David Morgan takes a look at the Isotera system, which is based on ‘Contactless Power’ technology removing the need for individual drivers thus making connecting LED fixtures as easy as clipping clothes pegs onto a clothes line.
An induction based LED lighting and power transmission system that simplifies the connection of electrical wiring to luminaires, increases system efficiency and extends the working life of LED luminaires is clearly good ‘news’. Surprisingly the underlying principal of induction is quite old and the technology is based on the work of the Hungarian electrical engineer Ottó Bláthy, who invented the transformer in c1885. In this way, distinctly old technology is transforming modern technology some 130 years after its invention.
Isotera, the company that has introduced this system, was formed in 2010 by a team of engineers who were experts in high-density, high-efficiency power conversion and high frequency power networks. Isotera is a spin-off from transformer company Tunewell, which has a history of making radio coils going back to the 1920’s.
The core elements of the Isotera system are a very high frequency power supply; the iHub (operating at 50 KHz); a double insulated twisted pair cable, the iBus; and a power coupler, the iClip, that transfers power via induction from the cables without any need to pierce the insulation.
The iBus cable can be up to 250 metres in length without being effected by voltage drop although the available power drops by around 12 watts per 100 metres. As this is a constant current system, volt drop on long runs is not a problem as it would be with a constant voltage system.
The iClip couplers can be attached and repositioned to the cable very quickly without needing skilled personnel giving the potential to reduce lighting installation costs and time significantly. Changes to wiring layouts and luminaires can be made much more easily than with traditional line voltage systems.
In addition to the standard iClip couplers there is also an emergency version, iEscape, so that an emergency pack with batteries can be connected to the system. No mains supply is needed to the emergency pack as the power comes via the iBus cable. A self-test function is included as standard and potentially any luminaire can be converted to emergency use on the system.
The iClip contains circuitry that converts the high frequency AC into DC power and also a constant current driver to run LED luminaires directly. The drive current is factory set in a range from 200mA up to 2.1 amps with an accuracy better than 1%. A separate 1 – 10V dimming circuit plugs into the iClip with a standard dimming range down to 5%. The dimming can be controlled by any industry standard 1 – 10V dimming system. At the moment there are two sizes of iClip – 20 watt and 45 watt – with a maximum operating efficiency of 95% at around 75% of full load. The efficiency drops slightly to 92.5% at full load.
It is understood that Isotera are developing a plug in converter for DALI and DMX dimming options that will enable the system to be used in a wider range of projects.
The iHub power supply is available in 250 watt and 500 watt ratings so that a large number of individual luminaires can be run from a single power supply rather than needing one driver per luminaire thus reducing the cost. Up to 50% of failures in LED lighting installations are due to driver issues. By separating the power supply from the driver circuit, the reliability increases significantly and Isotera offer a 10 year warranty and a 100,000 hour life expectancy.
Isotera are claiming high levels of efficiency for their luminaire range of up to 165 lumens per system watt when used in conjunction with the Isotera power system.
Other system components include an occupancy sensor that draws power from the iBus and a biased switch interface that generates a 1 – 10V signal allowing manual dimming from a wide variety of standard switch plates.
The system has a number of inbuilt safety features. If the iHub becomes disconnected from the iBus for any reason it will automatically shut down and if the luminaire is not connected to the iClip prior to attaching to the iBus that also will cause the system to shut down.
Isotera initially partnered on an exclusive basis with one of the major international lighting companies with the aim of working with lighting specifiers on a project basis. The company is however now working directly with end-users via wholesalers and focusing on the commercial, industrial and other functional lighting sectors with their own range of LED luminaires.
The Isotera luminaire range includes downlights, festoon lights, recessed ceiling panels and retrofit light engines in various formats. These luminaires all incorporate the iClip, making installation very simple.
Working with end users in the short term should help Isotera build market share along with awareness of the company and the benefits of induction lighting. In the medium to longer term it is understood that Isotera is aiming to work directly with luminaire manufacturers on a non-exclusive basis enabling a much wider range of lighting equipment to benefit from an induction system.
The Isotera system is highly compatible with LED luminaires and offers a wide variety of useful benefits in terms of installation cost reduction, increase efficiency and longer life.
Adoption by the conservative electrical contracting industry seems to be taking longer than expected but the potential for cost and time saving should overcome this resistance in due course.
Lighting manufacturers will also benefit from using the Isotera system with their luminaires, but although using a single source technology always poses issues of continuity this is unlikely to be a major issue. I am keen to explore the system in more detail with our own luminaires and lighting systems as it could be a good fit in many cases.
David Morgan runs David Morgan Associates, a London-based international design consultancy specializing in luminaire design and development and is also MD of Radiant Architectural Lighting.
Tel: +44 ( 0)20 83404009
© David Morgan Associates 2017