UL Compliance

Hi ,

I need some advise regarding compliance testing done by UL. We are intending to design a biomedical device ( an EKG machine) . And we want UL to do compliance testing aganist the following standards

  1. UL 60601-1 (2006)
  2. IEC / EN 60601-1 (1998+A1+A2)
  3. ANSI / AAMI ES60601-1 ( 2005+C1+A2)
  4. IEC EN 60601-1 (2005/2006 + C1+ C2) ( Europe, CE)
  5. 60601-2-26(2002)

I have no information about the testing methods or what kind of test UL will perform on this device. I do not know about reasons that they can use to reject the device.

EKG machine:

  1. Operated by UL approved 3.7V, 1A, LiIon battery. Battery can be charged by a UL approved charger. But when the battery is charging, EKG machine will be completely shut down by software. I am using the following "power connector"

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Is this connector a good choice?

  1. I am using the following box

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I do not know what should be the ingress ratings of the box and flammability ratings. Any advise!

  1. I have gathered following knowledge so far about the tests

  2. Single Fault Condition : I am not able to find any clear answer for that. Can anyone give a simple to undertsaned explanation?
  3. Ingress rating test: do not know how will they test
  4. EMC test
  5. Enclosuer mechanical robustness test.

What other tests should I keep in mind before we start designing this machine.

Jess

Reply to
jsscshaw88
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Best is to tell them into which market you want to go and they'll test to the right standards. My advice would be to also get a quote from a TUEV outlet in your area.

L'il red flag goes up: It is almost inevitable that at some point users will try to use the unit with the charger plugged in. You can (and should) prevent that via software but someone could still make the connection and try. Then the power source must also be 60601 and patient-contact rated, single-fault-proof, and so on. IME simple wall warts never are.

If you meant limited to 1A charge current it could work. I would never send the "rated" 5A over it.

Mine we always sealed. Watch that battery compartment. Hard to see but if it doesn't have a rubber ring seal chances are thatan incredible amount of crud accumulates inside over time.

It means that if any kind of fault occurs the unit must still fulfill

60601. Often at a relaxed spec, for example for leakage current.

Mind EMC, always a concern with plastic enclosures. Have an expert look over the design before committing because you have to go through EMC testing. Also, cleaning should be looked at. What if a user dunks it into water? No matter what the manual says, someone will do that. Also, check out G-ratings, for example if it falls onto a tile floor.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Hi,

I am using the following UL approved charger

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jess

Reply to
jsscshaw88

I meant to ask following

  1. How will UL measure leakage current.?
  2. How will UL run the tests for single fault condition? How many single fault condition tests they got for this device?
  3. How do they determine ingress testing? what knid of methods will they use? jess
Reply to
jsscshaw88

Why don't you go to the horse's mouth and ask the UL these questions??

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Michael Karas 
Carousel Design Solutions 
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Reply to
Michael Karas

That might not fly for an ECG, since leakage under no-fault in some jurisdictions is expected to be

Reply to
Joerg

They measure it with DC and RMS meters et cetera. S.F.C. will usually be reviewed from schematics and then, for example, the PE connection is popped. And so on. They'll look at what could go wrong and test under that fault.

Drip test, per IEC publication 529. But it depends on how you advertize the unit (outdoor use?). So it could either be drip, splash or watertightness tests.

Anyhow, it looks like you seriously need help from an engineer who is familiar with this stuff.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

There's touch current too in the new standard. And Risk Management, ugh.

Best to start with buying the standard(s) reading, and go to UL Universiity and take the courses. Or get a consultant. This is not a individual task, but a company task.

Cheers

Reply to
Martin Riddle

Same as in all EN standards. Sometimes I have the feeling that the paper industry had a hand in the 2012 changes :-)

Yup. And make sure the engineers read it, all of it. Because if you don't design with 60601 always in the back of your mind it is highly likely to fail. Just like one has to do it when branching into other industries. Before getting onto my first aerospace design I read RTCA/DO-160 several times cover to cover, on my own time.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

You should purchase the necessary specification, UL or otherwise. It may also require other specs such as UL 1998.

You may also want to consider another NRTL besides UL, like, Intertek (ETL) or CSA or TUV or whoever else can test the product because UL does not always follow the test spec.

Are there any FDA requirements as well ?

boB

Reply to
boB

Boy, do you EVER need advice. Pick one of these 60601-1 variants, and ignore the rest. And don't ask on the internet what the testing is, read the appropriate standard (and appendices)= that standard document IS THE ONLY SOURCE of information you can rely on.

Various agencies adopt and cross-adopt versions of the evolving standard from time to time; you've indicated you want to check your design against four different snapshots of the SAME STANDARD, which will multiply your certificatioin requirements unreasonably.

Reply to
whit3rd
  1. I tried to read the standards. The thing is that I need some time to get familiar with the way these standards have been written. In the meantime, I was hoping that someone can guide me to the easy to understand explanatio ns or material about single fault condition or leakage current testing.

  1. For example, I am using plastic enclosuer with DC battery ( No battery c harger connected at all). Now, the standard talks about leakage currents or single fault conditions with enclosuers tied to earth. My enclosuer is not tied to earth at all. The standard does not have any example covering my d evice.

  2. I do not understand that why UL will have problems with their own approv ed charger. The leakage current is 0.1mA as mentioned in its data sheet. I can not find any IEC and UL approved charger with lower leakage current. H ow will I explain this issue to UL if they come back to me saying that char ger is no good. Though if user plugs in the charger , the unit will disable itself and nothing can be done. jess
Reply to
jsscshaw88

Your ground return to human skin is not through the enclosure but through ECG electrodes.

You don't know that yet. It all depends on what your ECG unit will be categorized as. If cat CF then they will likely not bless an assembly with this charger. Have you thought about the category? I believe that should be the first action item here.

When UL approves something this does not mean it is approved for all kinds of uses.

That's why we always design our own iso barriers for anything with cardiac or skin contact :-)

But the user can still do that while the ECG electrodes are connected to his/her skin, wondering why the thing doesn't work. Meaning the risk isn't 100% mitigated by a SW disable upon charger connection.

Another issue, speaking from experience here: If the charger DC plug is a fairly common version users will try to cheat when they lose or damage the charger that came with your unit. They may by one from a local thrift store, plug it in, and "Hey, it works!".

IMHO there needs to be a full isolation inside the ECG unit. I always make mine cat CF and also defibrillator-proof.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

I hope that you are more proficient in understanding compliance standards than you appeared to be in understanding inductance, resonance, and Helmholz coils, a year or more ago.

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"For a successful technology, reality must take precedence  
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Reply to
Fred Abse

Well, I had to stop because of FEMM. I am still trying to understand FEMM.

Reply to
jsscshaw88

You don't need FEMM, at least not yet. What you do need is a good basic grounding in electrical theory. Sophomore level.

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"For a successful technology, reality must take precedence  
over public relations, for nature cannot be fooled." 
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Reply to
Fred Abse

So, UL will short all the inputs of the ADS1298 to ground ( Data sheet:

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and measure the leakage current. Am I right?

I am using ADS1298 to digitize the ECG signal. jess

Reply to
jsscshaw88

Normally that's how it's done.

[...]
--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

There is only one 60601-1 standard now, it's the 3rd Edition. He can pick a varianat suchas IEC or AMMI, but its still 3rd Ed. Jun 30th was the last day anyone would accept 60601-1 2nd Ed

Cheers

Reply to
Martin Riddle

The thing is that OSHA does not recongnize 2nd edition. jess

Reply to
jsscshaw88

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