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ARCOL Resistors Designed into Cost Saving and Protective Voltage Stabilisers

A quote from the Electricians Guide to the 17th Edition of the IEE Wiring Regulations (BS 7671): 2008 and Part P of the Building Regulations:

“Since the present supply voltages in the UK lie within the acceptable spread of values, Supply Companies in the UK have not reduced their voltages from 240V. This is hardly surprising, because such action would immediately reduce the energy use by customers (and the income of the Companies) by more than 8%”.

ARCOL Resistors, the UK’s specialist resistor manufacturer, have had their high power HS75 and HS100 Aluminium Housed Resistors designed into a range of single and three phase voltage optimisation products where it is a critical safety component of the energy saving voltage stabilising circuit.

UK-based energy supply innovators matt:e Ltd have developed a range of Voltage Optimisers for standard single phase power distribution, street lights, an Intelligent voltage optimiser and a micro generation connected Voltage Optimiser, all of which rely on the ARCOL products.

In the UK and worldwide micro generated energy supply technologies are being installed by the 1000s in order to reduce the use of fossil fuels which are the cause of serious environmental problems. However, there is a largely unrecognised and serious bi-product of utilising PV or micro-generated energy sources; localised over-voltage created by the inverters, which is at times higher than the CENELEC safety limit of 253VAC.

Due to the nature of localised power grid systems, inverters are raising the voltage to an uncontrollable level before cutting out. If multiple units are deployed on the same connection point then each invertor needs to raise its output Voltage to be able to export power.

As a simple example; if there are 3 PV systems on the same connection point in the same street, the 1st inverter (house 1) sees a grid voltage of 240v but wants to export energy. To do so it raises the voltage to 242v, house 2 now sees a grid voltage of 242v and wants to export, so it now raises the voltage to 244v and so on.

A subscriber to the same local grid connection point that either doesn’t have a PV system or has a house facing in the wrong direction will now find their electricity bills have become very high through no fault of their own and without using any additional electricity, as they now have a localised voltage during daylight (for PV) of 246v plus.

This safety and potential over-billing problem is the key reason behind the development the matt:e PV Direct Connect System. The system enables the location that is generating electricity to utilise the energy generated at a safe and more economic level, it also allows the inverter to see the grid voltage as it is and not through an optimised circuit complying with G83 standards.

This is excellent news for households generating their own electricity, as they can use more of what they are generating. However it is even more important for households to utilise a Voltage Optimiser if they do not have any micro-generation themselves as their bills will be going up without any knowledge or change of behaviour.

Matthew Hunt, Director and co-founder matt:e Ltd, comments, “Our range of domestic and commercial voltage optimisers offer safety and cost saving benefits to individuals and commercial operations. As our product is entirely made in Britain it is imperative for us to source components that are in line with our business ethos as we believe British is actually best. We select components based on specification, quality and ‘made in Britain’. ARCOL fulfil these requirements and offer unrivalled technical support on our doorstep.”

The background to Voltage Reduction/Regulation

As a result of European Harmonisation the electricity supply in the UK is now 230V (+10%/-6%). Electrical equipment manufactured for Europe and the UK is rated at 220V.

Reducing/optimising voltage towards this level leads to: lower energy consumption, reduced carbon emissions, extended lifespan of household appliances, lower operating temperatures and more efficient use of the generated energy from any Solar PV system.

We are seeing voltage pockets in the UK that are in some cases higher than the 253 volts permitted by CENELEC. Appliances in the home will still work under these conditions but with a drastically reduced lifespan.

Meters charge subscribers for ‘Real Power’. An appliance at 2400 watts and at 240 volts will use 10 amps of current (Watts=Volts x Current), so by using Ohms law V/I x R, the resistance would be 24 ohms. Current is proportional to Voltage, so at 220 volts, resistance is fixed at 24 ohms so current is 220/24 = 9.2amps. Power consumed is now: 220 x 9.2 = 2024 watts, a saving of 376 watts.

ARCOL’s HS75 and HS100 Aluminium Housed Power Resistors

To check stock of ARCOL’s extensive resistor range go to:

More information on ARCOL’s HS75 Aluminium Housed Power Resistors

More information on ARCOL’s HS100 Aluminium Housed Power Resistors

To discuss custom designed resistor solutions please call +44 (0)1872 277 431 or email email


ARCOL offer one of the widest ranges of resistors available to electronics designers and manufacturers including the market leading HS aluminium housed high power range, the MSR series of bare element resistors, the RWS precision power wirewound SMD resistor family, axial thin film, silicon coated types and precision passivated chip resistors and resistor packs.

Typical applications include traction, snubbers, switched mode power supplies and non-inductive resistors for high frequency and pulse applications.

ARCOL Resistors is a UK manufacturer of power resistors. It has been business since 1952 and has a customer base which extends throughout the world.

With a strong reputation and well-known brand name in the worldwide electronics marketplace, it has complete control of its own manufacturing processes, utilising a good level of automation within its production facilities.

ARCOL’s dynamic hub, located in England’s thriving South West, is an integral part of the secret of its success. A single location houses every process, from design and purchasing to manufacture, production and sales.

ARCOL prides itself on quality – its part of their heritage. ARCOL is fully-compliant with a host of quality standards – it is ISO 9001 approved and every range of resistors is fully RoHS compliant.

Materials and products are sourced from all over the world. Each one is made to the highest specification. Each one undergoes rigorous quality testing on site. Every step of the process at ARCOL is rooted in quality.

With its first-class financial management, ARCOL has a number of current strategic growth plans which include:

• Building an extension to the main production facility
• A new business system upgrade

About matt:e Ltd

matt:e Ltd are a Voltage Optimisation Development and Manufacturing Company, everything from our software, electronic boards and hardware components are made in Britain, we believe and are proof that resourcing within our Country is achievable and are very proud of this business model.

The matt:e PV Connect system allows an inverter to be connected straight into the unit via a dedicated un-optimised circuit via the dedicated MCB, allowing export pass through and additional optimised savings in one device.

This in return makes the PV system’s R.O.I. faster and the system more efficient utilising maximum available power through reduced voltage.

matt:e uses their own Toroidal type transformer that is more efficient and runs cooler than inefficient laminated type transformers. Voltage Mapping software enables Intelligent Voltage Reduction. Lightweight and compact the matt:e unit provides ease of installation.