In our latest podcast, Steve Grknic sits down with Tim Brown from Zip-Clip to discuss the impact zinc whiskers have on M&E supports within a data centre. Tim provides answers to the following questions:
There are currently over 6,041 data centres running across the world (Statista, 2021). This number will continue to grow with our insatiable demand for data. Tim has researched zinc whiskers for over twenty years and still, to this day, are often regarded as a myth. In this blog, we take you through the main findings from our podcast.
Zinc whiskers are microscopic crystalised filaments that form on the surfaces of steel that has been electroplated with zinc. Zinc whiskers are conductive to electricity and pose a particular risk to environments such as data centres, where many of the services and supports are coated in zinc.
Zinc whiskers were first discovered in the late 1940s by bell laboratory and NASA whilst examining telecommunication systems.
Zinc whiskers grow as a response to the stress placed upon a zinc plated surface. Commonly stress is placed upon a zinc plated surface in the following events:
Zinc whiskers are not visible to the human eye but can grow a few millimetres per year, the more stress placed upon the surface, the more chance they will grow.
They can grow on any zinc plated surface. Many, if not all, M&E services will be supported with zinc-based frames within a data centre. Typically zinc plating protects against rust and without a protective surface, it would be vulnerable to the moisture from the room climate and cooling system installed within data centres. Zinc whiskers are often reported to be found on cable management systems.
Many of the electrical and mechanical supports commonly found within data centres are zinc plated. As discussed earlier any stress placed upon a zinc layered surface can cause ‘zinc whiskers’ to grow. Data centres are designed with sophisticated HVAC systems ensuring hardware is kept in a temperature-controlled environment, reducing the risk of servers overheating.
The issue with sophisticated HVAC systems is that they could enable the free movement of zinc whiskers. As they break off and circulate around the air, they can travel into the hardware causing electrical shortcuts. As zinc whiskers are microscopic, they are not visible to the naked eye, and as a result, they are often rarely diagnosed as a cause for an electrical power fault. In most cases, people tend to diagnose power faults by looking at cable installation but if you observe the timings of the power shortages and see a high failure rate across a variety of hardware at random it could be zinc whiskers in your airflow (Data Span, 2020).
All products with a zinc coating are at risk. Typically, cable management such as cable trays are most likely to be exposed from zinc whiskers, due to the amount of stress placed on the base material during installation.
The only way to reduce zinc whiskers is by not using a zinc finish at all, but this simply is not a practical option. The only other choice is to reduce the risk as much as possible. As mentioned previously there are four main areas where stress is placed upon a zinc-plated section of steel; during the galvanising process, through transportation, cutting steel, and installation. There are two ways that we can reduce the risk of stress in cutting and transporting steel; the first is to cut the material off-site and the second is to enclose the zinc plated section in steel during transportation.
There is currently no British standard around the management of zinc whiskers. Many contractors write in their specifications to look out for zinc whiskers but there is no clear strategy to get rid of them or any standard to comply to.
According to Tim “if the big brands in the data industry provided a statement on their view of zinc whiskers, and solutions for them, then at least everyone could refer to a statement”. Over the past twenty years, there has been continuous research carried out around zinc whiskers. Zip Clip has also produced a CPD that discusses zinc whiskers in more detail.
Reference
Dataspan, 2020, [what are zinc whiskers and how do they affect data centers] available from: https://dataspan.com/blog/what-are-zinc-whiskers-and-how-do-they-affect-data-centers/
Statista, 2021, [Number of data centres worldwide in 2021] available from: https://www.statista.com/statistics/1228433/data-centers-worldwide-by-country/
