Control/Dimming Converting To LED

crocated

New Member
Joined
Mar 14, 2016
Location
Iowa
Hello everyone,

I apologize if this has been posted elsewhere, I have looked and have not been able to find anything.

So, an area high school brought me in to look at upgrading their system. For dimmers, they have two Leprecon MX-1200's. As of lighting fixtures, they have a couple of 360Q's in various conditions of broken and then some more 6" Fresnels.

I know that converting to LED isn't quite the best option, but I am mainly just interested in learning how it would work. I am aware that LED fixtures are not happy being run off of a dimmer, even if it is set to always on through the board.

Now I know that if it was an ETC rack I could switch it out to a sensor module, but I am not sure how the Leprecon works. However, the MX series has a "test" button. I don't think this would change the fact that it is still breaking up the electrical current but would this in anyway be safer to run an LED fixture off of?

Also, I know this might be completely ludicrous but what would happen if I (by I, I mean a more experienced electrician) came in and took the dimmer modules out? Would it then be possible to somehow connect the cables from the Electrics directly into the wall? Again, pretty sure that won't work but my main goal with this post is to learn.

Thanks in advance!
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
A shame to loose the dimming and sculpting ability of what is there with some work or replacement is needed. That more about the artistic look - you are not lighting a podium you are providing the ability to light art.

I am working with a local Junior High School right now in just having serviced all of their lights, dimmers and light board for the first time since bought. (Yet to get to the local High School in also needing help.) Added some proper cable and a few donated modern lights, for the key acting areas and next month, with some training on how to do looks and cues they have an inspired school custodian who is even re-wiring the patch bay and building a lighting desk on his own, and director that is ecstatic. Before now they were not persay talking to each other - now both look forward to their new arts program.

You have 360Q’s - they have at least 40 year old radial 750w 360's and DJ grade 1K PAR 64's at random located, with no Fresnels... and wondered why the 16ga wire on the patch bay was getting hot and with each show in re-patching wondering why they blew breakers constantly on their two sets of 2.4Kw x 6 dimmer shoe box dimmers. A lot of major work done to the Gymatorium after some professional advice, with more work inspired to come.

All that said, to more answer your questions - if the dimmer modules are removable (probably not), Leprecon probably also has LED dimming modules at this point, but more likely useful to what you are asking about, you would want relay modules that are just on/off switch modules. I have crappy internet connection but suspect your dimmers are not removable. Instead if really wanting to bypass the dimmers, I would send them to a professional lighting company for a service call and to bypass in output the dimmers. This would retain the circuit breaker protection and the control. Easy to do but needs to be done professionally.

In dimming even with a LED dimmer, dependant on the actual loading, you might still need a dummy/ghost loading on the dimmer for it to work properly. I’m currently working on a show with 80x micro LED Leko’s and given their last use in the fall, I had to make a 48 channel dummy load rack to make the ETC LED dimmers work properly. A lot of R&D went into what wattage of filament lamps on the dummy load in 65 watt worked best, but for the application 25 watt per channel minimum was sufficient for the show in use of micro Leko’s. A lot of engineering went into making a dummy load panel and distribution rack for it in doing so. But it’s feasible to as per the old school concept of doing low wattage on any chopping dimmer - just twofer a say 75 watt filament lamp fixture in a closet somewhere - but one fixture per dimmer circuit. This is if all if your LED loading per circuit is too small to control. Dimmable LED’s will work on normal dimmers also - a little flicker factor and small other problems we found in testing.

All problems dependant on what’s used and most larger output LED fixtures might just work fine on a LED dimmer module. Old standard is 75 watts for minimum loading on a dimmer to properly control it in possibly will also work (ETC members might correct at any point.). LED module dimmers might need less wattage and dim better but as above do still need some load to work properly if micro small. Working on some transformers also, believe it's 0.3 amps and 36 VDC as measured on the ETC Micro Leko - which gets complex in making transformer that will control a bunch of them. Way above my head in having an electronics dpt. to figure out what is needed for constant something or other.

Most main stage LED lighting fixtures to “replace” a Fresnel or Leko don’t require a dimmer. They can be used with dimmers easily, but mostly they are best in self DMX controlled dimming with direct power. Means relay modules or I would recommend hiring an electrical contractor to replace the dimmers if that’s what is wanted to best control them. Each LED light fixture will than require at least one control circuit if straight dimming channel and possibly more control channels per light. Can address multiple lights to the same control channels - but very possible what light board you have will quickly become much too small to sufficiently design cues for a show.

Main problem in just doing proper LED’s to solve the problems is cost - and it will be large. Perhaps get a few and have a electrician make dedicated “live” circuits for them. But overall if your theater has what it has, it would probably be most cost effective to work on the lights you have. Many articles posted about how to “save” older lights. What you seem to have in inventory isn’t any such thing other schools would not love to have. But if you can find budget to replace, certainly work on what you have - learn it and figure it out in why it's problematic, make safe and pass on to another school these more modern that what I'm for instance working with gear to another school. Perhaps once you learn to service what you have, you won't need to replace it, and instead might find supplement of the inventory with more modern in building a inventory would be more useful.
 
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crocated

New Member
Joined
Mar 14, 2016
Location
Iowa
Thank you for the reply.

To clarify, I know that the 360Q's will suffice. In fact cleaned up and rehung everything in this venue will work fine. That is now what I am asking though. I am more just trying to figure out how I could do it if I had the chance.

I was in the space today drafting it in Vectorworks and the idea just popped into my head, trust me I know the pitfalls of LED. I just had the idea and since I didn't know how to do it, of course I wanted to learn more about the subject. Especially with the new LED fixtures coming to market I think it is a very interesting problem for any venue that wants to make a switch over. Now of course ETC's S4WD also throws a curve ball at the problem...

Anyway, I hope that better explains where I am coming from.
 

Les

Well-Known Member
Joined
Feb 24, 2004
Location
DFW, Tx.
Removing the dimmers and running straight power is always an option, however it will require the services of a commercially licensed electrician like you said, of which the school district probably has several to choose from. You are correct that the existing dimmers won't be of much use in an LED system.

Another suitable approach might be to A). add proper relay/breaker panels as Footer suggested, or B). have an electrician add standard outlets at multiple hanging positions, with switches near the lighting console. You don't necessarily need DMX controlled relays (although they certainly streamline things), but having a way to shut down the LED fixtures every night is important if you want them to last. You will need to add DMX up there as well. Aside from doing an entire reno, I would just supplement the existing system with LEDs. Even some cheaper fixtures like the Elation Sixpar will give good performance and add a lot of additional functionality to the space without going "all-or-nothing". If in the future they find additional funding, the old system can be abandoned as more LED fixtures are added.

New circuits are easy to pull in these buildings, and Footer is correct that it will be a small portion of the cost. Depending on the size of the space it can be as simple as a few new circuits with standard 20A switches, or as complex as a breaker panel with/or ETC Echo relay solution.

Then you run your DMX (over Cat 5e through conduit), add opto-splitter if needed, upgrade console (if/probably needed), and hang happy LED fixtures.
 
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microstar

Well-Known Member
Joined
Jan 19, 2014
Location
Lawton, OK
Leprecon does indeed have relay modules available for their VX series dimmers. The time line is a bit confusing in that I think the MX series came after the VX series and now they've discontinued the MX series as of January 2015 and are still selling the VX series! No electrician necessary.
Best bet is to contact Leprecon and ask if the VX relay modules will work in a MX pack. A proper and safe way to provide non-dim power for LED fixtues. Another option is to investigate "mains dimmable" LED fixtures such as Altman Pegasus or certain Chauvet models.
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
Glad the 360Q's and Fresnels are back into active stock. Can never have enough lights. Interesting on the VX / MX above. Could be a great solution in only having to run DMX to the fixture. What's the budget would than be the next question in addition to how many dimmers as opposed to lights on them. Granted if going LED they probably would replace a few key lights on the same circuit. Good luck, by the way have fun. I love helping, training and advising other programs, it's a long term type of relationship as opposed to a show going out where it's "good luck, have fun."