Как спроектировать лучшую наружную телекоммуникационную шкафную систему
Ричард Ван 28 марта 2022 г.
1.Background of Outdoor Telecom Cabinet
Edgeware’s Telecom Cabinet is deployed in various countries and regions, and different regions have different requirements. This article describes the general design requirements for the Outdoor Telecom Cabinet based on our past experience.
2.Structural of Outdoor Telecom Cabinet
The Outdoor Telecom Cabinet system includes rectifier modules, monitoring unit, power distribution units, battery packs, temperature control and other equipment, they are installed in an all in one outdoor cabinet. The all in one outdoor cabinet is divided into an equipment compartment, a battery compartment, and a wiring channel. The Outdoor Telecom Cabinet system is installed in the outdoor environment, the environment is harsh, and the installation sites are generally relatively remote, such as the side of the road, the roof, the mountain, the telephone pole, etc. It can be installed on the floor, on the wall, or on the pole. Install. Therefore, the Outdoor Telecom Cabinet system has high requirements in terms of protection level, heat dissipation, anti-corrosion, anti-salt spray, anti-theft, and lightning protection. It is required to be easy to transport, fast to install, and easy to maintain. Most of the structural parts of the Outdoor Telecom Cabinet system are thin sheet metal parts and profiles, which are processed by cutting, stamping, bending, welding, riveting, surface treatment and other processes.
3.Outdoor Telecom Cabinet System Design
Use standard components and parts as much as possible to improve the compatibility and versatility of parts to reduce production time; use modular design as much as possible to divide the system into several functional modules, and at the same time, it should be replaced or repaired. The parts, components and functional modules can be independently loaded and unloaded as much as possible, which is convenient for organizing production, debugging and on-site maintenance, such as lightning protection modules, fan modules, dust filter modules, AC power distribution units, etc.
Structural design is closely related to processing technology and assembly technology. Different processes have different structures. The processing and assembly technology should be selected according to the actual production, batch size, delivery cycle, and processing cost of the enterprise. When the batch is small, laser cutting can be used to reduce the cost of the mold. At this time, the holes and blanking of the parts can be irregular, and the design will be more flexible; when the batch is large, die stamping is used to improve production efficiency. The blanking and blanking must be regular and can be processed by existing molds, and the design of the parts will be limited by the molds. Outdoor Telecom cabinets are mostly welded, and manual welding is used for small batches. Robotic laser automatic welding can be used for large batches to improve efficiency and reduce deformation. At this time, the feasibility of automatic welding of parts structure should be considered.
The power supply system of outdoor telecom cabinet is installed in the field environment, and the installation and maintenance conditions are complex. The feasibility and convenience of installation and maintenance operations, and the personal safety of operators should be considered in the design. For example, switches and buttons to be operated should be arranged at a height of 0.5m to 1.8m; the display screen should be arranged at a height of 1.0m to 1.6m; the parts to be dismantled and maintained should not be too heavy, and the installation height should not be too high.
4.The overall structure and layout of the outdoor telecom cabinet system
According to the electrical design, the outgoing and incoming line methods required by the customer, as well as the system installation site and installation method, the overall structural layout design of the system is carried out. When there is only one cabinet, the equipment compartment is at the top, the battery compartment is at the bottom, and the cable passages are on both sides. When there is more than one cabinet, separate the equipment cabinet and the battery cabinet. The rectifier module is the main heat source, and should be placed in the upper part of the cabinet, close to the air outlet of the cooling air duct. When the temperature of the monitoring unit is high, it will affect the stability of the system, so it is necessary to avoid high temperature heat flow.
The structural design and installation of the AC and DC power distribution units should ensure that the circuit breaker and other components can be easily replaced during maintenance, as well as the convenience and operability of wiring. The main changes in the power supply system of the same capacity are the number of input and output branches of the power distribution unit and the capacity of the load, which are reflected in the change in the number of circuit breakers and the combination of specifications. Therefore, the power distribution unit is modularized and its parts are generalized. Different power distribution requirements can be quickly combined and assembled, improving design and production efficiency, and facilitating maintenance and replacement.
Install rectifier equipment, monitoring unit, AC power distribution unit, DC power distribution unit and other accessories in the equipment compartment, and reserve space for the installation of communication equipment. There should be at least 4 installation posts inside the equipment compartment for installing equipment and fixing the shelf. The mounting column can be moved forward and backward, left and right, and can install standard 19-inch or 21-inch equipment
The battery compartment is used to install batteries. The battery types generally include lead-acid batteries and lithium iron phosphate batteries. The battery compartment should be compatible with batteries of various mainstream brands. For different types of batteries, the structural requirements of the battery compartment are different.
For air-conditioning and heat-exchange outdoor telecom cabinets, the battery compartment and equipment compartment where lead-acid batteries are placed must be completely isolated to avoid acid mist corrosion of power supply equipment and communication equipment. The cabin may not be isolated. There should be a hydrogen discharge device in the battery compartment to discharge harmful gases; the battery will heat up and swell during charging and discharging, so the distance between the batteries must be greater than 10mm; the battery support frame and tray must have sufficient strength; Damaged by vibration. The enclosure protection level of the battery compartment is required to reach IP44.
5.Cooling of Outdoor Telecom Cabinet
The cooling methods of the Outdoor Telecom Cabinet system include: natural cooling, fan cooling, heat exchanger cooling, and air conditioning cooling. Select the type of heat dissipation and whether heating is required according to the installation and use environment and the heat generation of the system.
FAN Cooling
The temperature-controlled DC fan is used to forcibly discharge the heat in the cabinet. The internal temperature of the cabinet is higher than the external ambient temperature. The cost is low, but it will bring external dust, moisture and corrosive gas into the cabinet, affecting the reliability of the equipment in the cabinet. All ventilation holes in the cabinet should be provided with corrosion-resistant screens and dust-proof nets to prevent the entry of insects and rodents, and the dust-proof nets and screens should be easy to clean, maintain or replace. The installation of the DC fan should be easy to install and remove for maintenance. We do not recommend the use of AC FAN, because the AC FAN system is a non-linear load and will generate a large starting current during startup, which puts forward high requirements on the UPS system.
Кондиционер
The most effective and fastest cooling method can make the internal temperature of the cabinet lower than the ambient temperature. It is suitable for high heat consumption equipment greater than 700W, but it has high cost and high energy consumption. When the AC power is off, the air conditioner does not work and needs to be maintained regularly. In addition, in the solar energy scenario, the power consumption of the air conditioner is obviously unacceptable, so this heat dissipation method has great limitations.
Теплообменник
The principle of the heat exchanger is that the air circulating inside and outside independently exchanges heat through the heat transfer medium, thereby reducing the internal temperature of the cabinet. The heat exchanger is placed on the top of the enclosure or on the front and rear door panels. The cabinet is fully enclosed, and the protection level can reach IP55 or higher, and the performance of waterproof, moisture-proof, corrosion-proof and dust-proof is excellent. Through temperature control, the temperature is lowered when the temperature is high, and the external circulation fan is turned off when the temperature is low, so that the heat can be kept warm. The cost of this cooling method is moderate, but the disadvantage is that the internal temperature is always higher than the external temperature.
Heater for Cold Area
For the low temperature environment where the monthly average temperature in winter is lower than -10°C, heating components or heaters are also required for heating and heat preservation. Why is it set at -10°C, because outdoort telecom cabinets usually have batteries, and it will be very difficult for batteries to discharge below -10°C. Therefore, for these scenarios, heaters become indispensable.
Outdoor Cabinet Thermal Insulation Properties
The doors, side panels and back panels of the cabinet adopt double-layer shell or sandwich panel structure to reduce the influence of solar radiation and heat preservation. The outer coating layer of the cabinet adopts a light color to reduce heat absorption and increase heat dissipation.
6.Ingress Protection of Outdoor Telecom Cabinet
The waterproof of the system must meet the requirements of IPX5 waterproof grade, the dustproof of air-conditioning cabinets and heat exchanger cabinets meet the IP5X grade requirements, and the dustproof of fan cabinets or natural cooling cabinets meet the IP4X grade requirements.
The three-proof design of the cabinet requires anti-moisture, anti-salt spray, and anti-mold; in the three-proof design, the protection level of the product should be determined according to the use environment of the equipment, and the protection system with the required protection performance should be selected according to the needs of the protection level. It is implemented into the design of the entire product [1]. The outer surface coating of the cabinet shall be corrosion-resistant and anti-solar radiation, and the internal structural parts of the cabinet shall be coated with corrosion-resistant coating or coating. Avoid stagnant water structures on the outside.
All outer layers and doors of the cabinet must be well grounded; AC cables, DC cables, signal cables, and ground cables should have independent cable entry holes, and should be routed and bound separately; long wires should not be used as much as possible; cable wires should not cross the device. and the hot air outlet; the copper bars are as short as possible; the monitoring module is as far away as possible from the AC power distribution unit and AC cables. The grounding screw and cable specifications must meet the standard requirements.
6.Conclusion
The design and manufacture of Outdoor Telecom Cabinet is a systematic project. A synthesis of experience in power supply, structure, protection, network, etc. is required. A good outdoor telecom cabinet system will greatly reduce OPEX. Edgeware’s consistent philosophy is that CAPEX and OPEX are equally important, and try to reduce customers’ OPEX as much as possible. Hope we can provide quality products at your side.