July 10, 2023

How much desk knowledge do you need to have as a low current engineer?

How much desk knowledge do you need to have as a low current engineer?


The cabinet is usually made of cold rolled steel sheet or alloy for storage of computers and associated control equipment. It can provide protection for storage equipment, shield electromagnetic interference, and place equipment in an orderly and tidy manner to facilitate equipment maintenance in future. Cabinets are generally divided into server cabinets, network cabinets, console cabinets, etc.

Cabinet - functions and uses

Many people think of cabinet as a cabinet for IT equipment. A closet is a closet, but that's not all. For computer itself, cabinet also plays an important supporting role with UPS power supply. A good cabinet means that computer can work in a good environment. Therefore, role of cabinet is no less important. Now we can say that only where there are computers, there are almost all cabinets. The cabinet systematically solves problems of high-density heat dissipation, a large number of fastening and cable management, large-capacity power distribution, and full compatibility with multi-vendor rack equipment in computer applications, so that data center can operate in a high-availability environment.

Currently, cabinets have become an indispensable product in computer industry. In large computer rooms, you can see different styles of cabinets. With continuous breakthrough in computer industry, functions performed by cabinets are also expanding. Cabinets are commonly used in network rooms, floor wiring rooms, central computer rooms, computer data rooms, network cabinets, control centers, monitoring rooms, monitoring centers, etc.

Cabinet - Base Type and Structure

Regular body colors are white, black and grey. (There are many types, such as orange pattern, fine sand, etc.); cabinet materials usually include aluminum profile cabinets, 10x profile cabinets, 16x profile cabinets and cold rolled steel cabinets. , There are also cabinets made of hot-rolled steel sheet. The steel sheet material, coating material and processing technology determine stability of cabinet. Generally, length is 600800mm, width is 6008001000mm, and height is 42U, 36U, 24U.

Most of cabinets used in early days were made from cast or angle steels joined or welded to cabinet frame with screws, rivets, and then made from escutcheons (doors) of thin steel plates. This type of cabinet was ruled out due to its large volume, high weight, and simple appearance. With use of transistors and integrated circuits and miniaturization of various components and devices, cabinet structure is also developing towards miniaturization and block building. In past, cabinet has evolved from a one-piece panel construction to an additional box and insert construction with a specific series of sizes. There are two types of assembly and arrangement of racks and inserts: dhorizontal position and vertical position. The cabinet materials are commonly used thin steel plates, steel profiles of various cross-sectional shapes, aluminum profiles, and various engineering plastics. The frame of cabinet is not only welded and screwed, but also glued.

Cabinet Cabinets can be divided into two main designs: profiles and thin plates, depending on load-bearing capacity, materials and manufacturing processes of components.

①Profile Structure Cabinet: There are two kinds of steel profile cabinet and aluminum profile cabinet. The steel profile cabinet consists of specially shaped seamless steel tubes in form of columns. The rigidity and strength of this cabinet is good for heavy equipment. The aluminum profile cabinet, which is composed of aluminum alloy profiles, has a certain rigidity and strength, and is suitable for general or light equipment. This type of cabinet is light in weight, less processing, beautiful in appearance, and widely used.

②Thin plate cabinet: solid plate body, side plate is formed by bending a single piece of steel plate. This type of cabinet has good rigidity and strength, and is suitable for heavy or general equipment. But since side panels cannot be disassembled, they are inconvenient to assemble and maintain. The structure of bent plate column cabinet is similar to that of profile cabinet, and column is made of bent steel plates. This type of cabinet has a certain rigidity and strength, and is suitable for general equipment.

The cabinet also houses necessary accessories. Its main accessories are fixed or retractable rails, locks, hinges, wire troughs, wire racks and shielding comb tabs, etc.

How much desk knowledge do you need to have as a low current engineer?

Technical requirements for cabinet

① It must have good specifications. The design of cabinet should be based on electrical and mechanical properties of equipment and requirements of environment of use, and necessary physical and chemical calculations should be made to ensure good rigidity and strength of cabinet structure. , as well as good electromagnetic insulation, grounding, noise insulation, ventilation and heat dissipation and other characteristics. In addition, cabinet must have anti-vibration, anti-shock, corrosion-resistant, dust-proof, waterproof, radiation-proof and other properties to ensure stable and reliable operation of equipment.

② ② should have convenient protection and safety features that are easy to operate, install and maintain, and can ensure safety of operators.

③ ③It should be convenient for production, assembly, commissioning, packaging and transportation.

④ ④ must comply with standardization, standardization, and serialization requirements. ⑤ Beautiful appearance, applicable and consistent colors.

Cabinet classification

With development of computer and network technologies, closet becomes an important part of it. IT tools such as servers and network communications equipment in data centers are evolving towards miniaturization, networking and shelving. The Cabinet of Ministers is gradually becoming one of main actors in this change. Ordinary cabinets can be divided into following types:

By function: fireproof anti-magnetic cabinet, power cabinet, monitoring cabinet, shielding cabinet, security cabinet, waterproof cabinet, safe box, multimedia console, file cabinet, wall cabinet

By application: outdoor cabinets, indoor cabinets, communication cabinets, industrial safety cabinets, low voltage distribution cabinets, power cabinets, server cabinets

Advanced classification: console, computer cabinet, stainless steel cabinet, monitoring console, instrument cabinet, standard cabinet, network cabinet

Introduction to server cabinet:

In IDC computer room, a cabinet usually refers to a server cabinet.

Server cabinet

Special cabinets for installing standard 19" equipment such as servers, monitors, UPS and non-standard equipment, server cabinets used to assemble panels, plug-ins, auxiliary units, electronic components, devices and mechanical parts and components, make it one-piece mounting box. The server cabinet consists of a frame and a cover (door), as a rule, has a rectangular shape and is installed on ground. It provides a suitable environment and protection for normal operation of electronic equipment. This is assembly level, second only to system level. A cabinet without a closed structure is called a rack.

The server cabinet has good technical characteristics. The design of cabinet should bedepends on electrical and mechanical properties of equipment and requirements of environment of use, and necessary physical and chemical calculations must be made to ensure good rigidity and strength of cabinet structure. , as well as good electromagnetic insulation, grounding, noise insulation, ventilation and heat dissipation and other indicators. In addition, server cabinet must have anti-vibration, anti-shock, corrosion-resistant, dust-proof, waterproof, radiation-resistant and other properties to ensure stable and reliable operation of equipment. The server cabinet should have good usability and safety protections, which are easy to operate, install and maintain, and can ensure safety of operator.

Server cabinet specifications:

A server cabinet has requirements for depth, height and load capacity of cabinet. There are three heights 2.0m, 1.8m and 1.6m, three widths 800mm, 700mm or 600mm, three depths 700mm, 800mm and 900mm.

It can be customized: special fixed tray, special retractable tray, power bracket, ground rollers, ground nails, cable management ring, cable management frame, L-bracket, extension beam, etc. Main frame, front and rear door, as well as left and right side doors can be quickly dismantled.

Fixed tray: used to install various equipment, different sizes, wide range of applications, there are standard 19-inch trays, non-standard fixed trays, etc. The depth of fixed trays in common configurations has specifications such as 440mm, 480mm . , 580 mm, 620 mm, etc. Fixed trays Bearing capacity of at least 50 kg.

Retractable Tray: Used to install keyboard and various other equipment, it can be conveniently pulled out and in; The standard 19" drawer fits any standard 19" cabinet. There are two drawer depth specifications in common configurations: 400mm and 480mm. The load capacity of drawer is at least 20 kg.

Power Distribution Box: Optional socket, suitable for any standard plug, with 19" mounting frame, flexible and diversified installation methods. Specifications: 6 outlets. Parameters: ~220 V, 10 A.

Cable frame: Standard 19" cable frame. Can be used with any cabinet in TOPER series. The 12-hole cable frame works best with 12-port, 24-port, and 48-port distribution frames.< /p>

Cable management ring: cable management device specially used for TOPER 1800 and TOPER Server series cabinets. It is very convenient to install and disassemble, and quantity and position can be adjusted arbitrarily.

L-bracket: The L-bracket can be used with a cabinet forRacking standard 19" equipment, especially heavy standard 19" equipment such as rack-mounted servers, etc.

Blanket: The blank is used to block free space in a standard 19" cabinet, etc., and has different specifications such as 1U, 2U, etc. There are two types of common blanks: 1U and 2U. .

Extension beam: A device specifically used for TOPER 1800 series cabinets and TOPER series servers, designed to expand mounting space in cabinet. Very convenient to install and remove. At same time, it can also be equipped with reasonable cable racks and power distribution boxes. The form is flexible and varied.

Installation nut (square nut): Suitable for any TOPER series cabinet, used to install all equipment in cabinet, including installation of most cabinet accessories.

Keyboard Bracket: Used to install a standard computer keyboard, compatible with all specifications of computer keyboards on market; it can be folded 90 degrees. The keyboard tray must be used with slide tray.

Variable Speed ​​Fan: Mounted on top of cabinet, fan speed can be adjusted according to ambient temperature and equipment temperature, effectively reducing noise in engine room.

Speed ​​control mode: manual, stepless speed control.

Rack Mount Fan Unit: 1U height, can be mounted at any height in a standard 19" cabinet and can be configured to match cabinet heat source.

Full Mesh Front Door: The cabinet front door has all ?3 round holes, which improves heat dissipation efficiency and cabinet shielding.

The height can match with 2.0m cabinet, 1.8m cabinet, 1.6m cabinet.

Network cabinets include server cabinets and are also used to combine installation panels, plug-in modules, auxiliary units, electronic components, devices, and mechanical parts and components into a single mounting block. The network cabinet is mainly used in electrical wiring, storage of routers, switches, monitors, wire racks, etc., and more used in engineering. Generally, depth of network cabinet is less than or equal to 800mm, and depth of server cabinet is greater than or equal to 800mm . The network cabinet should be convenient for production, assembly, commissioning, packaging and transportation. Server cabinets must meet requirements of standardization, normalization and serialization. The wardrobe is beautiful in shape, applicable and color coordinated.

Cabinet Accessories - Cabinet Cooler

Local superheating of showcase can be done by adding a cooling unit to increase flow rate and wind flow, it can also be installed in showcase with refrigeration equipmentIt is also possible to increase air flow in showcase cold air inlet. Cabinet cooler to solve local problem of overheating inside cabinet.

Compressed air passes through vortex tube and turns into two streams of cold and hot air. The hot air stream is expelled at a slightly increased pressure through swirl tube outlet, and cold air stream is introduced into heat generating part of chassis through divider, reducing and stabilizing internal temperature of chassis, while outside air will not enter case. With low cost and reliable operation of vortex tube cooler as main component, panel cooler can reduce compressed air temperature by 45 degrees. The cold air flow is introduced into heat generating part of screening cabinet through flow divider, and cabinet is pressurized so that outside air cannot enter, and screening cabinet is effectively cooled and cleaned. These small and compact multi-functional electronic control systems, variable speed drive systems, servo systems and programmable logic control systems are extremely sensitive to heat and contamination. Overheating causes failure of these sensitive electronic and electrical components, incorrect indication of digital display system, drift of control system, malfunction and shutdown of system when load is below rated load. The result is reduced productivity due to frequent shutdowns of machines or production lines. Fans can provide only an insufficient cooling effect and often bring dirty, humid and corrosive air from environment into cabinet, causing damage to electrical equipment. Air conditioners are bulky, difficult to install and require frequent maintenance, resulting in high operating costs. Vortex coolers have no loss of moving parts and only use an internal vortex tube to convert compressed air into low pressure, evenly distributed cold air in panel. Cool air flow in cabinet Generates a slight positive pressure to prevent dust or contaminants from entering, which is especially suitable for harsh working environments. From small computer control cabinets, touch screen control panels to large electronic screen cabinets, vortex coolers provide effective and reliable enclosure protection that will not cause a shutdown due to overheating and environmental pollution.

Working principle The vortex tube creates a vortex from compressed air and divides it into two streams - hot and cold. Compressed air enters a cylindrical vortex generator, which is larger than a heat (long) pipe, creating a swirling air flow, which is then forced along wall of heat pipe into heat pipe at a rotation speed of 1,000,000 rpm. A small amount of air at end of heat pipeexits as hot air through needle valve. The remaining air returns at a slower rate through center of swirling airflow entering heat pipe. The slower rotating hot air passes through faster rotating air entering heat pipes. This ultra-fast cold airflow passes through center of generator and exhausts cold air through cold air outlet.

Heat and dust, moisture, dangerous explosive or corrosive substances lead to malfunctions in electrical industrial control systems

1. Overheating leads to frequent shutdowns of production line at rated load

2. Exposed heat dissipation leads to dust accumulation and increased noise, which violates OSHA standards

3. A clogged air filter needs to be cleaned or replaced often

4. Overheating causes errors in electronic measuring, weighing, counting or recording instruments

5. Freon refrigerators cannot be used in food industry

6. Refrigerators using freon fail very quickly in harsh industrial conditions or at high temperatures

7. Condensation forms in electric air conditioners, which can damage internal components of unit

8. Electric air conditioners will vibrate and damage internal components of box

Scope of application 1. Cooling and environmental protection of programmable controllers and industrial microcomputer precision control systems

2. Heat dissipation and cooling of rectifier and converter components in high-power power supplies, cooling of high-frequency power systems

3. Cooling engine control center and electrical system microcomputer protection center

4. Cooling and constant temperature of relay control panel and sensitive LCD

5. Cooling of electronic control of CNC machining center

6. Cooling CCTV lens and blowing dust and water vapor

7. Environmental protection and isolation in hazardous environments such as electric chassis cooling and constant temperature, pollution and riot control

8. Laser body cooling, photoelectric sensor cooling, photoelectric lens cooling and cleaning

9. Electric chassis cooler kit for electronic scales with thermostat

Cabinet-based selection method

Follow checklist below to select a cabinet that meets your installation priorities (including safety, durability, compatibility and ease of installation) without breaking your budget. The first consideration should be safety. Placing critical IT equipment in lockable cabinets makes life easier for network administrators by limiting number of people who can open cabinet.

Physical requirements List all equipment requiredinstalled in cabinet and its full measurement data: height, length, width, weight. The overall height of these devices ultimately determines how much equipment can fit in a rack. Obviously, taller cabinets can hold more equipment and save space.

Of course, making most of height of cabinet is not only a matter of consideration, but also a large space at back of cabinet that can be used. This is reason for measuring depth of cabinet. If you choose a deeper cabinet, you can put two sets of hardware face to face to install more hardware. Using above method, two rows of equipment can be installed in cabinet, one row is loaded and unloaded through front door of cabinet, and other row is loaded and unloaded through back door. Cabinets must be adjustable. Once you've calculated your rack space (in "U or 1.75"), consider size of your room. You don't want to fill up your rack only to find out you need to fit more equipment into it. we bought a rack and after installation, these additional devices often appear. Therefore, as a rule, height of cabinet should be increased by 20% to 30% in order to prepare for expansion of system. These spaces also improve ventilation conditions of room. Hardware with brackets is not necessary Consider width because it is designed for width of cabinet, but for servers and other peripherals that cannot be mounted with brackets, width cannot be ignored.

Because total weight of equipment is often low, it is necessary to choose a cabinet that can hold about 1500 pounds, that is, choose a cabinet that is strong and has a good load-bearing design. In a closet, weight of equipment determines whether chosen sliding frame is standard or heavy, and also determines choice of other accessories. Choose cabinets that are 100% compatible with all servers and meet or exceed all OEMs.

Manufacturer Grade III Bracket Specification. If you want to install a tower or tabletop unit, you will need an extension frame and mounting accessories.

Because installation includes network cables, telecom cables, and power cables, it is necessary to purchase hook-and-loop slings or timing belts to efficiently and orderly secure cables in cabinet. It would be great if cabinet had a cable management module that would allow cables to be fixed directly into vertical mounting rails. In any case, there should be enough retaining rings (to protect cables) on top and side walls inside cabinet, and it is also possible to lift bottom plate of cabinet to facilitate wiring from below.

Cabinet class

Although cabinets look almost same, there are still several types of subdivision according to their different uses. Rare are cabinets used for wiring and cabinets used for housedservers. The cabinets used for wiring are generally used to accommodate multiple limit switches, so a lot of network cables will be connected, and it is inconvenient to have a cabinet door, so such a cabinet is more like a rack, and some cabinet manufacturers call this product is a mounting rack; also, cabinet used to house server must have a door and a lock to protect valuable equipment inside, so more expensive routers and firewalls are usually placed in such a cabinet.

As an example, server cabinet comes in different grades: it is a normal server cabinet with glass doors, server cabinet has four cooling fans, which are installed on top of cabinet, and are mainly used for ventilation and cooling. environment, and bottom of cabinet is hollowed out for ventilation and heat dissipation. The heat dissipation of servers at top of this cabinet is very good, but heat dissipation of servers in middle and bottom is not ideal.

The above cabinet is a relatively high-end server cabinet, which is ventilated and dispersed through tight vents on front and rear doors, so cold air of air conditioner in computer room can be well distributed to each room. server in cabinet and cooling effect of entire cabinet. They are all good, and this type of cabinet is made of exquisite materials, anti-rust and anti-corrosion, and its load-bearing capacity is relatively high.

Factors that users should consider when purchasing cabinets

Reliable quality assurance

It is very important to choose right server cabinet and wiring cabinet, a little carelessness can lead to huge losses. Regardless of brand of product, quality is first link that users should pay attention to.

Bearing Capacity Guarantee

As density of products placed in a cabinet increases, good load-bearing capacity is a basic requirement for a quality cabinet. Cabinets that do not meet specifications may not be able to effectively and properly protect equipment in cabinet due to poor quality of cabinet, which may affect entire system.

Temperature control system

The cabinet has a good temperature control system to avoid overheating or overcooling of food in cabinet to ensure efficient operation of equipment. The cabinet can be selected from a fully ventilated series, or it can be equipped with fans (the fan has a lifetime warranty), and in a hot room you can install an autonomous air conditioning system, and in a hot room you can install an autonomous heating and heat preservation system. harsh cold environment.

Anti-interference and others

A fully functional cabinet should provide various door locks and other features such as highWhat kind of protection against interference, such as dustproof, waterproof or electronic shielding; At same time, it should provide support for suitable accessories and installation accessories, so that wiring is more convenient. At same time, it is easy to operate, saving time and effort.

After-sales service

Efficient services provided by enterprise, as well as a comprehensive equipment protection scheme, can greatly simplify installation and maintenance of users.

In addition to above points, cabinet solution in data center must also consider design of cabling, power distribution, etc., to ensure that system works well and is easy to upgrade.

Power distribution system

How does cabinet cope with increase in power density? With growing trend of high-density IT system cabinet installation, cabinet can, whether or not it plays right role, power distribution system becomes a key link. Reasonable power distribution is directly related to availability of entire IT system and is an important baseline in determining whether entire system can work properly, and is also an issue that has been overlooked by many computer room managers in past. Due to miniaturization of IT equipment, equipment density in cabinet is increasing, in example of a 7U blade server, one blade server needs about 3 kVA of power distribution, and up to 8 blade servers can be installed in a 42U tall cabinet. servers, total need for electricity distribution will reach 24 kVA. This poses a serious problem for power distribution system in cabinet. At same time, increase in number of input and output ports also places high demands on reliability of installation of power distribution system. Considering current dual power requirements of most servers, power distribution in cabinet is becoming more and more complex.

The design of a reasonable cabinet power distribution system should be based on principles of reliability as foundation, designing specifically for cabinet system, and full coordination and seamless interaction with power distribution system. At same time, convenience should be considered for installation, as well as intelligent control, high adaptability, easy operation and maintenance, etc. The power distribution system of cabinet should bring power supply closer to load in order to reduce points of failure in path of power supply. At same time, local and remote load current monitoring and remote control of power distribution should be gradually implemented so that power distribution control can be integrated into overall intelligent computer room control system.

Cable layout

What to do if there is a problem with cable? In a huge computer room, it is still difficult to walk through numerous cabinets, not to mentionto quickly find and repair a faulty line. Whether a common solution for cabinet is in place and cable management in cabinet will be one of key links in investigation.

In terms of cabling connected to cabinet, modern data centers have a higher density of cabinet configuration, more IT equipment to house, and a large number of redundant accessories (such as Foshan electrical appliances, storage arrays, etc.). , Frequent changes, data lines and cables are added and removed at any time. Therefore, a sufficient number of cable channels must be provided in cabinet for cable entry and exit from top and bottom of cabinet. Inside cabinet, cable routing should be convenient and orderly, close to cable interface of equipment, so as to shorten wiring distance, reduce space occupied by cables, and ensure that equipment does not interfere with wiring during installation. , adjustment and maintenance, and make sure that heat-removing air flow is not obstructed by cables, at same time, in event of a malfunction, wiring of equipment can be quickly located.

When planning a data center that includes servers and storage devices, we often don't care about "details" such as cabinets and power supplies, but in actual installation and use of system, these aids also play an important role. a decisive role in reliability of system Impact. Prices for cabinets and shelving range from a few thousand yuan to tens of thousands of yuan, which is incomparable to cost of indoor equipment. Due to concentration of equipment inside cabinet, there are special “hard” index requirements for cabinet and rack, if you do not pay attention to this when choosing, trouble you will cause during operation can be huge.