In the first post we talked about a few things you needed to do for your first display. One of the most important parts of planning your display is the electrical aspect.
Today we are going to explore some of the electrical aspects you need to consider when planning your first synchronized Christmas light display.
Recent Christmas Lighting History

As late as the early 2000’s, the majority of Christmas lighting was still incandescent based lights. At that time LED’s had not yet reached a price point that appealed to the masses. As such, you were very limited in regards to the number of lights you could run on a standard household circuit.
Remember that the typical household circuit is about 15 amps. Since we do not go over 80% of the rated load on a circuit, this would give us about 12 amps to work with.
A standard string of 25 C9 bulbs would pull about 1.46 amps per string. When you do the math that would give you about 8 strings, or 200 lights for your display. If you switched to the miniature lights, a string of 100 could run about .34 amps per string. This means you could run about 35 strands on a 15 amp circuit. (Again, running a maximum of 12 amps.)
The LED Conversion
Once the price of LED’s started to come down they were used in more and more Christmas displays. Many people thought that since LED’s used less power, they didn’t need to worry about how many lights they put on a circuit. Do not fall for that thinking! We looked at a random string of lights out on the Internet, from a reputable dealer, and found that a a string of 100 Red/M5 lights used about .071 amps per string. This would give you the ability to run 169 strings on a 12 amp circuit.
Electrical Planning with Controllers
Now that you have some ideas about the history of lighting, let’s look at how you would calculate your usage on LOR lighting controllers.
For the purposes of this discussion we are going to use the blanket statement that both the Commercial and Residential controllers can handle a maximum of 30 amps each. (Note: These are the 16 channel AC controllers.) This assumes that you are using TWO power cords that are supplied with the controller. Remember, plugging both into a single outlet could overload that outlet or circuit!
As you read the documentation, you learn that a single channel can hold UP TO 8 amps. However, each side of the controller can hold 15 amps each. In other words you could put 7 amps on channel 1, and 0.5 amps on the other 7 channels, and you would still be within the electrical limitations of the controllers.
Example Configuration

Let’s take a look at just one example configuration. We’ll keep it simple for the purposes of this article. We’ll assume that the 100 count M5 LED strands are going to be used, and that all of them use .071 amps per string. As we previously discussed, you could run about 169 strings on a 15 amp circuit (rated down to 12 amps.)
This means that we should have very little worries about how they are connected to the controller. The important thing would be to make sure that you do not overload one channel, or side of the controller.
As you can see in this example we used 160 strings, and put 10 strings on each channel (or circuit.) Each circuit used .71 amps, for a total of 5.68 amps on each side.
NOW is the time to start planning your electrical. Really sit down and analyze your electrical situation. Get a feel for how many lights you can put on a controller, and how they might be set up in the display.
Next Up – Design
Once you have the electrical portions of your display analyzed, you can start planning out a design for your display. We’ll be working on our demo house over the next few weeks and have a new blog post up with how we designed it.
We’ll also be working on the blog post for the RGB post. (Which may already be done, see note above.) Once it’s ready, it will be posted online for you as well.