New 12v LED Fixture with Existing Panelized Lighting

[Jeremy Ragan]

Hello, I will be replacing an existing ceiling fixture with a new one but my project has a number of complications.

Old Fixture:

• 12-volt track-style fixture
• 12-volt WAC Lighting remote transformer SRT-300M-12V

New Fixture:

• 24-volt Nemo Ellisse Double LED Suspension Light
• Uses integrated transformer LPF-90D-24
• Apparently, for dimming, the fixture/transformer requires an additional 2 wires be run from the dimmer according to some things I've read

Power Source:

• Lutron Homeworks Interactive (circa 2004) Panelized lighting RPM/Dimmer

Questions

• Confirming that I will be bypassing/removing the existing WAC Lighting transformer...
• Will this fixture dim without running the extra 2 wires?
• Will the new fixture work/dim with the existing feed from the panelized lighting?
• If wires must be run for dimming, then where would they run from?

When I tried to clarify with the manufacturer, I received the following:

ELLISSE PENDANT DOUBLE is

• 24V
• Dimmable 1-10V (you need 2 wires)
• The driver inside the canopy is already dimmable: you need only a 1-10V controller

But this doesn't seem to clear up my confusion. 14-2 is already run to the existing transformer and then more 14-2 from the transformer to the existing fixture. Are they saying I need 2 more conductors in addition to the 2 in the ROMEX?

Thanks, Jeremy

 

[Richard Burns]

Hi
Yes remove or bypass entirely the WAC transformer.

The fixture will not be able to be dimmed without connecting a 1-10V dimmer switch to the fixture. Using the existing lutron dimmer may exhibit some sort of variable imprecise dimming but will probably cause problems / damage the light fitting instead.
However if it is used at full brightness on the Lutron dimmer it should work OK.

The usual approach is to provide a full line voltage to the fixture and have a separate feed from a 1-10V dimmer switch (these might be an option from Lutron) to another connector in the fixture.
Practically you would need a 1-10V dimmer switch fed with mains voltage and delivering 1-10V output. Then take both mains voltage and the 1-10 V output up to the light fitting.

I think your current system of dimming is designed for a mains voltage dimmer to supply a variable input into a transformer and the transformer will then supply a dimmed 12V to the light.

The two systems are not generally compatible.

 

[Jeremy Ragan]

...

Thank you so much for the excellent response and information. I can program the Lutron system to treat it as on/off instead of dimmable and we’ll just have to deal with it not being dimmable.

 

[Jeremy Ragan]

The transformer is in a pantry/closet adjacent to the fixture. There appears to be the "standard" corrugated blue conduit run from there to the fixture. I suppose I could try to fish an additional two conductors to the closet and throw a dimmer in there in the off-chance we wanted to dim the thing.

Which leads to some follow-up questions:

• What gauge wire should I pull for the dimmer control (assuming it's a 0-10v dimmer).
• Can I simply splice/tee/split the mains around the old transformer so one leg goes on to the fixture and one leg goes to the dimmer?

 

[Richard Burns]

1-10V control should be extremely low current so the wire size would be dictated only by the volt drop experienced, this is critical because the dimming is voltage dependent. Therefore I would tend to go for 14/2 but down to 18 should be fine as it sounds like a short run.

Remove the mains input from the old transformer and use the wire to both feed the light directly and to power the 1-10V dimmer in the cupboard.

 

[Jeremy Ragan]

1-10V control should be extremely low current so the wire size would be dictated only by the volt drop experienced, this is critical because the dimming is voltage dependent. Therefore I would tend to go for 14/2 but down to 18 should be fine as it sounds like a short run.

Remove the mains input from the old transformer and use the wire to both feed the light directly and to power the 1-10V dimmer in the cupboard.
View attachment 41367

Apologies for bringing back my old thread...
For the 0-10v conductors at 14 gauge, would it be best to pull stranded or solid (15 feet or 5 meters)?
Thanks again!

 

[Richard Burns]

That would be down to your personal preference, stranded would be more flexible if you have to go around corners, but either should be OK for a straight run.

 

[Jeremy Ragan]

Any limitations to jacket type if it’s going to be run in an existing “smurf tube” conduit with the existing 14-2 switched romex?

 

[Richard Burns]

Then you are into your regulations that may differ from those I am familiar with.
For UK regulations a mix of cables with different voltages must be insulated for the highest voltage present, so the 10V wiring should be suitably insulated for mains voltage to reduce the risk of cross connections.
This is probably a safe and complaint way to approach the situation.