Most strings of Christmas lights have a simple design. You will commonly find series-wired Christmas lights, although some larger strings of lights may be wired in parallel. Wiring lights in a series is a simpler construction, but it does mean that if a lightbulb goes out, the rest of the string will as well.
How Are Christmas Lights Wired?
Video of the Day
How are LED string lights wired? Many strings of Christmas lights are wired in a series. The current from the outlet when the string is plugged in travels down the wire to the first light. Then, it continues from a wire on the other side of that light and on to the second and so on until it reaches the last light in the string. Then, a wire returns back down the string of lights back to the plug to complete the circuit.
Video of the Day
Some lights have a plug on the other end so that you can string multiple lights together. The second plug is designed like an outlet so that the tongs of the second string of lights can be inserted to continue the electric circuit through the second string of lights.
This method is very simple, but it means that if a single light fails, then the entire string of lights will stop working. If that happens, you have to find and replace the broken bulb, which can be a time-consuming and sometimes frustrating process.
Other Wiring for String Lights
Some strings of Christmas lights, especially the larger strings of lights, are wired differently so that the entire string doesn't fail. Some strings will have multiple circuits instead of a single circuit. Electricity is sent down the wiring to each circuit in the string, and then each circuit is typically wired in series. You may have this type of wiring if only a section of the lights goes out.
Some strings of Christmas lights may use a shunt wire to prevent the lights from failing. A shunt wire runs through the entire string of lights and carries a lower voltage of electricity than the main wiring. Then, if a bulb goes out, breaking the main circuit, the current from the shunt wire allows the other bulbs to continue to shine.
Connecting Strings of Lights
Most Christmas lights can be connected to form longer strings rather than having to plug each individual string into an outlet. When considering how to connect two Christmas lights together, you will need to take a look at your lights. Many have a plug at both ends. One end can be plugged into an electrical outlet, and the other can be used to plug in the second string of lights.
There are also Christmas lights with only one plug. In some cases, these lights cannot be connected to other lights, but some have a stackable plug that is designed to allow you to plug in another string of lights to the single plug.
The number of strings you can connect varies depending on the type of lights and the capabilities of your home's electrical system. If you are investing in new lights for the season, opt for LED lights. These lights are more expensive up front, but they use less energy and stay cooler, which minimizes the risk of fire. You can also make a longer string of lights using LEDs than other types of Christmas lights.