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 past, design flaws in smart meter units have been known to cause serious fire hazards and spotty performance. This has caused a lot of concern for utilities and manufacturers of smart meters. To prevent problems like this, a new voluntary safety standard – UL 2735 – has been created for electric utility meters.
In the past, meters were tested to UL/CSA 61010-1, as was other Measurement, Control, and Laboratory Equipment. Meter manufacturers are increasingly migrating from UL 61010-1 to UL 2735.
UL 2735 covers:
- Meters rated up to 600V which measure, monitor, record, transmit, or receive electrical energy generation or consumption information
- Socket mounted plug-in (Type S) utility meters, and non-socket mounted, bottom connected (Type A) utility meters
- Meters provided with one or two-way communication capabilities by means of carrier signals, telephone, cable, or wireless communication
- Meters that provide signals, directly or wirelessly, for the control of electrical loads or electrical power generation equipment
These construction and performance requirements are included in UL 2735:
- Compliance with relevant component standards
- Used within their recognized ratings
- Includes plastics, PCBs, MOVs, wire, and transformers
- Accessibility of hazardous live parts
- Electrical spacings over-surface and through-air
- Isolation of current transformer secondary
- Endurance of load control switch
- Single component fault
- Polymeric enclosure flammability
- Battery protection, charging, placement and replacement
- Single component fault
- Enclosure environmental considerations
- Enclosure strength and rigidity
- Access panels
- Insulation resistance
- HV line surges
- Fast transient/burst
- RF interference
- RF conducted/radiated emissions
- Temperature rise
- Temporary overload
- Electrostatic discharge
- Environmental suitability
- Electrical ratings
- Installation instructions
- ANSI C12.10 nameplate
- Permanence and legibility
UL 2735 is not yet part of the NRTL Program, however MET Labs is already accomplished in testing to it. Learn more about MET’s highly-regarded testing of meter safety, reliability, and accuracy for manufacturers or utilities.
There was much discussion about the E3 Program (Energy Efficiency, Energy Performance & Energy Consumption), covered in Compliance Today previously.
The U.S. initially opposed the E3 Program because there is a lack of harmonization. As it stands, there is no assured reciprocity and there is no certificate issued, just a Statement of Test Results (STR). It is up to the reader of the STR to decide to accept or not.
UL and CSA have recently published harmonized versions of IEC 62368-1. It will, however, likely be a long time before this becomes a NRTL standard due to OSHA’s workload and their likely objection to its inclusion of hazard-based analysis. Major labs will list to it, but if a product is going into the workplace, then 60950 or 60065 must still be used.
Only the U.S., Sweden and Denmark have adopted 62368-1 in the Scheme per the CB website. Canada is to participate soon, as is France. The Netherlands may participate soon.
More about IEC 62368-1 is found in this Compliance Today post.
China is not currently accepting EMC within the Scheme. China’s objection may be that this was once voluntary and that the Scheme adopted EMC as mandatory and have not given China time to revise its standards.
At least one manufacturer thinks there is a need for motors to be in the safety CB Scheme. The only place a motor standard is covered is within the EMC Scheme. NEMA’s 1MG Section is continuing its conversation regarding the inclusion of electric motors as part of the E3 Program.
Next meetings are May 22-23, 2012 in Vancouver, Canada, and August 7-8, 2012 in Orange County, California.
Stay tuned – Up soon is a corresponding post on EMC compliance resources.
Standards & Schemes
CB Scheme The international certification program managed by the IECEE, with over 60 countries participating.
IEC The International Electrotechnical Commission publishes consensus-based International Standards and manages conformity assessment systems for electric and electronic products.
CENELEC The European Committee for Electrotechnical Standardization. It creates voluntary European electrotechnical standards (ENs).
UL Catalog of Standards UL has developed more than 1,000 standards for safety.
CSA Standards Canadian Standards Association Online Store.
BSI Standards The UK’s National Standards Body (NSB) and was the world’s first.
Standards Australia Australia non-government standards body.
Standards New Zealand New Zealand’s leading developer and publisher of standards.
ANSI American National Standards Institute is the voice of the U.S. standards and conformity assessment system.
IHS Standards Has a wide variety of standards available for purchase.
NFPA Codes & Standards National Fire Protection Association has developed more than 300 consensus codes and standards to minimize the possibility and effects of fire and other risks. Publishes NEC.
U.S. OSHA NRTL Program OSHA is responsible for managing the Nationally Recognized Testing Laboratory Program for U.S. product safety certification.
U.S. CPSC U.S. Consumer Product Safety Commission is charged with protecting the public from unreasonable risks of injury or death from thousands of types of consumer products.
U.S. MSHA Mine Safety and Health Administration works to prevent death, disease, and injury from mining in the U.S.
U.S. Laser Safety Regulations The U.S. Code of Federal Regulations outlines U.S. laser safety requirements.
Standards Council of Canada The SCC is responsible for accrediting certification bodies for the Canadian market.
EU Directives Includes links to harmonized standards references.
RAPEX The EU rapid alert system for dangerous consumer products, with the exception of food, pharmaceutical and medical devices.
CNCA Regulations of the People’s Republic of China on Certification and Accreditation and Applying China Compulsory Certification (CCC) Mark
RRA National Radio Research Agency, Korea’s regulatory agency for KC Mark.
BSMI Bureau of Standards, Metrology & Inspection is the authority responsible for standardization, metrology and product inspection in Taiwan.
GOST Russia Federal Agency on Technical Regulating and Metrology.
Publishers: Magazines & Blogs
IAEI Magazine Magazine for electrical inspectors.
IN Compliance Magazine Formerly Conformity, covers product safety along with other compliance disciplines.
Product Safety Letter Digital newsletter and website.
Test & Measurement World Covers product safety occasionally.
Hazardous Area International Magazine Coverage includes hazardous location and explosive atmosphere compliance.
Compliance Today Blog The latest news and resources to help electrical product manufacturers comply with regulatory and buyer requirements, from MET Laboratories.
Certification & Test Blog Information, from TRaC Global, on testing and certification services, ranging from telecoms & radio and environmental, through to analysis, safety and EMC.
Directive Decoder Blog Analysis of European legislation.
NEMA Currents Blog Blog of the Association of Electrical and Medical Imaging Equipment Manufacturers.
IEEE The Institute of Electrical and Electronics Engineers is the world’s largest professional association dedicated to advancing technological innovation.
PSES Email Forum A lively Listserv made up of about 700 engineers and technicians. Sponsored by IEEE.
Testing Equipment Suppliers Published by IECEE.
ICPHSO The International Consumer Product Health and Safety Organization.
What are your favorite online product safety compliance resources? Please leave a comment with a link to it.
IT manufacturers shipping to Europe take note: Today is the last day for EN60950-1 1st edition. Beginning tomorrow, all IT products must show compliance to EN60950-1 2nd edition. Products previously tested to EN60950-1 1st edition will not be grandfathered.
In general, the second edition adds consistency through clarification of either terminology or test methodology. Here are some of the primary changes:
- Section 184.108.40.206 – Resistance of Earthing Conductors and Their Terminations – now reflects the North American National Differences in the present CSA/UL 60950-1.
- Section 2.3.2 – Separation of TNV Circuits from Other Circuits and from Accessible Parts – was necessary as the former standard did not match up with currently-accepted ITE handling of TNV circuits.
- Section 4.2.11 – Rack Mounted Equipment – has new requirements for evaluating slide rail designs. However, these requirements do not apply to sub-assemblies that are not part of a completed rack/system cabinet.
- Both Voltage Dependent Resistors (VDR) and Audio Components get expanded attention throughout the new version of the standard.
- Good news for manufacturers of IT equipment weighing less than 15.4 lbs, as the 10° tilt stability testing will be waived.