ENCLOSURES & AIR MOVERS PRODUCTS POINTS TO CONSIDER WHEN PLANNING FUTURE RACK DEVELOPMENTS
When planning future rack developments, there are a number of important areas to consider, but one of the most critical steps is deciding the precise configuration of the internal components. Then, selecting which rack to install requires an understanding of its purpose, the routing of cabling for power supply and networks, and the ideal cooling solution. To help specify the right solution, and ensure the success of any future installation, Rittal has come up with a list of key questions to ask. What will the rack be used for? The number and type of components
will impact the size of the rack. If it will be used to house servers, then an IT rack 600mm wide will suffice. However, if it is primarily for network components, the rack should be 800mm wide to accommodate the cabling. Increasingly, enterprises are combining server and network components within individual IT racks. As IT takes on an increasingly significant role within organisations, more and more components are packed in to make best possible use of existing infrastructure. This means the largest available racks should be selected – in line with space constraints. An IT rack that is 42 units high, 800mm wide, and 1,200mm deep provides ample room for custom configurations, and allows for future expansion. What form of climate control is needed? Will the rack be installed
in a room that does not have an integrated cooling system? If so, then a suitable cooling system needs to be considered. If just a single IT rack is needed, then a cooling unit can simply be attached to it externally. The rack should also have a door with an air-tight seal. If entire room or row cooling is to be installed, then a perforated door will be needed to allow a continuous airflow. Why is sealing needed? There are various options for cooling IT rack
interiors depending on their use –inside server enclosures, for example, the cool air should flow from front to back; while in network enclosures it should move along the parts that need to be cooled. In both scenarios, it is important to seal off the 19” shelves to ensure cool air does not flow away from the targeted components. All open rack units should be closed off to separate warm and cool air. To help, a range of accessories are available to enhance cool-air routing, enable horizontal airflow, and more. Effective seals and climate control solutions tailored to the IT rack’s specific purpose will translate into improved energy efficiency. Where do you want your cables? A detailed plan for interior and
exterior cable routing should be in place before a server enclosure is purchased and configured. The power supply, in particular, has to be considered. Many active IT components require a redundant power supply which means there are two power distribution units (PDUs) making cable management more complex. Moreover, power and copper data cables must be kept apart to avoid interference. In addition, special attention must be paid to the minimum bend radius of the fibre-optic cables to prevent signal attenuation. If the racks are to be placed on a raised floor, then power and network cabling can be laid underneath. You can also mount cables under the ceiling and route them through the top of the rack. In this scenario, the roof plate needs to be configured correctly –
BUILDING IN ELECTRICAL SAFETY
Industry standards and regulations need to be followed to prevent personal injury or property damage as a result of issues such as fault currents. These also cover the potential equalisation between all the metallic parts of an enclosure. The TS 8 baying system from Rittal is an example of how safety can be built-in through automatic potential equalisation, without necessarily having to separately earth each individual panel. The earthing of metallic parts on electrical systems for safety reasons
is prescribed virtually everywhere. Once all the earthing straps have been correctly fitted, there is an equalisation of potential, and all the enclosure components can be earthed via the protective conductor of the voltage supply. However, the earthing straps have to be attached to enclosures by hand during their assembly – should a strap be forgotten, the finished switchgear will still be able to function despite the danger it might pose. To help limit this risk, Rittal has developed an effective solution with the TS 8 bayed enclosure system. During the assembly phase, the side panels, enclosure roof, rear panel and gland plates are automatically connected to the frame conductively, meaning potential equalisation
openings should be closed off with brush strips creating a tight seal, simplifying cable management and improving energy efficiency. It also means that even after cables have been installed, accessories (including roof plates with multiple parts) can be easily removed for simpler maintenance and retrofits. Rittal offers a choice of elements for effective cable management, enabling customised component configurations. Both open and closed cable duct systems are available – for horizontal and vertical cabling, and cabling between thermal zones. Typically, air-tightness and a defined air pressure must be maintained to prevent warm air and cool air from mixing. This consideration was built into the design of Rittal’s TS IT server
enclosure. The enclosure supports the need for air circulation in conjunction with the corresponding cable installation components. What about external cable management? Crowded IT racks have little
available space to squeeze in new components. One answer is to route cables outside of the racks such that cable ducts pass through the side of the rack, routing cabling over the top so that it re-enters the rack from the opposite side. Although this approach can save a great deal of space, it may make identifying individual cables more difficult, and maintenance work more complicated. Wherever easy maintenance is a priority, cables should be routed inside the racks. Pinpointing and replacing a single cable is then far simpler if there is a failure or if a reconfiguration is required.
Rittal
www.rittal.co.uk
can be achieved without necessarily having to connect these parts with earthing straps (although the final decision as to whether to leave earthing strips out completely is up to the user). The solution is implemented using special claws or washers which press through the electrically non-conductive surface coating of the panels during assembly to achieve a reliable contact. It means that all the flat panels are electrically connected to the frame, so that – in many applications – earthing straps are no longer needed. Instead, the earthing strap only needs to be attached to the enclosure door. The contact resistance between the panels and the enclosure frame is less than 0.1Ω, the value demanded by the DIN EN 62208 empty enclosures standard. This automatic potential equalisation reduces the amount of
material needed and enables easier assembly, simply because the time- consuming attachment of up to seven earthing straps per enclosure is no longer necessary. In addition, it is also easier to disassemble and re-assemble individual panels because the earthing straps do not have to be removed and re-attached each time.
Rittal
www.rittal.co.uk DESIGN SOLUTIONS | APRIL 2016 15
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
