- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Is it already committed to being all in parallel on one circuit, or is there an option to run it off more than one control?
Dimming LED
- Thread starter George Stolz
- Start date
- Status
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
I wondered that, too. Can it be separated into multiple zones and controlled by a single z-wave dimmer
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I have a feeling George has explored all he is going to and it sounds like he wont be back so I would let it go.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Good hunch.
All one switch leg, not interested in rewiring the church to break it up into multiple switch legs.
All one switch leg, not interested in rewiring the church to break it up into multiple switch legs.
- Location
- Massachusetts
Gar, you did not read the question, in your zeal to go highly technical you seemed to overlook the fact George had a specific question about a specific product and manufacturer.
Awesome, thanks for the travel tips.
No, I do not need to know any of that. All I really need is UL listing and labeling to be accurate. Anything beyond that is nice but should not be needed with listed products.
And from my perspective you have planted many more vines and trees.
When a person asks for a sip of water there is no reason to aim a firehose at them.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
160313-1353 EDT
George and iwire:
From post #1:
From post #5:
From post #19:
From post #31:
From post #37:
From post #44:
We have to assume all these posts relate to the same problem or question. Next we assume this existing circuit has a dimmer, likely rated at 650 W incandescent, and there are the equivalent of 650 W of incandescent bulbs on the circuit now.
For convenience assume 11 60 W incandescent bulbs is the present maximum load. To provide approximately the same light output with LED replacement bulbs will require about 11 9.5 W LED bulbs, or an average power of 9.5*11 = 105 W. This is well below the mentioned Lutron LED maximum of 250 W.
On CREE I measured a peak repetitive inrush of about 2.25 A and of rather short duration, about 30 microseconds. A dimmer with a load of 11 LEDs would produce a repetitive peak of about 25 A. Is this unreasonable for the likely size of solid-state switch in the dimmer? Probably not.
If the goal is to increase the maximum light output on said switchleg, then information on that is needed. Comparing all of the posts on the problem or question does not provide a clear indication of what the problem or question is.
iwire:
UL primarily relates to safety, and not directly to whether one or more products work well with each other.
Incandescent bulbs made with a tungsten filament for a given voltage, power, and lifetime were very close to one another from one manufacturer and batch to another. This is not true of LEDs, or even dimmers.
It was fairly easy to define the capabilities of a dimmer with respect to incandescent bulbs, and specify the dimmer in terms of the maximum wattage load. Not so simple for LEDs.
It is my opinion that having a reasonable knowledge of how dimmers and LEDs work, and what are their characteristics and limitations can greatly assist you in working with and combining these components. Your ccokbook approach may work for a minimial system, but may be of little value to troubleshoot a problem.
.
George and iwire:
From post #1:
From post #5:
From post #9:
From post #19:
From post #31:
From post #37:
From post #44:
We have to assume all these posts relate to the same problem or question. Next we assume this existing circuit has a dimmer, likely rated at 650 W incandescent, and there are the equivalent of 650 W of incandescent bulbs on the circuit now.
For convenience assume 11 60 W incandescent bulbs is the present maximum load. To provide approximately the same light output with LED replacement bulbs will require about 11 9.5 W LED bulbs, or an average power of 9.5*11 = 105 W. This is well below the mentioned Lutron LED maximum of 250 W.
On CREE I measured a peak repetitive inrush of about 2.25 A and of rather short duration, about 30 microseconds. A dimmer with a load of 11 LEDs would produce a repetitive peak of about 25 A. Is this unreasonable for the likely size of solid-state switch in the dimmer? Probably not.
If the goal is to increase the maximum light output on said switchleg, then information on that is needed. Comparing all of the posts on the problem or question does not provide a clear indication of what the problem or question is.
iwire:
UL primarily relates to safety, and not directly to whether one or more products work well with each other.
Incandescent bulbs made with a tungsten filament for a given voltage, power, and lifetime were very close to one another from one manufacturer and batch to another. This is not true of LEDs, or even dimmers.
It was fairly easy to define the capabilities of a dimmer with respect to incandescent bulbs, and specify the dimmer in terms of the maximum wattage load. Not so simple for LEDs.
It is my opinion that having a reasonable knowledge of how dimmers and LEDs work, and what are their characteristics and limitations can greatly assist you in working with and combining these components. Your ccokbook approach may work for a minimial system, but may be of little value to troubleshoot a problem.
.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Just because I have a thing about finishing off comatose horses....
George, was your comment about a shunt in post 19 a joke?
Are you still interested in a dimming solution, just not interested enough to search very far? Or has the ship sailed?
For what its worth, I think that gar's technical posts are useful to someone trying to solve this sort of dimming application, though not necessarily useful for someone looking for an 'off the shelf' product.
Lutron has a document that describes some of the problems that gar mentioned.
http://www.lutron.com/en-US/Education-Training/Documents/Controlling LEDs webinar.pdf
More importantly to someone who simply wants to buy a product, they have their 'LED Control Center of Excellence' where they have tested different LEDs with different dimming hardware. They have a product selector that lists the maximum number of lamps of a given brand that may be controlled with a particular dimmer that they sell.
See the last page of the above mentioned document:
Ways to reach us: – 1-877-DIM-LED8 – LEDs@lutron.com – www.lutron.com/LED
-Jon
George, was your comment about a shunt in post 19 a joke?
Are you still interested in a dimming solution, just not interested enough to search very far? Or has the ship sailed?
For what its worth, I think that gar's technical posts are useful to someone trying to solve this sort of dimming application, though not necessarily useful for someone looking for an 'off the shelf' product.
Lutron has a document that describes some of the problems that gar mentioned.
http://www.lutron.com/en-US/Education-Training/Documents/Controlling LEDs webinar.pdf
More importantly to someone who simply wants to buy a product, they have their 'LED Control Center of Excellence' where they have tested different LEDs with different dimming hardware. They have a product selector that lists the maximum number of lamps of a given brand that may be controlled with a particular dimmer that they sell.
See the last page of the above mentioned document:
Ways to reach us: – 1-877-DIM-LED8 – LEDs@lutron.com – www.lutron.com/LED
-Jon
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Do I need to sing it for you? I intended to swap out existing lamps for LED in the hopes of dimming them. A little research into the matter led me to the conclusion that my hope was for naught. I don't understand why this scenario is so outlandish that I cannot be believed even when I put it into math for you?
Again, none of that resembles the installation in question. As previously stated, I have one big room with 72 lamps on a switchleg, probably on it's own circuit. There are some unknown make, model and wattage of CFLs in them. I was called in to see if I could replace the switch they are on with a dimmer. Knowing that CFLs have a spotty track record dimming anyway, and not knowing what was in their fixtures, I was trying to take the easy out and suggest new LEDs that I have a little history with on a much smaller scale successfully dimming. It did not occur to me as the plan came into existence during the initial walk that I was up against an insurmountable task. I thought there might be something easy I was missing so, as usual, I came here with my question. Predictably, it went sideways, but that's all right because I'm fairly confident there is no answer to my riddle and I'm at peace with that.
I don't know how to phrase my problem any clearer any more than you can answer it.
Actually, we are required to abide by the listing of equipment by 110.3(B). It doesn't really matter how great a chef a fella believes he is, if I were to decide that the rating of the equipment were just a suggestion and that I am way smarter than that, then I alone stand before the court when I alone decide to ignore it - and if lives were lost because of a stupid dimmer I could find myself cooking for it.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
My daddy always said that if I have to explain that something was a joke, then it wasn't funny to begin with. Therefore, I plead the fifth.
To my knowledge the client is still awaiting an option, is aware of my roadblock, and I assume that if I came forward with something that fit the bill I would be hailed as a genius. Or competent, or slow, but eventually on point with solutions.
Thank you for the links.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Just an off the wall idea if you have space available and the components are still available:
Our church had dimmable linear fluorescents with an in wall Variac for dimming.
If you take phase chopped waveforms out of the equation you might be able to dim either new LEDs or the original CFLs.
You could test this hypothesis with an external variable sine wave AC source to see whether it is worth trying to find an in wall dimmer.
The ones I encountered were only good for about 600 watts of dimmable fluorescent ballast each and stuck out behind the far side of a 4" wall.
I recall that some LEDs will try to regulate to maintain constant output as the voltage is reduced, but sense the leading or trailing edge chopped waveform and respond to it. Others respond better to linear voltage reduction.
Last edited:
JFletcher
Senior Member
- Location
- Williamsburg, VA
I suppose this is too simple (or too wrong) a solution, but could you parallel dimmers, or use a 2000W HD dimmer in this application?
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
160313-2426 EDT
George:
Every post you have made provides new information that is hard to conclude from your first post. But still an incomplete story. Apparently you have an existing circuit with many sockets on one switch. But there is no explicit statment of the number of sockets, or what has been the existing load, and whether the existing circuit has an associated dimmer.
GoldDigger's suggestion is probably workable. I have previously in some other thread(s) mentioned that the CREE bulbs I have tested dim quite well with a variable sine wave. Much better than dimmable CFLs.
Tonight I tested both the CREE and Feit dimmable bulbs that I have with a Variac. Both are quite comparable in their range and transfer function from voltage to brightness. I did not run a parallel test. There is essentially no repetitive inrush current. The frequency of oscillation of the currrent waveform varies with voltage going lower at lower voltage.
At about 10 V AC RMS sine wave is where the bulbs drop out and the brightness is quite low, appoaching what can be done with an incandescent. Brightness vs voltage is quite different than for an incandescent, and this is to be expected.
I don't know if the bulbs are rated to operate at low voltages.
Variacs for the current range of your interest are moderately expensive. But probably lower than your labor costs.
.
George:
Every post you have made provides new information that is hard to conclude from your first post. But still an incomplete story. Apparently you have an existing circuit with many sockets on one switch. But there is no explicit statment of the number of sockets, or what has been the existing load, and whether the existing circuit has an associated dimmer.
GoldDigger's suggestion is probably workable. I have previously in some other thread(s) mentioned that the CREE bulbs I have tested dim quite well with a variable sine wave. Much better than dimmable CFLs.
Tonight I tested both the CREE and Feit dimmable bulbs that I have with a Variac. Both are quite comparable in their range and transfer function from voltage to brightness. I did not run a parallel test. There is essentially no repetitive inrush current. The frequency of oscillation of the currrent waveform varies with voltage going lower at lower voltage.
At about 10 V AC RMS sine wave is where the bulbs drop out and the brightness is quite low, appoaching what can be done with an incandescent. Brightness vs voltage is quite different than for an incandescent, and this is to be expected.
I don't know if the bulbs are rated to operate at low voltages.
Variacs for the current range of your interest are moderately expensive. But probably lower than your labor costs.
.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Okay. Then there are a few more resources which I think will be useful to you.
1) The dimmer manufacturers list LED bulb compatibility.
Lutron (previously posted) http://www.lutron.com/en-US/Education-Training/Documents/Controlling LEDs webinar.pdf
http://www.lutron.com/en-US/Service...al/Design-SelectionTools/LEDDimmerMatrix.aspx
Leviton has various lists but I can't find a useful one for your application.
2) The bulb manufacturers list dimmer compatibility.
http://www.usa.philips.com/consumer...ssets/pdf/PhilipsDimmerCompatibilitySheet.pdf
http://creebulb.com/media/document/file/d/i/dimmer-compatibility-new-2.pdf
http://www.feit.com/Dimmer_Compatibility
I would suggest contacting the dimmer and bulb manufacturers and ask if they have a _tested_ solution for the number of bulbs you want to have on a single switch leg.
Gar's postings should make it clear that there are lots of hairy details going on between dimmers and LED bulbs. IMHO while you are correct to not 'take ratings as suggestions' or 'roll your own' solution, his information will help you separate real solutions from marketing fluff. The key take-away is that LED dimming function depends on the driver circuitry in the bulb; you must use a compatible dimmer.
Using a variac based dimmer makes theoretical sense; they are available with high current ratings, and won't be 'fussed' by short duration current spikes....but IMHO only if the LED manufacturer specifically rates for that use, and expects to maintain compatible products in the future.
-Jon
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
I may have missed something, but George has 72 Edison a-19 bulbs....
Were these originally 60-watt bulbs?
Like 4320 watts of incandescent? 36 amps on one switch leg?
Hmmm. I wonder if this switch is turning on the coil of a 3-pole contactor?
Idk, just thinking into my keyboard
Were these originally 60-watt bulbs?
Like 4320 watts of incandescent? 36 amps on one switch leg?
Hmmm. I wonder if this switch is turning on the coil of a 3-pole contactor?
Idk, just thinking into my keyboard
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
George said, as I recall, "some kind of CFL"
He was more optimistic about dimming if he replaced the unknown CFLs with known dimmable LEDs.
Chances are good that LEDs would be available that would track better than a mix of originals and eventual replacement CFLs even if the existing ones were dimmable.
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
right. But I don't recall whether that was the original building lighting or if that's simply what was in place when he arrived
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
I think it is pretty clear that that 72 fixture circuit was never incandescent!
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
Alrighty. I just thought....wouldn't it be funny if he was trying to dim a contactor coil?
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Hear hear! When I returned with my notes and started doing some math I noticed the same thing - there could be a contactor involved in the present setup, but if the magical 650W dimmer fell out of the sky then I was going to deal with that as a gimme.
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
It just seems conveniently divisible by 3.....24 lamps, 12 amps, etc
I would look into whether there are multiple circuits. If so, here's possibly an answer from Cooper:
Add a switch for each circuit near panel or contactor. Use this wired 300w l.e.d. dimmer for each circuit:
http://smile.amazon.com/Cooper-Wiri...8&qid=1458020093&sr=8-1&keywords=Cooper+9540n
Then use a total of (1) wireless dimmer (mount in original switch location), which is said to work with up to 5 other Z-wave devices:
http://smile.amazon.com/Cooper-Wiri...bxgy_60_2?ie=UTF8&refRID=03CJTZ865T9A7GS0SAFX
I'm not a Z-wave pro, but have a little experience with them. Might call Cooper about this setup if you find multiple circuits
- Status