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.
Inspeksjoner: Hvem trenger dem og hvordan de fungerer
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.
Når grov-inspeksjonen er bestått, kan du fullføre installasjonen med isolasjon, vegger, brytere og inventar før den endelige inspeksjonen. Når du sjekker lavspent LED-lys og -systemer, vil inspektøren sjekke om strømforsyningene er tilgjengelige og klasse 2-kompatible. De vil også sjekke om armaturene er godkjent av et nasjonalt anerkjent testlaboratorium (NRTL), for eksempel Underwriter Laboratories (UL) eller Intertek (ETL).
Når inspektøren godkjenner at prosjektet oppfyller profesjonelle standarder, kan du begynne å bruke de nye kretsene dine trygt og trygt i samsvar. Lurer du på hva du kan gjøre for å sikre at prosjektet ditt blir godkjent? Deretter går vi gjennom alle belysningsprosjektkomponentene.
Sjekkliste for overholdelse av klasse 2
Makt
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 Klasse 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.
Kabling
De fleste elektroniske ledninger er belagt med en-gummibasert isolasjon for å forhindre korrosjon og kortslutning-. Dette er trygt nok for innendørs installasjoner som bruker vegguttak, for eksempel for å drive en lampe i stua eller en videospillkonsoll. Men for en permanent hard-kabelinstallasjon må flere forholdsregler tas for å være klasse 2-kompatibel.
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.
Belysning
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 sertifiseringskatalog is to use the E-file number. For the ETL-katalog, søk med firmanavn eller produktnummer og navn.
Ytterligere ressurser
Want to dig deeper? The Nasjonal brannvernforening (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.
Klar til å inspisere
Nå som du vet hvordan du klargjør lavspentinstallasjonen slik at LED-lysene, strømforsyningene, tilkoblingene og ledningene er klasse 2-kompatible, er du klar for inspeksjon. Du kan være trygg på at inspeksjonen vil gå problemfritt og at installasjonen vil forbli trygg og sikker i årene som kommer.
