Conformity Magazine - November 2007 - (Page 28)

safe.” This means that plaintiffs cannot merely claim that a product was unreasonably dangerous; instead, they have to demonstrate that a reasonably alternative design would render the product safe. The existence of published technical standards for safety constitutes just such a reasonably alternative design. If the plaintiff can show that compliance with published safety standards would have made the machine reasonably safe, the plaintiff can demonstrate not just that a manufacturer is liable for the injury (as per §2(a)), but that the manufacturer is responsible for an unreasonably unsafe product. This combination can lead to onerous financial damages to the manufacturer who is exposed to such a scenario. Therefore, assessing a product for compliance with published technical standards prior to it being placed in service in a workplace is an inexpensive form of liability protection for the machinery manufacturer. Field Evaluation for New Machinery Field evaluation may be performed for new machines being placed on the market. In general, field evaluation is an acceptable and economical process for new machines when the following conditions apply: • The machine is a custom-built machine for a special application; • The machine is being manufactured on a non-repetitive basis; • The machine is being sold in limited quantities. If machines do not meet the above requirements, it is normally more desirable to perform an NRTL listing. Especially when the machine is manufactured in production quantities, individual field evaluation becomes economically prohibitive. Field Evaluation for Used Machinery Field evaluation is also a common requirement for used machines. When machines are purchased off the used machinery market, the new owner of the machine often discovers that the AHJ for their area requires an NRTL evaluation for the machine before it may be placed in service. Since this can add considerable expense in retrofitting an older machine to comply with current regulatory requirements, purchasers of used machine tools often contract with an NRTL for a pre-sale review in order to understand the extent of modifications required. In addition, machinery owners who move installed equipment to a new location often find that the AHJ requires that unlisted equipment, which may have been in service for many years, be evaluated by an NRTL. Field labeling is a good method to demonstrate to an AHJ that the machine has been examined, and complies with current regulatory requirements for safety. 28 Conformity noVEmBEr 2007 Finally, when a machine that has been previously fieldlabeled or listed by an NRTL is modified in a substantial, and safety-relevant, manner, an NRTL field label examining the modifications is a good method of demonstrating continued compliance with safety regulations after the modifications have been made. Technical Standards for Field Evaluation Machines that undergo a field evaluation process are assessed per published technical standards. The definition of applicable standards follows a hierarchy. First, the standards defined by OSHA as applicable standards under the NRTL program should be applied. Since these standards are legally required by OSHA under U.S. statutory authority, they have precedence over all other technical standards. The list of standards required by OSHA for use by NRTLs in approving products is publicly accessible at www.conformity.com/1141. After the OSHA-required standards, the second most important source of defining applicable standards for equipment is the National Electrical Code. The NEC itself is always applicable. In addition, where specific requirements for products exist, the NEC defines product safety standards in Annex A, Product Safety Standards. This list of standards is informational, but it should be followed wherever possible. Third, standards that are published by standards development organizations in the United States, such as the NFPA, ASME, or are recognized by ANSI (American National Standards Institute) should be followed if there is no directly applicable OSHA recognized standard or no direct requirements in the NEC. Compendium of Common Standards for Machinery Field Evaluation Generically, all machines in the United States are assessed to two separate technical standards, ANSI/UL508A, Industrial Control Panels, and NFPA 79, Electrical Standard for Industrial Machinery. UL508A, being an OSHA-recognized standard, is the primary standard, and applies to all industrial control enclosures on the machine. The overall machine is assessed per NFPA 79, which addresses wiring outside the machine enclosures, as well as machinery-related requirements such as interlocking devices, guarding, and so forth. In addition, special requirements exist for special types of machines. These requirements are applied over and above the basic requirement for ANSI/UL508A and NFPA 79 compliance. Examples of these requirements are the ANSI B11 series of standards for metal working machines, the ANSI B151 series of standards for injection molding machines, the ASME B20.1 and B30.13 standards for factory automation machinery, and the ANSI RIA R15.06 standard for industrial robots. http://www.conformity.com/1141

Table of Contents Feed for the Digital Edition of Conformity Magazine - November 2007

Conformity - November 2007 Contents Editor’s Note Commission Sets Date, Terms for 700 MHz Auction FCC Reaffirms Roaming Obligations Commission Moves to Improve USF Management FCC Proposes Fines for Violations of E911 Handset Requirements Commission Levies $1 Million Plus Fines for Unsolicited Fax Advertisements GR-3150 - Lithium Battery Certification Levels Based on Criteria for General Product, Safety, and Performance, Part 2 ESD Open Forum Machinery Field Evaluation for the United States Validation, Verification, and Immunity Testing Techniques for EMC for Functional Safety Thermal/EMC Simulation Addresses New Mechanical Design Challenges Product Safety Equipment Buyer’s Guide FCC Releases Report on Telephone Numbering Resource Utilization Canada Still Has PCS Spectrum to Assign Updated Standards List for the EU’s Medical Devices Directive Updated Standards List for EU Directive on Active Implantable Medical Devices Call for Papers for the 2008 EOS/ESD Symposium Announced Mobile Phone Use in Hospitals May Be Dangerous CPSC Actions in the News IEC Standards Update UL Standards Update Telcordia Standards Update From Our “You Can’t Make This Stuff Up” Department Product Reviews Looking Back: Items from Past Issues of Conformity Upcoming Events Advertisers

Conformity Magazine - November 2007

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