LV Dimming?

[tedge]

Hey all,

Ran into a new problem recently and thought someone could help. I took over a big job after the original EC went broke. In a walk in closet there are 2 120v lights and 2 12v puck lights on the same switch. The wiring goes through the 120v lights first then to a JB with a small 75W "Tombstone" type solid state transformer for the pucks. The HO then decides they want to put Lightolier Onset dimmers in the whole house. I've tried both the line voltage and inductive low voltage dimmers, but all the closet lights flicker when dimmed. I was told, and have found, that these transformers can be dimmed by regular line voltage dimmers with no problems.

So are the Onset digital dimmers more sensitive somehow, and do they make a specific dimmer for this purpose? Do I need to split the line voltage from the low voltage? Any thoughts?

 

[stickboy1375]

IMO, LV lights powered by an electronic transformer, will always flicker when dimmed by a non- electronic dimmer.

 

[mdshunk]

Try a Lutron magnetic rated dimmer and watch your problem go away!

 

[Dennis Alwon]

In a walk in closet there are 2 120v lights and 2 12v puck lights on the same switch.

Little off topic but I would be curious to know where these pucks are installed in this closet that would make them legal?

 

[LarryFine]

Little off topic but I would be curious to know where these pucks are installed in this closet that would make them legal?

I don't care for pucks myself. I would advise them to get the pucks out of there.

 

[benmin]

Check the transformer for a min/max rating. I've had the same problem caused by a transformer that had a min wattage rating.

 

[pbeasley]

Hey all,

Ran into a new problem recently and thought someone could help. I took over a big job after the original EC went broke. In a walk in closet there are 2 120v lights and 2 12v puck lights on the same switch. The wiring goes through the 120v lights first then to a JB with a small 75W "Tombstone" type solid state transformer for the pucks. The HO then decides they want to put Lightolier Onset dimmers in the whole house. I've tried both the line voltage and inductive low voltage dimmers, but all the closet lights flicker when dimmed. I was told, and have found, that these transformers can be dimmed by regular line voltage dimmers with no problems.

So are the Onset digital dimmers more sensitive somehow, and do they make a specific dimmer for this purpose? Do I need to split the line voltage from the low voltage? Any thoughts?

have you tried the OS300QE "Low Wattage electronic low voltage dimmer". it is designed for solid state transformers and incandescent loads up to 300va total. While I have not used it, it is the one that seems to fit your needs.

 

[electricmanscott]

Try a Lutron magnetic rated dimmer and watch your problem go away!

Sounds like an electronic transformer though.

 

[e57]

Try a Lutron magnetic rated dimmer and watch your problem go away!

Lutron doesn't suggest this application - but I will say that it does work in only a few situations depending on the transformer. But a general rule of thumb is not to mix lighting types when dimming, and use the right dimmer. That is IF this electronic transformer is even supposed to be dimmed - dimmable in the first place...

Do not use regular incandescent dimmers for
electronic low-voltage lighting.​

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​

​

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When a magnetic low voltage
or incandescent dimmer is used on electronic
transformers, there is interaction between the fixture
and the dimmer. This interaction will cause any
combination of the following: dimmer buzz, fixture buzz,
lamp flickering, interaction between circuits, Radio
Frequency Interference (RFI), and may damage the
dimmer or transformer. To eliminate these problems,​

use Lutron ELV (electronic low-voltage) dimmers.

http://www.lutron.com/applicationnotes/362219b.pdf

 

[wyreman]

smoke and fail,

smoke and fail,

Try a Lutron magnetic rated dimmer and watch your problem go away!

So I always prefer to remote mount a magnetic xfmr and go.
But here I had this art gallery and the guy is moving and he says his mr16 track doesn't hum. Well they hum in the new place.

Now I have seen incandescent LV dimmers controlling electronic LV loads and they smoke and then fail. Long after the installer has cashed the check...

So electronic lv dimmers work by clipping the ac wave.
But Lutron magnetic rated dimmers don't come with autotransformers, do they?

So two parts to this reply?
Why exactly does it matter for the dimmer: electronic or magnetic? I've seen incandescent smoke and fail, but not magnetic dimmer on electronic load.

Second, will magnetic on electronic load squelch the buzz of these only electronic heads?

Only other choice is lower wattage, go incandescent or tear out and remote mount...