Electrical Review: To move to Modular

The market for modular UPS is certainly showing no signs of slowing down as global researchers predict its ERexpected growth to reach £260m by 2017. Driven by the rising demand on data centres to process increasing amounts of information in the world, modular is fast becoming the chosen approach due to its inherent flexibility. But what are the key considerations when looking at modular UPS and what does the future hold in terms of emerging technology of this nature? Leo Craig, general manager of Riello UPS discusses.

The Government report ‘Seizing the data opportunity’ states: “Data has been likened to the “new oil” of the 21st century, but unlike oil, we are not going to run out of it. On the contrary, we will continue to amass more and more data.” Clearly, the data revolution of the 21st century is well underway. Data now underpins everything we do in the world – from business banking and financial services to the NHS, emergency services and other industries. As a nation we’re becoming more ‘information hungry’ than ever – consuming cloud services, social media applications, shopping, banking and working online.

So where does this leave us in terms of having the infrastructure for storing, managing and processing this data? This increased reliance on the internet is sure to impact on the data centres supporting it. It means that more than ever, today’s data centres need to be flexible, agile, nimble and able to provide optimum performance at all times.

Data centre priorities

The modern data centre not only has to ensure constant availability but also has a number of other driving factors such as carbon reduction and profitability targets. Ultimately, data centre owners are looking for the best products to help them to achieve their three main driving factors – flexibility, efficiency and availability.

A recent survey among UK and European IT managers revealed that data centre consolidation and infrastructure upgrades were among the top investment priorities for 2015. The report stated that data centre owners understood that modern business networking needed even more powerful servers capable of ‘seamless virtualisation and on-demand scaling’. These demands, particularly for scaling, have led to the development of new technology such as modular UPS.

Make way for modular

In the past, future proofing meant that data centre owners were forced to install much bigger UPS to meet capacity for the years to come. But rightsizing a UPS now makes it possible to invest only in the functionality required for the current load requirement, minimising up-front costs for capital equipment and maximising efficiency. Modular allows the system to be scaled up or down to meet future demands.

When deciding whether the modular approach is the right one, data centre managers should consider the following factors.

Most manufacturers offer both standalone and modular component UPS systems which can be used to implement the ‘modular’ approach as recommended by the 2012 Best Practice Guide for the EU Code on Data Centres. The type of UPS adopted is dependent on where in the power distribution chain the UPS installation is to be made (ie. Power plant room or data centre floor) and the floor space in the data centre itself.

Standalone UPS may be floor standing or rack mounted and can generally be connected in a parallel/redundant N + X architecture to create systems up to 6 MVA. The typical individual on-line UPS ranges in size from 800kVA to as low as 1kVA and is supplied as a single cabinet. Modular component UPS systems comprise of standard UPS modules ranging from 10-50 kVA. Multiple modules can be connected in parallel within a single system cabinet. This achieves a higher kVA output and/or level of N + X redundancy.

Modular maintenance

Modular component UPS systems have a 25 per cent lower Mean Time to Repair (MTTR) because they are slightly easier to service and repair in situ. This is because a failed UPS module can be ‘hot swapped’ and the failed or suspect module returned to the service centre for investigation. To return a standalone UPS system to active service may require a board swap. The modular component UPS system may require a less qualified technician to perform a module swap out but any system fault beyond this will require a UPS engineer to attend site.

In terms of choosing who carries out this maintenance, the industry is beginning to see more manufacturers opt for ‘open protocol’ systems. This means that, rather than locking a vendor in to the manufacturer for maintenance, they can choose a qualified engineer to carry out the work. Riello UPS is a strong advocate for this and has a ‘Certified Engineer’ scheme which gives customers the ability to verify that the engineer they are choosing is fully qualified to carry out the work.

Modular redundancy, resilience and availability

In a modular component UPS system it is possible to build in a level of redundancy simply by connecting an additional UPS module. This is generally limited by design to an N+1 level of redundancy. This may not satisfy some data centres and their service level agreements to clients. In this instance, the level of redundancy of a modular component UPS system is limited by the total overload rating capacity and the alarm monitoring capabilities of the UPS cabinet itself.

In terms of resilience, both modular and standalone UPS approaches can be configured to provide similar levels of availability. Modular component UPS systems have a premium price compared to standalone UPS but when the space saved and the total cost of ownership are considered, the overall price is comparable.

Resilience is a major factor and when selecting a modular solution close attention should be paid to any single points of failure such as a common controller as should this fail, the whole system will fail in spite of any redundant module. Due diligence is always recommended when selecting the right modular solution.

Floor space flexibility

Floor space within a data centre is often limited and required for revenue generating server racks. Modular component UPS systems can be expanded vertically provided there is room within the existing cabinet for additional UPS modules. Alternatively a modular component UPS system can expand horizontally with the addition of a further UPS cabinet. This approach can save valuable space within a data centre. Advances in the design of standalone UPS systems have also led to the introduction of smaller-footprint systems and taller cabinet designs. Although a modular UPS system can offer a more ‘future proof’ approach with right-sizing, no UPS should ever be 100 per cent loaded as this leaves no room for expansion and leads to increased component stress.

The data centre of the future

Continued pressure on data centres to comply with environmental legislation and to cope with bigger data demands than ever mean that this type of technology will play a central role in the future. Modular UPS has the potential to be a game changer in the data centre environment and impact on efficiency, resiliency and cost – all key factors for consideration by the data centre manager.

The most advanced power supply yet

Riello UPS has recently launched its Multi Power UPS, a modular three-phase double conversion system scalable for any business requirements.

With a power density of 400kW/m2, the Multi Power a leader in its field. Using up to 28 power modules of 42kW each, it gives complete scalability from 42kW to 1176kW.

It also maintains high efficiency in online mode operation of up to 96.5 per cent even at low loads of 20 per cent. The Multi Power UPS demonstrates how high levels of resilience can easily be achieved and still be affordable with N+2 redundancy.

A sophisticated connectivity panel on the front allows full status visibility of the UPS modules and battery. Maintenance is also simpler as the units can be accessed from the front of the system and the modules are hot-swappable, reducing any maintenance related downtime.