Dimmable Flourescents

All fluorescent fixtures, before dimming, should be burned in for at least 100 hours. If that is not done, it will dramatically shorten the life of your fluorescent lamps, as well as lead to other problems with the dimming curve. Turn on the lights, and leave them on for the 100 hours....


Dimmers usually have to have different settings (or a completely different module) to be able to dim fluorescent fixtures properly - depending upon the type of ballast.

There are 3 main types of fluorescent dimming ballasts, that I know of.

2 Wire

This type of ballast is able to dim just like a regular incandescent lamp would - with a hot and a neutral running through a dimmer. (In ETC world a D20) The settings on the dimmer usually need to be different than they would be for an incandescent fixture, but it can be done nonetheless. The Advance Mark X (read Mark 10) ballast is one of this type.

3 Wire

This ballast takes a different type of dimmer module. (In ETC land, it would take a D20F) This ballast uses a dimmed hot, a constant hot and a neutral.

4 Wire ballasts

This ballast can use a standard dimmer module (in switched mode) or a relay module. There also needs to be a 0-10v analog source that works in conjunction with the dimmer or relay. The switched source provides constant power to the module with the 0-10v provides the control signal while the ballast does the actual dimming based upon that signal.

See this thread. Strand C21 dimmers seem to require "Advance Mark X" (Mark 10) ballasts.