Christmas lighting can be considered a temporary electrical installation, which makes it less resistant than permanent wiring protected by conduit. However, the temporary nature of Christmas lights does not mean that electrical safety must be compromised. As with any other electrical device, careless use can cause a fire.
There are three main ways to minimize fire risks from Christmas lighting. The safety recommendations provided for conventional lighting also apply in this case.
- Using products that meet applicable UL standards .
- Using LED Christmas lights, which have a much lower heat output.
- Do not connect an excessive number of sets of lights in a string.
Also consider that Christmas lights are plugged into outlets like many other appliances, and the underlying installation must also be safe. If an electrical outlet is unsafe, any decorative lighting plugged into it will also be unsafe.
UL Standards for Christmas Lighting
After all, Christmas light sets are electrical products and as such are subject to industry standards. Underwriters Laboratories (UL) is a world-renowned company that offers safety certification for electrical products, including Christmas lights. They are specifically covered by the UL 588 Standard for seasonal and holiday decorative products.
Lighting products that meet UL standards have already been subjected to demanding laboratory tests and the results validate their safety. If you purchase UL listed Christmas light sets, you can be assured that they have been tested by qualified professionals.
The UL 588 standard covers lighting products with an input voltage of up to 120 V, intended for temporary use of up to 90 days. It is important to highlight that the standard does not only cover sets of lights, but also decorative ones with Christmas shapes that use one or more lights – the stars commonly used to top Christmas trees are a good example.
Safety Advantages of LED Christmas Lights
LED Christmas lights have significant advantages over incandescent products. Firstly, they consume around 80% less electricity, which translates into savings on your energy bill during the festive season. LED lights are also less likely to start a fire due to their reduced heat production and their lower current reduces the chance of the wire overheating.
However, be careful when using LED and incandescent Christmas lights. If you connect an incandescent light set to the end of an LED set, the current through the LED set will now be the sum of both, and this continues to increase as more light sets are connected.
Another safety advantage of LED Christmas lights is that burns are unlikely to occur when accidentally touched. On the other hand, incandescent Christmas lights can become very hot with prolonged operation. Consider that Christmas lights are installed in easily accessible locations, while conventional luminaires are often out of reach.
Safety Considerations When Connecting Light Sets
As described previously, connecting multiple sets of Christmas lights adds their current. Each set of lights carries its own current plus that of all lights connected downstream.
- For example, if you connect five sets of lights, the first one carries the full current.
- The third set of lights carries its own current, plus the current from sets #4 and #5.
The maximum number of light sets that can be connected together is normally provided by the manufacturer. As you would expect, LED lighting allows for longer connections because the wattage of each light is five times less. When the number of consecutive sets of lights allowed by a manufacturer is exceeded, the wiring in the first set will tend to overheat and melt. This exposes the conductors, eventually causing a short circuit or line failure.
An excessive number of stringed Christmas lights is dangerous even when using LED products that meet the UL 588 standard. Installation must follow the instructions provided by the manufacturers.
Christmas lights that are not UL recognized may be priced lower than their listed counterparts, and incandescent light sets are cheaper than LED versions. However, in this case, the low-cost option has significant limitations: a higher operating cost, a shorter service life and an increased risk of fire .
