Andrew Wilson, Commercial Manager at Varilight, explains how advances in dimmer technology can give electricians new conﬁdence in installing dimmable LED lighting.
Where dimmable LED lighting is concerned, it may be a case of “once bitten, twice shy” for some electricians and installers. Early experience of poorly performing dimmable LED lighting may still make some installers reluctant to offer dimming options to end users. However there has been a series of step-changes in LED dimming technology over recent years which have combined to take the guesswork out of LED dimming.
When LED lighting ﬁrst appeared, very few lamps were dimmable and even those that were could give unreliable results. This was compounded by a lack of information to explain that specialist LED dimmer switches would be required for the best results. Traditional dimmers, designed for incandescent lighting, were often used to control dimmable LEDs which often resulted in a combination of buzzing, ﬂickering and strobing effects, along with a limited dimming range.
As well as influencing contractors, these factors may also have contributed to reluctance among some householders to select LED lighting in circumstances where dimming was required. Additionally, some householders may have upgraded to LED lighting without realising that their existing dimmer would be under-loaded and ill-equipped to control an electronic light source, such as an LED lamp.
Experiences like this have no doubt contributed to the perceived uncertainty around dimming LED lamps. The good news is that, with a suite of advanced features, the best LED dimmers on the market today take the guesswork out of dimming LED lighting.
Trouble-free LED dimming
Five years ago, Varilight was the ﬁrst major manufacturer to develop a specialist LED dimmer with wide compatibility. This first-generation “V-Pro” dimmer technology answered many of the problems faced by installers, but as the number of LED lamp manufacturers in the market sky-rocketed it became clear that, instead of a standard approach being taken, there were nearly as many variations in LED driver technologies as there were lamp manufacturers and that a continual development program would be required to maintain the wide compatibility of the V-Pro dimmer as new LED driver technologies emerged.
“The terms “trailing-edge” and “leading-edge” refer to the way in which the mains power received by the dimmer is controlled to reduce the power received by a lamp.”
Versatile dimming technology
In our opinion, the best LED dimmer switches on the market are able to dim LEDs which require trailing-edge dimming as well as LEDs requiring leading-edge dimming. Typically this is achieved by designing a dimmer that is able to operate in different modes for different types of LED load. The terms “trailing-edge” and “leading-edge” refer to the way in which the mains power received by the dimmer is controlled to reduce the power received by a lamp. For certain lamps, manufacturers may specify the type of control best suited to the electronics in the lamp or LED driver.
For example, in its default mode, out of the box, the Varilight V-Pro dimmer operates in an extremely versatile trailing-edge dimming mode. For the vast majority of dimmable LED lamps on the market, a trailing-edge dimming mode provides an excellent dimming performance. For some lamps, however, the performance can be improved by switching to a leading-edge dimming mode. The Varilight V-Pro dimmer has an additional special mode developed for LED drivers that are particularly difficult to dim.
In addition to a choice of dimming modes, quality LED dimmers also offer an adjustable minimum brightness setting to enable the full stable dimming range of a given LED load to be exploited.
High power options
As LED lighting technology has developed, with improvements in measures such as lumens per watt and the colour rendition index, dimmable LED lighting is increasingly being specified for commercial and larger domestic installations, resulting in a requirement for LED dimmers with higher power capabilities. For a period of time only “leading-edge” dimmers were available for high power LED dimming but some dimmer manufacturers have now added higher wattage trailing edge dimmers to their ranges. For example, new technological advances at Varilight mean that V-Pro dimmers are now available with high wattage capabilities for LED loads up to 300W, or 30 lamps.
Adding value with LED dimming
There are very few situat//ions where a lighting installation doesn’t benefit from the ability to control light levels. By encouraging customers to upgrade to dimmable LED lighting using proven dimmer technology an electrician can improve the client experience while benefiting themselves from upselling.