Hello Christine,
I am referencing the 2008 NEC. Excuse the large sections excerpted, but they cover the relevant information. The bold and italic text is from the code. I have underlined what I think are some of the critical items. 90.7 Examination of Equipment for Safety. For specific items of equipment and materials referred to in this Code, examination for safety made under standard conditions provide a basis for approval where the record is made generally available through promulgation by organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service-value determination through field inspections. This avoids the necessity for repetition of examinations by different examiners, frequently with inadequate facilities for such work, and the confusion that would result from conflicting reports on the suitability of devices and materials examined for a given purpose. It is the intend of this Code that factory-installed internal wiring or the construction of equipment need not be inspected at the time of installation of the equipment, except to detect alterations or damage, if the equipment has been listed by a qualified electrical testing laboratory that is recognized as having the facilities described in the preceding paragraph and that requires suitability for installation in accordance with this Code. 100 Definitions Listed. Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose. 110.3 Examination, Identification, Installation, and Use of Equipment. (A) Examination. In judging equipment, considerations such as the following shall be evaluated: (1) Suitability for installation and use in conformity with the provisions of this Code FPN: Suitability of equipment use may be identified by a description marked on or provided with a product to identify the suitability of the product for a specific purpose, environment, or application. Suitability of equipment may be evidenced by listing or labeling. The final item I have is OSHA’s NRTL program. http://www.osha.gov/dts/otpca/nrtl/index.html#nrtls Now we can start putting this together. If your NRTL is shown on OSHA’s list, and UL 60950-1 is shown under that NRTL’s scope of accreditation, then the Listing of your product should be valid in most jurisdictions. Your equipment would be considered Listed as described by Article 100. Next, Article 110.3, particularly the Fine Print Note (FPN) indicates that the inspector may determine compliance based on the Listing of the product. Finally, Article 90.7 indicates that the intent of the Listing is so that the local inspector doesn’t make his/her own evaluation of a products suitability. It is assumed to be suitable if determined as such by the NRTL. Your local inspector could make other arguments. You may have to show that the NRTL has approved your product for the installation method and use which the inspector is reviewing. However, if the NRTL determined that creepage and clearance requirements were met, then the Listing should be sufficient for the inspector. The final question is whether you expect more of your products to be installed in this jurisdiction. If not, it may be worth fighting this inspector. If you are going to face this inspector in the future, you may need to find a more amicable way of resolving your difference of opinion. Otherwise, this inspector may choose to throw everything he/she can find at you on your next installation. Regards, Ted Eckert Compliance Engineer Microsoft Corporation [email protected] The opinions expressed are my own and do not necessarily reflect those of my employer. From: Christine Rodham [mailto:[email protected]] Sent: Wednesday, May 13, 2009 8:55 AM To: [email protected] Subject: Re: NRTL Mark vs. NEC Inspector What is a "NEC (National Electrical Code) inspector" ? - The local city inspector that enforces the NEC. I will have to get the formal information ( chapter and verse) from the installer ( who is out-sourced by us ) I received a voice-mail this morning regarding this incident. Thanks Christine --- On Wed, 5/13/09, Brian O'Connell <[email protected]> wrote: From: Brian O'Connell <[email protected]> Subject: RE: NRTL Mark vs. NEC Inspector To: [email protected] Date: Wednesday, May 13, 2009, 8:11 AM What is a "NEC (National Electrical Code) inspector" ? In any case, the electrical/fire inspector should have noted specific NFPA70 clauses. You cannot conform to code until you know the requirement. Fault conditions, as described for Type Tests in a product safety standard, are not defined in the NEC. The NEC 'tends' to describe required construction for various combinations of specific ratings and environments. The biggie is for > 150V to P.E., where all exposed metal must be 'grounded' for Class I construction. I do not like this, but there is an NEC clause that allows an exemption for insulated heat sinks. -----Original Message----- From: [email protected] <http://us.mc5 7.mail.yahoo.com/mc/[email protected]> [mailto:[email protected] <http://us.mc557.mail.yahoo.com/mc/[email protected]> ]On Behalf Of Christine Rodham Sent: Wednesday, May 13, 2009 7:38 AM To: [email protected] <http://us.mc557 mail.yahoo.com/mc/[email protected]> Subject: Re:NRTL Mark vs. NEC Inspector List Members, We have an interesting problem. We sold an OEM product ( very high end Home Theater Movie Projector , better than a movie theater quality) which was listed by a well known NRTL. ( We modify and enhance the SW for high end performance) The projector was installed in a public place and the installation was evaluated by a NEC ( National Electrical Code ) inspector. The projector has a metal ungrounded heat sink attached to the chassis that was added for cooling but was evaluated and approved by the NRTL. The NEC inspector will not sign off on the installation stating non-current carrying exposed metal parts that may be accidentally energized must be grounded to the chassis. Grounding the heat-sink to the chassis will be difficult due to the design of this special aluminum heat-sink. Here are my questions: * What is the criteria to determine if a metal part can become accidentally energized? The only way it could happen in this case is if the power cord that is near the heat-sink is damaged and then touches the heat-sink. The power cord is UL approved and properly rated. * How many fault conditions ( single vs multiple ) are considered to determine if a metal part can become accidentally energized. * What would be our best option in arguing this ruling. Should we request another inspector or get the NRTL involved? Note that this unit is ceiling mounted and only trained service people would have access to it after the initial installation. Thank you! Christine Rodham - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected] <http://us.mc557.mai .yahoo.com/mc/[email protected]> > All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
