How do you know that new appliance you bought won’t burn your house down? Take a look at any electrical appliance, and you’ll find it marked with at least one, and most often, several safety certification marks such as UL, DIN, VDE, CSA or BSI. Practically every electrical product that plugs into utility supply needs to go through a mandatory certification process to ensure it meets these conformity test requirements. Some examples include domestic and industrial electrical appliances, tools, electrical accessories, consumer electronics and medical electronics.
When you look through a typical safety test standard, you’ll notice it breaks down the various tests in two categories. “Type” tests are conducted on prototypes and samples of the final product or its individual parts and components, and are not generally repeated unless there are changes in design or materials. “Acceptance” tests are routine verification tests conducted on 100% of the products produced. For example, a typical Type test would be used to check the fire retardant properties of the plastics used in the manufacture of the product during development, while a Routine test would be carried out to check for high voltage breakdown or leakage and touch currents on the production line.
Nowadays, a majority of countries around the world adopt standards created by international organizations such as IEC, ISO, and ITU, then fine tune them to suit local requirements. The IEC works by distributing its work across almost 170 Technical Committees and Subcommittees which are entrusted with the job of creating and maintaining standards. One of these committees is “TC89 Fire hazard testing” whose job is to provide “Guidance and test methods for assessing fire hazards of electro-technical equipment, their parts (including components) and electrical insulating materials”. These tests are why we feel safe enough to plug something in and still sleep at night.
Practically all electrical products need to confirm to this set of tests as part of their “Type” test routine. This committee produces fire hazard testing documents in the IEC 60695 series of standards. These documents range from general guidelines on several fire hazard topics to specific instructions on how to build the test equipment needed to perform the tests. It’s interesting to see how some of these tests are carried out and the equipment used. Join me after the break as we take a look at that process.
Continue reading “Fire Hazard Testing”
The International Electrotechnical Commission (IEC) is an international body that issues standards on a wide range of electronics-related topics. How wide? Their mandate seems to span rules for household product safety to the specification of safety logic assemblies in nuclear power plants. Want to know how to electrically measure sound loudness? Test methods for digital door lock systems? Or maybe you’re interested in safety interlock systems for laser processing machines. There’s an IEC standard for that too.
Unfortunately, this information is kept behind a paywall. OK, it’s a lot more like a pay fortress. They really, really don’t want you accessing their documents without first coughing up. This is a shame.
The IEC doesn’t just make the standards in a vacuum, however. Before the scribes touch their chisels to the stone tablets, there are draft versions of the standards that are open for public comment by those knowledgeable in the field. And by “those knowledgeable”, we mean you, dear hacker. Head on over to the public commenting page, sign up, and you’ve got free access to every document that’s currently up for discussion.
Now, it does look like the IEC doesn’t want you sharing these PDFs around — they watermark them with your username and threaten all sorts of things if you use them for anything other than commenting purposes — so don’t go abusing the system. But on the other hand, if you are a private individual who knows a thing or two about a thing or two, we think you’re entirely right to look over their shoulders. Let us know in the comments if you find any gems.
They’ve even got a weekly update feature (in the registration pages) that’ll keep you up to date. And who knows, maybe your two cents, submitted to your country’s chapter of the IEC, will influence future international standards.
Thanks to [Johann] for the great tip!
After months of cross-disciplinary meetings, some of the largest professional associations just announced their plans to submit an entire standard set for engineers with egos too fragile to accept design criticism. The Special Snowflake Standard or S2 (in compliance with Godwin’s law) ensures compromised mechanical and electrical integrity by ignoring proper design methodologies for more fluid definitions of success. The Special Snowflake Standard allows the modern engineer greater flexibility in avoiding self-improvement in their field while maintaining an advanced level of apparent competency.
The Standard follows an ingenious randomly generated naming scheme to hinder cross-checking and look-up. The honesty being the only change from the current system. It took us a while to navigate the websites built to serve the standards, as they themselves were built to the W3C.S2.01.d.f4r.7 Special Snowflake Standard For Geriatric Exclusion From The Study of Modern Web Development and therefore were only accessible through the Gopher protocol running specifically on SPARC workstations.
Nonetheless, after working through multiple W3C.S2.u.r.f4.u17 Probably PEBKAC Self Exclusion Of Responsibility Standard errors, we found a few standards we’re really excited about. Let’s take a look at a the highlights:
Continue reading “World Standard Organizations to Release Entirely Reworked Standards”