(1) Switch type lightning arrester:
Its working principle is that it exhibits a high impedance when there is no instantaneous overvoltage, but once it responds to a lightning overvoltage, its impedance mutates to a low value, allowing the lightning current to pass through. Devices used for such devices include: discharge gaps, gas discharge tubes, thyristors, etc.
(2) Limit pressure type lightning arrester:
Its working principle is that when there is no instantaneous overvoltage, it is high impedance, but with increasing surge current and voltage, its impedance will continuously decrease, and its current-voltage characteristic is strongly non-linear. Devices used for such devices include: zinc oxide, varistors, suppression diodes, avalanche diodes, and the like. Today's surge arresters are mostly limited pressure type.
(3) Shunt type or turbulent type surge protector shunt type: In parallel with the equipment to be protected, it presents a low impedance to the lightning pulse and a high impedance to the normal operating frequency.
Turbulence: In series with a protected device, it exhibits a high impedance for lightning pulses and a low impedance for normal operating frequencies.
Devices used for such devices include: choke coils, high-pass filters, low-pass filters, 1/4-wave short-circuiters, and the like.
2, according to use points:
(1) Lightning protection device: lightning protection device for AC power supply, lightning protection device for DC power supply, lightning protection device for special power supply (wind power, solar energy), etc.
(2) Signal lightning protectors: digital signal lightning protection devices, analog signal lightning protection devices, and antenna feeder lightning protection devices.
(3) Combination lightning arresters: SPDs that protect a variety of signals and power supply at the same time, such as lightning protection devices that integrate video lightning protection and power supply lightning protection at the camera end in the surveillance system. The lightning protection device that provides both Ethernet signal and power protection at the same time in communications.
3, according to lightning protection points:
Class B SPD: General nominal current is above 30KA. Switch type and pressure limiting type.
Class C lightning protector: The general nominal current is between 15~20KA, all of them are pressure limiting type.
Class D lightning arrester: Generally nominal current is between 5~10KA, all of which are pressure limiting type.
Woven Fence are weaved by galanized Wire , PVC wire or Stainless steel wire.
The woven fence contains Chain link fence, Field fence , Gabion , Bullet-Proof Mesh
1. Chain Link Fence is extensively used as fences for playground and gardens, super highway, railway, airport, port, residence, etc. Also can be used for breeding of animals.
Chain link fence can be with barb wire, Razor Wire on top for high security.
2. Field Fence also called Grassland garden mesh(Hinge Joint Fence) usually made from hot dip galvanized wire with zinc coating of 230g/m2.
Top and bottom wire: 2.5mm
inner wire: 2.0mm
3. Gabion Basket made of hexagonal Galvanized/PVC/Zinc-Al double twised mild steel wire mesh.
Gabion baskets can be supplied in various lengths, widths and heights. In order to strengthen the baskets, all the edges of the structure shall be selvedged thicker wire diameter.
4. Bullet-proof mesh is the most popular as window screen. It made of stainless steel wire and powder coating.
The Bullet-proof mesh transparent without any sense of vertigo, it is like a layer of transparent colored glass when looked from inside to the outside of the rom and hazy and blurred from outside to the inside of the room.
Woven Fence
Chain Link Fence,Field Fence,Bullet-Proof Mesh,Woven Fence
Anping Deming Metal Net Co.,Ltd , https://www.wovenfence.nl