Re: [PSES] 61010-1 hazardous live classification

2024-02-26 Thread Richard Nute
of the duty cycle. The shorter the duty cycle, the less human sensation of the pulse. Chances are that the pulse is not detectable by a human finger any more than 60 volts DC. But the standard does not allow such a determination. You are stuck. Best regards, Richard Nute Bend, Oregon

[PSES] Household safety in the Internet era

2024-02-26 Thread Richard Nute
For those who use IEC 60335. here is a superficial (and non-technical) look. https://etech.iec.ch/issue/2024-01/household-safety-in-the-internet-era Richard Nute Bend, Oregon, USA - This message is from the IEEE Product Safety

Re: [PSES] 61010-1 Stability test, Para 7.4 Stability

2024-02-13 Thread Richard Nute
. (By the way, the same requirement as in 1010 is in IEC 60950-1.) If a redesign is warranted, I suggest spring-mounting the mast such that a toppling force is not transmitted to the base. Richard Nute Bend, Oregon, USA Ps: It is clear that the requirement assumes a monolithic construction

Re: [PSES] Reduce Speed of Moving Part to Reduce Risk

2024-01-29 Thread Richard Nute
Hi Doug and Brian: I thought I would offer my (radical) point of view on the issue of “speed of moving parts.” Consider moving aluminum foil and moving aluminum block, both at the same speed. The aluminum foil has very little mass, while the aluminum block has relatively high mass.

Re: [PSES] Products requiring dielectric voltage withstand test on RJ45 and XLR sockets

2024-01-17 Thread Richard Nute
Hi Chuck: I don't know why your lab wants to do the primary-circuits-to-ground hi-pot test to "unearthed socket terminals." I assume your secondary circuits are grounded, and, if so, the pins of sockets (RJ45 and XLR) are therefore referenced to ground and are subject to the

Re: [PSES] Is certification 'voided' by improper operational conditions?

2024-01-08 Thread Richard Nute
Hi Lauren: The part was run for 8 hours at a temperature above its rated temperature. Supposedly, the manufacturer's rated temperature is the maximum temperature for "non-deterioration" of the part and its materials. So, the part, supposedly (and we must expect), has suffered some

Re: [PSES] American Vs. European 30 Ground Fault Leakage Current Standards

2023-11-21 Thread Richard Nute
Hi Ronan: GFEP North America: https://www.eaton.com/us/en-us/skuPage.GFEP130.pdf GFEP Europe: https://library.e.abb.com/public/a9cd966c1794415d945b232fb2d7a9ee/1SXU430091 L0201_GFEP_Info_Tool.pdf According to: https://forums.mikeholt.com/threads/gfci-vs-gfep.116424/ "GFCI and

Re: [PSES] The NPR news quiz

2023-11-10 Thread Richard Nute
if I had known any of the answers. And I feel really smart not paying any attention to all of that. -- Ken Javor (256) 650-5261 From: Richard Nute mailto:ri...@ieee.org> > Reply-To: mailto:ri...@ieee.org> > Date: Friday, November 10, 2023 at 4:38 PM To: mai

[PSES] The NPR news quiz

2023-11-10 Thread Richard Nute
Final score: 5/11. Lackluster. https://www.npr.org/2023/11/10/1211700159/donald-trump-election-debate-gop-a nimals-npr-news-quiz?utm_source=npr_newsletter_medium=email_content= 20231110_term=9074533_campaign=news_id=61871060=151_at t1= -

Re: [PSES] UL1007 vs VW-1 Flammability ratings

2023-10-30 Thread Richard Nute
Hi Steve: VW-1 is roughly equivalent to V-1 except applies to wire. Richard Bend, Oregon From: Stephen Clarke [U3C] Sent: Monday, October 30, 2023 8:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] UL1007 vs VW-1 Flammability ratings Hello Experts I have a battery box

[PSES] Exploding lithium batteries are causing fires in Oregon's landfills

2023-10-21 Thread Richard Nute
etc) can be recycled at many major tool retailers and rechargeable device retailer. They are also accepted at the Hazardous Waste Facility." Best regards, Richard Nute - This message is from the IEEE Product Safety Engin

[PSES] safety under single fault

2023-10-11 Thread Richard Nute
Hello from Bend, Oregon: On September 4, 2022, a plane carrying 10 people crashed into Puget Sound's Mutiny Bay near Whidbey Island. The National Transportation Safety Board, which investigated the crash, said Thursday that a single component of a critical flight control system failed, causing

Re: [PSES] BBC news article re Li-ion batteries...

2023-08-07 Thread Richard Nute
In my career, I investigated (in the USA) a large number of field failures (mostly fires) of safety-certified products. The claims were against us as the manufacturer, not the certifier. The claimant or his insurance would hire an investigator to identify the cause of the fire, where

Re: [PSES] Woodgate's reply on residential Immunity field strength

2023-07-27 Thread Richard Nute
I'm a product safety engineer. This discussion is based upon a safety standard specifying a limit for the accessible electric field strength. Doug Smith said: "These days we think 10 V/m is dangerous." See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553569/

Re: [PSES] 6dB pad

2023-07-15 Thread Richard Nute
This discussion not only applies to EMI testing, it also applies to high-frequency and fast risetime pulse voltage measurements. A 6 dB (2x voltage attenuation) or 10 dB (~3x voltage attenuation) in a 50-ohm system which would otherwise be subject to reflections due to impedance

Re: [PSES] Machine status visual Indicators

2023-06-23 Thread Richard Nute
Go for it! Rich From: Steve Brody Sent: Friday, June 23, 2023 11:52 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Machine status visual Indicators Experts, I have a client who would like to use a single LED capable of multiple colors instead of a mutli-lamp light tower

[PSES] FW: Regulatory & Standard Updates / Oct 2021

2023-06-21 Thread Richard Nute
Hi Brian: I have found this listing to be useful. Unfortunately, I don’t know how to subscribe. Good luck! Rich From: TÜV Rheinland North America Sent: Tuesday, November 30, 2021 8:58 AM To: ri...@ieee.org Subject: Regulatory & Standard Updates / Oct 2021 If you

Re: [PSES] Tracking standards updates

2023-06-19 Thread Richard Nute
Hi Brian: Here are two suggestions: Nemko "News in Brief" by Trond Sollie https://www.nemko.com/newsletter-signup?utm_campaign=GL+%7C+News+In+Brief+%7 C+2023

Re: [PSES] Looking for AI or machine vision related ISO standards for safety

2023-06-07 Thread Richard Nute
Hi David: If you are looking for product safety, I would say that product safety should be independent of AI, or, indeed, of any software. However, some new power distribution schemes involve "handshaking" (which is software controlled) before power can be delivered. So, before power

Re: [PSES] PLC password

2023-06-02 Thread Richard Nute
Hi Steve: A possible analogy might be providing a 3-to-2-wire adaptor for your product. Clearly, doing so results in a misuse of the product (operating a Class 1 product without a ground). Safety standards require the product be safe in the event of misuse. Giving the password to

Re: [PSES] EN/IEC 61010-1 insulation question

2023-05-16 Thread Richard Nute
11:08 AM To: EMC-PSTC@LISTSERV.IEEE.ORG; Richard Nute Subject: Re: [PSES] EN/IEC 61010-1 insulation question Thanks Richard! Richard Nute wrote Hi James: My answers to your questions: 1. Does 6.7.3 apply for the clearance between the secondary winding and earth

Re: [PSES] EN/IEC 61010-1 insulation question

2023-05-15 Thread Richard Nute
Hi James: My answers to your questions: 1. Does 6.7.3 apply for the clearance between the secondary winding and earth as indicated? Yes. 2. If NO to 1) then what parts should this insulation be between? 3. If YES to 1) then: a. what is the safety hazard that is

Re: [PSES] Compliant needle-flame test material vs V-0 material

2023-04-18 Thread Richard Nute
Hi Scott: The answer to your question: “is it possible the V-0 material does not meet the needle-flame test?” is: Yes. See: https://www.caplinq.com/blog/ul-94v-certification-vs-ul-94-vtm-certification_190/ Best regards, Rich From: Scott Xe Sent: Tuesday,

Re: [PSES] Multiple electrical power sources

2023-04-06 Thread Richard Nute
Hi Steve: The TV broadcast industry electronic products have used two (redundant) AC sources for their products for many years. You may have some help there. Rich From: Steve Brody Sent: Thursday, April 6, 2023 1:42 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES]

Re: [PSES] Low Voltage connectors called out on CCL

2023-04-06 Thread Richard Nute
Hi Ryan: UL makes some of its money through certifications. Regardless of product safety, components, including connectors, are certified; their required use in end-products justifies the requirement for certification of those components. So, this is one of those unwritten requirements.

Re: [PSES] Ferrules

2023-04-03 Thread Richard Nute
Hi Steve: More than you need to know about ferrules and UL 508: https://www.youtube.com/watch?v=3B09qSLek8Q I suspect that few commercially available ferrules are V-0. I found ferrules that were nylon or vinyl. Nylon is HB. However, UL certifies ferrules, UL 486F. Para.

Re: [PSES] X-Caps after Diode Bridge

2023-04-03 Thread Richard Nute
Hi Brian: I found these explanations on the web: https://www.tecategroup.com/products/capacitors/ac-safety-capacitors.php X Capacitors: Also known as "across-the-line capacitors." Class X safety capacitors are used between the "live" wires carrying the incoming AC current. These

[PSES] FW: [PSES] Non-NRTL Field Inspection Service Provider in the Michigan / Midwest Region

2023-03-24 Thread Richard Nute
> Subject: FW: [PSES] Non-NRTL Field Inspection Service Provider in the Michigan / Midwest Region From: Richard Nute mailto:ri...@ieee.org> > Sent: Thursday, February 23, 2023 13:01 To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Non

Re: [PSES] Non-NRTL Field Inspection Service Provider in the Michigan / Midwest Region

2023-02-23 Thread Richard Nute
t regards Charlie Charlie Blackham Sulis Consultants Ltd Tel: +44 (0)7946 624317 Web: https://sulisconsultants.com/ Registered in England and Wales, number 05466247 From: Richard Nute mailto:ri...@ieee.org> > Sent: 22 February 2023 23:33 To: EMC-PSTC@LISTSERV.IEEE.ORG &

Re: [PSES] Non-NRTL Field Inspection Service Provider in the Michigan / Midwest Region

2023-02-22 Thread Richard Nute
Hi Carl: I’m not able to identify candidate FEBs as you requested. Most NRTLs, small to large, also are FEBs. I only found one accredited FEB who wasn’t an NRTL, SGS in Switzerland (a very big company). Here is a good and complete (straight-forward) explanation of the field

Re: [PSES] AC Adaptor - Singapore - Brand Name?

2023-02-10 Thread Richard Nute
Hi Ryan: Designate the model number as your brand name. Best regards, Rich From: Ryan Jazz Sent: Friday, February 10, 2023 9:34 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] AC Adaptor - Singapore - Brand Name? Hello Members, We have an AC Adaptor we purchase and rebrand

Re: [PSES] Electrical Safety - Fundamental Standards and Concepts

2022-12-07 Thread Richard Nute
Hi James: Understanding the basic physics and rationale of the safety standards requires reverse engineering of the requirements. And an understanding of the people (and their biases) that wrote the standard. Very difficult. And, the safety standards are not necessarily in

Re: [PSES] Secondary creepage/clearance

2022-12-02 Thread Richard Nute
Hi Steve: Mains circuits are subject to lightning and switching transients both line-to-neutral and line/neutral-to-ground. The transients are normal; to prevent insulation breakdown and consequential electric shock, the electric strength of mains-to-ground and mains-to-other

Re: [PSES] Pending Regulatory Change to UKCA Program

2022-11-07 Thread Richard Nute
“It’s a fact the CE mark adds way more cost than the return on investment of performance improvement.” Reminds me of a marketing manager saying to me that safety (and, I assume, safety certification and EMC) do not generate sales. Rich -

Re: [PSES] Magnetic fields, human exposure standards, and pacemakers

2022-11-03 Thread Richard Nute
Mains power lines running overhead make magnetic fields at 50/60 hertz…. I lived near Barcelona, Spain, for almost two years. The local trains used overhead lines. The stations used color CRT displays for train info. You could tell when a train was arriving as the display would distort

Re: [PSES] Surge Protection Device required by NEC

2022-11-01 Thread Richard Nute
” a higher-than-normal power-line voltage or is it an impulse from switching or lightning? Does “effectively protected” mean passing the dielectric (hi-pot) test? Richard Nute Bend, Oregon, USA (Several inches accumulation of snow this morning, but above freezing.) From: Doug Powell

Re: [PSES] Confusion about IEC 60601-1-11 Power Cord Requirements and Functional vs Protective Earth Terminals

2022-10-18 Thread Richard Nute
Hi Matthew: According to IEC 60601-1 Sub-clause 6.2: ME EQUIPMENT energized from an external electrical power source shall be classified as CLASS I ME EQUIPMENT or CLASS II ME EQUIPMENT Its okay to have Class I equipment with Class II construction throughout. However, you are likely

Re: [PSES] Confusion about IEC 60601-1-11 Power Cord Requirements and Functional vs Protective Earth Terminals

2022-10-18 Thread Richard Nute
Hi Matthew: In answer to your question how to distinguish between functional earth circuits and protective earth circuits: Protective earth (PE) circuit carries fault current to earth. Presumably, the fault current is from a mains-to-earth fault. Functional earth (FE) circuit

Re: [PSES] Assess risk of electric shock from charged capacitors

2022-10-17 Thread Richard Nute
Hi Scott: Many dual channel scopes (whether digital or analog) include an “add” function for the two channels. One channel must be inverted to measure the charged capacitance. The resistance of the two probes must be accounted for in the capacitance discharge time. (The same –

Re: [PSES] Wearables and UL 62368 vs UL 964 Electrically Heated Bedding

2022-10-05 Thread Richard Nute
Hi John: I assume the power is distributed more-or-less evenly throughout the garment. See: https://learn.adafruit.com/experimenting-with-conductive-heater-fabric/what-is-it (Be sure to click on the blue “placement” near the bottom of the page and the subsequent pages.)

Re: [PSES] List of Common Misuses

2022-10-05 Thread Richard Nute
Misuse is using a product for a use which is not a normal use. An example is using a chair (which is for sitting) as a stool. Or, using a screwdriver for prying. Or using a hammer for breaking concrete. Each of these misuses can lead to injury. Identifying misuse for a TV, a laptop,

Re: [PSES] High Touch Current and GFCIs

2022-08-29 Thread Richard Nute
Hi Brian: “Touch current” is current through the body when it touches two conductors. By convention, touch current is measured through a 2,000-ohm resistor in series with the PE conductor. Touch current only exists if two conductors are touched, for example, when the PE is open. If

Re: [PSES] High Touch Current and GFCIs

2022-08-27 Thread Richard Nute
www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK It all depends On 2022-08-25 19:12, Richard Nute wrote: I wish to make two points: 1. Kirchoff’s Current Law states that the sum of currents entering a node equals the sum of currents leaving the node. The Law a

Re: [PSES] High Touch Current and GFCIs

2022-08-25 Thread Richard Nute
I wish to make two points: 1. Kirchoff’s Current Law states that the sum of currents entering a node equals the sum of currents leaving the node. The Law applies to summation of leakage (touch) currents (e.g., through a 2,000-ohm resistor) and to summation of protective

Re: [PSES] Leakage Current Testing (Touch Current) Reference

2022-07-20 Thread Richard Nute
Hi Brian: 1. IEC 61010-1 references IEC 60990 for leakage current tests. The test you describe (MD connected to L1) is NOT in 60990. 2. The PE and N (“grounded” conductor) are connected together at the electrical service entrance to the building and connected to a ground

Re: [PSES] UK plug adaptors with fuse?

2022-04-27 Thread Richard Nute
Travel adapters are rarely certified. The problem is that the plug must comply with a country national standard, while the receptacle must comply with a different country national standard. A certification house (or manufacturer) rarely is qualified for certifying a plug or receptacle

Re: [PSES] Trouble with IEEE Xplore

2022-04-13 Thread Richard Nute
What happens is that I sign in, find the paper, click on 'PDF', putting the paper in my cart, then I click on the 'Purchase' tab. That takes me back to the sign-in page and empties the cart. Does anyone else have this problem? Yes! Exactly. I’ve never been able to obtain a paper. Best

Re: [PSES] [EXTERNAL] Re: [PSES] Protective Earth Terminal-Protective Bonding terminal -interpretation

2022-04-08 Thread Richard Nute
Hi Ryan: I want to make several points. First. In Europe, a circle around a symbol means the symbol is an imperative; it must (or is permitted to) be done. (A diagonal line through the circle is a negative imperative; it must not be done.) For example, a letter "P" in a circle

[PSES] Medical Device Leakage Current Production Line Test Setup

2022-03-19 Thread Richard Nute
Hi Gary: The measurement of "leakage current" (or "touch current") in the protective earthing conductor simulates the human body in series with the protective earthing conductor. Supposedly, it is a measure of the human body reaction to the current magnitude. However, if the

[PSES] Medical Device Leakage Current Production Line Test Setup

2022-03-18 Thread Richard Nute
Hi Gary: The measurement of "leakage current" (or "touch current") in the protective earthing conductor simulates the human body in series with the protective earthing conductor. Supposedly, it is a measure of the human body reaction to the current magnitude. However, if the

Re: [PSES] Medical Device Leakage Current Production Line Test Setup

2022-03-17 Thread Richard Nute
Hi Gary: The measurement of "leakage current" (or "touch current") in the protective earthing conductor simulates the human body in series with the protective earthing conductor. Supposedly, it is a measure of the human body reaction to the current magnitude. However, if the

Re: [PSES] Medical Device Leakage Current Production Line Test Setup

2022-03-13 Thread Richard Nute
Comments by Savino Macias and Boštjan Glavič triggered some thoughts about EARTH LEAKAGE CURRENT (IEC 60601-1 defined term) and measurement schemes. 1. EARTH LEAKAGE CURRENT in IEC 60601-1 (and most other safety standards) is the current in the protective earthing conductor from

Re: [PSES] Fuse designations

2022-03-02 Thread Richard Nute
Here is some info: https://www.swe-check.com.au/pages/learn_fuse_markings.php https://www.littelfuse.com/~/media/files/littelfuse/technical-resources/documents/reference-documents/littelfuse_5x20mm-iec-fuse-cap-marking_guide.pdf Rich From: Brian Kunde Sent: Wednesday,

Re: [PSES] Risk assessment versus HBSE

2022-02-23 Thread Richard Nute
Hi Doug: See: https://www.tandfonline.com/doi/pdf/10.1080/01446193.2016.1274418?needAccess=true Best regards, Rich From: Douglas Nix Sent: Wednesday, February 23, 2022 8:57 AM To: Richard Nute Cc: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Risk assessment versus

Re: [PSES] Numbers of insulation layers in transformer (IEC62368)

2022-02-16 Thread Richard Nute
p://www.randolph-telecom.com From: Richard Nute [mailto:ri...@ieee.org] Sent: Wednesday, February 16, 2022 5:09 PM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Numbers of insulation layers in transformer (IEC62368) Hi Amund: Since

Re: [PSES] Numbers of insulation layers in transformer (IEC62368)

2022-02-16 Thread Richard Nute
Hi Amund: Since the unit does not have grounding/earthing, it is therefore double-insulated with respect to the input 230 volts (and must bear the double-insulated symbol). This requires all accessible conductive parts and accessible surfaces to be double-insulated from the 230

Re: [PSES] Earthing -- Star vs Spring/Split Washers

2022-02-15 Thread Richard Nute
Hello James: As for resistance of the connection, I doubt that there is significant difference. I have tested both with a high-current-sourcing milliohmeter. You can repeat the test and see if there is a difference in the resistance. (Even a loose connection will still pass the high

[PSES] Risk assessment versus HBSE

2022-02-12 Thread Richard Nute
I don’t like the Risk Assessment process because it is highly subjective and not very repeatable. When I was with Hewlett Packard, three of us developed “Hazard Based Safety Engineering,” HBSE. The basis for HBSE was James J. Gibson’s (Cornell University) research into child injury

Re: [PSES] EN 62368-1 : 2020 Ed 3

2022-02-11 Thread Richard Nute
I would say “…risk assessment WILL have variants…” The risk assessment process is subjective. If you perform a risk assessment on an ordinary extension cord, you can find that it is marginally safe. Rich From: scott...@gmail.com Sent: Friday, February 11, 2022 9:14 AM To:

Re: [PSES] Machinery Leakage Current

2022-02-03 Thread Richard Nute
GFCI = Ground Fault Circuit Interrupter RCD = Residual Current Device In North America, GFCI’s typically are included in an outlet that is part of a branch circuit. The GFCI may have a number of outlets downstream. Under normal conditions, the residual leakage current in the

Re: [PSES] UL Standards - Old School Spacings

2022-01-25 Thread Richard Nute
Hi Doug: I don’t have any history. But I do have data for how air behaves as an insulator and protection methods for creepage distances. The data for air insulation as a function of distance (2000 meters altitude) and field shape was given in IEC 664, first edition, 1980. The

Re: [PSES] IEEE Xplore access

2021-12-15 Thread Richard Nute
I have the same problem. Rich Life Fellow From: Douglas E Powell Sent: Wednesday, December 15, 2021 12:58 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] IEEE Xplore access All, I have been an IEEE member for over 15 years and member of the EMC, PES, and PSES societies.

Re: [PSES] Will 5G Be Bad for Our Health?

2021-10-15 Thread Richard Nute
Hi Manny: Thanks for your comments. I found that if you replace “non-ionizing radiation” with “COVID19” or your favorite issue, the paragraph defines what we all must do with various issues. There's a myriad of opinions on the topic of non-ionizing radiation hazards, some

[PSES] Will 5G Be Bad for Our Health?

2021-10-14 Thread Richard Nute
https://spectrum.ieee.org/will-5g-be-bad-for-our-health - 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 All emc-pstc postings

Re: [PSES] UL 510 Flame retardant tape

2021-10-08 Thread Richard Nute
Hi Charlie: Rather than guess: https://www.kaptontape.com/PDF/Kapton_Films_Datasheet.pdf https://www.dupont.com/content/dam/dupont/amer/us/en/products/ei-transformat ion/documents/DEC-Kapton-HN-datasheet.pdf https://www.dupont.com/content/dam/dupont/amer/us/en/products/ei-transformat

Re: [PSES] Suitable Test equipment for Touch temperature Testing in accordance with EN 62368-1

2021-09-22 Thread Richard Nute
Hi Phillip: As far as I know, 62368-1 does not specify the method for measuring touch temperatures. Be aware that certification houses usually measure touch (and all other) temperatures with a thermocouple. Stay safe, and best regards, Rich From: Philip Stevenson Sent:

Re: [PSES] Creepage and clearance requirements

2021-09-15 Thread Richard Nute
fe Fellow IEEE PSES 2020 Distinguished Lecturer <http://www.researchgate.net/Peter%20Perkins> www.researchgate.net search my name <mailto:p.perk...@ieee.org> p.perk...@ieee.org Entropy ain’t what it used to be From: Richard Nute mailto:ri...@ieee.org> > Sent: Sund

Re: [PSES] Creepage and clearance requirements

2021-09-12 Thread Richard Nute
Hi Amund: If no accessible conductive parts, then you can designate the secondary circuits as part of the primary circuits, which means there is no need for isolation between primary and secondary circuits. No creepage or clearance requirements! OVC would not apply primary-to-(a

Re: [PSES] Over Reliance on Automated Safety Controls (Friday question)

2021-09-03 Thread Richard Nute
Hi Doug: For safety, the issue seems to be reliance on the correct functioning of devices. As equipment becomes more and more complex, we are more reliant on the correct functioning of devices. An example is the modern day airplane. One specific example is the Air France flight

Re: [PSES] Touch temperature limits for accessible parts

2021-09-02 Thread Richard Nute
Hi Scott: A 1st degree skin burn occurs when skin temperature is 44 C. Plastic material has relatively high thermal resistance. 80 C plastic is unlikely to cause a burn regardless of contact time. In a separate message, I will send separately my paper on thermal injury from the 2014

Re: [PSES] Multiple Power cord-sets bundled with product Redux UK Plugs BS 1363 as the standard plug

2021-08-04 Thread Richard Nute
Hi Chuck: https://spectrum.ieee.org/why-does-the-world-harbor-so-many-different-voltag es-plugs-and-sockets https://www.iec.ch/world-plugs Stay safe and best regards, Rich From: Chuck August-McDowell Sent: Wednesday, August 4, 2021 7:50 AM To:

Re: [PSES] Friday question

2021-06-26 Thread Richard Nute
Hi Doug: My employer had a course entitled “Zero Defects.” We were encouraged to apply it to our function. Mine, of course, was safety certification and all that it entailed. Good course as it wanted a scorecard for each activity. Using the scorecard, all my submittals went

Re: [PSES] What percentage of products pass first time?

2021-05-25 Thread Richard Nute
Hi John: “Therefore safety, standards compliance and EMC standards compliance REALLY MUST be an integral component of engineering education – and ALSO for company management…” While I agree, in practice the only time company management addresses safety and other compliance matters

Re: [PSES] What percentage of products pass first time?

2021-05-24 Thread Richard Nute
Hi Charles: Not what you asked for, but a set of principles for success with third-party testing, from a product safety point of view: 1. The design engineer and the product safety engineer should be able to predict the outcome of any test. 2. Testing simply confirms (or

Re: [PSES] Ganged Conductors in Machinery

2021-05-21 Thread Richard Nute
Hi Mark: Here’s a start: https://www.ecmag.com/section/codes-standards/conductors-connected-parallel- each-set-must-have-same-electrical https://www.electricallicenserenewal.com/Electrical-Continuing-Education-Cou rses/NEC-Content.php?sectionID=297.0

Re: [PSES] South African SABS EMC Testing

2021-05-17 Thread Richard Nute
Hi Carl: I cannot confirm that the SABS accreditation requires re-testing. However, this not unusual. I have experienced this same situation in safety testing. If a failure, the complete complement of tests is repeated on the “fixed” unit or another unit. The test house doesn’t

Re: [PSES] EU DoC on Thumb Drive?

2021-05-14 Thread Richard Nute
The symbol ISO 7000-3500 "Electronic instructions for use" is for medical equipment. The related EU regulation is: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:072:0028:0031:EN:PDF This regulation specifies, among other requirements, “exclusive use by

Re: [PSES] Ground Bond Tests

2021-05-13 Thread Richard Nute
Hi Steve: First, one of my clients has been told by their 3rd party NRTL that a ground bond test is required as part of factory/production routine tests, even though it is not required by 61010-1. I have never run into this requirement in my work history and I would be interested in

Re: [PSES] UL Standards Effectivity Dates

2021-05-06 Thread Richard Nute
Hi Doug: In my opinion: 1. UL certifications for a particular equipment are good for the lifetime of the equipment, and don’t need to be updated… unless... 2. If the equipment is refurbished or updated, UL has a program to update the certification to the latest version

Re: [PSES] Schuko CEE 7/7 Plugs for Appliances Sold in Italy?

2021-04-29 Thread Richard Nute
See: https://www.worldstandards.eu/electricity/plug-voltage-by-country/ https://www.iec.ch/world-plugs The US Dept of Commerce used to annually publish a book with all the world plugs, but I can’t find it. Stay safe, and best regards, Rich From: MIKE SHERMAN Sent:

Re: [PSES] Determination of Maximum transient voltage on naval ships

2021-03-03 Thread Richard Nute
Hi Charlie: If the ship can be connected to shore power, then the ship may be subject to "normal" (shore-based) transient voltages, in which case your equipment must meet the clearances for 2,000 volts peak. However, the specified at-sea ship-board 1,000 volts peak is reasonable since

Re: [PSES] Electrical safety certification for US / Canada

2021-02-16 Thread Richard Nute
USA: https://www.osha.gov/nationally-recognized-testing-laboratory-program/current-list-of-nrtls Canada: https://www.scc.ca/en/accreditation/programs/product-process-and-service-certification/directory For both countries, check the standards or products for which a certification

[PSES] FW: Help with petition to be an IEEE President Elect candidate in 2021

2021-01-22 Thread Richard Nute
See following message. You must be an IEEE member to sign the petition. After you log in to your IEEE account, you will get the petition page. Click on the "Annual Election Petition," and you will get the petition page. Best regards, and stay safe! Rich -Original Message- From:

Re: [PSES] UL = IEC ??

2021-01-21 Thread Richard Nute
Hi Amund: First and foremost, both the IEC and UL make money selling standards. Second, UL does not adopt any IEC standard, or most other non-UL standards. UL will test to an IEC standard, and may issue a CB test report, but not the right to use their certification mark. UL will

Re: [PSES] NFPA Codes, law or not?

2020-10-30 Thread Richard Nute
Hi Doug: If I remember correctly, the intro to the NEC says that it is a model for adoption by various AHJs. In Oregon, each edition of NFPA 70 is formally adopted with exceptions and additions. So, most of NFPA 70 is law. The amendments are freely available. Many other

[PSES] electric shock from capacitor discharge -- late adds

2020-10-04 Thread Richard Nute
Here is a summary of capacitor discharge situations with late adds: Operator conditions: Vacuum tube radio/tv with isolated metal trim. (John Woodgate) Service conditions: Vacuum tube radar servo controller. (Doug Powell) Service conditions: UPS capacitor discharge (automatic or

Re: [PSES] electric shock from capacitor discharge

2020-10-03 Thread Richard Nute
Here is a summary of capacitor discharge situations: Operator conditions: Vacuum tube radio/tv with isolated metal trim. (John Woodgate) Service conditions: Vacuum tube radar servo controller. (Doug Powell) Service conditions: UPS capacitor discharge before servicing. (Bansi

Re: [PSES] EMF harmonised standards

2020-10-02 Thread Richard Nute
Hi Brian: Be careful that the customers’ requests are not just asking by rote. Way back when, we had customers asking about UV emissions from a crt. Most glass is a good attenuator of UV, but the asking (non-technical) customers were asking because someone in their company asked

Re: [PSES] electric shock from capacitor discharge

2020-09-29 Thread Richard Nute
with stored energy above x joules have to discharge within N seconds of power off... Cheers, -Lauren Sent from my mobile phone - please excuse typos, brevity, etc. On Sep 29, 2020, at 4:27 PM, Richard Nute mailto:ri...@ieee.org> > wrote:  I am interested in knowing what constru

Re: [PSES] Low Voltage Products and EN 62368-1 and -3

2020-09-29 Thread Richard Nute
Hi Scott: Certification is not a function of the safety standard; it is a function of the certification house. Most certification houses would be happy to certify a low-voltage product. Keep in mind that the various safety standards also address matters other than electric

[PSES] electric shock from capacitor discharge

2020-09-29 Thread Richard Nute
I am interested in knowing what constructions, situations, and products where a capacitive discharge into a body could take place. I am aware of the X and Y capacitors discharge at the prongs of a power plug. I don't immediately know of other situations or products that might discharge a

Re: [PSES] IEEE 291

2020-07-09 Thread Richard Nute
Hi John: Two questions: 1. Can an IEEE member get to see IEEE 291, even if it's only 'read only', free of charge? No. I am an IEEE member and I cannot get any free copy of IEEE 291. By the way, it was withdrawn on January 16, 2004. 2. Is its contents superseded by part of IEEE

Re: [PSES] EN/IEC 62368-1 Instructional Safeguards

2020-06-25 Thread Richard Nute
Hi Jim: IEC 62368-1 contradicts itself. In 8.5.2, the standard specifies two symbols (for moving pats). In F.5.2, the standard references graphical symbol standards, and gives the option of designing a specific symbol. So, the question is: Which sub-clause takes precedence?

[PSES] correct URLs for Canada product certification rules

2020-05-25 Thread Richard Nute
In my earlier message, the URLs got split by my e-mail program. Here are the un-split URLs: https://canada.ul.com/wp-content/uploads/sites/11/2018/05/Acceptance-of-Elec trical-Products-in-Canada-1.pdf http://www.scc.ca/en/accreditation/product-process-and-service-certification

Re: [PSES] Electrical safety testing US and Canada ... Mandatory ?

2020-05-25 Thread Richard Nute
Hi Amund: In the USA, the federal government workplace rules and most other jurisdictions require certification by a NRTL. Most certification houses are NRTL. Here is the current list of NRTLs: https://www.osha.gov/dts/otpca/nrtl/nrtllist.html All NRTLs are "approved" for the standards

Re: [PSES] 61010 vs 60601

2020-05-21 Thread Richard Nute
Hi Steve: I would think that 60601-1 certification is sufficient, and that 61010-1 is not needed. After all, 60601-1 *should be* the more severe standard. Some years ago, I certified a printer that was certified as EDP as medical equipment too. Easy. If you ask a

Re: [PSES] IEC 61010-1:2010 hazardous DC voltage

2020-03-04 Thread Richard Nute
Pete Perkins said: “A major difficulty is that the body effects are from the current while the product committees would like to specify voltage, which is easier to measure and verify compliance.” I’ve had occasion to review a number of IEC safety standards for limits on voltage and

Re: [PSES] IEC 61010-1:2010 hazardous DC voltage

2020-02-27 Thread Richard Nute
Hi Ian: The hi-pot test voltages are from IEC 60664-1, Table F.5. See IEC TR 62368-2, sub-clause 5.4.2.4. IEC 60664-1 is a “… a Basic Safety Publication intended for use by technical committees in the preparation of standards…” See Table A.1 for derivation of the withstand

Re: [PSES] IEC 61010-1:2010 hazardous DC voltage

2020-02-25 Thread Richard Nute
Hi Regan: The “bump” occurred from 1st edition, 1990, to 2nd edition, 2001. The 2nd, 2001, and 3rd, 2010, are the same. Be careful with your math and DC interpretation. The rms voltage limit is 33. The ac peak is 1.414 x 33 = 46.7. The DC is 70, which is unrelated to the AC

Re: [PSES] Mandatory certification

2020-02-20 Thread Richard Nute
Hi Regan: Yes, if that piece of equipment is not within any NRTL purview. Best regards, Rich From: Regan Arndt Sent: Thursday, February 20, 2020 1:22 PM To: Richard Nute Cc: EMC-PSTC@listserv.ieee.org Subject: Re: [PSES] Mandatory certification Hi Rich. If you

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