Time marches on and so does the energy efficiency LED lamp market. Some parts of the market are not so good; all that cheap stuff being promoted is affecting the industry enormously. However, other reputable manufacturers and suppliers are putting some great LED products into the market.
What should you be looking for in this regard is a big query I hear from electricians all around the nation. Hopefully, the information here will help especially when retrofitting MR16 halogens with LED equivalents.
"you get what you pay for" is especially relevant in this regard. Many of the lower cost options don't ut it when considering using dimmers, the extent of lamp life and quality light output. I am sure a call from your customer having a whine about the recent installation you have done is not something you would be looking forward to! All the extra costs to you to fix the problem will probably blow cost savings on the purchase price of the cheap LED lamp.
There would be many installations using old technology in power supplies, and possibly dimers to run their halogen down lights, and as such this could cause some big issues by a simple LED replacement.
Of recent times I have presented the issues of incompatible power supplies to these MR16 replacement LEDs. Effectively, they can put a lot of stress on the power supply, because of the way the LED electronics are configured to drive the LED. Cheaper LEDs are continually switching the power on and off at short intervals and create a "fish bone" sharp wave form which puts an inordinate amount of stress on the power supply.
A reputable LED runs to a much smoother wave form and switches at regular intervals on the ac sine wave, thereby placing minimal stress on the power supply.
Matched with this is the operation of the cheaper LEDs at a very poor power factor, and you have a real issue with the overall efficiency.
Another major problem can be the replacement LED may not work well at the lower load level that an LED installation incurs. For instance, the replacement of one or more halogens in an installation may only be running at a very low level, and as such the existing power supply may not be able to work the LED as expected. As a result, the lights may flicker or may not even start.
The ability of the power supply to work at a steady limited load affects its compatibility with LED lamps.
Look the the manufacturers installation and technical instructions to check on power supply compatibility, as most reputable LED lamps will work with a wide range of electronic and magnetic transformers. If the power supply already installed is not compatible, it needs to be replaced.
Similarly with dimmers it is advised to review the manufacturers installation and technical instructions for compatibility. At lower dimming levels, an already installed dimmer may be incompatible with the replacement LED lamp, and as such may cause flicker or even cease providing any light output.
Bear in mind this compatibility issue extends to the expected life of an LED lamp. By simply replacing the halogen and not considering any other parts of the installation, you may be pushing limits and as such the LED will fail to perform in light output level and life expectancy.
Clipsal by Schneider