General knowledge and essentials of lightning protection grounding check
1. Check the steps of surge protection grounding
Test the grounding resistance of lightning rods, high-rise buildings and other facilities to ensure that lightning can be smoothly introduced into the earth.
Lightning protection grounding test method:
1. First find the grounding lead or equipotential connection box of the lightning protection grounding network.
2, with the grounding resistance tester to measure the grounding resistance (there are two test pile 0.4M to insert soil, a distance from the test point 20 meters, a 40 meters, so the test point around 42 meters to have soil)
3. The smaller the grounding resistance value, the better. The specific qualified value must be specified according to the design requirements when the design has requirements.
2. What does the lightning protection check mainly detect
1. Test the effectiveness of the lightning protection device, connectivity of the connector, lead-off, grounding device, etc.
2. The effective grounding resistance of the grounding system must be less than or equal to 10Ω.
3, power supply lightning protection system to the ground insulation impedance is in the allowed value, the grounding system is reliable, instantaneous clamp pressure value is changed, etc.
4, information system signal lightning protection system, for the connection resistance is the parameter allowable value, instantaneous clamp pressure value is changed, the normal value of insulation resistance to the ground, etc.
General lightning detection is basically these aspects, but also according to the local requirements of the territory, after all, the requirements of the high thunderstorm area will be higher.
3. Check and maintain items and precautions during the operation of the lightning protection device
When the lightning protection device is in operation, it is necessary to strengthen inspection to detect and handle anomalies and defects in time to prevent the lightning protection device from being useless or the performance of the lightning protection device is degraded.
Specific inspection items are as follows:
(1) The lightning lead part of the lightning protection device, grounding lead line and grounding body are well connected.
(2) The grounding resistance should be regularly tested during operation, and the grounding resistance should meet the specified requirements.
(3) Lightning arresters should be regularly done preventive tests.
(4) Lightning rod, lightning conductor and its grounding wire should be free of mechanical damage and corrosion phenomenon.
(5) the lightning arrester insulation sleeve should be complete, the surface should be without cracks, no serious pollution and insulation peeling phenomenon.
(6) Regularly transcribe the movement times of the arrester as indicated by the discharge recorder.
(7) The grounding part should be well grounded. In addition, before the annual thunderstorm season, a comprehensive inspection, maintenance, and necessary electrical preventive tests should be carried out.
The specific test items (in which the lightning arrester part is the valve type lightning arrester for example) are as follows:
(1) Measure the grounding resistance of the grounding part.
(2) Residual pressure test under nominal current of arrester.
(3) power frequency discharge voltage test of arrester.
(4) arrester seal test, etc.