Having your business’ sign lit up at night and keeping other lights on so potential customers can easily find their way to you must always be a top priority. But, saving power via LED technology and/or light dimming strategies is just as important.

While all dimmers lower light intensity by controlling the power output to the lamp, there are many different options to choose from. Dimmers can be manual or automatic, suitable for LED lights or for incandescent, and work reduction or intermission of the voltage stream. The latter method varies the amount of time in which the lamp has or does not have full voltage is referred to as “phase dimming.” Phase dimming consists of both forward and reverse phase dimming.

What are the advantages of forward phase dimming versus reverse phase dimming?


Benefits of Forward Phase Dimming

Forward phase dimming is the most common dimming method used in the U.S., with over 150 million controllers in current operation. While it is surpassed by reverse phase dimming in some ways, it still has many important benefits, which include:

  • Perfect for incandescent lamps. Incandescent lamps work well with virtually all dimmer technologies, so they can still be well worth having.
  • No re-wiring is needed to use forward phase dimming, whereas reverse phase often requires re-wiring and replacement of incompatible existing dimmers.
  • Using forward phase dimmers on incandescent lights will boost their energy efficiency significantly and extend lamp life. This is an investment that can pay for itself.
  • Forward phase works with magnetic low voltage light sources, which can handle loads up to 10,000 Watts. They also protect magnetic transformers from overheating or suffering damage due to voltage spikes/surges.
  • Forward phase also works with neon, cold cathode, and some LEDs that are compatible with incandescent. This makes modern forward phase dimming a great option for retrofit jobs.
  • LED drivers designed to work with two-wire forward phase dimmer controls help eliminate common “bugs,” such as flickering, ghosting, pop-on, and drop-out.
  • Finally, forward phase dimmers are the overall least expensive option.


Benefits of Reverse Phase Dimming

When electronic instead of magnetic transformers are used with low-volt systems, reverse phase dimming must be used. Some of the advantages of reverse phase include:

  • Extremely silent operation across the full dimming range. The use of electronic transformers limits you to around a 150 Watt output.
  • Reverse phase dimmers are more expensive, though it does tend to outlast their forward phase counterparts.
  • Reverse phase dimming usually gives you better overall control and smooth dimming down to 5% light levels, while forward phase normally dims smoothly down to 10%.
  • Generally works better with LED light sources and all electronic low-voltage systems.


Must I Be “Stuck With” Only Forward or Reverse Phase Dimmer Controls?

Every lamp type and transformer will have its own ideal dimmer type, and many are compatible only with forward or reverse phase dimming. You should follow manufacturer’s instructions and consult with an expert before making a final decision.

However, you can purchase modern, highly efficient, and durable dimmers that are compatible with both forward and reverse phase systems. There will be times when you are better off with one or the other, but versatile units compatible with both can save you money if you change your preferences later on.

To learn more about forward phase and reverse phase dimmers orÊto order a specific dimming product, feel free to contact ERP Power atÊ805-517-1300 or visit ERPÊonline.