Pemsa BLACK C8 coating avoids the emergence of the phenomenon of Zinc Whiskers, or loosening of filaments of zinc, which can be a serious problem within the electronics of clean rooms in Data Processing Centers

Cable Management Systems 

One of the most widely used cable management systems in electrical installations before the emergence of CPD’s, or Data Processing Centers, were conduits. However, because of their small cross sections, and their limitations for changes or modifications, today they are only used primarily to accommodate a small number of cables and where they are accessible to the public or need high protection against mechanical hazards. 

On the contrary, cable trays have gone from the minority to one of the most used cable management systems, precisely because of their greater cable capacity and the ease of making subsequent modifications to the installation. 

Among these trays are Wire Mesh Trays that, despite the campaigns that have tried to discredit and limit them, have continued to be one of the preferred systems used by the installers thanks to its capacity, flexibility and ease of use both in electrical installations and in data and telecommunications

Features of Wire Mesh Tray 

Design 

The Rejiband® tray, made up of an open mesh of high quality steel, combines good ventilation of the cables which improves the efficiency of the installation, with a high mechanical resistance, which allows it to support a high number of cables. 

The strength and flexibility of the steel mesh ensures the greatest advantage of the capacity of the tray and its easier adaptation to the needs of the installation. It also allows and facilitates that any subsequent changes or modifications of the cables can be made at the lowest cost. 

 Behaviour in the event of fire 

 In the event of fire this tray poses no risk since it is not combustible and, unlike plastic trays such as PVC, does not produce toxic or opaque fumes, does not propagate the fire, and can even help keep the installation running to give the necessary time to carry out the evacuation of personnel. 

Resistance to corrosion 

Proper selection of the finish or anti-corrosion protection of the tray, depending on the location or environment of the installation and the presence of water or moisture, will maintain the installation under the conditions necessary for its correct operation. 

The current edition of the standard for trays, UNE EN 61537, classifies the corrosion resistance from class C0, for untested or undeclared, to class C8 for metal coated steel trays and C9 exclusively for stainless steels.

For example Hot Dip Galvanizing, one of the most frequent zinc-based finishes for wet environments or outdoor installations, would be classified according to the micron thickness of the zinc coating from C5, the most common, to C8, but only for very specific cases. 

The future edition of the tray standard will include the revision of the classification table to consider new coatings, such as those based on zinc and aluminum alloys, or the new high strength protections such as the ‘Black C8’® finish. 

‘Black C8’® and 'Zinc Whiskers' 

 The ‘Black C8’® finish has an excellent aesthetic appearance and a high resistance to corrosion, which makes it suitable for installations with high humidity or presence of water, but also its characteristics make it highly suitable for installations in Data Processing Centers. 

 The zinc filaments that could grow in some zinc-based finishes, commonly known as "zinc whiskers", could also break away and lead to problems in the microelectronics of very sensitive facilities, such as those located in clean rooms of data processing centers. Although studies to date have not yet accurately clarified the process of forming these filaments, initially detected by using false floors with electro-galvanized steel plates, it appears that they would form mainly on the large surfaces of these finishes, and due to the intergranular tensions originated in the material that is subjected to variable stresses. 

 These filaments could be released later with the passage of time and even reach the interior of the equipment, depositing on some printed circuit boards and causing malfunctions of this equipment

Rejiband® “Black C8”® incorporates a seal that prevents the possible detachment of these filaments, assuming that they were created in the first place, thus avoiding any possible effect on the electronic equipment of the CPD’s. 

We can conclude that the Wire Mesh Trays, thanks to their good features, remain as one of the most widely used cable management systems in data processing centers

If you would like more information, please contact our technical team for free support on technical@dpbuildingsystems.co.uk or 0121 706 7777