EBME Forums Forums Free discussion Free discussion IEC 62353 - MISSED OPPORTUNITY?

I think in Europe that most purchasers and operators of electrical safety testers intended for routine electrical safety testing would be deterred from purchasing instruments with a dielectric withstand test unless they're manufacturers; given the risk of damage to products and injury to operators.

I'm not certain if these functions wouldn't be disabled by OEM sellers if being sold into certain markets.

Perhaps this is down to an awareness of the health & safety implications and H&S legislation as much as the electrical test standards that are applicable. It doesn't make sense for manufacturers of medical electrical safety testers to provide a product that damages devices and potentially makes them unsafe.

Just a tip: the discussion on leakage current measurement i said before can be read at
http://ewh.ieee.org/soc/pses/Downloads/newsletters/88v01n8.pdf

There´s also an interesting discussion on the pitfalls of pass/fail test in http://ewh.ieee.org/soc/pses/Downloads/newsletters/90v03n1.pdf

In the Technically Speaking column.

Well, the problem is that people buy a separate hipot.

Thanks for that - actually it was a bit of a rhetorical question just to illustrate what I'm getting at RE: 62353 versus 60601-1 and the potential for not necessarily achieving comparable safety tests, using different standards intended to ensure safety of medical devices, in all cases.

Not that I have anything against individuals posting others opinions or information, rather than expressing their own ideas or opinions, or technical understanding.

Unless the operator is fully aware of what's being measured and typical values that are expected plus the maximum limits under NC and SFC then 62353 may not be equivalent to or compatible with tests undertaken by 60601-1, under all circumstances, in my opinion.

I think to be credible then 62353 must have comparable leakage limits to the 3rd edition 60601-1 standard for example - it uses the same patient equivalent load doesn't it?

By a definitive pass/fail what I'm getting at is that an IUT may pass under one standard and not necessarily in another, under certain circumstances, if limits, etc, are not fully compatible and given the different methods and limits used to test devices.

This is bound to lead to confusion at some point when routine testing, if devices manufactured to 60601-1 fail 62353 for example, when changes in leakage limits are not aligned between standards, concurrently.

My point previously being that this is only required if they're a manufacturer since Hi-pot is potentially damaging, i.e. stresses, the IUT. Otherwise if they're routine testing then this is not required.

That surely will lead to confusion. Now imagine devices tested according to the new 60601, in which manufacturers have the option to reduce or increase the limits as needed and if the risk remains acceptable.

The truth is,they´re trying to fix a problem - the lack of a strong link between pre and post production, that in reality can only be solved by one player - the manufacturer.

I think we're at crossed purposes here - we're discussing routine testing of medical devices, i.e. 62353, not manufacture, and I'm comparing aspects of the standard we use for routine tests, a subset of 60601-1, with aspects of the 62353 standard and thinking about the possibility of incompatibility between them if a department uses both standards for acceptance, evaluation and routine tests.


That is exactly my argument. My problem with 62353 being an independant standard having the potential to have different limits for leakage compared to 60601-1 is that we are testing the same devices using the same methods hence I expect the leakages to be the same under NC at least. Have you looked at 62353 and compared to 60601-1 3rd edition?

When one standard changes limits then the other must surely have compatible limits considering leakages at least? Also earth bond, IR, etc, etc. If you look at the 62353 standard are all the leakage limits equal to those for 60601-1 3rd edition under NC at least? If not then why not? Are earth bond limits the same under all conditions?

Yes 60601-1 is a manufacturing standard for medical devices but, de-facto, it has become established as a standard whose non-destructive tests and limits are used for routine testing of medical devices in the field. One feature that is not usually included in such devices (I've used many) is Hi-pot testing; this is generally reserved for use in manufacturing since it's a requirement to test assemblies during development/manufacture and not generally in the field.


Essentially I agree but it would go some way to fix the problem if basic leakage and earth bond limits were unified for the same type of tests. Also if both standards were updated concurrently or 62353 were a subset of a 60601-1 standard that included aspects of servicing/maintenance provision generally.

I'd like to see the manufacturers test every device out there - it's got to be done with the cooperation of those performing testing in the field, 3rd parties and purchasers servicing organisations. All interested parties in fact - not a range of manufacturers trying to sell products on the back of standards, in my opinion.

Well, the limits are different simply because they do not have to be too strict or because they cannot be too strict (for example the earth resistance adding 100 mOhm, as explained on the annex to 62353). I understande your point when you say that it can be confusing having different limits for the "same" tests, but this is the point..the objective of the tests aren´t the same. And yes, i know that IEC 60601-1 is used for routine tests, and this was the main motivation for IEC 62353, for people to stop using 60601 as it´s not "fit" for routine tests.

Your comment about cooperation i just what i tried to illustrate with the third edition risk management comment - manufacturers, as the experto on the devices, should make it clear what tests are needed and should inform and cooperate the other interested parties.



I think you got to the point, at least in my view of things. This standard was published in a bad time, a transition from the old standard which a lot of people used in a fixed way, and a new standard which is as open as it can get.

If this is the case then why does IEC62353 use the 2nd Ed 60601-1 leakage limits then? Limits for leakage under NC and SFC become particularly important when considering potential for micro-shock. Medical devices and standards that test for them should be consistent if the standards are to be compatible and conducive with patient safety - seeing as the patient load and risk of micro-shock remains the same at similar currents irrespective of the different standards.

Wow, the limits are the same? Are we talking about the same document?