An electrical contractor recently asked me about a municipality that inspected electrical signs and outline lighting systems at in-house manufacturing facilities. His question regarded the Underwriters Laboratories (UL) listing requirement of those signs and outline lighting systems and if the city could approve them by their electrical ordinance and place compliance stickers on the enclosures.

What’s the difference between an “approved,” “listed” and “labeled” sign system? Let’s cite the differences between the two procedures used by cities that inspect and approve electrical signs and outline lighting systems. Cities with their own departments for performing such inspections use Underwriters Laboratories (UL) standards, with past experience and historical data that the organization has gathered.

The following UL standards are the ones most used by sign-inspection departments when inspecting and approving in-house manufactured signs:

• Electrical Signs—UL 48

• Portable Electric Lamps—UL 153

• Special Transformers—UL 507

• Gas Tube Cable—UL 814

• Electrode Receptacles—UL 879

• Neon Transformers and Power Supplies—UL 2161

What about municipal or city-approval of signs and outline lighting systems? To understand the term “Approved” and how cities use their own inspection departments, we must apply the National Electrical Code (NEC) to operate this type of inspection program, first review 600.3, title head “Listing.” The NEC reads: “Electrical signs, section signs, and outline lighting—fixed, mobile, or portable—shall be listed and installed in compliance with that listing, unless otherwise approved by special permission.”

Cities use the phase “special permission” to accept signs or outline lighting systems per 90.7, 110.2 and 110.3(B) of the NEC to develop and set up their approval program. Section 110.2 and “Approved” reads: “The conductors and equipment required or permitted by this Code shall be acceptable only if approved.”

To understand how inspectors use “Approved” to accept unlisted signs, unlabeled electric signs and outline lighting systems, refer to Article 100 of the NEC.

“Approved,” when defined, simply means acceptable to the authority having jurisdiction (AHJ).

Section 90.4 “Enforcement” explains the AHJ as follows: “The AHJ for the enforcement of the NEC will have the responsibility for making interpretations of the rules, for deciding upon the approval of granting the special permission contemplated in a number of rules.”

For “Identified,” the FPN to this definition in Article 100 of the NEC must be read and understood.

Authority having jurisdiction

The AHJ may waive specific requirements in the NEC or permit alternate methods where it is assured that equivalent objectives can be achieved by establishing and maintaining effective safety. The NEC may require new products, constructions or a material that may not yet be available at the time such Code is adopted.

In such an event, the AHJ may permit the use of the products, constructions or materials complying with the most recent edition of the NEC that is adopted by the jurisdiction. The cities that used their own inspection program to approve electrical signs and outline lighting systems take on the full responsibility of ensuring that the components and elements used are safe and do not present a fire hazard to property or electrical shock to personnel.

Listed and labeled sign systems

When not using the “Approved” method of acceptance, jurisdictions typically require the entire system to comply with the following definitions:

• Labeled—Equipment or materials to which has been attached a label, symbol or other identifying mark of an organization acceptable to the AHJ and concerned with product evaluation, which maintains periodic inspections of production of label whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner

• Listed—Equipment or materials included in a list published by an organization acceptable to the AHJ and concerned with product evaluation, that maintains periodic inspection of listed equipment, or materials whose listing states either that the equipment or materials meets appropriate designated standards or has been tested and found suitable for use in a specified manner

• Identified—this definition and its FPN to Article 100 of the NEC must be read and fully understood.

Identification of listed equipment may vary for each organization concerned with product evaluation, some of which do not recognize equipment as listed unless it is also labeled. The AHJ should use the system employed by the listing organization to identify a listed product.

Equipment that is listed and labeled by UL or another qualified electrical testing laboratory is considered to be safe. It is not a city’s responsibility to certify or list equipment that has already been listed and labeled. Such listed equipment eliminates the city’s need for a manufactured sign-inspection program.

STALLCUP is the CEO of Grayboy Inc., which develops and authors publications for the electrical industry and specializes in classroom training on the National Electrical Code and other standards, including those from OSHA. Contact him at 817.581.2206.