A small treatise on network cabinets / server racks Contents: 1: 19? Network Wardrobe Basics 2: A variation of the 19? Network cabinet: the 19? Server cabinet 3: Small network enclosures for wall installation: 19? Wall case 4: General function of a network cabinet / server rack 5: Netzwerschrank / server cabinet low polluted and / or damp environment 6: network cabinet / server cabinet and high temperatures 7: The following is the choice of cabinet cooling into account 8: Network Security Cabinet and 9: A few tips about which one is in front of a cabinet installation thoughts making should be 1: 19 "Network Rack – Basics Network enclosures are standardized for the inclusion of components in 19zoll – construction. 19? corresponds to a width of 482.6 mm. Internationally, the standard known as IEC standard 297, and in Germany as DIN 41494th A network cabinet is typically 600 or 800mm wide and 600 or 800mm deep. A network cabinet has front (and rear) 19? Mounting rails for the hostof 19? devices. The amount of equipment is specified to be incorporated in so-called height units (U), with a rack unit is 44.45 mm. DB Pro, there are two holes at a distance of 31.75 mm. Network cabinets are usually between a few rack units up to 47 units high (or higher) as a special construction. The most common height is 42U, which roughly corresponds to a height of 2m. Netzwerkschrank SZB PRO, 600 × 42HEx600, image: Door with swing handle, side panels with quick locking, roof ventilation 4 x 19?-Profile rails, including ground bar and ground wires. 2: A variation of the 19? Network cabinet: the 19? Server A server rack cabinet – as well as the network cabinet – 600 or 800mm wide. The server cabinet is deeper than a network in cabinet while 900 or 1000mm deep (sometimes) even deeper. This greater depth is required) through the deep to be incorporated into the server (or other applications. A server rack is constructed generally stable and can thus increase the loadwill. Often, the server cabinet is equipped with a 100mm base and integrated anti-tilt. This is important so that the cabinet does not) (for example, extracted servers can tilt forward. An optional or additional protection is anchoring the server rack with screws to the floor. Often, server cabinets with perforated doors and / or side walls are fitted to the airflow – and thus improve the heat dissipation – to. Worth mentioning: It must be remembered always that the depth of a cabinet (eg non-1000mm) can be fully exploited. First, the 19? Profile rails usually start around 3 – 5cm away from the door edge (both front and rear), on the other hand is needed for the wiring always a little space in front and behind, above all the server. In our case, the maximum depth server chassis would lie at about 850 to 900mm. Netzwerkschrank SZB SE image: 800 × 42HEx1000, perforated doors / walls and anti-tilt, 6 x 19?-Profile rails, roof belüfet with eingebuatenRoof vents. including ground bar and ground wires. 3: Small network cabinets for wall installation: 19? Housing wall-mounted cabinets are usually 18HE to 4U high, 400mm to 600mm deep. Be required for smaller distributions. two-part housing SD 4: General function of the network cabinet network cabinet (= in the following also applies for the server closet) is the nexus in structured cabling. He is the host and the protection of passive and active network components such as fiber-optic splice boxes, patch panels, bridges, routers, switches and hubs, computers, servers, monitors, etc.. Network cabinets are available in different equipment and functional variants. Must work 5: Netzwerschrank low polluted and / or humid conditions a particular network cabinet is a cabinet of low polluted and / or humid environment. In such an environment would be a common network cabinet (with a low density of, eg IP20 or IP41 (in the sense of a dust-and waterproof according to DIN)), the installedComponents are not very long to protect against dirt and moisture. It would inevitably lead to a system failure. Such IP-only and low cabinets for clean and dry premises (offices, server rooms) determined. Only a cupboard with a high IP (and good cooling) ensures a long-term functioning of the system in a polluted and / or humid conditions! 6: network cabinet, and high temperatures caused a further and often underestimated problem is a network closet in the high temperatures (through external influence and by the built-active components). A geräteverträgliche temperature in the cabinet is about 25 ° to 30 ° C. If it is warmer in the closet, one should worry about the heat flow. Particular problem areas in the cabinet itself are called hotspots. Points in a cabinet where it is especially hot. In the cabinet itself, the average temperature is OK under certain circumstances, but in each cabinet areas (eg, above a server)critical temperature is exceeded. There are several ways to lower the temperature in the closet. 7: The following is the choice of cabinet cooling taken into account: * The easiest way is to install a 19? Slot fan. This can be retrofitted without major expense. The inset fan has the task of revolutionizing the air in a closet and leave the temperature of the "outer cabinet. Important: The Eischublüfter must be installed so that it comes in the airflow in a cabinet. It must not be built over top or bottom (the power would be lost or damaged) lead of the fan. The basis for this operation: The outside air must be cooler than the air in the cabinet umgeältzte. Which may be made only as heat. 19? Slot if the fan controlled by a thermostat – turn on the fan at a specific temperature – it should be noted that the measurement of the temperature at the hottest pointshould take place in the cabinet. * Another simple way is to lower the oven temperature to the installation of a roof fan. The roof vents have the task to suck the cold air from the outside (usually on the bottom rack / cabinet base), carry out the closet and on the roof again hinauszublasen. The basis for this operation: The air sucked in from outside must be cooler than the temperature in the cabinet. The greater the temperature difference the more effective the cooling. Roof vents * Weden For cabinets with high-density and the use of fans have taken care that the used filter fan) and outlet filter (technology from the industry also have a high density of min (optimally. IP 54). Important: If only one opening on the cabinet are not met, the IP default (it was a fan of the "not dense", or a cable guide that was not properly sealed), the cabinet loses its default IP. * A heat exchanger (air / air) is only effectivework if the outside temperature is lower than the desired Innenschranktemperatur. The difference must be there singnifikant, otherwise the heat will not work very effectively. * An air conditioner as the most effective type of cooling should be used only when at least IP54 cabinets () = high density. An air conditioner works like a refrigerator. The outside temperature can be higher than the required Schrankinnetempeartur (but not higher than about 55 ° C as the coolant used to air it can no longer runterkühlen). If the cabinet would not especially tightly, in the closet condensation to occur upon a large difference between outdoor and indoor temperature. Condensation in the cabinet would mean that the installed devices would be very fast. Please note: If a cabinet installed on cooler days (eg during winter), it should already be taken into account this time as the temperatures in the installation space on warm days (egdue to strong sunlight or heat buildup in summer?). 8: Network Security A network cabinet closet and always serves as the backup of the installed components against unauthorized access. A network cabinet should always be locked () via the key and lock different systems depending on permissions. A startled but can also be equipped with a cabinet monitoring system (vandalism, moisture, fire, vibration, access, etc.). Such systems can also be controlled and monitored the phone and via the corporate network or Internet. A special form of protection is an EMC-cabinet (electromagnetic compatibility). An EMC cabinet is an electromagnetically sealed cabinet Faradeyschen similar to a cage. With this cabinet can secure these "can not be intercepted," as it emits no radiation outside elektromagetische (applies to the protection), both from inside to outside and vice versa. An EMC cabinet is important for example in highly sensitive areas informatinstechnisch(=) Information espionage. Specific network enclosures are flame retardant cabinets that can protect the built-in components even in case of fire over a certain period (usually 60 or 90 min). A few tips about which you should do before installing a cabinet thoughts: * Choose an adequate wardrobe size. If enough space is available, always choose a larger cabinet. The default size of the network cabinet range is 800mmx42HEx800mm (WxHxD). When the racks 600mmx42HEx1000mm (because usually less "wired side" is). * For "good temperature" in the closet (make up to 30 ° to 35 ° C) – is still a use of fans / heat exchangers / air conditioning units required?? Matching solution to choose. Even an "expensive" air conditioning technology at the cabinet is usually less expensive than the failure of equipment (resulting in hardware defects, loss of work, reinstalling, etc.) * lockable cupboard should at least be () with a key system! *If multiple boxes are placed in series?? Savings side walls – there will be less needed. * If the devices soils of sufficient size () with respect to depth and payload?? * Other accessories account (connection strips, lighting, swing frames, etc.). * Grounding Bar should be integrated in the cabinet. * Clean cable management account () via cable and cable clamp rail bracket. Simplified va later, the work on the cabinet (for example) for a retrofitting of the applications. Clean up is a good "business card". * Required: Installing the UPS cabinet or connected to a UPS system to prevent system failures or to ensure a clean runterfahren too. * Must be a cupboard with a high density?? High density is associated with a higher price. In a clean environment is necessary (offices, server rooms, etc.). If a cabinet system to be extended at a later date, should a brand product to be bought. The cabinet areaare the life cycles of a high quality manufacturer cubicle very long term oriented. No-name a cabinet and its accessories, you can buy one or maybe not even two years ago. * There are high-end cabinets that are absolutely justified (special design, wide range of accessories, high density, etc.), but in most cases, a solid cabinet with a good enough Preis-/Leistungsfähigkeit. Conversely, one should also look not only at the price because the cheapest solution may impact negatively on the quality (weak design, imperfect fit, etc.). Joachim Hennig http://www.zetbox.de