Branch KCP-G Series Cabinets electromagnetic shielding electromagnetic shielding cabinet for the outside world to prevent the transmission of information data photoelectric switch data exchange system electromagnetic interference shielding is a measure to prevent the spread of high-frequency electromagnetic field in space with a shield. Electromagnetic waves or electromagnetic waves through a metal barrier layer has a damping effect, will be a certain degree of attenuation that these metals or barrier shielding effect, shielding effectiveness of the size and nature of electromagnetic waves and properties of the metal itself or about the barrier layer. Physical processes metal plate electromagnetic shielding when an electromagnetic wave incident on the air on both sides of a metal plate, a portion of the energy is reflected, the reflection loss; transmission wave propagation in the metal plate is partially attenuated termed absorption loss; in the second will again produce when the interface is reflected to the first interface reflection, and so on ad infinitum, until all the energy is attenuation and transmission, this phenomenon is shielded theory of multiple reflections should be considered a correction factor. Permanent seams on the shield gap shield generally refers to the use of welding the two metal plates connected together, this permanent joint metal plate itself is almost equal to the RF impedance; when an electromagnetic wave shielding waveguide cutoff frequency is lower than the waveguide cutoff frequency, will have a significant attenuation in transmission. Commonly used cutoff waveguide has a circular, rectangular and hexagonal. Park waveguide cut-off frequency: fc = 17.6 * 109 / D (HZ) D- inner diameter of the circular waveguide of the waveguide have sufficient attenuation should be met: fc "ff- electromagnetic frequencies l≥3D l- cutoff waveguide length from ventilation Cooling to consider, in order to obtain adequate ventilation area, in order to meet the required ventilation can be many root cutoff waveguide next arranged together to form a group of the cut-off waveguide array of ventilation holes. Conducted interference is the interference filter, for example by a metal conductor wires or any metal structure spread all metal wire into the shielded room (cabinet) must be within the filter, electronic filters are centralized or distributed circuit elements (such as resistors, inductors, capacitors , or a combination thereof, or of various components equivalents) of networks that certain frequency or dc small revolt, while blocking other frequency channels or shorted. Filters can be roughly divided into: electrical filter, filter and control communications line filters. The main structural components of the shield case: cold-rolled steel plate welded into a fully enclosed cabinet, after galvanizing and paint anti-corrosion treatment; screen door: high-quality materials and processing crafted shield reed, cold-rolled steel plate welded into the screen door leaf thereof; filter: mains filter with wide suppression band and high insertion loss; ventilation waveguide window: honeycomb ventilation waveguide window, the top waveguide window has four miniature axial fan, single exhaust volume 1.4 m3 / min; ① because shielded cabinet sealed structure, will produce some heat considering the equipment cabinet work, request the heat problem, we recommend that the actual use of the space inside the cabinet does not exceed 60%, leaving a certain device is placed over quantity; transmission window: transmission window has a copper pipe with a collet of transport; ② standard configuration 10 Ф8.1 * 100 copper waveguide; six cable shield light pipe: φ14 * 100 fiber optic transmission conduit; ③ Standard Configuration 3 server bracket: vertically adjustable front and rear mounting bracket location server; electrical outlet and switch: a single input 6 GB three plug PDU; power: AC 220V * 16A; ④ shielding performance to shield the cabinet before threading is not basis; enter shielding cabinet shielded cable is double-shielded cable; C grade shielded cabinet: 14KHz ≥ 70dB 150KHz ≥ 100dB 450MHz ≥ 100dB 930MHz ≥ 90dB according to GB12190-90 standard test methods; installation debugging environment: temperature -25 ℃ - - + 70 ℃ ≯85% relative humidity to prevent contact with corrosive substances and gases; equipment move only to determine the location, remained stable, the four bolts next tune, prevent the cabinet from shifting; shielded cabinet should be grounded, grounding resistance should be ≤1Ω, grounding pile extraction terminal and the shield to the cabinet grounding bolt bonding resistance should ≤0.1Ω. Must be grounded before power; earth leakage protector can not be before the power outlet, because the filter is composed of capacitance and inductance, capacitance charging and discharging effect there, or in the front socket plus an isolation transformer or a dedicated power outlet; cabinet when not grounded shield to ground resistance should be greater than 1000Ω.