10 things to know RIGHT NOW before you dim LED lamps

Choose the best dimming method

While there are untold numbers of LED lamps and fixtures on the market, there are only four main types of dimming method:

1. Mains dimming
2. 1-10v
3. Dali
4. DMX

(These are explained in more detail in the sub-panel)

Don't buy cheap LED lamps or drivers

Most lighting control systems offer a variety of dimming

Protocols - the languages which they use to communicate with the lamp or driver. When you've chosen the method that's right for your installation you will need to buy LED lamps or drivers that match the performance and the protocol.

The most common problem lies with the design and build quality of the LED driver, leading to poor performance and even complete failure of the LED.

For instance, with a DALI driver it may not be able to dim down to the level that you wish to set. Beyond a certain threshold of dimming, the LED lamp may simply switch off!

Similarly, while DMX signaling is ideal for a colour-change installation, only quality LED brands will be able to render the desired colour with accuracy. Most commercial colour DMX lamps use more pure colours to create a wider gamut than is possible with just RGB. Pure colours of amber and white are often added without which the available spectrum may create some poor lighting effects.

The old adage of “you get what you pay for” should be borne in mind. Avoid cheap products, particularly of items like LED tape and always check with the control manufacturer that your intended LED product is compatible with their system.

Test before you buy

In the domestic and light-commercial environment, its very likely the customer will be using phase-dimmable LED lamps. Especially if they are retrofitting existing lamps (tungsten or halogen) with LEDs.

This creates cost-effective installations but, being designated ‘retrofit', customers tend to think that just a quick lamp swap is all there is to it. The situation is exacerbated by LED manufacturers who promote the same concept in their marketing and packaging.

Being an unregulated market place, it's very important to check that the proposed LED lamp works with the dimmer before committing to purchase.

Test before you buy. If in doubt ask the dimmer manufacturer if they have a free testing service and submit a number of samples for risk-free approval.

Although safety standards are required in the manufacture of the LED because it's an electrical product, there is no standard based on the performance of an LED. LED products are often made by sub-contractors (OEM) in China and, because each company's brand may have different design parameters and cost points, two apparently similar LEDs can have completely different designs and hence very different performances.

Use dimmers designed for LEDs

LEDs can have higher in-rush currents due to the nature of the power supply built into them. Therefore, it's important to select a dimmer which can cope with this and provide regulated power to the LED.

In some cases the load of the LED is too low for stable performance and the addition of a Dummy Load may be required.

Check the LED lamp fits - many don't

Retrofit LEDs are intended to replace existing tungsten or tungsten halogen lamps. However, due to the size of the electronic components and cooling components used to alleviate heat dissipation, some LED lamps simply don't fit existing fixtures. But that hasn't stopped some manufacturers making them anyhow! It might make for a better engineered product but, if it doesn't fit into the required illuminare, its not much use. So again, check before buying and, if in doubt ask the supplier.

Only buy brands you trust

In LED lamps with larger wattages - for example, spot track lights used in retail, or ceiling mounted recessed down lighters - the LED chip is mounted on a dedicated aluminium heatsink, while the circuitry is mounted in a separate gear case. This allows for more component spacing, better cooling and a longer life span.

In a retrofit LED lamp all the components have to be contained within the given physical space of the lamps body & base. This can cause thermal and mechanical stress which, combined with component quality, will adversely affect lamp life. Most commonly the first thing to fail in an LED lamp is its internal power supply.

It's important to buy a reputable brand and preferably one recommended by the dimmer manufacturer. Not only will a reputable LED brand have performed extensive testing, but the dimmer manufacturer will also have tested compatibility with their product. Additionally, a dimmer manufacturer may have performed a strip down test to check for basic component quality and thermal management of the LED before making that recommendation.

Only use quality GU10 lamps

GU10 LED lamps are replacements for mains voltage tungsten halogen lamps and are the most popular of all LED retrofit lamps.

Because the ceiling mounted downlighter is so ubiquitous the GU10 has become something of a standard within the lighting world both for new and retrofit.

A dimmable GU10 lamp is a compact piece of engineering; it needs to house the LED driver components as well as a power supply. If you're looking for a dimmable version, it's all the more important to check with the dimmer manufacturer before buying!

Please check the Futronix list of approved GU10 lamps here: