What is UL?
UL stands for Underwriters Laboratories, Inc. It is a not-for-profit privately owned organization that develops safety standards for products and systems.

“Underwriters” is a reference to the organization’s intention to provide standards that are useful for the insurance industry. “Laboratories” is a reference to their focus on testing and research. UL maintains a network of 66 laboratories that test and develop standards for all types of products.

How are these standards used?
UL standards are used in several ways:

1. Standards for Installation. Regulatory authorities (such as electrical or building inspectors) may use UL standards as guidelines or references in their certification or authorization of projects under their jurisdiction.
2. Standards to Incorporate into other Standards. Other groups that develop codes and standards (such as the NFPA for their National Electric Code) incorporate UL standards in their standards and codes.
3. Standards for Certification. Certification and licensing groups (such as the IBEW/NECA for electricians) may require their members to learn UL standards and to use UL listed products.
4. Standards for Manufacture. Manufacturers (such as CAST) may develop and manufacture their products according to UL standards when and where they apply.
5. Standards for Insurance. Insurance companies may require their clients to use UL listed or certified products in their work. Claims may be denied if failed equipment was not UL listed or certified.

Are UL standards laws?
No, UL standards are not laws. Regulatory and legislative agencies make the laws. Applicable laws may come from the federal, state or local municipalities. When there are overlapping laws from these three levels, the local takes precedence over the state, and the state over federal. These agencies may choose to incorporate UL standards (or codes that contain these standards) into their laws.

How are UL standards developed?
UL has it’s own laboratories that it uses to gain information and it draws upon industry experts and other standards agencies. UL makes an effort to modify standards to represent best practices as new products and systems arise. It also works closely with NFPA to attempt to develop standards that comply with the National Electric Code. The development of new UL standards and the modification of old ones is a slow collaborative process that generally takes years.

Does UL “Approve” products?
No, UL does not “approve”; they “list”, “recognize”, “classify” and “certify”:

• UL Listed – This designation refers to a product that complies with a specific UL standard.
• UL Recognized – This designation refers to a product that is found to be an acceptable component of a UL Listed product.
• UL Classified – This designation refers to a product that UL finds to be in compliance with a regional or international standard from another organization.
• UL Certification – This designation comes from a UL service (the Online Certifications Directory) that lists the names of companies who are authorized to use the UL mark on their UL Listed, Recognized or Classified products. 

What does a company need to do to get (and keep) the UL mark on their products?
To obtain a UL Listing, a company needs to provide detailed engineering drawings, product samples and other supportive materials. Products need to be tested, manufacturing facilities need to be inspected and hefty fees are paid.

Of course, the company also needs to make sure their products comply with the applicable UL standards. These standards are very rigorous. After obtaining the UL mark, products and manufacturing facilities are periodically inspected (unannounced) to ensure continued compliance with the standards. Maintaining the UL mark is a significant ongoing investment for the manufacturer.

What UL standards apply to Low Voltage Landscape Lighting Systems?

UL 1838 – Low Voltage Landscape Lighting Systems. This is a long and complex standard that sets requirements for a system of transformers, wire and fixtures. It specifies materials used in the manufacture of these items, their electrical wiring configurations and functional performance. It also specifies how performance and compliance is to be tested. Contained in UL 1838 are references to several other UL standards as they apply to the components.

It is a common misconception that UL 1838 applies only to transformers and not to the entire system. The standard also applies to landscape lighting wire and fixtures. If a contractor wants to claim that his installations are UL 1838 compliant then he must use wire and fixtures that comply with this listing. If the wire and fixtures are not UL listed, then the system is not UL 1838 compliant.

Does a Landscape Lighting System need to be UL 1838 compliant to be a safe UL Listed system?
The simple answer is “No”. As long as each component of the system is UL Listed for its intended use, then the system is assuredly safe according to the strict UL standards. The complicated answer is that there is controversy as to whether or not installers must adhere to UL 1838 since that is the only UL standard that specifically identifies Low Voltage Landscape Lighting as the intended use. However, UL 506 is also a standard that applies to transformers (actually Specialty Use Transformers). The intended use of these 506 transformers could also apply to a landscape lighting application (although it is not specifically mentioned).

The relevant difference between 1838 and 506 is the limitation of secondary voltage potential. In UL 1838 there is a 15-volt limit. The establishment of this limitation was the result of reference to studies that questioned the safety of higher voltages. Since that time, both empirical and anecdotal evidence have proven the safety of voltages as high as 30 volts. Industry representatives have been trying to raise the voltage limit for many years but UL has been slow to make this change.

In light of the proven safety of higher voltages and the occasional need to use higher voltages for larger installations, manufacturers such as CAST have adopted the UL 506 standard. This in no way compromises the safety of the system while allowing voltages up to 22 volts.

CAST Journeymen Series Transformers are UL 1838 Listed while our Master Series and Power Pro Series are UL 506 Listed.

Will the use of UL Listed products offer protection to a contractor from liability claims?
In the unfortunate event that a contractor’s work causes damage to persons or properties, the issue of legal liability arises. In this case, two parties are involved – the courts and the insurance companies. Both parties may consider whether or not the contractor used UL Listed products and conformed to applicable codes. In fact, NEC code requires that landscape lighting systems use UL Listed components. Combine this with the fact that most municipalities require adherence to NEC code and you have a compelling case for contractors’ religious use of UL Listed products. It only takes one big lawsuit to bury a small business!