Electronics > Projects, Designs, and Technical Stuff

Operating a CE marked power supply out of spec

(1/2) > >>

Mark:
Hello,

If we purchase a CE marked power supply that has a DC input voltage range Vmin to Vmax but we intend to operate it outside that range (lower than Vmin) will it invalidate the CE mark?. 

Thank you. 

grifftech:
Will it even work?

Mark:

--- Quote from: grifftech on February 26, 2019, 03:00:35 pm ---Will it even work?

--- End quote ---

Suppose the manufacturer specifies a DC-DC power supply for 120VDC minimum.  If we want to use the PS at 90VDC, and we test it down to 80VDC and "it works"....

I am thinking that is a Bad Idea because we need to treat the PS as a black box.  The lower voltage will result in a higher input current and could cause components or traces to overheat, maybe the transformer winding will get too hot and damage the insulation so that it fails sometime in the future when used at a higher voltage...


Gyro:
It depends how it is specified - for instance a universal input SMPS  that is specified for 120 - 240V [EDIT: AC] mains with actually be designed to operate over a 90 - 264V input range to cope with mains voltage tolerances. Of course operating at 90V gives you no further negative tolerance allowance. 80V sounds too low.


--- Quote ---I am thinking that is a Bad Idea because we need to treat the PS as a black box.  The lower voltage will result in a higher input current and could cause components or traces to overheat, maybe the transformer winding will get too hot and damage the insulation so that it fails sometime in the future when used at a higher voltage...
--- End quote ---

Exactly so (although transformer insulation damage is probably less of a concern). The switching devices etc will certainly be under higher current stress though. EMC emissions could also possibly go outside limits.


EDIT: Of course, in a production environment, using any component, be it a resistor or a 'black box', outside its specifications is very bad (unacceptable) practice that will usually end in tears.

SiliconWizard:
Who is "we", and what's the intended purpose? Are you designing a product or is it as an end-user?

If you're designing a product, want to use a power supply for it (that you'd buy as a CE-marked end-product), and this power supply would be an integral part of your product, the CE mark of the power supply, which would then just be a component of your product, doesn't really matter. The CE mark of a product is not a simple addition of already CE-marked parts. So if this is your question, you're probably asking it wrong.

Whatever you do, you'd have to CE-mark your product as a whole. Power supply included. The fact that you'd be using it out of spec is a clear indicator, IMO, that you'd be using it as a component of your product and not just as an off-the-shelf accessory, so again its own CE mark is not the question. Its compliance to some standards (UL for instance) would certainly help in your CE mark process, but if you're using it out of spec, obviously you can't claim the standards it's compliant with. So not only will you have to prove your whole product is compliant, including the power supply and all testing concerned, but you would also lose any warranty or ability to get back to the manufacturer of this PS in case of any fault (even if not related to your using it out of spec...)

Overall, this all sounds like a very bad idea, because you'd take full responsibility for the PS and would have to have it re-tested with your own specs, which could be costly, but also you'd probably never be able to get complete compliance without having the technical documentation, include the schematics...

If, OTOH, you're asking this as an end-user, then this is a different question and yes that would invalidate any claimed compliance, thus ultimately the CE mark, and also any warranty. Possibly if that ever caused a fire, you could also get into nasty troubles with your insurance company.


Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod