Electrical equipment that has a poor quality power supply will operate with reduced efficiency, causing energy to be wasted, and electricity bills to be higher than necessary. In the UK, the electricity supplied to commercial and industrial sites is deteriorating in quality. As the diversity of the UK’s generating plant increases, with relatively small-scale renewable power stations replacing older fossil fuel and nuclear plants, more switching is required to match supply with demand. This means harmful transients are therefore becoming more common.
Generally, power is also supplied at a voltage that is higher than the ideal level for most electrical devices. Significant energy savings can therefore be achieved by optimising the power supply at source, allowing the entire electrical load to run at high efficiency.
Energy-saving strategies often fail to consider the effects of a non-ideal power supply on electrical equipment, because it is often taken for granted that power quality in the UK is good, and the effects of an incorrect supply are often difficult to see. Yet it is estimated that around 90% of sites in the UK receive a voltage at a much higher level than the optimum operating point for most electrical equipment. The statutory supply band for electricity in the UK is 230V +10% to -6% (i.e. 216V to 253V), following European harmonisation in 1995. However, the average voltage supplied from the national grid is 242V, whereas the average European voltage is 220V.
Most electrical equipment used in the UK is manufactured to European standards, designed for 220V and will operate effectively down to 200V. Forcing appliances to operate at a higher voltage in the UK leads to significantly higher energy consumption, increased heat losses and a reduced life span.
A 230V linear appliance used on a 240V supply will take 4.3% more current and will consume almost 9% more energy.
Electricians Guide BS7671
It is estimated that 90% of sites in the UK are operating at too high a voltage and could therefore benefit from installing powerPerfector. Typically sites also suffer from harmonic disturbance and potentially destructive transients, and imbalance between three-phase voltages is frequently caused by inconsistent distribution of single-phase loads, which can dramatically reduce the efficiency of three-phase equipment.
