In the lightning rod detection, there are many factors that cause the grounding resistance tester to be inaccurate. To sum up, there are generally nine reasons for the following.
First, since the grounding resistance tester tests the ground resistance of the grounding body by emitting and receiving current through the iron, the mutual interference between the two irons and the distance between the two brazing and the grounding body will occur, and thus An error has occurred. Therefore, when measuring. The grounding body, the voltage pole and the current pole are arranged in sequence, and the three points are in a straight line, which is 20 m apart from each other.
Second, the depth of the iron insert should be greater than 1/4 of the length of the iron, otherwise, test errors will occur. therefore. When testing, try to deepen the iron.
Third, in the case of "common ground", the grounding device generates a certain ground voltage to the ground due to poor insulation or short circuit of the equipment, and the reading is unstable when measured. At this time, the power should be turned off for detection, or the place where the card is disconnected should be disconnected for detection to avoid the influence of the ground voltage on the detection.
Fourth, poor contact. When the object to be measured is rusted or the test line is broken, the phenomenon of time-breaking or large resistance is found during the test. At this point, the rust should be removed first. If it still cannot be eliminated, check the continuity of the test line with a multimeter digital display meter battery 15V resistor.
Fifth, when testing high-rise buildings, the lines used are too long and too thick, causing the line resistance and induced voltage to increase, causing measurement errors. In this case, use a wire with a lower wire resistance to minimize the measurement error.
Sixth, when there are materials such as soil or sandstone in the measured place, the measurement error is caused by the difference in soil resistivity between the upper and lower layers. At this time, deep iron brazing should be applied to make full contact with the soil under the cushion or avoid the soil layer, so that the measurement error is reduced.
Seventh, when the metal objects such as the grounding device and the metal pipe are buried, the current direction of each pole of the measuring instrument may be changed to cause poor measurement or instability. At this point, you should first understand the layout of the grounding body and the metal pipe, and select the place where the influence is relatively small for measurement.
Eighth, the measurement is inaccurate due to the potential difference or strong magnetic field on the surface. At this time, try to keep away from the place with large potential difference or strong magnetic field. If it is unavoidable, the detection line should be shortened relatively and the measurement error should be reduced.
Ninth, the operation is not in accordance with the instructions, the instrument is faulty and not timely repaired, the instrument is inaccurate or has not been identified for a long time, and other factors may cause measurement errors.
First, since the grounding resistance tester tests the ground resistance of the grounding body by emitting and receiving current through the iron, the mutual interference between the two irons and the distance between the two brazing and the grounding body will occur, and thus An error has occurred. Therefore, when measuring. The grounding body, the voltage pole and the current pole are arranged in sequence, and the three points are in a straight line, which is 20 m apart from each other.
Second, the depth of the iron insert should be greater than 1/4 of the length of the iron, otherwise, test errors will occur. therefore. When testing, try to deepen the iron.
Third, in the case of "common ground", the grounding device generates a certain ground voltage to the ground due to poor insulation or short circuit of the equipment, and the reading is unstable when measured. At this time, the power should be turned off for detection, or the place where the card is disconnected should be disconnected for detection to avoid the influence of the ground voltage on the detection.
Fourth, poor contact. When the object to be measured is rusted or the test line is broken, the phenomenon of time-breaking or large resistance is found during the test. At this point, the rust should be removed first. If it still cannot be eliminated, check the continuity of the test line with a multimeter digital display meter battery 15V resistor.
Fifth, when testing high-rise buildings, the lines used are too long and too thick, causing the line resistance and induced voltage to increase, causing measurement errors. In this case, use a wire with a lower wire resistance to minimize the measurement error.
Sixth, when there are materials such as soil or sandstone in the measured place, the measurement error is caused by the difference in soil resistivity between the upper and lower layers. At this time, deep iron brazing should be applied to make full contact with the soil under the cushion or avoid the soil layer, so that the measurement error is reduced.
Seventh, when the metal objects such as the grounding device and the metal pipe are buried, the current direction of each pole of the measuring instrument may be changed to cause poor measurement or instability. At this point, you should first understand the layout of the grounding body and the metal pipe, and select the place where the influence is relatively small for measurement.
Eighth, the measurement is inaccurate due to the potential difference or strong magnetic field on the surface. At this time, try to keep away from the place with large potential difference or strong magnetic field. If it is unavoidable, the detection line should be shortened relatively and the measurement error should be reduced.
Ninth, the operation is not in accordance with the instructions, the instrument is faulty and not timely repaired, the instrument is inaccurate or has not been identified for a long time, and other factors may cause measurement errors.
Single core Armored Cable
Standard: IEC 60502
Rated Voltage: 0.6/1kV
AWA (Aluminium Wire Armour)
SSWA ( Stainless Steel Wire Armour)
Sheath/Jacket: PVC (Polyvinyl-Chloride)
Applications: Armoured Cable for power networks, industrial plants, switch-boards, underground and in cable ducting where better mechanical protection is required.
Single Core Armored Cable,Types Of Armoured Cable,Single Core Wire,Armored Cable Power
Shenzhen Bendakang Cables Holding Co., Ltd , https://www.bdkcables.com