FAQs - Voltage Optimisers

Domestic type voltage optimisers are generally sold as ‘fit and forget’ types and use static torroidal core technologies. Larger voltage optimisers for commercial or industrial sites including single and three phase systems may be either static transformer or mechanical stabiliser types and should be inspected for wear and tear and maintained annually. Fixed voltage optimisers should also be checked to ensure that their voltage reduction settings match the needs of the site; the mains power supply voltage on a site can change during a 24hour period with load and seasonal demands.

Most building loads can be classed as resistive, inductive or capacitive. Using voltage optimisation for resistive or inductive type loads including uncontrolled motors, incandescent lamps, switch start fluorescent lighting and other high energy consuming equipment can achieve the highest energy savings. Voltage optimisation does not generally achieve savings for capacitive loads such as IT servers and computers due to the operation of their switch mode power supplies.

In the UK, electricity is transmitted from generating stations and renewable power sources at a higher voltage to cover transmission losses due to cable resistance, power problems (harmonics) and weather conditions. Local electricity supplies can also be higher within areas where there are a number of renewable power generating sites (solar PV and wind turbine). In European countries, electrical equipment is designed for 230Vac (single phase) operation. Voltage optimisers lower the incoming mains power supply voltage (which can be higher than 240Vac) to 230Vac or below and this reduces the amount of power drawn by the connected loads which is billed in kilo-watt hours. Voltage optimisation is also known as voltage reduction and can achieve energy savings of 15-30% or more in electricity costs.