect the grounding resistance of a hoisting machine.

The purpose of this utility model is achieved through the following technical solutions:

A ground resistance detector, comprising a voltage coil 1, a current coil 2, a voltage generator 11, a current amplifier 12, and a magnet jaw 3, the voltage coil 1 is connected to the voltage generator 11 through a lead wire, and the current coil 2 Connected to the current amplifier 12 through the lead wire, the voltage coil 1 and the current coil 2 are wound on the magnet jaw 3, the voltage coil 1 is covered by the first shielding layer 5, and the current coil 2 is covered by the second shielding layer 6 A third shielding layer 7 is provided between the voltage coil 1 and the current coil 2, and the voltage coil 1, the current coil 2 and the third shielding layer 7 form a closed circle of equal size. the

Compared with the prior art, the beneficial effect of the utility model is that the detection device can conveniently clamp various types of grounding wires and can accurately detect the grounding resistance of the hoisting machinery, and has the advantages of convenient operation and strong anti-interference ability.

Description of drawings

Fig. 1 is the electrical schematic diagram of the utility model;

Fig. 2 is a structural representation of the utility model.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is further described. As shown in Fig. 1 and Fig. 2, the utility model comprises a voltage coil 1, a current coil 2, a voltage generator 11, a current amplifier 12, a magnet jaw 3, and the voltage coil 1 is connected to the voltage generator 11 through a lead wire, The current coil 2 is connected to the current amplifier 12 through the lead wire, and the voltage coil 1 and the current coil 2 are wound on the magnet jaw 3 . The voltage coil 1 is covered by the first shielding layer 5, the current coil 2 is covered by the second shielding layer 6, the third shielding layer 7 is set between the voltage coil 1 and the current coil 2, the voltage coil 1, the current coil 2 and the The third shielding layer 7 forms a closed circle of equal size. the

The biggest feature of the utility model is that the thickness of the clamp head is relatively thin, and the inner diameter of the clamp head is relatively large, so it can conveniently clamp the ground wire 4 with a slightly larger cross-sectional size or the ground wire slightly closer to the wall. 4. The voltage coil 1 and the current coil 2 are placed in a jaw 3. When operating, you only need to press the jaw 3 wrench of the ground resistance detector, open the jaw 3 to clamp the ground wire 4 to be tested and release the wrench, the jaws 3 is closed, and the voltage coil 1 and the current coil 2 also form a closed loop at the same time. The voltage generator 11 of the tester outputs an oscillating voltage, which will generate an induced current in the ground wire 4 of the ground loop, and the induced current is received by the current coil 2 and input to the current amplifier 12 circuit of the tester, the oscillating voltage and the induced current are The current is converted into the corresponding grounding resistance by the data processing circuit in the tester, which can be directly displayed on the display screen of the tester.

As shown in Figure 2, it is a longitudinal sectional view of the jaw 3 measuring head of the ground resistance detector, that is, the joint surface of the two halves of the jaw 3 . Among them, the voltage coil 1, the current coil 2 and the shielding layer between them form a closed circle of equal size. The voltage coil 1 and the current coil 2 have a shielding layer outside, which is cast in the casing 10 by engineering plastics. The casing 10 is connected to the grounding resistance detection. The casing of the instrument is integrated into one piece. Since the voltage coil 1 and the current coil 2 are placed in the same jaw 3, electromagnetic interference will be generated, which will affect the measurement accuracy, and the clamp head part of the existing ground resistance detector is relatively thick, and the inner diameter enclosed by the clamp head is relatively small , it will be more troublesome when clamping the ground wire 4 with a slightly larger cross-sectional size or the ground wire 4 that is slightly closer to the wall, or even cannot be clamped. The utility model has taken two measures: 1. A shielding layer is provided on and between the voltage coil 1 and the current coil 2, which can effectively prevent the mutual interference between the oscillating voltage and the induced current; 2. The clamp head The thickness is 30mm, and the inner diameter of the clamp head is 80×80mm. Therefore, it is more convenient for the clamp head to clamp the ground wire 4 with a slightly larger cross-sectional size or the ground wire 4 that is closer to the wall. The measured grounding resistance value has the advantages of convenient operation and strong anti-interference ability.

In addition to the above-mentioned embodiments, the utility model can also have other implementation modes, and all technical solutions formed by equivalent replacement or equivalent transformation all fall within the scope of protection required by the utility model.

Claims (1)

1. earth resistance tester, comprise potential winding (1), current coil (2), voltage generator (11), current amplifier (12), the jaw of magnet (3), described potential winding (1) links to each other with voltage generator (11) through extension line, described current coil (2) links to each other with current amplifier (12) through extension line, potential winding (1), current coil (2) is wound on the jaw (3), it is characterized in that, described potential winding (1) is coated by the first screen layer (5), current coil (2) is coated by secondary shielding layer (6), establish the 3rd screen layer (7) between potential winding (1) and the current coil (2), potential winding (1), the large closed levels such as current coil (2) and the 3rd screen layer (7) formation.

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