The preceding may not have completely addressed the question. You are probably looking to identify what standards to apply while designing the product before an NRTL has a chance to evaluate and determine what they think is the appropriate standard(s). This is where experience and a working relationship with the NRTL comes in handy. We often design to a few different standards when possible. If there are conflicts, well then we have to make a judgment call. With some prior history we know what standards the NRTL has used on similar product. We can also get preliminary input from the NRTL on what standards they would apply. In particular during a preliminary quote cycle with basic product description the standards to be used for certification will have been identified in the NRTL certification quotes.
-Dave -----Original Message----- From: Nyffenegger, Dave Sent: Tuesday, April 04, 2017 3:02 PM To: 'Kunde, Brian'; [email protected] Subject: RE: [PSES] E-Box Layout on Factory Machines Brian, I assume you're asking about US requirements and the inspectors you are asking about are local AHJs or OSHA. So OSHA and perhaps the AHJs have a basic rule that all equipment used in the workplace is NRTL approved/listed except for custom built equipment that can be certified as safe by the manufacturer on the basis of test data. I don't know if or how the exception may apply with local AHJs, no experience with that one. The first thing the local electrical/building/OSHA inspector is going to look for is the NRTL mark. They see that they are usually happy and done. That pushes your question off to the NRTL who gets to evaluate the product and determine what standards to apply. Basically the same procedure for a NRTL lab certified product or NRTL field inspected/marked product. If you don't have a listing of field inspection mark, well then you're going to be up for challenges with the local inspectors. The various standards have their own scope definitions and the NRTL is going to review to determine which standard(s) are most appropriate. In some cases it may not be simply black and white and it may be possible for the NRTL to choose between this standard or that standard. I have run into this on several occasions. The NRTLs cannot use NFPA 79 as a UL listing standard but they do use it as a reference standard alongside of a primary listing standard. Typically they will refer to it for anything that qualifies as machinery. For large industrial equipment which has a "industrial control panel(s)" driving external motors and such, i.e. a system of multiple large components rather than a single self-contained product in a "box" , you may get away with an NRTL listing on the control panel assembly alone (i.e. UL 508A). The control panel must be installed and used according to conditions specified in the NRTL report. Some of those larger systems may be the ones that fall into the category of custom built and certified by the manufacturer. -Dave -----Original Message----- From: Kunde, Brian [mailto:[email protected]] Sent: Tuesday, April 04, 2017 1:55 PM To: [email protected] Subject: Re: [PSES] E-Box Layout on Factory Machines I never studied the VSA, but ships built for the Federation had panels in hallways that could be removed without a tool with high voltage plasma coils and flux capacitors behind them. And kids lived aboard these ships. Open Jeffares tubes without locked doorways where common. Space stations appeared to have locks on grain storage bins, but it didn't keep out domesticated pets (Tribbles). And there was that "one room" aboard the submarine Sea View that when anyone entered, we all knew that someone was going to get electrocuted. I guess the future makes no more sense than the present. I am interested in the criteria inspectors use to decide if a product should meet these requirements or not. Or is it completely voluntary. I would imagine if NECA, NEMA and NFPA 79 is involved then inspectors are going to require following what they say. Here is an example of what I'm looking for. You have two cut-off saws; one is about the size of a lunchbox, sits on a table, has a 1/8hp motor, and cuts 1/8" steel rods into 1 gram samples to be analyzed for carbon/sulfur content. The other is huge, weighs 1000lbs, floor mounted, 3-phase power, has a 35hp motor, and can cut an engine block into slabs for hardness testing and metallurgical analysis. Technically both do the same function. Both are considered "prep machines for analytical analysis". So then both can be considered "laboratory equipment" even though the big one is more messy and makes a lot more noise. Neither is marketed or sold for any other purpose even though they could be used to cut many things for many reasons. Now let's say there are 10 more saws of different sizes and hp that fit between the two I mentioned above. At what point (criteria) do we apply the NFPA 79 and the like? At what point will inspectors expect to see a different set of design rules applied, or again, is it all voluntary how you design a product? Thanks for the help. The Other Brian -----Original Message----- From: Brian O'Connell [mailto:[email protected]] Sent: Tuesday, April 04, 2017 12:01 PM To: [email protected] Subject: Re: [PSES] E-Box Layout on Factory Machines Agree vehemently, but also codified per NECA 1-2015, and the various workmanship standards of the Vulcan Science Academy. UL508A does not do much for 'workmanship', just materials and construction and performance. And do not want to see a safety standard that tells me stuff has to be built pretty. Brian From: IBM Ken [mailto:[email protected]] Sent: Tuesday, April 04, 2017 6:15 AM To: [email protected] Subject: Re: [PSES] E-Box Layout on Factory Machines I think those types of products are engineered once, and then built and serviced for decades. Overly neat designs lend themselves to less problems in production and service over the years, even when the original designers are no longer available to help. I don't think there are any criteria which require that type of construction (aside from tradition). It's like asking why every facilities engineer has a large keyring, a pocket protector containing no less than three writing instruments, and a AA mini Maglite on their belt. On Tue, Apr 4, 2017 at 8:54 AM, Kunde, Brian <[email protected]> wrote: I notice that most industrial factory machinery is designed with a large metal electronic box with a hinged door and some kind of keyed lock. Inside the components are DIN mounted and the wiring is all dressed very neatly in these gray plastic cable runs with snap-on lids. Every wire is labeled with a small tag. Why are these machines so similar in design? Even among different manufacturers, they look similar. Is there a standard or standards that dictate exactly how this is done? What criteria is used to determine if your product must follow these construction rules? Seems strange to me that they are so similar and if required to be that way, then standards and/or governments are dictating design. Even if it was for the “greater-good”, I thought that was a no-no. Dictate design, stifle creativity, invite those who would take advantage for financial gain. Just curious. I’m most interested in the criteria question, though. The Other Brian - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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Thank you. - ---------------------------------------------------------------- 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]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 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]> - ---------------------------------------------------------------- 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]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 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]>
