Intro, Wiring RGB parallel vs series

[eholden79]

Well, I thought I posted this a few days ago but I think I may have forgot to click submit.  

Obviously I'm new here, new to LOR as well.  I did decorate may home with about 5000 LED lights last year using a Gemmy 6 outlet "controller."  It was fun, but I wanted more individual control.  So far I have been playing with the LOR software, the only hardware I have is the USB adapter and a CMB24 controller.  I'm anxiously awaiting the spring sale so I can get a few AC controllers!

 

     As  my first project / experiment in this realm I plan to re wire some old solar landscaping lights with 12v rectangular RGB modules (from holiday coro) and control them with the CMB24 (in standalone mode).  I have also ordered a 12v/33amp/400watt power supply from holiday coro to power the RGB lights.  My question is can the RGB modules be wired in series or do they have to be parallel.  For the wiring I have 7 conductor 18 gauge direct burial sprinkler wire - I plan to use one conductor each for RGB and 3 conductors for the common positive (not sure if this is overkill).  The total length of this wire would be about 50 feet.  It seems to me the most practical way to do this for ease of repair, etc is to splice the male end 4 conductor connectors (also from holiday coro)  to the areas in the main wire where I would like to place the lights and attach the other end of the connector to the RGB module / fixture.  So this would be wiring the RGB lights in parallel rather than series.  Is there any concern about reduced resistance and overloading the modules when wiring in parallel?  I only had a few physics classes in college but I believe wiring in parallel actually reduces resistance (although maybe this only applies to actual resistors).  It seems the advantage to wiring in parallel vs series would be less resistance and therefore all of the lights should be evenly bright even the one at the end of the line although I know the length of the wire may cause some resistance and some decrease in voltage 50 ft down the line.  Anyway It is late and I'm rambling, any advise would be helpful.  Thanks. 

One more thing, does anyone have any experience with the holiday coro "rain proof" power supply I mentioned above?  Is it reliable and does it provide consistent voltage?

[Darryl Lambert]

All of the string RGB modules that you buy on are already wired in series.

You said the run will be 50 feet but not how many module's. There is voltage drop when dealing with DC power & you need to know the length of wire as well as the amount of power that is required to run those modules.

You might be able to just "y" your connection from the CMB24D & go to each end of the string.

BTW welcome to the madness /addiction!

[Max-Paul]

I think you gents have things slightly mixed up. If I understand what the OP has then its like this. First these are dumb RGB modules from what I gather. And you bought them as a string of modules. Even though they are in a string or daisy chain. Each module is parallel. The voltage comes in and then goes back out the other side. This is not your fathers lights where one goes out they all go out (series). Let me ask this. Is there 4 wires coming in one side of the module and 4 wires leaving the module?

 

As for the wire, your plan to use 3 wires for the common and one wire for each color is a good plan. But I did not hear what gauge wire this is nor what kind of current load the modules will create. So it is impossible to even guess if the wire will work for your application. I imagine you have more that enough power from the power supply to add a few more down the road.

[eholden79]

The modules are dumb RGB with 4 wires going in and 4 wires coming out on the other end. I don't have them yet, I'm waiting for my pre sale order to be shippped. They come in strings of 20 but it is my understanding that these can be separated into smaller strings and even individual modules, at least it looks that way from some of their videos. According to the website each string of 20 consumes 1 amp at 12v when all colors are on full ie white. That implies 0.05 amp per module. Of course I would test this to make sure it is accurate. I plan to use about 12 individual modules...one per fixture. I will separate the individual modules and connect each of them from one side only (only one set of 4 wires going into the module will be connected) to the main wire which will be connected to the controller. The main wire is 18-7 each of the 7 conductors are 18 gauge. I'm wondering if I may overload the modules by wiring this way. Maybe I'll just have to try and see if it works...

[eholden79]

And yes I believe I'll have more than enough power for the landscape lights, I got that supply to cover some of the bigger plans that I have for Christmas

[Darryl Lambert]

Max-Paul is correct . I had it backwards. I ordered these modules as well from holidaycoro. I have another prop that is wired this way & is no problem. You'll have to waterproof the wires coming out of the other end that your not using though.

You can calculate the voltage drop by using a online calculator like this one.

Based on 50 feet & 12 modules with 18 gauge the drop is less than 0.5 volts. So you should be fine.

It's always best practice to test everything first before you go through the trouble of installing just to make sure.

[eholden79]

Great, thanks! I had not considered before that even though they appear to be wired in series they are actually parallel and the wires on both ends are simply traveling through the module to carry the current to the next one. Thanks to both of you.