6 November 2012 – The African sub-continent is, in general, an emerging economic region and as such lags in terms of infrastructure development compared to the more industrialised countries of the world. This is according to Jack Ward, MD of Powermode, a power provisioning company, who says it is especially true when it comes to power supplies and service delivery in South Africa.

He says unreliable power and heavily loaded networks are the cause of unstable and inconsistent power levels that are driving organisations in South Africa to standardise on specially equipped uninterruptible power supply (UPS) systems.

“Ruggedised, transformer-based UPSs are significantly more robust than the transformer-less UPSs that were common in times past when SA power consumers enjoyed relatively stable utility power.”

Ward identifies a clear trend towards the adoption of ruggedized, low-frequency UPS technology, driven by the on-going and escalating degradation in the quality of utility power in South Africa, especially in more outlying and rural areas, particularly in the Northern Province and Limpopo.

He says the key disadvantage of a transformer-less UPS system is its inability to provide stable output when utility power quality is less than ideal. It is also vulnerable to damage from power spikes and brownouts.

“On the other hand, industrial strength UPSs, while more bulky than their standard counterparts, are more robust and reliable. Characterised by transformer-isolated inverter output, they are ideal in environments where there is the likelihood of electrical noise and transient voltages,” he says.“The transformer protects the inverter from load disruption and provides galvanic isolation between input and output.”

He adds that modern technology is such that both designs (transformer-less and transformer-based) provide a similar level of performance. The main trade-offs centre on their impact on the upstream power supply and their ability to operate in harsh environments.

“Consequently, these ruggedized units are no longer specified only for industrial and mining applications, but now industrial strength UPSs are finding favour in general power protection applications such as found in retail stores, data centres, laboratories and offices.”