Hello Rich, This issue has been decided by the "chief engineer" for all USA medical labs at NRTL2. The interesting part is that the staff safety engineers at NRTL2 appear to agree with me (including Sr engineers there). I'm told that it's the responsibility of the chief engineer to worry about liability, and I certainly sympathize with those concerns in the overly litigious USA. However, in this case we're dealing with a potted wall-wort power supply with a 3m 15 V dc output cable on the secondary. Engineering judgment still should have its place within our (compliance engineering) world.
In the past I've worked with the oldest (hint, hint, say-no-more) NRTL in the USA on ITE and even industrial hazardous locations products with external bricks and wall-worts and this additional dielectric voltage withstand test was not imposed by them. Same story with another German based NRTL with presence here in the USA concerning an IVD device. No problems. Thanks to all for your views. Carl -----Original Message----- From: Richard Nute [mailto:[email protected]] Sent: Monday, April 29, 2013 5:03 PM To: Carl Newton Cc: [email protected] Subject: Re: NRTL requiring duplicate testing Hi Carl: I suggest you take it up a notch with NRTL2. Take it up the management chain at NRTL2. NRTL managers tend to be more open to issues of added cost to their client, especially where the value of the requirement is questionable. At the same time, the manager has some duty to support his engineers even though the imposed requirement may not be clearly a good or logical one. So, a high degree of finesse is necessary. Ideally, you want the NRTL2 engineer to take it up the management chain. You have to ask the NRTL2 engineer if he can present your case without bias. If this fails, you should be prepared to physically visit the NRTL2 site and discuss it with their management. This is an interesting requirement because there is no money in it for NRTL2. Usually, not accepting NRTL1 involves re-testing the requires you to pay NRTL2 for the same work as NRTL1. But, here, it appears that NRTL2 gets no money by imposing testing on you. Good luck! Rich On 4/29/2013 11:54 AM, Carl Newton wrote: > > Customer has a medical wall-wort power supply that has the typical > NRTL (call them NRTL1) safety mark that you'd expect to see on a power > supply marketed within the USA. Customer's entire device is located > within the secondary of that wall-wort power supply and includes no > connections to other mains connected devices. > > Now another one of the large well-known NRTLs (I'll call them NRTL2) > which is handling the AAMI 60601-1 project for customer's end product > is requiring that 100% dielectric voltage withstand testing be > repeated on the power supplies. The power supply manufacturer has > provided sections of their NRTL1 File that details the requirement for > 100% testing of their supply in manufacturing as well as the voltage > amplitude and duration required. Still, customer's NRTL2 is demanding > that this test be repeated upon 100% of the power supplies at > customer's premises. It appears that I have no choice but to agree to > repeat the additional testing. This adds cost to manufacturing and > flies in the face of great efforts on the part of American > manufacturers that try to keep their operations within the USA by > maximizing productivity. I've worked on many other projects with > wall-wort and external brick power supplies with other NRTLs and this > has never been a requirement. > > I try to keep an open mind even when I'm disagreed with. But I think > that this is the first time in my 30ish years of compliance work that > I've seen engineering judgment _completely_ thrown out the window. I'm > interested in other points of view. > > Carl > > - ---------------------------------------------------------------- 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://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]>
