I have seen things that were independently tested retested when they were used as a part of a subassembly or component of a system. This was medical stuff but even if they took 1 piece of equipment, bolted it to a cart, and connected it to another piece of equipment with a serial connection, they would need to test the whole apparatus, even though one of the equipments was being tested and sold for a decade, I was told because they decided to re-sell it together, because the product they advertised required both pieces of equipment to do what it was meant to do. The only difference was the brackets and 8 attachment screws and the cart, but they still retested the whole thing.
I don't know if you can get around it by having two sections on your website, one of power supplies, and one of drivers, and make no real statements as to what the power supply is used for. I would consider it to be unethical and against the spirit of the laws though.
* I don't know consumer stuff though, I only saw medical/industrial to big vendors that tended to care.
I don't know if it still applies to kits, but I am pretty sure if you make an enclosure that has a power plug on it to mains, and all the crap is wired inside with a harness, you need to test it as a new product. I would like to know where a bunch of distributed crap connected by loose wires that is meant to be mounted all over a wall stands and where the line is drawn. Maybe regulations related to telecom and wired LAN apply? I never even glanced at those though.
I am almost certain if you put it in a enclosure and have a
harness its a product that needs to be tested as is with wiring as will be, even if everything is tested independently. Maybe if every subassembly has its own AC mains input you don't need to test so long you meet electrical code requirements? That would be no different then stacking everything in a shelf.. but then again you don't wanna sell a shelf that makes interference problems. It must have something to do with mechanical mounting and wiring harnesses.
Also, customers tend to get angry if you say they can use your thing as a subassembly, then they find out its built like shit and gives them EMC problems, so they compare your work to their work and go like WTF is this SHIT? That's when you get invaded by a boarding party that starts making demands to your assembly line, if you wanna play with the big boys.
At that time you basically have a parole officer that starts making nonsense demands and throwing their weight around. Best not to attract attention. Because quality. I have also seen the moods and facial expressions of those effected.
I have seen it happen (not only once) and its well documented.
microwaves101.com
"Boarding party
Customer group on a fact-finding trip to your lab, to see why you are late and over budget (or a group that your company sends to a vendor for similar harassment, which is much more fun.)"
And it can be harmful and beneficial to a company, they might offer help but it means more procedures and overhead and sometimes downright retarded horse shit involving cleanliness and organization. Your ISO book will get fatter. I suspect this is why managers that no one knows the reason for start to appear. This tends to hurt the wallet and damper important R&D.
Have also heard about this from a friend of mine that started to do government contracts. I don't remember but I think it started because of quality problems with welding and turned into floors not being clean enough.
Also with my other friend that had overseas management start appearing and making demands because of some bad shipments. Most were irrelevant to the fault, equipment that worked fine started being replaced.. all sounds good till you realize its wasteful and your employees are pulling longer shifts for no god damn reason replacing furnaces and doing stupid preventative maintenance tasks that don't fit the profile of the factory. I think because of an uncalibrated thermocouple and easily controlled humidity problems. So they had went from a normal schedule that Americans find reasonable to some kind of 11 hour 5 days a week shit with a extra day or two off every two weeks or something ridiculous like that. I heard it was soul grinding.
Don't get pinched son