I am brand new to EE/ECE and am aware that companies such as UL offer a gammit of services such as:

  • Circuit verification (they verify your schematic does what its supposed to do and doesn't have any design smell to it)
  • Circuit testing (they verify the functional correctness of your circuit/electronic system)
  • Circuit certification (not sure how this really differs from testing, but the end result is that you get to put their fancy "certified" logo on your product)

I completely understand the value of the first two: verification gives you confidence from a 2nd set of eyes that your design is valid. Testing gives you confidence that you are in fact ready for production (or at least prototyping). But the certification service is what has me baffled. As a consumer, it would never naturally occur to me to check some new stereo, MP3 player, or remote control helicopter for a "UL" logo prior to using it. You guys might, but then again, you're EE/ECE peoples :-)

So is the certification just for establishing trust/confidence in the product? Does it have implications with regulatory bodies or insurance carriers? If so, what bodies/carriers/policies? Are there "electronics insurance carriers" that specialize in selling "Electronics Liability" policies to electronics suppliers, and perhaps they only sell the policies for "certified" products? Of what real-world, practical use is the certification?

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    \$\begingroup\$ The practical use is to sell your product to a customer requiring the certification. \$\endgroup\$ – Eugene Sh. Jul 8 '15 at 14:46
  • \$\begingroup\$ Thanks @EugeneSh. (+1) - can you comment about the insurance-centric questions...ever heard of anything like carriers that specialize in "electronics liability" policies, etc.? Thanks again! \$\endgroup\$ – smeeb Jul 8 '15 at 14:47
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    \$\begingroup\$ Certifications are done against specific standards that, in turn, are sets of generalized requirements from specific types of products. Each institution/industry is employing some of the standards as their general requirements based on the use cases and sensitivity of the application. So if you are developing a product for, say, military, they will have a strict set of standards your application will have to be certified against, meaning it passed all of the required tests to be compliant with military requirements. \$\endgroup\$ – Eugene Sh. Jul 8 '15 at 14:53
  • \$\begingroup\$ Thanks again @EugeneSh. (+1 again) - and so in no way, shape or form does insurance enter into the equation for certification? \$\endgroup\$ – smeeb Jul 8 '15 at 14:58
  • \$\begingroup\$ An insurance company/institution might require from the insured to use some equipment only compliant with a specific standards, which they believe minimize the risk of insurance claims. For example an auto-insurance company might require your auto breaks to be checked(certified) every year. In case of electronics, if for example you have a TV which did not pass some safety certifications and then caused a fire in you home, the insurance company might come and say "Ok, you have used an unsafe TV, we are not going to cover it." \$\endgroup\$ – Eugene Sh. Jul 8 '15 at 15:03

UL listing is most common in consumer goods, and appliances in particular. The reality is the consumer doesn't really care whether or not a product is listed. The people that care are the retailers and insurance companies.

Consider a Wun Hung Lo toaster with so many corners cut in design and manufacture, it's a circle. Walmart buys a shipping container at $1 per piece, and sells them for $4.99, until someone's house gets burnt down by the shoddy design and assembly. Walmart gets sued. The alternative is doing the same thing with a UL listed design. The UL listed design is insanely unlikely to burn down someone's house because it's been tested torture tested to standards to prove it won't. Retailers are glad to carry such products and insurance companies willing to insure the manufacturers because the risk is much lower.

That's not to say the UL label is a guarantee of safety. There are a lot of products coming out of China with fake certifications, including UL and CE. Just look at some tear downs of fake Apple chargers. They're criminally dangerous, but marked just like the genuine products. Only trust the marking if it comes from an authorized distributor.

  • \$\begingroup\$ Thanks @Matt Young (+1) - please see my question/comment underneath JRE's answer - I have the same question for you. Also, you mentioned that certification is "extremely" expensive. Any general idea what you mean by "extremely"? $10K USD? $100K USD? $100 million USD, etc.? Thanks again! \$\endgroup\$ – smeeb Jul 8 '15 at 15:35
  • \$\begingroup\$ @smeeb I don't really play in that field, but the only place I would expect any kind of UL listing requirement would be the battery charger since it connects to mains. For our products that connect to mains, we use UL certified power supplies from reputable companies. I seem to remember hearing that UL certification was about $100k. For your helicopter though, you'll have some considerable expense in EMC testing. It will be an intentional radiator, and depending on your design choices those tests can come in close to $50k. \$\endgroup\$ – Matt Young Jul 8 '15 at 15:50

A very large part of the meaning of the certification comes from the full name. UL is short for "Underwriter's Laboratory."
Back when UL was founded, Underwriter was a term for insurance companies. The labs were founded to give the insurance companies a way to check materials and devices before agreeing to insure a company that used or produced the materials or devices. To this day, insurance companies will get real picky about paying out on a policy if they determine that, for example, a fire was caused by a device without a UL certification.

As a consumer, I wouldn't buy or use a device without UL certification. Any company that doesn't have their stuff certified has probably cut corners somewhere (if they are producing mass market consumer goods. Low volume specialty stuff is a different thing entirely.)

An exception is when I know the danger, will not use the device continually, and am ready to deal with bad things that might happen.

I'm NOT gonna give my kids an un-certified wall-wart for a cellphone. I might use an uncertified one if I'm lashing together something that will only be used for a few minutes and might destroy the wall wart anyway.

I certainly won't leave un-certified devices where the wife or kids could get at them, and honestly I don't know when I last bought (or had to not buy) a piece of equipment that wasn't certified.

In response to Matt Young: This all applies to household, mains powered devices.
I agree that there are things that are intrinsically safe enough that I won't worry - like your calculator, provided it runs only on batteries. If it has a battery charger, though, I'll be looking for the certification.

UL-Listing isn't a binary good/bad but is a good way for a consumer to avoid bad things. Yes, some companies will fake it, but you've got to start somewhere.

If it is mains powered but not UL-Listed, there's got to be a good reason for me to trust that device - known manufacturer, special use equipment, only source for a particular device or just flat out emergency and have to use what is available.

  • \$\begingroup\$ None of our products are UL listed. Does that mean we cut corners? No, not at all. The process is very expensive, and just doesn't make sense unless it's a high volume product, or the customer requests it. \$\endgroup\$ – Matt Young Jul 8 '15 at 15:22
  • \$\begingroup\$ Yeah, but you say yourself you aren't producing for a mass market. I'd expect you (the company) to take more care with products like that, if for no other reason than to protect your reputation. And whatever it is you produce might fall into that category of "gotta use it anyway, but watch it like a hawk." \$\endgroup\$ – JRE Jul 8 '15 at 15:28
  • \$\begingroup\$ Thanks @JRE (+1): I guess a concrete example would help ultimately answer my question. If I was making, say, an RC helicopter, what types of insurance carriers/policies would I be engaging (aside from normal general liability, professional liability, etc.) that are specific to electronics. In other words: what carrier/policy actually requires the UL/CE certification? Thanks again! \$\endgroup\$ – smeeb Jul 8 '15 at 15:34
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    \$\begingroup\$ My problem here is you're treating UL listing a binary safe or not safe. There are tons of products on the market that are perfectly safe and never will be UL listed. Take the TI-86 on my desk for example, CE marked, not UL listed. It's never going to hurt anyone, unless you throw it really hard. I think it's important to note that it really doesn't matter until you plug something into mains. \$\endgroup\$ – Matt Young Jul 8 '15 at 15:38
  • \$\begingroup\$ Right you are. I was thinking entirely in terms of mains powered equipment. Most battery powered stuff doesn't matter, and I don't bother to look at that. Anything household device that has a substantial battery will also have a certification for the charger and other things. No, UL certification isn't binary good/bad but is a good starting point and a device either needs to be obviously safe (like your calculator) or have some good reason why I should use it with out a certification. \$\endgroup\$ – JRE Jul 8 '15 at 15:57

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