Re: [PSES] MD vs LVD for Laboratory Equipment

[Nyffenegger, Dave]

With regards to “electrical requirements for the LVD and mechanical 
requirements for the MD,” the MD already states that the safety objectives of 
the LVD apply to the MD.

Machinery Directive 2006/42/EC ANNEX 1 section 1.5.1 states ”The safety 
objectives set out in Directive 73/23/EEC shall apply to machinery. However, 
the obligations concerning conformity assessment and the placing on the market 
and/or putting into service of machinery with regard to electrical hazards are 
governed solely by this Directive.”  The Guide to Application of the Machinery 
Directive 2006/42/EC 2nd Edition June 2010  clarifies

§ 63 Machinery covered by the Low Voltage Directive
One of the objectives of the revision of the Machinery Directive was to clarify 
the
borderline between the scope of the Machinery Directive and the Low Voltage
Directive 2006/95/EC20 (formerly Directive 73/23/EEC as amended) in order to
provide greater legal certainty.

Article 1 (2) (k) lists the categories of low voltage electrical and electronic 
machinery that are excluded from the scope of the Machinery Directive. 
Electrical machinery that is not in any of the categories listed in Article 1 
(2) (k) (and that is not concerned by one of the other exclusions) is in the 
scope of the Machinery Directive. When such machinery has an electrical supply 
within the voltage limits of the Low Voltage Directive (between 50 and 1000 V 
for alternating current or between 75 and 1500 V for direct current), it must 
fulfil the safety objectives of the Low Voltage Directive – see §222: comments 
on section 1.5.1 of Annex I. However, in that case, the manufacturer’s EC 
Declaration of Conformity should not refer to the Low Voltage Directive.

-Dave

From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Friday, March 31, 2017 2:55 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MD vs LVD for Laboratory Equipment

I’ve said this before, but laboratory equipment is the Redheaded Stepchild of 
Regulatory Compliance. It’s like the powers-to-be didn’t know what to do with 
us so the latest move was to toss us in the mix with Industrial Machinery. But 
the MD is not a good marriage. Our users are not the same. The environment is 
not the same.

Laboratory Equipment is not new. It’s been around for hundreds of years.  
Scientists, engineers, technicians, chemists, etc. perform tests on materials 
using fire, heat, ovens, ice, liquid nitrogen, electricity (ever see a 
Frankenstein Movie), sharp tools, glass containers, chemicals, solvents, 
flammable liquids, plasma, lasers, tools and machines that cut, grind, polish, 
crush, vibrate, pulverize, burn, ionize, liquefy, vaporize, and nebulize 
materials for scientific analysis.  The users of such equipment are trained and 
educated to work in such an environment without getting hurt.

Take the average person off the street, put them in a laboratory, and they will 
most likely get injured or be dead before lunch.  Put the same person in an 
Industrial factory, give them 10 minutes of instruction, and they can run a 
press for 20 years without losing a finger. Why, because the safety rules and 
training of Users are completely different.

Most of you work in an EMC, Product Safety, Engineering, or R Laboratory so 
you should know what I’m talking about. You know by personal experience that 
there are hazards you are exposed to everyday that are just part of the job.  
Bring an OSHA or Union Inspector through your lab and they’ll probably shut you 
down (unless they are knowledgeable in such matters, which most are not).

Ultimately, manufacturers of laboratory equipment needs some kind of 
representation in Europe. But because of the small volumes we deal with, we are 
mostly small companies who just do not have the resources.  We must rely on 
consultants, 3rd party labs, and discussion groups, like this one, for advice 
on what to do.

But our greatest burden is dealing with inspectors at our customer site who 
doesn’t know what a Thermographic Analyzer is so they review it as a an 
Industrial Factory machine under the MD and write up a list of non-compliances. 
And though we have to work through dozens of these every year costing us 
hundreds of thousands of dollars in manpower, we have never had to make a 
mechanical change to even one of our instruments. They have all been resolved 
through educating inspectors and providing information and test results they 
cannot perform in the field.  Who pays for this?

Many believe that if we declared to the LVD instead of the MD, that our 
products would be looked upon differently from inspectors and they wouldn’t be 
forced to try and apply the EHSR of the MD to products that just don’t fit. All 
I know for sure is that before the 2006 version of the MD, life was good. I 
dream of better days.

The Other Brian


From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Friday, March 31, 2017 12:54 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: 

[PSES] significant digits

[Richard Nute]

 

See:

 

https://www.physics.uoguelph.ca/tutorials/sig_fig/SIG_dig.htm

 

 

 

From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] 
Sent: Friday, March 31, 2017 4:23 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

 

At the risk of drifting off topic, and if I may be so bold, “300” is 
unambiguously three significant digits, while “ 3 x 102 ” is one significant 
digit of precision.   All trailing zeros count toward precision, at least 
that's what they taught when I was in engineering school.

 

 

Ralph McDiarmid

Product Compliance

Engineering

Solar Business

Schneider Electric

 

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

[Ralph McDiarmid]

At the risk of drifting off topic, and if I may be so bold, “300” is 
unambiguously three significant digits, while “ 3 x 102 ” is one significant 
digit of precision.   All trailing zeros count toward precision, at least 
that's what they taught when I was in engineering school.


Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Richard Nute [mailto:ri...@ieee.org]
Sent: Friday, March 31, 2017 4:11 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak



Hi Doug:

From your message, I don’t know if your question is about the concept of 
“significant digits” or the standard itself.  Perhaps I can answer both.

The number 300 can have one, two, or three significant digits.  One, for sure.  
If we multiply by the square root of 2 to get the peak, and if we follow the 
significant digits rules, we can only say 400, not 420 or 424 without knowing 
the significant digits in the value of 300.  0.300 x 103 would be three 
significant units, in which case the peak value would be 424.

(Standards committees have little understanding or patience for significant 
digits.)

In the standard, the 300 volts was chosen because, throughout the world, mains 
voltages are either comfortably below or above that value, e.g., 220, 230, 240, 
including tolerances.  240 +10% would be 264, which is comfortably below 300.

Working backwards, 420 divided by the square root of 2 is 296, still 
comfortably above 250.  This bit of discrepancy doesn’t get in the way of 
determining the clearance for almost any of the world’s mains voltages, 
including tolerances.

If you look at the “rms” values for Table K, they are:

50.2 rms for   71 peak (for   50 rms)
148   rms for 210 peak (for 150 rms)
296   rms for 420 peak (for 300 rms)
593   rms for 840 peak (for 600 rms)
Etc.

Maybe you can round to the nearest 10 when multiplying by square root of 2.  
But, it may not always work since committee judgement was used to arrive at the 
values.  You may have to resort to something like “If more than 150 and not 
more than 300, then Table K.”

Table L only applies when the “working voltage” exceeds the mains voltage.  
This was to account for the switching voltage of a SMPS exceeding the mains 
voltage.

Back in the days of IEC 60950-1, 2nd, little attention was paid to IEC 60664-1. 
One of my colleagues said: “Unlike all other engineering disciplines, safety 
engineering is consensus driven, not research driven.  It is almost devoid of 
physical laws to guide its practitioners.”

Best regards,
Rich



From: Doug Powell [mailto:doug...@gmail.com]
Sent: Wednesday, March 29, 2017 5:49 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

All,

I am reviewing the requirements of "2.10.3.3 Clearances in primary circuits" 
and it seems interesting to me that the math is off by just a little bit.  In 
particular "For an AC MAINS SUPPLY not exceeding 300 V r.m.s. (420 V peak)". 
When in actuality the calculated peak of 300 Vrms is 424 Vpeak.  Using three 
significant digits instead of two.  This value is important to spacings 
determination in that it invokes using tables 2K plus 2L instead of table 2K 
alone.  I checked the Edition 2 of IEC, ANSI/UL and CSA standards and they all 
have the same statement.  Edition 1 of IEC 60950-1 does not include this value 
within parenthesis which tells me it was probably added as a clarification by 
the committee in Edition 2.

I am one to build excel-based spacings calculators and this has changed the 
math somewhat, rounding up to the nearest 10 Volts

=IF(10*ROUNDUP(Vrms*SQRT(2)/10,0)>420,"Tables 2K + 2L","Table 2K")

instead of using

=IF(Vrms*SQRT(2))>424,"Tables 2K & 2L","Table 2K")

(Note: use of =MROUND() could potentially round down and not up)

In several other sections of the standard another pair of voltages appear 
together in at least 8 locations and are rendered "42,4 V peak, or 60 V d.c"; 
which is correct for three significant digits.  I know the consequences are 
probably minimal and it has raised my curiosity as to why this happened. Was 
anyone in this forum present during this part of the revision discussions and 
can shed some light?


thanks Doug


--

Douglas E Powell

mailto:doug...@gmail.com
http://www.linkedin.com/in/dougp01

__
This email has been scanned by the Symantec Email Security.cloud service.
__
-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html
Attachments are 

Re: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

[Richard Nute]

 

 

Hi Doug:

 

>From your message, I don’t know if your question is about the concept of 
>“significant digits” or the standard itself.  Perhaps I can answer both.

 

The number 300 can have one, two, or three significant digits.  One, for sure.  
If we multiply by the square root of 2 to get the peak, and if we follow the 
significant digits rules, we can only say 400, not 420 or 424 without knowing 
the significant digits in the value of 300.  0.300 x 103 would be three 
significant units, in which case the peak value would be 424.  

 

(Standards committees have little understanding or patience for significant 
digits.)

 

In the standard, the 300 volts was chosen because, throughout the world, mains 
voltages are either comfortably below or above that value, e.g., 220, 230, 240, 
including tolerances.  240 +10% would be 264, which is comfortably below 300.  

 

Working backwards, 420 divided by the square root of 2 is 296, still 
comfortably above 250.  This bit of discrepancy doesn’t get in the way of 
determining the clearance for almost any of the world’s mains voltages, 
including tolerances.  

 

If you look at the “rms” values for Table K, they are:

 

50.2 rms for   71 peak (for   50 rms)

148   rms for 210 peak (for 150 rms)

296   rms for 420 peak (for 300 rms)

593   rms for 840 peak (for 600 rms)

Etc.

 

Maybe you can round to the nearest 10 when multiplying by square root of 2.  
But, it may not always work since committee judgement was used to arrive at the 
values.  You may have to resort to something like “If more than 150 and not 
more than 300, then Table K.”  

 

Table L only applies when the “working voltage” exceeds the mains voltage.  
This was to account for the switching voltage of a SMPS exceeding the mains 
voltage.

 

Back in the days of IEC 60950-1, 2nd, little attention was paid to IEC 60664-1. 
One of my colleagues said: “Unlike all other engineering disciplines, safety 
engineering is consensus driven, not research driven.  It is almost devoid of 
physical laws to guide its practitioners.”

 

Best regards,

Rich

 

 

From: Doug Powell [mailto:doug...@gmail.com] 
Sent: Wednesday, March 29, 2017 5:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

 

All,

 

I am reviewing the requirements of "2.10.3.3 Clearances in primary circuits" 
and it seems interesting to me that the math is off by just a little bit.  In 
particular "For an AC MAINS SUPPLY not exceeding 300 V r.m.s. (420 V peak)". 
When in actuality the calculated peak of 300 Vrms is 424 Vpeak.  Using three 
significant digits instead of two.  This value is important to spacings 
determination in that it invokes using tables 2K plus 2L instead of table 2K 
alone.  I checked the Edition 2 of IEC, ANSI/UL and CSA standards and they all 
have the same statement.  Edition 1 of IEC 60950-1 does not include this value 
within parenthesis which tells me it was probably added as a clarification by 
the committee in Edition 2.

 

I am one to build excel-based spacings calculators and this has changed the 
math somewhat, rounding up to the nearest 10 Volts

 

=IF(10*ROUNDUP(Vrms*SQRT(2)/10,0)>420,"Tables 2K + 2L","Table 2K")

 

instead of using

 

=IF(Vrms*SQRT(2))>424,"Tables 2K & 2L","Table 2K")

 

(Note: use of =MROUND() could potentially round down and not up)

 

In several other sections of the standard another pair of voltages appear 
together in at least 8 locations and are rendered "42,4 V peak, or 60 V d.c"; 
which is correct for three significant digits.  I know the consequences are 
probably minimal and it has raised my curiosity as to why this happened. Was 
anyone in this forum present during this part of the revision discussions and 
can shed some light?

 

 

thanks Doug

 

 

-- 

 

Douglas E Powell

doug...@gmail.com  
http://www.linkedin.com/in/dougp01


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

[PSES] Switchgear in Europe

[Peter Tarver]

Greetings.



I am researching requirements for switchgear in Europe and there are two 
prevailing series of standards: 60947-x and 61439-x. These series of standards 
are both produced by TC 121/SC 121A and there seems to have more than 
significant overlap in their scopes..



It does appear that 60947-x are for individual devices, while 61439-x appears 
to be for assemblages of devices, perhaps any number of 60947-x devices. I'm 
not certain I have that right.



I have seen products the identify compliance with 60947-x and don't mention 
61439-x.



Neither standard series is mentioned in the list of harmonized standards for 
the LVD and are not excluded in Annex II. The application is for less than 1 
kVac.



Some 60947-5-x are mentioned in the Mach Dir., but 61439-x are not. (For the 
end-product application, the MD does not apply, though low voltage switchgear 
is in scope of the MD.)



Interestingly, several 60947-x and 61439-x are mentioned in the list of 
harmonized standards for the EMCD.



I note that the CENELEC web site identifies these standards as intended for use 
to demonstrate conformity with the essential requirements of the:

  * LVD

  * EMCD

  * RED



and of these three, only the EMCD mentions any 60947-x or 61439-x standard. 
CENELC doesn't mention the MD at all, except for 60947-5-3 and 60947-5-5, which 
is at least consistent with the lists of harmonized standards for the MD.



How does one choose the correct standard(s) between the two series?



I am aware of 61439-0, but haven't yet purchased that document to discover what 
guidance it can give.





Peter Tarver



The information contained in this message may be privileged and confidential. 
It is intended to be read only by the individual or entity to whom it is 
addressed or by their designee. If the reader of this message is not the 
intended recipient, you are on notice that any distribution of this message, in 
any form, is strictly prohibited. If you have received this message in error, 
please immediately notify the sender and delete or destroy any copy of this 
message!

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] MD vs LVD for Laboratory Equipment

[John Woodgate]

This is an example of 'SME victims' (SME = Small and Medium-size Enterprises' 
and actually it includes quite big companies, but not the hyper-giants, of 
course).
 
Such companies can't act individually, as you say. The solution is to set up a 
'trade body' – the 'World-wide Lab Kit Makers' or some such (It may already 
exist.) If you can get 20 companies to contribute an affordable $500 per year, 
you can fund a presence in the councils of the mighty. As an 'SME body' , it 
would be welcomed, because it proves that the Commission cares, and not just 
about its expense allowances.
 
With best wishes DESIGN IT IN! OOO – Own Opinions Only
  www.jmwa.demon.co.uk J M Woodgate and 
Associates Rayleigh England
 
Sylvae in aeternum manent.
 
From: Kunde, Brian [mailto:brian_ku...@lecotc.com] 
Sent: Friday, March 31, 2017 7:55 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MD vs LVD for Laboratory Equipment
 
I’ve said this before, but laboratory equipment is the Redheaded Stepchild of 
Regulatory Compliance. It’s like the powers-to-be didn’t know what to do with 
us so the latest move was to toss us in the mix with Industrial Machinery. But 
the MD is not a good marriage. Our users are not the same. The environment is 
not the same.
 
Laboratory Equipment is not new. It’s been around for hundreds of years.  
Scientists, engineers, technicians, chemists, etc. perform tests on materials 
using fire, heat, ovens, ice, liquid nitrogen, electricity (ever see a 
Frankenstein Movie), sharp tools, glass containers, chemicals, solvents, 
flammable liquids, plasma, lasers, tools and machines that cut, grind, polish, 
crush, vibrate, pulverize, burn, ionize, liquefy, vaporize, and nebulize 
materials for scientific analysis.  The users of such equipment are trained and 
educated to work in such an environment without getting hurt.
 
Take the average person off the street, put them in a laboratory, and they will 
most likely get injured or be dead before lunch.  Put the same person in an 
Industrial factory, give them 10 minutes of instruction, and they can run a 
press for 20 years without losing a finger. Why, because the safety rules and 
training of Users are completely different.
 
Most of you work in an EMC, Product Safety, Engineering, or R Laboratory so 
you should know what I’m talking about. You know by personal experience that 
there are hazards you are exposed to everyday that are just part of the job.  
Bring an OSHA or Union Inspector through your lab and they’ll probably shut you 
down (unless they are knowledgeable in such matters, which most are not).
 
Ultimately, manufacturers of laboratory equipment needs some kind of 
representation in Europe. But because of the small volumes we deal with, we are 
mostly small companies who just do not have the resources.  We must rely on 
consultants, 3rd party labs, and discussion groups, like this one, for advice 
on what to do. 
 
But our greatest burden is dealing with inspectors at our customer site who 
doesn’t know what a Thermographic Analyzer is so they review it as a an 
Industrial Factory machine under the MD and write up a list of non-compliances. 
And though we have to work through dozens of these every year costing us 
hundreds of thousands of dollars in manpower, we have never had to make a 
mechanical change to even one of our instruments. They have all been resolved 
through educating inspectors and providing information and test results they 
cannot perform in the field.  Who pays for this?
 
Many believe that if we declared to the LVD instead of the MD, that our 
products would be looked upon differently from inspectors and they wouldn’t be 
forced to try and apply the EHSR of the MD to products that just don’t fit. All 
I know for sure is that before the 2006 version of the MD, life was good. I 
dream of better days. 
 
The Other Brian
 
 
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org] 
Sent: Friday, March 31, 2017 12:54 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: Re: [PSES] MD vs LVD for Laboratory Equipment
 
All,
 
   Well letting it stew longer usually makes the soup thicker.   
 
   The mfgrs of semi processing equipment worked to get 
clarification hoping to use 61010 as the basis for the electrical portion of 
their CE certification but using the needed machinery standards for mechanical 
hazards.  This would allow a full CE cert invoking both the MD and the LVD.  
The EU fathers, however, didn’t want to go that direction so another part of 
60204  has been developed to with cover these units – done in parallel the TC66 
efforts to develop their -2-120 machinery standard covering the needed 
mechanical req’mts.  
 
   So it appears that those folks have two paths to full 
certification and could invoke both the MD and the LVD in their Declaration 
(which, it seems, is most pleasing to low level approval folks 

Re: [PSES] MD vs LVD for Laboratory Equipment

[Kunde, Brian]

I’ve said this before, but laboratory equipment is the Redheaded Stepchild of 
Regulatory Compliance. It’s like the powers-to-be didn’t know what to do with 
us so the latest move was to toss us in the mix with Industrial Machinery. But 
the MD is not a good marriage. Our users are not the same. The environment is 
not the same.

Laboratory Equipment is not new. It’s been around for hundreds of years.  
Scientists, engineers, technicians, chemists, etc. perform tests on materials 
using fire, heat, ovens, ice, liquid nitrogen, electricity (ever see a 
Frankenstein Movie), sharp tools, glass containers, chemicals, solvents, 
flammable liquids, plasma, lasers, tools and machines that cut, grind, polish, 
crush, vibrate, pulverize, burn, ionize, liquefy, vaporize, and nebulize 
materials for scientific analysis.  The users of such equipment are trained and 
educated to work in such an environment without getting hurt.

Take the average person off the street, put them in a laboratory, and they will 
most likely get injured or be dead before lunch.  Put the same person in an 
Industrial factory, give them 10 minutes of instruction, and they can run a 
press for 20 years without losing a finger. Why, because the safety rules and 
training of Users are completely different.

Most of you work in an EMC, Product Safety, Engineering, or R Laboratory so 
you should know what I’m talking about. You know by personal experience that 
there are hazards you are exposed to everyday that are just part of the job.  
Bring an OSHA or Union Inspector through your lab and they’ll probably shut you 
down (unless they are knowledgeable in such matters, which most are not).

Ultimately, manufacturers of laboratory equipment needs some kind of 
representation in Europe. But because of the small volumes we deal with, we are 
mostly small companies who just do not have the resources.  We must rely on 
consultants, 3rd party labs, and discussion groups, like this one, for advice 
on what to do.

But our greatest burden is dealing with inspectors at our customer site who 
doesn’t know what a Thermographic Analyzer is so they review it as a an 
Industrial Factory machine under the MD and write up a list of non-compliances. 
And though we have to work through dozens of these every year costing us 
hundreds of thousands of dollars in manpower, we have never had to make a 
mechanical change to even one of our instruments. They have all been resolved 
through educating inspectors and providing information and test results they 
cannot perform in the field.  Who pays for this?

Many believe that if we declared to the LVD instead of the MD, that our 
products would be looked upon differently from inspectors and they wouldn’t be 
forced to try and apply the EHSR of the MD to products that just don’t fit. All 
I know for sure is that before the 2006 version of the MD, life was good. I 
dream of better days.

The Other Brian


From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Friday, March 31, 2017 12:54 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MD vs LVD for Laboratory Equipment

All,

   Well letting it stew longer usually makes the soup thicker.

   The mfgrs of semi processing equipment worked to get 
clarification hoping to use 61010 as the basis for the electrical portion of 
their CE certification but using the needed machinery standards for mechanical 
hazards.  This would allow a full CE cert invoking both the MD and the LVD.  
The EU fathers, however, didn’t want to go that direction so another part of 
60204  has been developed to with cover these units – done in parallel the TC66 
efforts to develop their -2-120 machinery standard covering the needed 
mechanical req’mts.

   So it appears that those folks have two paths to full 
certification and could invoke both the MD and the LVD in their Declaration 
(which, it seems, is most pleasing to low level approval folks who have to 
accept the Declaration and don’t want to  spend too much time deciding if all 
the necessary things have been covered.

   The nightmare is spreading, equipment is getting more complex 
and larger so the boundaries are being stretched or broken down.  Hopefully, 
the system will get some sense and work to allow any combo of technical 
requirements to show compliance – electrical requirements for the LVD and 
mechanical requirements for the MD.  We’ve done  that many times in the past 
and it has worked well technically.  o

   I vote for watering the soup and not serve stew.

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant
PO Box 23427
Tigard, ORe  97281-3427

503/452-1201

p.perk...@ieee.org

From: Peter Tarver [mailto:ptar...@enphaseenergy.com]
Sent: Friday, March 31, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MD vs LVD for 

Re: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

[Richard Nute]

 

 

Hi Doug: 

 

I can address both of your questions.  I’ll do the easy one first:

 

In several other sections of the standard another pair of voltages appear 
together in at least 8 locations and are rendered "42,4 V peak, or 60 V d.c"; 
which is correct for three significant digits.  I know the consequences are 
probably minimal and it has raised my curiosity as to why this happened. Was 
anyone in this forum present during this part of the revision discussions and 
can shed some light?

 

The 42.4 number is square root of 2 times 30 (the rms limit value), rounded and 
truncated to 0.1 place.  This is the limit for ac (peak) touch voltage.  Safety 
engineers would not allow over 42.4 volts even though the voltage 
calculated from the rms is 42.42640687119285 etc.  

 

The 60 number is the limit for dc touch voltage.  I suppose this is 60.0 ad 
infinitum, but only expressed one, maybe two, significant digits.  Safety 
engineers would not allow over 60. volts.  

 

The two numbers are unrelated to each other as the body physiological response 
to ac and dc is quite different.

 

Best regards,

Rich

 

 

 

 

From: Doug Powell [mailto:doug...@gmail.com] 
Sent: Wednesday, March 29, 2017 5:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] IEC/ANSI/UL/CSA 60950-1 ed.2 Mains Vrms vs Vpeak

 

All,

 

I am reviewing the requirements of "2.10.3.3 Clearances in primary circuits" 
and it seems interesting to me that the math is off by just a little bit.  In 
particular "For an AC MAINS SUPPLY not exceeding 300 V r.m.s. (420 V peak)". 
When in actuality the calculated peak of 300 Vrms is 424 Vpeak.  Using three 
significant digits instead of two.  This value is important to spacings 
determination in that it invokes using tables 2K plus 2L instead of table 2K 
alone.  I checked the Edition 2 of IEC, ANSI/UL and CSA standards and they all 
have the same statement.  Edition 1 of IEC 60950-1 does not include this value 
within parenthesis which tells me it was probably added as a clarification by 
the committee in Edition 2.

 

I am one to build excel-based spacings calculators and this has changed the 
math somewhat, rounding up to the nearest 10 Volts

 

=IF(10*ROUNDUP(Vrms*SQRT(2)/10,0)>420,"Tables 2K + 2L","Table 2K")

 

instead of using

 

=IF(Vrms*SQRT(2))>424,"Tables 2K & 2L","Table 2K")

 

(Note: use of =MROUND() could potentially round down and not up)

 

In several other sections of the standard another pair of voltages appear 
together in at least 8 locations and are rendered "42,4 V peak, or 60 V d.c"; 
which is correct for three significant digits.  I know the consequences are 
probably minimal and it has raised my curiosity as to why this happened. Was 
anyone in this forum present during this part of the revision discussions and 
can shed some light?

 

 

thanks Doug

 

 

-- 

 

Douglas E Powell

doug...@gmail.com  
http://www.linkedin.com/in/dougp01

-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
 >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators:
Scott Douglas  >
Mike Cantwell  > 

For policy questions, send mail to:
Jim Bacher  >
David Heald  > 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] MD vs LVD for Laboratory Equipment

[Pete Perkins]

All,

 

   Well letting it stew longer usually makes the soup thicker.   

 

   The mfgrs of semi processing equipment worked to get 
clarification hoping to use 61010 as the basis for the electrical portion of 
their CE certification but using the needed machinery standards for mechanical 
hazards.  This would allow a full CE cert invoking both the MD and the LVD.  
The EU fathers, however, didn’t want to go that direction so another part of 
60204  has been developed to with cover these units – done in parallel the TC66 
efforts to develop their -2-120 machinery standard covering the needed 
mechanical req’mts.  

 

   So it appears that those folks have two paths to full 
certification and could invoke both the MD and the LVD in their Declaration 
(which, it seems, is most pleasing to low level approval folks who have to 
accept the Declaration and don’t want to  spend too much time deciding if all 
the necessary things have been covered.  

 

   The nightmare is spreading, equipment is getting more complex 
and larger so the boundaries are being stretched or broken down.  Hopefully, 
the system will get some sense and work to allow any combo of technical 
requirements to show compliance – electrical requirements for the LVD and 
mechanical requirements for the MD.  We’ve done  that many times in the past 
and it has worked well technically.  o

 

   I vote for watering the soup and not serve stew.  

 

:>) br,  Pete

 

Peter E Perkins, PE

Principal Product Safety & Regulatory Affairs Consultant

PO Box 23427

Tigard, ORe  97281-3427

 

503/452-1201

 

  p.perk...@ieee.org

 

From: Peter Tarver [mailto:ptar...@enphaseenergy.com] 
Sent: Friday, March 31, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MD vs LVD for Laboratory Equipment

 

I’m with you here, Dave. Just because a product contains a cooling fan should 
not mean the MD applies. But then, the products you cite are explicitly 
excluded from the scope of the MD (I’m sure you know this, since it appears you 
took the text directly form the MD).

 

However, in Article 2 of the MD, where the text Doug mentions is located, goes 
on to say that they’re, “intended for lifting loads and whose only power source 
is directly applied human effort.” This encompasses:

 

• automotive lifts and jacks

• come-alongs

• block and tackle sets (if sold as a unit)

 

 

Peter Tarver

 

From: Nyffenegger, Dave

Sent: Thursday, March 30, 2017 17:40

 

But there are products meeting that definition of machine that are covered by 
the LVD and specifically excluded from the  MD:

 

— household appliances intended for domestic use,

— information technology equipment,

— ordinary office machinery,

 

-Dave

 

From: Douglas Nix 
Sent: Thursday, March 30, 2017 5:20 PM

 

I concur with Michael Loerzer. IMO, the test labs didn’t feel comfortable doing 
MD evaluations, so they used the “out” that was in the text of the previous MD 
(98/37/EC) that said that if the hazards were ‘predominantly electrical in 
nature” then the MD needn’t apply. Many machines were “slid-past” based on this 
misuse of the text of the MD, which is why the text was changed in the 2006 
edition.

 

If the device is “an assembly of linked parts, at least one of which moves” 
it’s a machine.

-- 
Doug Nix
d...@mac.com  

The information contained in this message may be privileged and confidential. 
It is intended to be read only by the individual or entity to whom it is 
addressed or by their designee. If the reader of this message is not the 
intended recipient, you are on notice that any distribution of this message, in 
any form, is strictly prohibited. If you have received this message in error, 
please immediately notify the sender and delete or destroy any copy of this 
message! 

-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
 >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators:
Scott Douglas  >
Mike Cantwell  > 

For policy questions, send mail to:
Jim Bacher  >
David Heald 

Re: [PSES] MD vs LVD for Laboratory Equipment

[Peter Tarver]

I’m with you here, Dave. Just because a product contains a cooling fan should 
not mean the MD applies. But then, the products you cite are explicitly 
excluded from the scope of the MD (I’m sure you know this, since it appears you 
took the text directly form the MD).

However, in Article 2 of the MD, where the text Doug mentions is located, goes 
on to say that they’re, “intended for lifting loads and whose only power source 
is directly applied human effort.” This encompasses:

• automotive lifts and jacks
• come-alongs
• block and tackle sets (if sold as a unit)


Peter Tarver

From: Nyffenegger, Dave
Sent: Thursday, March 30, 2017 17:40

But there are products meeting that definition of machine that are covered by 
the LVD and specifically excluded from the  MD:

— household appliances intended for domestic use,
— information technology equipment,
— ordinary office machinery,

-Dave

From: Douglas Nix
Sent: Thursday, March 30, 2017 5:20 PM

I concur with Michael Loerzer. IMO, the test labs didn’t feel comfortable doing 
MD evaluations, so they used the “out” that was in the text of the previous MD 
(98/37/EC) that said that if the hazards were ‘predominantly electrical in 
nature” then the MD needn’t apply. Many machines were “slid-past” based on this 
misuse of the text of the MD, which is why the text was changed in the 2006 
edition.

If the device is “an assembly of linked parts, at least one of which moves” 
it’s a machine.
--
Doug Nix
d...@mac.com

The information contained in this message may be privileged and confidential. 
It is intended to be read only by the individual or entity to whom it is 
addressed or by their designee. If the reader of this message is not the 
intended recipient, you are on notice that any distribution of this message, in 
any form, is strictly prohibited. If you have received this message in error, 
please immediately notify the sender and delete or destroy any copy of this 
message!

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] MD vs LVD for Laboratory Equipment

[Nick Williams]

I agree with everything Charlie says. 

Try talking to some Machinery Notified Bodies instead of ex-LVD Notified 
Bodies. 

Happy to help further if you want to contact me directly. 

Nick. 


> On 30 Mar 2017, at 20:22, Charlie Blackham  
> wrote:
> 
> Brian
>  
> Few comments:
> The scope of the Directive determines applicability, not the scope of the 
> standards – standards are just a way of demonstrating compliance with 
> Directives, which are law (when transposed in national legislation). 
> Directive comes first, standard a distant second.
> There aren’t any Notified Bodies to the LVD, (check here 
> ),
>  so all you are getting is a report from a lab that is accredited against a 
> standard, and an accredited report is not a 100% guarantee that the correct 
> thing has been done.
> The manufacturer is always legally responsible
> “But sir, that’s what they do” is not a legal defence I’d recommend :)
> You can apply any standards you wish to support compliance to the MD – 
> there’s nothing to stop you using EN61010-1 for clause 1.5.1 (and probably a 
> few others)
> The LVD update was just an NLF alignment for market enforcement, and did not 
> change its scope
> Machinery Directive Notified Bodies only really deal with Annex IV
>  
>  
> My view is:
> The application of the Machinery Annex I EHSRs to something that is not very 
> “machine like” shouldn’t be too onerous
> If in doubt, applying the MD instead of the LVD would only mean that you may 
> have done too much, so would always be a defensible position, the reverse is 
> not true.
>  
> Regards
> Charlie
>  
> Charlie Blackham
> Sulis Consultants Ltd
> Tel: +44 (0)7946 624317
> Web: www.sulisconsultants.com 
> 
> Registered in England and Wales, number 05466247
>  
> From: Kunde, Brian [mailto:brian_ku...@lecotc.com 
> ] 
> Sent: 30 March 2017 19:19
> To: EMC-PSTC@LISTSERV.IEEE.ORG 
> Subject: [PSES] MD vs LVD for Laboratory Equipment
>  
> Sorry to say, this issue has once again reared its ugly head. I appreciate 
> any and all input.
>  
> History: For many many years, laboratory equipment fell under the Low Voltage 
> Directive (LVD), even products with moving parts. It was specifically 
> excluded from the Machinery Directive (MD). The Safety Standard for 
> Laboratory Equipment EN 61010-1 is harmonized to the LVD.  Life was good.
>  
> Then a new version of the MD was released which did not exclude Laboratory 
> Equipment. Many of the EHSR from annex I did not apply and there were no 
> harmonized standards specific to laboratory equipment. So the same set of 
> safety rules that apply to Industrial/Factory Machinery must somehow be 
> applied to Carbon Analyzers, Calorimeters, Hardness Testers, and Mass 
> Spectrometers. Life sucks. 
>  
> BUT then the New Safety Standards EN 61010-1 3rd Ed. was released which 
> included hazards from Moving Parts and referenced a Risk Assessment for any 
> hazards not covered by the standard.  The standard now covered all hazardous 
> conditions associated with Laboratory Equipment including moving parts, 
> electrical, chemical, hot/cold temperatures, radiation, pressurized fluids, 
> everything. AND THEN the new LVD was released which was aligned with the NLF. 
>  Can Life be Good Again?
>  
> The Topper:  Recently we have been contacted by two different Notified Bodies 
> in Europe which has informed us that we should be using the LVD and not the 
> MD.  When I asked for a reason why they basically said what I just typed 
> above.  One NB lab in Italy just performed a Safety Evaluation on one of our 
> Cut-Off Saws (considered a prep machine for scientific analysis) and they 
> evaluated it to the EN 61010-1:2010 and the LVD.  When I questioned this and 
> inquired about the MD, they argued that the LVD and EN 61010-1 NOW covers all 
> hazards assessed within the product and the MD would not be the appropriate 
> Directive.
>  
> We have also started to see several of our business partners (companies we 
> work with to produce buy/sell options and laboratory peripherals with moving 
> parts like sample loaders)  declaring compliance to the LVD instead of the 
> MD.  As first I tried to correct them but then they sent us test reports from 
> NB labs in Europe evaluating their products to the LVD.  Whodathunkit?
>  
> However, I checked with the TUV:SUD lab we use here in the states and they 
> are still saying that the MD is the correct directive to use.  Ok, now I’m 
> officially confused. 
>  
> So, has it officially changed? Or is it changing? Can manufacturers of 
> laboratory equipment go back to declaring compliance to the LVD even if their 
> products have moving parts?  Has anyone seen any