A UPS is the Ultimate Voltage Optimiser
Since the European Union introduced measures to harmonise the single-phase mains supply voltage across countries throughout the union, many large electricity consumers have found that much of the electrical equipment they use to run their businesses is operating inefficiently and thus wasting considerable sums of money each year on energy bills.
Companies offering voltage optimisation technology to stem the problem have popped up but can they really be recommended for mission critical applications and is such technology really the best option?
Prior to 1995, variation existed (country-to-country) between the single-phase mains supply voltage from 220, 230 or 240Vac 50Hz. It was down to manufacturers of electrical equipment to ensure their products were optimised for each country or European region. A transition period between 1995 and 2008 saw a Europe-wide change in which 230Vac became the nominal standard (prior to which the UK operated at 240Vac). Three-phase mains nominal voltage was harmonised to 400Vac in the UK.
When powered from a higher or lower mains voltage, switched-mode power supply (SMPS) loads run at less than their optimal switching frequency, which results in losses in the form of heat and noise, thus making them inefficient. In a large organisation, operating several hundred or even thousands of such products, the resultant waste in energy bills can be huge. The purpose of a voltage optimiser is to provide steady-state 230Vac or 400Vac supply to ensure optimal load voltage efficiency.
Voltage optimisers are designed with built-in automatic bypass to prevent supply disruptions to loads but I question the advisability of this – especially for mission critical loads?
Firstly, UPS protect connected loads from breaks in mains supply AND from mains-borne power problems such as sags, surges, brownouts and so on, which a voltage optimisers cannot do as effectively.
Secondly, although most online UPS are installed as 230Vac (single-phase) or 400Vac (three-phase) output, they can be configured manually to provide 220/230/240Vac or 380/400/415Vac. As the output is digitally generated, loads are automatically supplied with the level of voltage and current required to perform at their optimal frequency. UPS also provide battery back up and/or connection to an alternative energy source (such as a generator) so loads are protected in the event of a mains failure. Today’s online UPS can also achieve operating efficiency figures of 96% and higher (if operated in certain power modes).
It is true that voltage optimisers costs less than UPS but they do not provide the higher levels of power protection required by the critical loads that run today’s always on businesses. In my view, UPS are a far superior – and ultimately cost-effective option.