UL Question Corner: Are there “UL Authorized” Service People?

Are there “UL Authorized Service People” who can modify UL Listed equipment in the field with no need of a UL field inspection or a field evaluation?


No. See the Guide Information for  Electrical Equipment for use in Ordinary Locations (AALZ), under the heading Field Modifications, located on page 55 (also located on page 46) of the 2015-16 UL White Book PDF located at www.ul.com/whitebook , and also on UL Product Spec  at www.ul.com/productspec and enter AALZ at the category code search field.

The UL Mark applied to the product when originally manufactured at the factory is the manufacturer’s declaration that the product meets the UL requirements in effect at the time of manufacture. UL does not know what the effect of a field modification may have on the safety of the product unless the modifications have been specifically investigated by UL. Unless UL investigates a modified product, UL cannot ascertain that the product continues to meet UL’s safety requirements. Some exceptions to this are when a UL Certified/Listed product has specific markings for field installed equipment or the replacement of components, or a UL Certified/Listed product has been evaluated for installation in specified equipment, such as a UL Certified/Classified retrofit kit. For example, a switchboard may have specific grounding kits added in the field. The switchboard is marked with a list of specific kit numbers that have been investigated for use in that particular switchboard. Only grounding kits that are included on the product have been investigated for use in that product.

If a party wishes UL to determine if the modifications made to a UL certified (Listed) product comply with UL requirements, a UL Field Inspection or Field Evaluation can be initiated to investigate the modifications. This evaluation will only be conducted after UL consults with the AHJ to ensure that UL’s evaluation addresses all areas of concern and meets all of the AHJ’s needs.

To inquire about a UL Field Evaluation or Field Inspection, contact UL Field Services at 1-877-UL-Helps (1-877-854-3577), prompt #2 or visit www.ul.com/field.



Some products or spec sheets are marked “meets UL standard” or “complies with UL standard.”  Is this sufficient evidence of certification?


No, such a statement is not evidence of certification. A product is not certified (Listed) by UL unless it bears the UL Certification Mark, which consists of the UL symbol and other elements that are described in the UL Guide Information for each product category. Individual UL product category Guide Information can be located in 2015-16 UL White Book PDF located at www.ul.com/whitebook, and also on UL Product Spec at www.ul.com/productspec. Such claims of compliance to a UL standard could be a manufacturer’s self-declaration or another testing organizations effort to credential themselves as qualified to evaluate such products.

In order to allow a manufacturer to display the UL symbol (UL in a circle) on their spec sheets, website, product packaging, or any other published means, the product must be UL certified/Listed.

On a spec sheet or other published means, if you see only a statement that the product meets or complies with UL standards, this may be a manufacturer’s declaration and is not sufficient evidence of a UL certification.  Always look for the UL Mark on the product as evidence of UL certification (Listing).

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