# What dimmer for 2-wire fluorescent dimming ballast?



## MarkyMark (Jan 31, 2009)

Not for long.

I've seen them installed by mistake and they burn out the ballasts. Someone else may be able to give a more technical reason.

Hunt Dimming makes a phase control dimmer that you can usually get for about 10% - 20% less than Lutron.


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## Dennis Alwon (May 9, 2009)

I would only use a product that was rated for the purpose. Some low voltage transformers state that a standard dimmer will work- in that case go for it but I am not aware of a fluorescent ballast that states a standard dimmer will work.


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## Electric_Light (Apr 6, 2010)

So, I think the concept is the same, but the useful range is smaller, so that the range of firing angles are narrower.

Lutron 3-wire system uses "dimmed hot" for control only(so basically you could construct it out of a switch and a non-switched dimmer) 

At minimum setting, you can only delay to 120deg and maximum setting won't go less than 40 deg delay. 

Cheapo incandescent dimmer I have go 145deg to 25deg. I guess a delay less than 40 deg won't increase the output anymore and delay over 120 degree won't decrease it anymore or might even cause it to glitch. 

Now, the TuWire actually carries power over the wire, so the range might be even smaller and it could even be a trailing edge type..


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## cdnelectrician (Mar 14, 2008)

I installed some P&S dimmers for some PL potlights at work the other day. I was totally unaware that you no longer need a 3 wire ballast and dimmer until now! Stuff changes so fast...They seem to work well though, and very nice to install. I am interested in how this technology works though. Are different ballasts and dimmer manufacturers interchangeable?

I realize that P&S does not make ballasts and these dimmers were used on Advance quicktronic dimmable ballasts. When they first turn on there is some flickering for a few minutes, but after that no problem.


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## Electric_Light (Apr 6, 2010)

merged w/ below


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## Electric_Light (Apr 6, 2010)

I got it working fine with a $20 dimmer from Home Depot designed for CFL. The key is calibrate for mild dimming. If you set the low-end too aggressively, much of the slide controls span becomes useless and all the dimming gets pushed to the upper 3/4 of the control. 

It's basically a standard dimmer that lets you lock out the low-limit, then spread it out over the full span of the control slider.

If you calibrate it right, it works well. In factory setting, its garbage. You can calibrate it in shop in advance using a scope or an incan lamp + a true RMS DVM. Send me a message if you're interested in how-to


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