Whether you’re a contractor or building manager, it is important to keep Class 2 compliance in mind when retrofitting or creating new construction with low voltage LED lights and systems. The National Electric Code (NEC) requires that low voltage power supplies and electrical wiring be Class 2 compliant. The code was created to prevent electrical fires and shock.
Inspections: Who needs them and how they work
If you are creating new construction or adding major modifications, you will most likely require an inspection. New construction requires a work permit that must be obtained from a local safety or electrical inspector. Some small jobs may not require a permit but it is in your best interest to get a safety inspection to avoid any unintended problems. For example, if you re-wire a kitchen or basement without having it inspected and then try to sell the house, an inspector may ask you to tear the walls down to check the wiring. Also, if faulty wiring that wasn't inspected starts an electrical fire, your insurance company might challenge the claim.
To begin the permit process, you’ll need to present a detailed wiring diagram of your project to your local inspector. Once a work permit is granted, the inspection consists of two visits: the ‘rough-in’ inspection and the ‘final’ inspection. The rough-in inspection consists of checking that all wiring is properly installed before any switches, fixtures, insulation and walls are added. For low-voltage installations, this is when the inspector will specifically check to see if the wiring is Class 2 compliant. Basically, the skeleton of the installation will be reviewed to see if the correct gauge wire is installed and harnessed correctly, as well as other measures.
Once the rough-in inspection is passed, you can then complete the installation with insulation, walls, switches and fixtures before the final inspection. When checking low voltage LED lights and systems, the inspector will check to see if the power supplies are accessible and Class 2 compliant. They will also check to see if the fixtures are approved by a National Recognized Testing Laboratory (NRTL), such as Underwriter Laboratories (UL) or Intertek (ETL).
Once the inspector approves that the project meets professional standards, you can begin using your new circuits safely and confidently in compliance. Wondering what you can do to make sure your project gets approved? Next, we run through all the lighting project components.
Class 2 Compliance Check List
Power supplies convert the 120V power into low voltage 12V or 24V power. For power supplies to be Class 2 compliant, 12V DC drivers must be 60W and under and 24V drivers must be 96W and under. Power supplies that comply with the Class 2 regulation are always marked or labeled as so.
Also for NEC compliance, Class 1 circuits (up to 600V) and Class 2 circuits must be separated. To pass inspection, a junction box must be installed to encapsulate a 120V AC wire connection to a 12-24V DC power converter (driver). Junction boxes provide a safe, grounded fireproof enclosure, preventing wire nuts from coming loose and causing a short and possible electrical fire. This Lo-Pro Junction Box is one example of how to separate high and low voltage wiring within the same enclosure.
For large projects such as kitchen remodels, office upgrades or new commercial spaces, a large amount of power is often required. In this case, you have two options: You can install several 60W drivers, or you can install a high wattage multi-tap driver such as the 12V 300 Watt Class 2 Driver. This driver contains 5 separate 60W outputs, and each of the outputs has its own circuit breaker so in the case that one of them experiences a surge, the others will not be affected. It’s like having several drivers and junction box in one unit, and is a more affordable and easier to install solution than using several separate 60W drivers. Only one switch will control all outputs, so you do not need multiple switches unless you need a section of lighting with an individual control such as a dimmer.
Most electronic wiring is coated in a rubber-based insulation to insure prevention from corrosion and short-circuits. This is safe enough for indoor installations using wall outlets, for example, to power a lamp in your living room or a video game console. But for a permanent hard-wire installation, more precautions must be made to be Class 2 compliant.
Most wire you see at the hardware store isn’t rated for permanent installation and cannot be installed inside walls, under floorboards, or as a structural component of a building. For example, for an installation where you would want to hide wires behind a wall, the wires could be surrounded by insulation, creating a warmer environment. The wires could crack or melt, leading to sparks or fires. Class 2 In-Wall Rated Wire provides an extra layer of installation that is more resistant to cracking or melting, and is approved by the NEC to be installed inside walls.
As we mentioned earlier, all low-voltage lighting fixtures must be certified by an NRTL to pass inspection. To verify that a product is UL or ETL listed, check the product details in the lighting company's catalog or website. If you can’t locate the information you need, you may want to contact the manufacturer directly. For extra precaution, you can look up the number listed on the official websites for UL and ETL to make sure the certification is authentic. The best way to search the UL Online Certifications Directory is to use the E-file number. For the ETL Directory, search using the company name or product number and name.
Want to dig deeper? The National Fire Protection Association (NFPA) provides more detailed information about Class 2 compliance, who it impacts and why it is important. You can buy the latest NEC handbook through the NFPA website or even on Amazon. You may also contact your local inspector on how to best prepare your project for inspection.
Ready to Inspect
Now that you know how to prepare your low-voltage installation so that the LED lights, power supplies, connections and wiring are Class 2 compliant, you are ready for inspection. You can rest assured that the inspection will go smoothly and that the installation will remain safe and secure for years to come.