Lightning protection is a very important task for building lightning protection. According to relevant regulations, all buildings should be routinely tested once a year. So what are the main points of lightning protection detection?
Detection point 1: lightning protection detection of the lightning device
The lightning-receiving device is a defense device for direct lightning strikes, and is composed of a lightning rod, a lightning protection belt, a lightning protection net, and a lightning protection line. In addition, metal roofing, metal components, etc. on the top floor of the building can be used as lightning receptors. The lightning protection detection contents of the lightning device are mainly:
1. Material type and specification of the lightning protection belt, laying method, welding standard between the connection point and welding standard with the down conductor;
2. The equipotential bonding between the down conductor of the lightning rod and the lightning protection belt and the net, whether the metal bracket is used as the base of the down conductor, etc.;
3. Grid size of lightning protection net; material type and specification; welding quality and welding standard with down conductor.
Detection point 2: lightning protection detection of the down line
1. When the weld is completed and the concrete is not poured, the test contents include: whether the main rib is used as the down conductor and whether it is electrically connected from top to bottom; the specification, quantity and position of the down conductor And spacing; welding quality.
2. Before the plastering of the exterior wall, it is necessary to test the down-conducting line of the Ming-clad, mainly including the welding standard of the down-conductor and the grounding body, the welding standard between the down-conducting line, and the grounding resistance value.
3. When the first layer of the down conductor is completed, the material specifications, quantity, position, height, etc. of the lightning protection disconnecting clip shall be tested.
Detection point 3: lightning protection detection of the grounding device
The type of grounding device, the welding standard of the steel bar in the building, the depth of the foundation body, the grounding material, and specifications all affect the discharge current of the lightning current. The lightning protection detection contents of the grounding device mainly include:
1. When the cap welding and pile foundation have been completed and the concrete is not poured, the specific contents of the test are: welding quality; the type of grounding body; the quantity and type of the reducing agent; the depth and type of the auxiliary grounding body; Main rib diameter; base type and depth, etc., and measure the grounding resistance value.
2. When the ground beam welding work has been completed and the concrete is not poured, the specific contents of the test are: the type of the grounding body; the quality of the weld of the ground beam and the cap; the specification, quantity, position and spacing of the down conductor; The type of wire, the welding quality of the ground beam, whether it is marked with paint, whether the electronic information and the grounding lead of the power distribution system are configured as required, and the grounding resistance value is measured.
Detection point 4: lightning protection detection of surge protector
Surge protectors are mainly lightning protection devices that limit transient over-voltage and over-current. They are necessary protection measures for low-voltage electrical buildings. (钧 and electronic surge protectors are mainly used in military, petroleum and petrochemical places, etc.) Protection modes such as phase, relative ground, relative midline, midline to ground, and combinations thereof.
The lightning protection detection content of the surge protector mainly includes the specification model, installation position, connection method and length. The power surge protector should be installed at the front end of the equipment. The installation method should first consider using the “V” type connection method. When the “V” type connection method cannot be realized, the parallel connection should be adopted, and then the ground should be connected to the ground with the shortest path. Keep it straight and the length should be less than or equal to 50cm.
Detection point 5: detection of lightning protection grading ring
1. When the pressure equalizing ring adopts the floor ring beam, the test content includes whether the main ribs of two or more are used as the equalizing ring, the welding standard of the main rib, the welding standard of the down conductor and the grounding resistance value.
2. When the pressure equalizing ring does not use the floor ring beam, the test content includes the material and specifications of the pressure equalizing ring, the welding quality of the down conductor, the welding quality of the flat steel and the grounding resistance value.
3. Whether the metal door and window is equipped with a side lightning protection device and its standard.
4. Is there a grounding terminal reserved between the glass curtain wall and the equalizing ring, and the quantity is up to standard.