Frequently Asked Questions
Here we answer customers Frequently Asked Questions regarding Claude Lyons Products and Services
FAQ General Questions
  • What is the voltage range equipment can accept?

    All electrical equipment sold in the EC needs to be capable of working with a supply voltage anywhere between 207 and 253V (230V ± 10%). Operating at a fixed, reduced, voltage of 220V (or even 210V for maximum saving) is therefore realistic with a Claude Lyons Energy Saving Regulator.

  • Does the equipment require a By Pass Switch?
    The equipment should have the ability to be isolated for maintenance or shutdown works and so we always recommend the fitting of a bypass switch.
  • Where can I buy your systems?
    You can order standard systems online at for larger/bespoke requirements please contact us

    Outside the UK? please locate your local distributor using our locator map

FAQ Voltage Optimisation PowerSave
  • How does reducing the voltage save power?
    Generally, the mains supply voltage in the UK is greater than necessary. For many types of electrical equipment if the voltage is reduced the current drops. Power consumption is the product of voltage and current, so in these loads, as voltage is reduced the power reduces.
  • What is the typical supply voltage in the UK?
    This varies widely (which is why a site survey is so desirable and recommended) but typically, although the official nominal supply voltage is 230V, the actual voltage fluctuates around an average of 242V.
  • What are the benefits of the Claude Lyons Energy Saving Regulator units over other Voltage Optimisers in the market?
    Claude Lyons energy-saving regulators are designed to maintain the supply at the optimum voltage and achieve this dynamically.  Other products on the market simply give a fixed reduction in voltage, crudely step change and so do not truly optimise the voltage, or offer the same levels of savings or protection from supply variations.
  • What is the difference between a transformer and a stabiliser?

    A transformer reduces the voltage by a fixed percentage. A stabiliser reduces the voltage to a fixed (preset) value. This has numerous advantages – the reduction in voltage (and therefore saving in power) can be greater, and the equipment being fed operates at an optimum stable voltage ensuring more consistent performance and longer life.

  • If I install a voltage reducer, what happens if the mains voltage drops?
    Unstable mains voltage (voltage drops) are likely to be more prevalent as supply capacity decreases. If the voltage reducer is a transformer, it will continue to reduce the now reduced incoming voltage, which can drop below the safe operating voltage for the equipment being supplied. On the contrary, a stabiliser will automatically compensate by decreasing the degree of voltage reduction, preserving correct equipment operation.
  • Some suppliers claim that voltage regulation equipments cannot be used for voltage reduction purposes. Is that correct?
    No, To the contrary, Voltage regulation offers significant advantages over basic fixed or switched tap voltage reduction equipment not least of which being its ability to maintain the supply at a customer adjustable optimum voltage and maintain each phase voltage to within 1%.
  • What is the average savings by voltage reduction?
    Each individual site will have unique characteristics and a variety of plant and equipment, however, in our experience savings of up to 25% can be achieved.
  • What types of load are better suited for energy savings by voltage reduction?
    Most loads benefit from voltage reduction as the un-reduced voltage is higher than the optimum design voltage of the equipment. As an example resistive loads and fluorescent lighting generally show the highest savings.
  • What are the benefits of Claude Lyons Energy Saving Regulator to the environment?
    Benefits include reduction in Carbon footprint as well as a reduction in equipment replacement and maintenance requirements.
  • What is the optimum output voltage setting?
    Claude Lyons Energy Saving Regulators set at 220V output upon leaving the factory; however, this can be set as per customers requirements and adjusted on site to meet optimum voltage for the specific site equipment / load profile.
  • Can each phase output voltage be set individually?
    Yes, although it is normal to ensure all three phases are set at the same Voltage.
  • Does the equipment have surge protection?
    Yes, supplied as standard
  • Why do we need to have a site survey and three phase logging to establish possible savings and carbon reduction?
    In order to accurately establish site suitability and energy saving potential a detailed survey and electrical logging are required. Surveying a site and understanding the load types that exist on the site and the specific way in which they are applied together with accurate data will enable a full technical analysis and assessment to be made. Without this level of detail any report is likely to be inaccurate and could potentially cause severe operational problems particularly if non regulating products were to be installed.
FAQ Frequency Converters
  • What is a Frequency Converter?
    A Frequency Converter is a device that converts the AC of one frequency to another frequency. In addition, usually the Frequency Converter will also convert the voltage, providing a variable output.

    These systems can also be referred to as Frequency Changers or AC to AC Frequency converters.

  • What is difference between SFC and RFC?
    SFC Static Frequency Converter – This the modern method of frequency conversion with no moving parts, utilising electronic solid state Pulse Width Modulation units.

    RFC Rotary Frequency Converter – This was the chosen method prior to SFC systems, using electro mechinical motor to generate/adjust the frequency of the waveform.

FAQ Regavolt Autotransformers
  • Do these come with an operating Knob and Dial?
    As standard the Regavolt Range is supplied without Knobs or Dials but theses are available as Options
  • Are they supplied with an enclosure?
    As standard the Regavolt Range is supplied without an Enclosure but these are available as Options
  • Can you supply customised units?
    We have in house Design and Engineering Facilities which enable us to tailor equipment to customers specifications
  • Can you supply customised Three Phase units?
    We offer a very wide range of Three Phase Units as standard as well as offering bespoke designs where required.
FAQ Installation and Servicing
  • Does Lyons Instruments provide installation?
    Yes, either directly or via our dedicated approved installation contractors.
  • How long does installation take?
    Each site has specific requirements and so each individual installation should be looked at separately. All works will be completed prior to switch over to limit equipment downtime.
  • Will my site be without electrical power during maintenance?
    Some models incorporate internal No-Break by pass switches alleviating the need for any power disruption during maintenance. Where no internal bypass is available, an external bypass switch is recommended allowing our equipment to be isolated for maintenance. This would involve a brief loss of power.
  • Does the equipment require maintenance?
    All electrical plant and equipment needs to be maintained. We would generally recommend an annual Inspection / Maintenance Visit.