The National Electrical Code (NEC) Article 600 and UL 48 Standard for Safety for Electric Signs are used to evaluate the field installation and construction of electric signs in the U.S. In Canada, the relevant guidelines are the Canadian Electrical Code (CEC) and CSA 22.2 No. 207.
All signs that are electrically operated and/or electrically illuminated are covered, regardless of voltage, including:
- High intensity discharge (HID)
- Light-emitting diode (LED)
- Cold cathode
Not included are:
- Illuminated clocks operating at 600V or less
- Exit signs
- Trailer of a trailer-mounted sign
- Luminaires mounted to function as outline lighting
- Luminaires mounted within an awning sign
- Luminaires intended for billboard illumination
- Fiber optics or fiber optic illuminators
- Signs for use in hazardous locations
- Procedures to ensure required testing is conducted and documented
- Test logs showing all required information
- Non-conforming products are reworked and tested
- All applicable personnel are trained to perform required tests
The latest edition of UL48 (15th edition) requires three tests: ground continuity (6.1-6.3), strain relief (5.4.1-5.4.4), and exclusion of water (5.9.1-5.9.2).
Documentation requirements include:
- Component traceability records
- Checklist for wiring diagrams, schematics and marking
- Personnel assigned to Sign Shop listing
- Checklist for sign documentation
- Sign label log
Certified (Listed) signs follow the marking requirements of NEC Section 600.4 and UL 48. A sign must be marked with the identification of the manufacturer or an identifying trade name or trademark, along with electrical voltage and current ratings. All required markings and the MET Certification (Listing) Mark are to be permanently applied to the exterior surface of the sign.
MET Certified labels are the manufacturer’s declaration of compliance and can only be affixed by the manufacturer at the place of production. The application of a MET Mark in the field is only permitted when an inspection is performed by one of MET’s Field Safety Group after a field evaluation.
MET Labs is widely considered the responsive alternative to UL, with a business-friendly service and allowance for use of any component that is certified by any Nationally Recognized Testing Laboratory (NRTL).
In the U.S. workplace, the Occupational Safety and Health Administration (OSHA) mandates that all electrical equipment be safety certified. Many state, county and local jurisdictions also have similar requirements.
However, equipment is sometimes installed that has not been certified or has been modified after installation.
Then, a field evaluation may be necessary, as determined by the authority having jurisdiction (AHJ).
OSHA has an accreditation program for Nationally Recognized Testing Laboratories (NRTLs), but no similar program exists for organizations that evaluate products in the field. Therefore, there are dozens of testing companies that claim competency to conduct field evaluations of electrical equipment.
NFPA 790, Standard for Competency of Third-Party Field Evaluation Bodies
This standard establishes minimum competency requirements for organizations that perform field evaluations, including:
- Using nationally recognized standards
- Demonstrating technical expertise on the equipment being evaluated
- Barring conflicts of interests, such as being owned by a manufacturer
- Barring modifications required for a product to achieve compliance
- Personnel are required to meet competence criteria
- Maintenance of records related to technical staff qualifications, training and experience
NFPA 791, Recommended Practice and Procedures for Unlabeled Electrical Equipment Evaluation
This standard was developed to describe recommended field evaluation procedures for field evaluation bodies, including:
- Field evaluations should be drawn principally from the applicable nationally recognized product safety standard
- Equipment must be capable of being installed in accordance with the NEC
All deficiencies are identified in a report that is provided to the client and the AHJ. Corrective actions may be taken to resolve these deficiencies, and when all issues are satisfactorily resolved, a label is applied by the field evaluation body to the equipment.
MET Labs is now operating a NFPA 790 & 791 Quality Management System.
Get information about the steps MET Labs takes during a field inspection.
Inquire about NRTL product safety certification for a new or modified product.
2011 National Electrical Code (NEC) Updates Standard for the Safe Installation of Electrical Equipment
The National Electrical Code (NEC) – or NFPA 70 – was updated in 2011, as part of its 3-year change cycle. The NEC is published by the National Fire Protection Association (NFPA), and is commonly adopted by U.S. state or local political subdivision, and enforced by the Authority Having Jurisdiction (AHJ).
Many NEC requirements refer to “listed” or “labeled” devices, as defined in Article 100 of the NEC. The NRTL (Nationally Recognized Testing Laboratories) program accredits those organizations – like MET Labs – that, by whose labeling, the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
Following are some of the key changes that were incorporated into the 2011 edition:
- 110.24 Electrical service equipment must now be marked in the field, with the maximum available fault current at the incoming terminals of the equipment and the date that the fault current calculation was made.
- 110.3(A)(1) Any special conditions that may be essential to the safe use or functioning of the equipment could be included as a part of the listing and labeling.
- 200.4 Neutral conductors shall not be shared unless they are specifically permitted to be shared, as indicated elsewhere in the code.
- 210.8 Ground-fault circuit interruption for personnel are required to be installed in a readily accessible location.
- 210.8(B)(5) GFCI receptacles are now required to be used near sinks in healthcare facilities. Exception No. 2, for receptacles located in patient bed locations of general care or critical care areas of health care facilities other than those covered under 210.8(B)(1), GFCI Protection shall not be required.
- 210.12(A) Types MC (metal clad) and, steel armor type AC (armor clad) cable may now be used between the panel and the first device, when arc-fault circuit interrupter (AFCI) protection is required for that circuit.
- 210.12(B) When modifications or extensions are made to an existing branch circuit in a residence and the code requires that the area have AFCI protective devices, the modified or extended branch circuit must now have an AFCI device installed.
- 230.44 If cable trays contain service entrance conductors (types SE (service entrance), MC, MI (mineral insulated), and IGS (integrated gas spacer)), then the trays must be labeled with the wording “Service Entrance Conductors.”
- 250.92(B) Bonding conductors are required around reducing washers and concentric or eccentric knock-outs for all service entrance conduit connections at the service entrance equipment.
- 300.4(E) Cables, conduits, boxes, and other raceways are not permitted to be installed closer than 1½” in exposed or concealed locations under metal-corrugated sheet roof decking.
- 300.5(C) Type MI and MC cables that are listed for direct burial or in concrete are permitted to be installed within the concrete, below buildings.
- 300.11(A)(1)(2) When independent electrical equipment support wires are installed within dropped-ceiling areas, they shall be distinguished by color, tagging, or other permanent effective means.
- 300.50(B) The interior of underground raceways shall be considered to be wet locations. Therefore, any connections and splices shall be approved for wet locations.
- 310.10(H)(1) Conductors smaller than 1/0 are no longer permitted to be paralleled for increased ampacity.
- 348.42 angle connectors for flexible metal conduit (FMC) are not permitted to be concealed.
- 392.18(H) Cable trays containing conductors over 600 volts are now required to be marked “Danger–High Voltage–Keep Away”.
- 406.4(D)(5) For installations in which tamper-proof receptacles are required and receptacles are being replaced, the installer is now required to install “listed” tamper-proof receptacles.
- 406.13 Tamper-resistant receptacles are now required in all guest rooms and guest suites.
- 410.16 Luminaires in clothes closets are permitted to be either surface or recessed LED, with completely enclosed light sources, fluorescent, or totally enclosed incandescent fixtures.
- 410.130(G)(1) For existing installed luminaires without disconnecting means, at the time a ballast is replaced, a disconnecting means shall be installed.
- 450.14 Transformers other than Class 2 or Class 3 are required to have line-side disconnecting means within sight of the transformer, or the disconnecting means must be lockable, and the location shall be field marked on the transformer.
- 500.2 A definition has been added to define the parameters, or make up of, combustible dusts.
- 501(B)(5) This new code paragraph clarifies the differences between Class 1, Division 1, and Division 2 installations, where metallic conduit does not provide sufficient corrosion resistance, listed flexible conductors, factory elbows and associated fittings shall be permitted, where restricted public access and only qualified persons service the equipment.
- 517.13(B) The requirement for redundant grounding conductors has been clarified and states that the insulated bonding jumper from the metallic box to the equipment grounding conductor is permitted.
- 517.16 Isolated ground receptacles are not permitted to be installed within any patient care areas.
- 517.17(B) If there is only one level of overcurrent protection between the incoming service entrance and transfer switches, the second level of ground fault protection that is normally required for healthcare facilities shall not be installed downstream of the transfer switches.
- 517.18(A) Receptacles in patient bed locations shall not be a part of a multi-wire branch circuit (i.e., have a neutral in common with another phase conductor).
- 517.160(A)(5) Conductors for an isolated power system shall be identified by a continuous, distinctive colored stripe other than white, green, or gray along their entire length.
- 547.5(G) For engineers designing barns, the code no longer permits deleting GFCI protection on an outlet for a piece of dedicated equipment when that piece of equipment is within 3’ of another GFCI outlet.
- 620.53 Exception: Disconnects are required for elevator cab lights and ventilation, but if the ventilation motor is less than 2 HP or less an 300 volts, a general-use snap switch may be used as this disconnecting means.
- 645.17 The requirements for power distribution unit (PDU) panelboards used for information technology equipment, shall be permitted to have multiple panelboards within a single cabinet, if the power distribution unit is utilization equipment and is listed for information technology application.
- 690 Due to the wide popularity of photovoltaic (PV) systems, broad changes have been made in this section.
- 694 A new article to address wind-powered electric generating systems.
- 695 The code for electrically driven fire pumps has been modified to closely correlate to the requirements of NFPA 20.
- 700.10(D)(1) Feeder circuit cables for emergency systems must now be rated for a minimum 2 hours fire rating.
- 700.27 Exception: Selective coordination is no longer required for overcurrent devices that are installed in series if no loads are connected in parallel with the downstream device.
- 701.6(D) There is now a requirement for ground fault indication for legally required standby systems of 150 volts to ground and circuit protective devices rated 1000 amperes, which is similar to that previously required only for emergency systems.
This list was modified from a more detailed list featured in Consulting-Specifying Engineer.
For Canada, the Canadian Electrical Code was updated for 2012.
Staying compliant with electrical product safety in the United States can be a challenge. Here is a basic primer for contractors and facility owners.
Electrical product safety is specified at the federal level and the local level:
- Federal law governs electrical equipment utilized in the workplace
- Local building code officials enforce local standards ordinances and laws pertinent to a given occupancy
On the federal level, the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) requires safety for employees. As specified in 29CFR1910 subpart S, electrical equipment used in the workplace must be certified by a Nationally Recognized Testing Laboratory (NRTL), like MET Labs.
Approval of NRTL certifications is governed by the policies of the local authority having jurisdiction (AHJ), which is typically a governmental electrical inspector, fire marshal or third party inspection agency.
The AHJ also enforces local building codes. These codes can be state, county, or city, and they do not apply to equipment used by employees in the workplace. Historically, electrical inspectors have only looked at the fixed wiring within the installation, but have recently increased surveillance of installed equipment for electrical safety compliance.
There are thousands of local jurisdictions in the U.S., and regulations are not uniform across all localities. The AHJ can defer to the NRTL recognition (as with San Francisco) or may specify its own list of approved labs for product certification.
Typically, local code is based on NFPA 70 National Electrical Code (NEC), although there are addendums to the NEC in many jurisdictions.
Under local electrical codes, an inspector must sign off on the installation before it can be energized. If the equipment is not already safety certified (listed or labeled), it can be field evaluated if required by the AHJ to satisfy the requirements of federal or local regulations.
Read more about field evaluation and listing/labeling.