Technical side of 0-10V dimming, and remote switching.

[fastline]

We are redesigning a facility for manufacturing. The design is using UFO LED lights. I am highly recommending dimming, as most fixtures have it. However, I am realizing based on supplier talks that I may not fully understand the engineering side of dimming in the drivers because these dimmers are wattage or current limited. It was always my understanding that the 0-10VAC (or is it DC?) was only a signal voltage. Apparently they consume or transfer quite a bit of power. I asked them if the dimmer is a simple rheostat but they didn't know what that was.

Understanding them will be vital to me designing the circuit diagram.

As well, as I lay this out, I'd like to see if there are any products for commercial use to move lighting switching to more remote locations? As an example, the customer may desire to have all light switching in a single location, in a building that is over 300ft long, creating long, pointless runs of power wire. I have considered running contactors to handle the loads, but there has to be a better way.

 

[brantmacga]

Lutron Vive.

Also, the lighting vendor should be able to provide assistance in the photometric layout and controls system.


Sent from my iPhone using Tapatalk

 

[electrofelon]

. It was always my understanding that the 0-10VAC (or is it DC?) was only a signal voltage. Apparently they consume or transfer quite a bit of power. .

I also used to think the 0-10 was just a reference for the fixture to follow, so you could supply an essentially unlimited amount of fixtures off a 0 to 10 dimmer (I mean how much power does a voltage measuring circuit take, microamps?). But that doesn't seem to be the case, I don't fully understand it.

 

[solarken]

We are redesigning a facility for manufacturing. The design is using UFO LED lights. I am highly recommending dimming, as most fixtures have it. However, I am realizing based on supplier talks that I may not fully understand the engineering side of dimming in the drivers because these dimmers are wattage or current limited. It was always my understanding that the 0-10VAC (or is it DC?) was only a signal voltage. Apparently they consume or transfer quite a bit of power. I asked them if the dimmer is a simple rheostat but they didn't know what that was.

The dimming you are talking about is signal based dimming, either 0-10V or 1-10V, and it is DC. Checking the dimmers recommended by a few lighting manufacturers I find they typically have a 5A to 15A max current. I have not found the typical sink current of a fixture yet but I would think it would be just a few mA.
See https://www.ledlightexpert.com/Dimming-High-Lumens-LED-0-10v_ep_43-1.html

 

[James L]

There is a current draw of the dimming component of a driver, somewhere from microamps to milliamps. It's not "quite a bit" like a power circuit.

I think the maximum current capacity of the dimming circuit in the dimmer is 2 milliamps. So you would have to add up the draw of the dimming components of the drivers, Just like calculating any other kind of load

I've been looking at Lutron Vive for chandeliers at my church so I don't have to run wires on the finished ceiling. It looks like a great option

 

[hbiss]

The dimming you are talking about is signal based dimming, either 0-10V or 1-10V, and it is DC. Checking the dimmers recommended by a few lighting manufacturers I find they typically have a 5A to 15A max current

The 0-10 or 1-10 volts is a low current limited DC control voltage. Zero volts represents fixture off. Ten volts represents fixture at maximum brightness. The control voltage comes from the fixture driver(s). Shorting the control wires together will create a zero volts condition, leaving them open will create a 10 volt condition.

Many drivers will only go down to one volt not zero, reason being that they don't want the dimmer to be used to turn the lighting off. Zero volts would mean that the lighting is off but the driver is still powered wasting energy and reducing its life. So, all the way down on the dimmer results in a 1 volt, 10% lighting level with a conventional switch used to actually turn the lighting power off.

This is why dimmers have a current rating and line voltage run through them to the fixture(s). That's only for the SPST switch to turn the power off the fixtures(s). Nothing to do with the dimming voltage.

You can indeed control the brightness using a simple pot (rheostat) or resistor or if making your own controller. For a single fixture, 10k=10% brightness on up to 100k= 100%. For multiple fixtures, use 10k/n where n= the number of fixtures in the group that have their control wires paralleled.

-Hal

 

[ptonsparky]

I'm slow.
I have 3 fixture.
10k per fixture for 30k total
Or
10,000/3=3333

 

[ptonsparky]

Garage exterior lighting is 0-10 volt dimmable.
I feed 1-10 volts to the dimmer control wires via a CLICK analog output. 1v=10%, 10v=100%

 

[hbiss]

I have 3 fixture.
10k per fixture for 30k total
Or
10,000/3=3333

Yes. 10,000/3=3333. Divide the 10k by the number of fixtures.

-Hal

 

[Strathead]

What Hal said. Each and every light fixture is the "source" for the typical 0-10 volt dimming system. But there two classes of low voltage dimming, sink and source. The one we have discussed is sink and would certainly apply to your application. Source dimming is where the dimmer switch provides the voltage. DMX dimming is an example of source dimming. It would change the answer.

 

[solarken]

The 0-10 or 1-10 volts is a low current limite
This is why dimmers have a current rating and line voltage run through them to the fixture(s). That's only for the SPST switch to turn the power off the fixtures(s). Nothing to do with the dimming voltage.

You can indeed control the brightness using a simple pot (rheostat) or resistor or if making your own controller. For a single fixture, 10k=10% brightness on up to 100k= 100%. For multiple fixtures, use 10k/n where n= the number of fixtures in the group that have their control wires paralleled.

-Hal

I'm not an expert in lighting, but what you describe is not true for all fixtures out there. Some require a 10V analog signal from a dimmer and do not source the control signal from the fixture.

 

[hbiss]

I'm not an expert in lighting, but what you describe is not true for all fixtures out there. Some require a 10V analog signal from a dimmer and do not source the control signal from the fixture.

@Strathead mentioned that above.

-Hal

 

[Flicker Index]

The current contribution per ballast is 2mA or less, but quite often 0.5mA and you can add them up up to the limit of the dimmer.
For general purpose dimming, the dimmer is just a voltage regulator that claims it down to voltage based on the slider position, whether you have 2 fixtures or 15 fixtures.

However, the slider position vs terminal voltage may, or may not be a straight line. This is all explained in:

https://assets.lutron.com/a/documents/048587_web.pdf

LED ballast's output may or may not correspond linearly to dimming terminal voltage.

Logarithmic curves are sometimes used so the slider position roughly corresponds to perceived brightness (Dim to 25% output = 50% "perceived")

The real problem is when there's a variation between different ballast models used within the same control circuit. If you have linear responding and logarithmic responding ballasts mixed together, then some will provide 25% output at 5v while others will provide 50% output at 5v.

As far as having hundreds of lights controlled under one control input, you'd use a lighting panel.

Here's some likely useful info.

https://assets.lutron.com/a/documents/3672532_0_10v_solutions%20brochure.pdf

https://assets.lutron.com/a/documents/10v.pdf

 

[fastline]

The current contribution per ballast is 2mA or less, but quite often 0.5mA and you can add them up up to the limit of the dimmer.
For general purpose dimming, the dimmer is just a voltage regulator that claims it down to voltage based on the slider position, whether you have 2 fixtures or 15 fixtures.

However, the slider position vs terminal voltage may, or may not be a straight line. This is all explained in:

https://assets.lutron.com/a/documents/048587_web.pdf

LED ballast's output may or may not correspond linearly to dimming terminal voltage.

Logarithmic curves are sometimes used so the slider position roughly corresponds to perceived brightness (Dim to 25% output = 50% "perceived")

The real problem is when there's a variation between different ballast models used within the same control circuit. If you have linear responding and logarithmic responding ballasts mixed together, then some will provide 25% output at 5v while others will provide 50% output at 5v.

As far as having hundreds of lights controlled under one control input, you'd use a lighting panel.

Here's some likely useful info.

https://assets.lutron.com/a/documents/3672532_0_10v_solutions%20brochure.pdf

https://assets.lutron.com/a/documents/10v.pdf

Really appreciate both the detailed response and the tech links that are sorting this in my brain. Will admit, I haven't made it through all of this but here is what I have absorbed so far, if I am reasonably on point. The two wires on an LED driver, one is 10V source, one is sink. Contrary to my understanding, but obvious with any connections of these without connecting dimming, the 10V source side is actually the one being "sensed", but driving it's voltage down through 'sinking' it's power. The sink side is merely there to eat the power but probably also to provide a compliment feedback loop.

Gotta have some mA of power to sink so I get that. I would think any old rheostat control could do this, though not precisely, and obviously just burning off power. That part does not add up for me, unless people want this 'perfect control' factor knowing that 1V=10% of WFO.

One might first think you could just run the 10V side to a variable resistive building ground, but the DC side of the LED driver is electrically isolated, so it needs that return...?

Am I reasonably on base so far? Again, just taking a dive here so I can fully understand all of this. Seems like the BS of sizing dimmers on fixture watts is just that, and should rather be sized on the mA of dimming required, and max mA ability of a dimmer.

 

[Strathead]

Really appreciate both the detailed response and the tech links that are sorting this in my brain. Will admit, I haven't made it through all of this but here is what I have absorbed so far, if I am reasonably on point. The two wires on an LED driver, one is 10V source, one is sink. Contrary to my understanding, but obvious with any connections of these without connecting dimming, the 10V source side is actually the one being "sensed", but driving it's voltage down through 'sinking' it's power. The sink side is merely there to eat the power but probably also to provide a compliment feedback loop.

Gotta have some mA of power to sink so I get that. I would think any old rheostat control could do this, though not precisely, and obviously just burning off power. That part does not add up for me, unless people want this 'perfect control' factor knowing that 1V=10% of WFO.

One might first think you could just run the 10V side to a variable resistive building ground, but the DC side of the LED driver is electrically isolated, so it needs that return...?

Am I reasonably on base so far? Again, just taking a dive here so I can fully understand all of this. Seems like the BS of sizing dimmers on fixture watts is just that, and should rather be sized on the mA of dimming required, and max mA ability of a dimmer.

I am pretty sure you aren't correct. Your entire use of source and sink are incorrect. Source and sink are used to represent the method of providing and controlling the 0-10 volts. They are "logically" named from the perspective of the dimmer control vs. the controlled load. So, in a sink style 0-10 volt dimming system the dimmer control or dimmer, receives the control voltage and varies it, thereby "sinking" it down from the max available to somewhere in between. I a source system, the dimming control or dimmer is the source of the control voltage and not only provide the voltage, but provides it with the variation in voltage. Hope this makes sense. A driver either sends out 10 volts and then gets back 3 volt s and dims accordingly in a sink system, or it is static and merely receives a 5 volt signal from the dimmer and dims accordingly.

 

[electrofelon]

I am pretty sure you aren't correct. Your entire use of source and sink are incorrect. Source and sink are used to represent the method of providing and controlling the 0-10 volts. They are "logically" named from the perspective of the dimmer control vs. the controlled load. So, in a sink style 0-10 volt dimming system the dimmer control or dimmer, receives the control voltage and varies it, thereby "sinking" it down from the max available to somewhere in between. I a source system, the dimming control or dimmer is the source of the control voltage and not only provide the voltage, but provides it with the variation in voltage. Hope this makes sense. A driver either sends out 10 volts and then gets back 3 volt s and dims accordingly in a sink system, or it is static and merely receives a 5 volt signal from the dimmer and dims accordingly.

That seems complicated. Why do they do it that way? Why not have the dimmer put out the voltage and have the fixture measure it?

 

[tank728]

That seems complicated. Why do they do it that way? Why not have the dimmer put out the voltage and have the fixture measure it?

For field testing. I can energize a group of lights and short out the 0-10 volts and the lights will go off or dim to their lowest setting. This test can be done without the dimmer. Most systems today are sinking. Few are sourcing.

I have heard many stories of architects and design teams mixing up these systems when they first came out. It was sort of like a vhs vs Betamax thing but for lighting control. Sinking ultimately won.