What is Class 2 | A Guide to UL, NEC, Power Supplies, & Strip Lights

Strip lights are becoming more commonly used due to their ease of installation and flexibility in many residential and commercial applications. Understanding the associated certifications and power supplies can increase safety and reduce fire risk. This blog discusses the Class 2 code, the relationship between UL standards and the National Electrical Code (NEC), and how these codes affect the maximum run length of a strip light. 

UL and NFPA Explained 

UL Solutions and the National Fire Protection Association (NFPA) are the two regulators for the Class 2 Power Supplies. 

• UL is an organization working to improve sustainability and safety standards for various products, including lighting, batteries, healthcare equipment, and more. They establish their own requirements for a product, service, or system to obtain certification.

• NFPA is a nonprofit organization founded in 1896 to increase fire prevention safety through lesson plans, blogs, codes, and more. These codes range from regulations for sprinklers and fire extinguishers to electrical codes, which we will discuss in this blog.

Why Do These Matter?

The UL and NFPA standards increase consumers' safety and help manufacturers verify their products are safe to use. Understanding what Class 2 means simplifies your shopping experience for power supplies and strip lights. 

Class 2 Power Supplies Explained

UL 1310 Safety Standard and articles 411 and 725 of the NEC, as published by the NFPA, set the regulations for Class 2 power supplies. 

What is UL 1310?

UL 1310 is a safety standard for Class 2 power supplies which defines construction, wiring requirements, and overcurrent protection to reduce the risk of fire, electric shock, and overheating. This standard requires low voltage and current regulation ranges, and is in place for indoor and outdoor use. UL 1310 states that a power supply produces a maximum of:

• 60 volts DC or 30 volts AC 

• 5 amps

• 100 VA (Volt-Amperes - this is calculated by multiplying the output current by the output voltage; equivalent to Watts in DC power.)

What is the Purpose of the National Electrical Code?

The NEC requirements revolve around installing strip lights, power supplies, and maximum power limits. The 2017 NEC Code has two sections related to the requirements in UL Class 2: Article 411 and Article 725.

• NEC Article 411 explains the code requirements for low-voltage luminaires and luminaire fittings (can refer to strip lights), power supplies, and appropriate cord, conductors, and cables. NEC 411 requires that these components be UL Listed. While the UL Class 2 listing for power supplies was mentioned above, for a strip light to be UL Listed, it must meet the safety requirements stated in the UL 2108 Code. UL Listed strip lights have been tested and proven safe to install.

  We carry many indoor and outdoor UL Listed LED strip lights. Similar to UL, Article 411 refers to low-voltage as being 30 VAC or 60 VDC for dry applications, and 15 VAC or 30 VDC for wet.

• NEC Article 725 outlines the code for power circuits. Section 725.121—Power Sources for Class 2 and Class 3 Circuits states the regulations for class 2 circuits for various class 2 power sources, including power supplies, to protect from fire hazards. This standard mainly relates to in-wall wiring and system insulation.

How Does Class 2 Relate to Strip Lights? 

The standards of Class 2, specifically those focusing on the power supply's output variables, will affect strip lights connected to it in a couple of different ways: 

1. Ensure the strip light is compatible with the power supply for proper function. This includes verifying the strip light matches the output voltage of the power supply without exceeding the Class 2 power supply’s maximum wattage or amperage ratings. 

2. Strip lights are UL Listed for use with Class 2 power supplies. Powering UL Listed strip lights with a non-Class 2 power supply will void the UL Listing. This  ensures safety as Class 2 power supplies have been proven to reduce the risks of fires or electrical shock. If a UL-Listed strip is installed with a power supply that is not Class 2, there is no longer a safety guarantee.

3. Matching the power supply's specifications to the strip light will also help you determine the appropriate maximum strip run.

What Is the Correlation Between These Regulations and the Max Run of a Strip Light?

There are two main factors that limit the maximum run length of strip lights, voltage drop and Class 2 power supply limits. Exceeding the recommended run length will cause a noticeable brightness loss as voltage drops the further you are from the power source. For Class 2 compliance, the max run may not exceed the 100-watt and 5-amp limits. In some cases, the Class 2 limits may be more restrictive than the length at which lumen loss becomes noticeable.

Pay attention to the wattage per foot and current draw rating of a strip. Connecting multiple strips together that exceed the 100W or 5A limit can cause a malfunction or premature failure of a  Class 2 power supply.

Why Should I Use Certified Power Supplies and Strip Lights? 

There are many reasons to consider a Class 2 power supply and UL Listed strip lights for your application. Some of these include: 

• Building inspectors may require Class 2 power supplies for approval. Check with your local government offices. 

• You can achieve solid peace of mind by knowing your lights have been tested and are safe for installation.

• Business owners or contractors might choose to install certified strip lights or Class 2 power supplies even if the inspector or local authority doesn’t require it as a liability prevention and safety precaution. 

Class 2 vs Class II 

To clarify, there is a difference between a Class 2 power supply and a Class II power supply. Class II power supplies refer to the standards set by the International Electrotechnical Commission (IEC) and refer to a power supply’s internal capacities. For example, one requirement is double insulation to protect consumers from electrical shock and high heat. You can use the logos below to determine a product's classification. We carry power supplies holding both classifications, such as this constant current LED driver.

Check out this blog for more information on the difference between Class 2 and Class II power supplies.

Shop Now

Get started looking for the Class 2 products you need today. We carry a wide selection of Class 2 power supplies and LED strip lights in many colors, lengths, styles, and more. For specific product details or assistance in selecting what you need, contact our product support specialists at 866-590-3533 or fill out our contact form with your information and details on what you need help with.