UL Compliance

[[email protected]]

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"

http://www.digikey.com/product-search/en?lang=en&site=us&KeyWords=cp-065b-nd

Is this connector a good choice?

2. I am using the following box

http://www.okwenclosures.com/products/okw/ergo.htm

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

3.

I have gathered following knowledge so far about the tests

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

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

Jess

 

[Joerg]

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.

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.

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"

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.

http://www.digikey.com/product-search/en?lang=en&site=us&KeyWords=cp-065b-nd


Is this connector a good choice?

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

2. I am using the following box

http://www.okwenclosures.com/products/okw/ergo.htm

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

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.

3.

I have gathered following knowledge so far about the tests

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

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.

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

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.

 

[[email protected]]

Hi,

I am using the following UL approved charger

http://www.digikey.com/product-search/en?lang=en&site=us&KeyWords=T1233-P5P-ND

jess

 

[[email protected]]

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

 

[Michael Karas]

[This followup was posted to sci.electronics.design and a copy was sent
to the cited author.]

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

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

 

[Joerg]

Hi,

I am using the following UL approved charger

http://www.digikey.com/product-search/en?lang=en&site=us&KeyWords=T1233-P5P-ND

That might not fly for an ECG, since leakage under no-fault in some
jurisdictions is expected to be <10uA. My copy of 60601 lists 10uA for
no-fault and 50uA for S.F.C. for cat CF equipment. If you can get away
with cat BF (I usually can't) maybe it's ok but ask UL about it.

Personally I would never go above 10uA even if it was BF.

 

[Joerg]

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?

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.

3. How do they determine ingress testing? what knid of methods will they use?

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.

 

[Martin Riddle]

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.

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

 

[Joerg]

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

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

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.

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.

 

[boB]

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"

http://www.digikey.com/product-search/en?lang=en&site=us&KeyWords=cp-065b-nd

Is this connector a good choice?

2. I am using the following box

http://www.okwenclosures.com/products/okw/ergo.htm

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

3.

I have gathered following knowledge so far about the tests

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

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

Jess

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

 

[whit3rd]

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)

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.

 

[[email protected]]

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

2. For example, I am using plastic enclosuer with DC battery ( No battery charger connected at all). Now, the standard talks about leakage currents orsingle fault conditions with enclosuers tied to earth. My enclosuer is nottied to earth at all. The standard does not have any example covering my device.

3. I do not understand that why UL will have problems with their own approved charger. The leakage current is 0.1mA as mentioned in its data sheet. Ican not find any IEC and UL approved charger with lower leakage current. How will I explain this issue to UL if they come back to me saying that charger is no good. Though if user plugs in the charger , the unit will disableitself and nothing can be done.
jess

 

[Joerg]

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 explanations or material about single fault condition or
leakage current testing.

2. For example, I am using plastic enclosuer with DC battery ( No
battery charger 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 device.

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

3. I do not understand that why UL will have problems with their own
approved charger. ...

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.

... 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. ...

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

... How will I explain this issue to UL if they come
back to me saying that charger is no good. Though if user plugs in
the charger , the unit will disable itself and nothing can be done.

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.

 

[Fred Abse]

I need some advise regarding compliance testing done by UL. We are
intending to design a biomedical device ( an EKG machine) .

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.

 

[[email protected]]

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

 

[Fred Abse]

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

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

 

[[email protected]]

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

through ECG electrodes.

So, UL will short all the inputs of the ADS1298 to ground ( Data sheet: http://www.ti.com/lit/ds/symlink/ads1298.pdf)

and measure the leakage current. Am I right?

I am using ADS1298 to digitize the ECG signal.
jess

 

[Joerg]

So, UL will short all the inputs of the ADS1298 to ground ( Data
sheet: http://www.ti.com/lit/ds/symlink/ads1298.pdf)

and measure the leakage current. Am I right?

Normally that's how it's done.

[...]

 

[Martin Riddle]

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.

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

 

[[email protected]]

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