Shielded Cabinet Configuration Specifications

Cabinet: Fully enclosed enclosure welded from 1.5mm thick cold-rolled steel sheet, treated with galvanization and powder coating for corrosion resistance
Shielded Door (Front Single Door): Shielded door composed of a door panel welded from cold-rolled steel plate and a shielding spring plate meticulously crafted and treated from premium sheet
Equipment Brackets: Positions adjustable vertically and horizontally; includes 50 sets of mounting bolts
Server Shelves: Equipped with 3 shelves (1 shelf for cabinets under 1.6m)
Ventilation Waveguide Windows (2 sets): Honeycomb design, 300x300mm each for top and bottom
Swivel Casters/Support Feet: Sturdy and durable, enabling smooth multi-directional and multi-angle movement
Axial fans with MTBF exceeding 18,000 hours, each delivering 1.4m³/min airflow (4 units)
Power filter featuring wide suppression bandwidth and high insertion loss; AC 220V X 16A: 1 conduit
Electrical outlet PDU, 16A, 1 x 8-port GB standard five-hole socket
Network cable conduit: 10 x Ф8.1*100 copper wave guide tubes (shielded Category 6 network cables configured one-to-one)
Fiber optic conduit: 5 x 14*140 galvanized fiber optic transmission tubes
Grounding copper strip: 1 copper strip
Performance meets BMB 19-2006 Class C requirements

Shielded cabinets are primarily used to

Prevent the leakage of confidential information generated by computers, network servers, and communication electronic equipment during operation;
Protect the aforementioned equipment from external electromagnetic interference during operation, ensuring their normal functioning;
They are applied in industries with high-level confidentiality requirements, such as government agencies, national defense, banking, securities, military, education, and scientific research.

Principle of Electromagnetic Shielding

Electromagnetic shielding employs a shielding structure to block the propagation of high-frequency electromagnetic fields through space. When electromagnetic waves pass through metal or barrier layers that attenuate electromagnetic waves, they undergo a certain degree of attenuation. That is, these metals or barrier layers provide shielding. The effectiveness of this shielding depends on the properties of the electromagnetic waves and the inherent characteristics of the metal or barrier layer.

Physical Process of Metal Plate Electromagnetic Shielding

When electromagnetic waves strike a metal plate flanked by air, part of the energy is reflected—this is known as reflection loss. The portion of the transmitted wave that is attenuated as it propagates within the metal plate is termed absorption loss. When the wave is reflected back to the first interface at the second interface, it undergoes further reflection. This cycle repeats until all energy is either consumed or transmitted. This phenomenon constitutes the multiple reflection correction factor that must be considered in shielding theory.

Seam Shielding

Permanent seams on shielding structures typically refer to welded joints connecting two metal plates. These permanent seams exhibit RF impedance nearly identical to that of the metal plates themselves.

Filters

Conducted interference propagates through metallic conductors such as wires or any metal structures. All metal entering the shielded enclosure (cabinet) must be filtered. A filter is a device designed to eliminate interference noise, effectively filtering out specific frequency points or frequencies outside that point. Its function is to either pass a specific frequency or block a specific frequency.

Precautions

Shielded cabinets must be reliably grounded.

Do not install a residual current device (RCD) before the power filter input. (The RCD can be installed in the distribution box within the shielded room, or an isolation transformer can be installed between the power filter input and the RCD to resolve tripping caused by leakage current. Alternatively, a fuse and a non-RCD circuit breaker can be installed before the power filter input.)

Order Code	Capacity	Width	Depth	Height	Internal Dimensions	Packed Volume	Weight
PB-7714	14	700	700	1000	19"x550x620
PB-7014	14	700	1000	1000	19"x870x620
PB-7720	20	700	700	1250	19"x550x900
PB-7020	20	700	1000	1250	19"x870x900
PB-7726	26	700	700	1550	19"x550x1200
PB-7026	26	700	1000	1550	19"x870x1200
PB-7733	33	700	700	1850	19"x550x1500
PB-7033	33	700	1000	1850	19"x870x1500
PB-7737	37	700	700	2000	19"x550x1650
PB-7037	37	700	1000	2000	19"x870x1650
PB-7742	42	700	700	2200	19"x550x1850
PB-7042	42	700	1000	2200	19"x870x1850