UL Question - Page 1
Forum section: electronics / general

author: LaserSteve
author_rank: Super Contributor
timestamp: February 24, 2025, 08:15:23 pm
content: So we have a UL approved product at my new employer.UL came in, found an FPGA and a RAM chip with different markings during an inspection, and we are trying to reply.Anyone been through this before. I question the need to recertify based on a standard RAM, and the FPGA is identical as well.Just the factory changed the laser marking for programming the part. FPGA is supplied by a vendor who orders the completed modules from my employer.So costs? Defense for a simple change? Etc.The persons who handled compliance left long ago.Steve

author: Ice-Tea
author_rank: Super Contributor
timestamp: February 24, 2025, 08:32:29 pm
content: Well, say your RAM IC got a die spin (ie shrink) that tends to mean the die is not only smaller but also faster. So rise/fall times may increase and thus radiated emissions may be impacted. If they changed manufacturing sites, potentially the process has changed as well. There's an argument to be made for a lot of stuff like that (not saying it all makes sense).So, I guess you'd have to argue that no die step happened or site change or anything like that has happened. If it's just a laser marking: the manufacturer will have change notices about these, explicitely stating nothing has actually changed.

author: Smokey
author_rank: Super Contributor
timestamp: February 24, 2025, 08:41:56 pm
content: What is the actual compliance standards that your product is said to be violating now? UL has been more of a safety thing in my experience than an emissions thing, which is FCC typically in US.

author: LaserSteve
author_rank: Super Contributor
timestamp: February 24, 2025, 09:45:43 pm
content: UL is changing that number to UL/CSA 61010-1, was UL-508Thanks for the tip on change notices.It is a safety thing.I'm in for a long slog, and the web portal is indecipherable.Steve

author: tszaboo
author_rank: Super Contributor
timestamp: February 24, 2025, 09:51:27 pm
content: Quote from: LaserSteve on February 24, 2025, 09:45:43 pmYour product has a E-File number, go to UL inspector with that, and look up what it's certified for. Or do the same with your company's number.I'm new to certifications in the USA, but I can tell you wholeheartedly that I hate it with every single fiber of my body. So good luck.

author: Analog Kid
author_rank: Super Contributor
timestamp: February 25, 2025, 12:12:57 am
content: Quote from: tszaboo on February 24, 2025, 09:51:27 pmWelll, it's a necessary evil, wouldn't you say?

author: rsjsouza
author_rank: Super Contributor
timestamp: February 25, 2025, 12:53:42 am
content: One thing that I recall from a past life is that, if the part number or marking changes, a formal letter from the device manufacturer attesting compatibility was enough to keep the certification agency at ease.Given certification is mostly a CYA operation, they are ok to have a paper trail that can be used to pass the bucket of responsibility to someone else (the part manufacturer).

author: Analog Kid
author_rank: Super Contributor
timestamp: February 25, 2025, 01:01:05 am
content: Quote from: rsjsouza on February 25, 2025, 12:53:42 amIs it really? If you believe that, or behave as if that's the case, then maybe you shouldn't complain when your wall wart starts smoking ...

author: mwb1100
author_rank: Frequent Contributor
timestamp: February 25, 2025, 01:59:27 am
content: Consider that the certification authority isn't an expert in the product being certified. They don't know the product details inside and out, up and down - all they know is that a certain configuration passed the tests. If that configuration changes, how can they know if it's as good as the configuration that was tested?The two ways that come to mind are:- get some traceable documentation that the things that changed the configuration are equivalent (or better) than the parts that were replaced- retest

author: tszaboo
author_rank: Super Contributor
timestamp: February 25, 2025, 05:20:25 pm
content: Quote from: Analog Kid on February 25, 2025, 12:12:57 amNo, the system is just broken. In the EU we have the same standards applicable to 27 countries. The USA you don't have the same standards for two certification agencies.It's like a good working system from here was run through a dystopian nighmare from Alien, where companies have the absolute power.And they take months to certify something that they know already satisfies the requirements. I hope Musk fires them all.

author: Analog Kid
author_rank: Super Contributor
timestamp: February 25, 2025, 06:51:53 pm
content: Quote from: tszaboo on February 25, 2025, 05:20:25 pmOK. But it's still a necessary evil. The system ought to be fixed, not cast out altogether.Unless it's a system like the financial sector, where the system isn't broken at all but is functioning exactly as it was designed to.

author: bdunham7
author_rank: Super Contributor
timestamp: February 25, 2025, 07:31:47 pm
content: Quote from: Analog Kid on February 25, 2025, 06:51:53 pmA regulatory system is necessary but shouldn't be evil. IMO Fixing that would require openly developed, publicly available standards and regulations, not the privately controlled rent-seeking mess we have right now. That fix really would involve casting out the current system entirely.

author: LaserSteve
author_rank: Super Contributor
timestamp: February 25, 2025, 09:57:09 pm
content: I note the standards are UL/ANSI now, not just UL.So someone did not update a picture in a file, probably on their side.. We have a very subtle change in board layout, an optocoupler being rotated and two additional sources for an FPGA. Schematic is identical. If anything, arc tolerance has improved. I'll let you know what I can from here on out, but it looks like someone simply did not update a picture.Steve

author: Smokey
author_rank: Super Contributor
timestamp: February 25, 2025, 10:29:52 pm
content: Quote from: tszaboo on February 25, 2025, 05:20:25 pmI agree the system is broken in a number of ways, but I'm not sure consolidating standards is one of them.At least on the emissions side of things, CE is significantly more involved (and costly) to test against. Maybe if they hadn't consolidated there would be options that are more friendly to people who are actually trying to make things. Don't get my wrong, FCC was already a pain, but EU really upped the pain threshold with what CE presently is and that does restrict what enters the market.

author: LaserSteve
author_rank: Super Contributor
timestamp: February 26, 2025, 03:55:11 pm
content: MY CTOs next question is minor software revisions. Going from 1.16 to 1.17 for a cosmetic issue. Product has been on the market for over twenty years, no issues. One customer finds a minor issue in a daffynition on a returned number. I spend weeks dealing with the issue. Lesson: Define things well in your manuals.In a change of pace, asking for help on the forum is now approved by CEO / CTO of our 18-employee small business when appropriate. He says "Thanks".We're going to try for "Industry Standard Part" as suggested in a PM due to mergers, re-markings etc. Changing the label to 1.17 worries him, I'm trying to explain that compliance is in the buffer circuits (optos etc) and board layout. I can't find it in the agreed upon file, but will not assume, but check. Watch those vendor brand changes from mergers. If your wondering why you still have say, "LT on the AD"data sheets as an example, I think I know why. It is not just brand recognition implemented by marketing.We'll also ask for an EE for our inspector. Be prepared to teach your inspector the basics if needed.Basically, keep the product compliance below N dollars or drop the product, is my new issue.Some recent examples:Yes, there are UL standards for the Optos, and not surprisingly two different ones. Inspector had an issue with Peak Withstand and RMS across the parts, evidently both manufacturers comply but under two different but equal standards and tests. The wording on the data sheet is expressed in different scientific units.Potting material company changed names, outer case vendor changed names, but plastic and potting used both had proper, current tags and approvals.Point of the matter is you have to keep on the ball with compliance, teaching purchasing to check before buying is going to add a layer. We have documentation from the previous owners, so I will say "Document, Document, Document" when producing the product.Expect your inspector to flip through the provided laptop looking for applicable standards to ask about.Steve

author: rsjsouza
author_rank: Super Contributor
timestamp: March 01, 2025, 04:17:32 am
content: Quote from: Analog Kid on February 25, 2025, 01:01:05 amYes. It is not a belief. I have been working on/off for several years in compliance and testing of our products. In particular, UL was a company that actually had knowledge about the products it was testing, thus creating standards and testing for product safety and reliability - in other words, the buck stopped there in several cases. Given the extreme complexity of products nowadays that would require immense resources locally, they rely more and more in published standards they follow but the in-house knowledge is waning. Compounding to the problem, managing the paper trail has higher margins, thus minute details such as parts rotation and second sourcing (as mentioned by the OP) will take you to a rabbit hole of cash and time just to move paper. Of all the many compliance tests I have ever done in my life, the amount of paper and bureaucracy towers over any real testing done on the product.As a glimpse of the past, I happen to be in the middle of repairing a Hallicrafters radio on my bench that is certified by UL - certainly for the galvanic insulation between its metallic housing and the internal transformerless "All American Five" design. Back in 1950 they were spearheading all this. I am pretty sure other agencies were doing the same back then.

author: LaserSteve
author_rank: Super Contributor
timestamp: March 05, 2025, 08:49:11 pm
content: There is a difference between "Bill of Materials" and "Critical Parts List". Parts cited in inspection were "BOM", not critical parts.Just an FYI for the next person who has to deal with this. Inspector has an Engineering degree, just in a field where all parts are Critical Parts due to extreme pressure and temperatures. Some Education was required on "Jellybean" parts. My supervisor was sweating bullets.A carefully thought-out letter citing JEDEC equivalent parts, quoting IC maker data sheet statements on mergers, and house marked parts used for security reasons, solved most of the problem. One of our BGA parts comes from our customer with house markings, we don't have the design files on that in house. At one point, twenty years ago, one of our designers might have known a bit about it, and what is inside. A sale and a merger later, well... I can tell what it does from the schematic. If it fails, automatic testing and self-testing will catch it.Also, our end customer for this unit pulls samples and tests. If there was a problem we would have heard about it. Mission critical unit for them.With regards to three UL experiences so far:Document, Document, Document... Keep old desktop computers, Have the ability to recover hard drives from 20 years ago. That helped tremendously, as did bringing the designer out of retirement for a day. Worth having an archive off site, which one retired software designer, and one former technician have. They have agreements allowing that with the previous owners of the company. Document your source code.In all three cases, my company did nothing wrong. We simply do not have the compliance staff the company had in its heyday, new owner brought one out of retirement, but her benefits package limits her to part time. While branching out for new opportunities to use the SMD production line as a contract manufacturer, Legacy Product pays the bills.PS, 1970s to 1980s programmers refer to an exclamation point (!) in code as a "Bang" when speaking. The retiree would be speaking, and I had to ask what a "Bang" was. Explosive change in the compiler's operation was what I was told.DOCUMENT< DOCUMENT < DOCUMENT!Steve