Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

“… does a palliative involve an interchange of energy?

 

Yes, chemical energy.  But, no injury.  

 

Rich

 

 

 


-

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] Medical device risk assessment - faulty chargers

[Nick Williams]

I knew someone would come back with that reply. 

Technically, it may or may not be correct (does a palliative involve an 
interchange of energy?) but in practice it stretches the original assertion 
beyond any useful application. 

As ever, real life is more complex than it is possible to express in one neat, 
pithy phrase. 

Nick. 




> On 17 Apr 2018, at 21:05, John Woodgate  > wrote:
> 
> If the device transfers energy, but the energy proves ineffective, that is 
> still an 'energy interchange'.  If the device fails to transfer energy, there 
> is no 'cause' to produce an 'effect', so any injury is not due to the device 
> but to some other energy interchange.
> 
> Do we rename the list 'IEEE Philosophical Society'?(;-)
> John Woodgate OOO-Own Opinions Only
> J M Woodgate and Associates www.woodjohn.uk 
> Rayleigh, Essex UK
> On 2018-04-17 20:24, Nick Williams wrote:
>> In the medical device context, no this is not correct because the failure of 
>> the device to provide the claimed medical benefit can be a cause of ‘injury’.
>> 
>> Nick. 
>> 
>> 
>>> On 17 Apr 2018, at 20:17, Richard Nute >> > wrote:
>>> 
>>>  
>> 
>> 
>>>  
>>> Do you agree or disagree with James Gibson’s assertion that
>>>  
>>> “Injuries to a living organism can be produced only by some energy 
>>> interchange”?
>>>  
>>> (ISO 14971, C.2.5 recognizes energy transfer can result in injury.)   
>>>  
>> 
>> -
>> 
>> 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 >
> 

Nick Williams
Director
Direct line: +44 1298 873811
Mobile: +44 7702 995135
email: nick.willi...@hucklow.net 

-

Hucklow Net Limited
The Old Methodist Chapel, Great Hucklow, Buxton, SK17 8RG England
Tel. +44 1298 873800, www.hucklow.net 
Registered in England, Company No. 08500758


-

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:  

Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

“Injuries to a living organism can be produced only by some energy interchange.”

Not all risk are of energetic nature:

Risk is never a function of energy interchange.  Risk is the “combination of 
the probability of occurrence of harm and the severity of that harm.”

 

Injury is a function of energy interchange.  The objective of product safety 
endeavor is prevention of injury, which is prevention of energy (more than body 
tolerance) interchange.

 

Rich

 


-

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] Medical device risk assessment - faulty chargers

[Gert Gremmen; ce-test]

Life is consist of risk assessments!

If you cross a road, you quickly assess the risk of safely getting to 
the other side.


What you call a scientific method, is a risk assessment based on 
physical hypotheses , but the hypothesis might be wrong tomorrow, or in 
another place. But the chance of getting bitten is that low that you can 
get away with it : Risk assessment.


What we call risk assessment in medical product safety evaluation (and 
now also in LVD and other EC directives to come), is a formal method of 
ranking the risks (visualize FMEA here). Seeing them ordered and (though 
arbitrarily quantizized) allows one to compare to earlier versions of 
the product, helps placing a red line (do not cross that risk level)and 
helps in prioritizing risks.


Risk analysis is not scientific, indeed, it is a method to get hand on 
dangers of all kind of nature.


“Injuries to a living organism can be produced only by some energy 
interchange.”


Not all risk are of energetic nature:

Trivial example:  An interpretation fault risk happened in medical 
staff  paging system where both S and 5 were used to indicate the 
location of  emergencies in numbered corridors in a hospital. At that 
time 8-segment displays were common and renumbering the corridors by not 
using the S was a proposed solution. Risk assessment allowed us to find 
other hazards that might happen if a single segment was defective. 6 
versus b, 7 versus 1. The manufacturer decided that a 7-segment display 
was not the way to go.





Gert Gremmen



On 17-4-2018 1:22, Richard Nute wrote:


… how do you test *objectively* the adequacy of a symbol like the ! in 
a triangle…


The ! is not a safeguard.  Ultimately, the safeguard is some 
prescribed behavior on the part of a person.  The manufacturer of 
equipment can only describe the desired behavior.   The behavior can 
be tested to determine its effectiveness at safeguarding a body.  
However, the manufacturer cannot enforce a behavior.  Hence, a 
behavior safeguard is not necessarily an effective safeguard as is a 
physical safeguard.


… requirement for two layers of plastic film or insulation, in case 
one layer had a pinhole…


The pinhole was a hypothesis.  We totally ignored the fact that the 
insulation system is comprised of solid-air-solid (a thin layer of air 
separated the two layers).  The voltage divides inversely according to 
the capacitance.  Most of the voltage appears across the thin layer of 
air, not the two solid insulations.  So, we built in a failure 
mechanism to thwart a hypothesis.  Fortunately, the system has 
sufficent electric strength and the transient voltages at the electric 
strength voltage are years apart and of short duration that breakdown 
during equipment lifetime is not likely.


Product safety is rife with “conventional wisdom.”

Rich

-


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] Medical device risk assessment - faulty chargers

[John Woodgate]

If the device transfers energy, but the energy proves ineffective, that 
is still an 'energy interchange'.  If the device fails to transfer 
energy, there is no 'cause' to produce an 'effect', so any injury is not 
due to the device but to some other energy interchange.


Do we rename the list 'IEEE Philosophical Society'?(;-)

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-04-17 20:24, Nick Williams wrote:
In the medical device context, no this is not correct because the 
failure of the device to provide the claimed medical benefit can be a 
cause of ‘injury’.


Nick.


On 17 Apr 2018, at 20:17, Richard Nute > wrote:






Do you agree or disagree with James Gibson’s assertion that
“Injuries to a living organism can be produced only by some energy 
interchange”?

(ISO 14971, C.2.5 recognizes energy transfer can result in injury.)


-


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] Medical device risk assessment - faulty chargers

[Nick Williams]

In the medical device context, no this is not correct because the failure of 
the device to provide the claimed medical benefit can be a cause of ‘injury’.

Nick. 


> On 17 Apr 2018, at 20:17, Richard Nute  wrote:
> 
>  


>  
> Do you agree or disagree with James Gibson’s assertion that
>  
> “Injuries to a living organism can be produced only by some energy 
> interchange”?
>  
> (ISO 14971, C.2.5 recognizes energy transfer can result in injury.)   
>  


-

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] Medical device risk assessment - faulty chargers

[Richard Nute]

 

“… well understood risk management process provides a quite scientific and 
systematic method for identification of safety related issues in the 
construction…” 

 

I don’t agree that the risk management process “provides a scientific… method…” 
 

 

ISO 14971 requires identification of the hazards in equipment.  “Hazard” is 
defined as a “potential source of harm.”  “Harm” is defined as “physical 
injury… of people…”  

 

“Risk” is defined as “combination of the probability of occurrence of harm and 
the severity of that harm.”

 

If we apply risk analysis to an ordinary power cord, the severity of the harm 
can be as high as death (due to mains voltage in the power cord).  The 
probability of failure of the power cord insulation can be “tolerable,” which 
would not be acceptable in most risk analyses.  Yet, we accept this risk every 
day.

 

This is one reason why I don’t agree that risk management is an 
all-encompassing safety program.

 

Do you agree or disagree with James Gibson’s assertion that

 

“Injuries to a living organism can be produced only by some energy interchange”?

 

(ISO 14971, C.2.5 recognizes energy transfer can result in injury.)   

 

Rich

 

 

 


-

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] EN50131-1 Battery spec vs. Environmental class

[Doug Powell]

Amund,

You may consider heaters for the low temp ambients and if necessary coolers
for the high.

You might also consider operationally limiting your charge cycles to only
times when the ambient is within acceptable limits and make this a part of
your certification by placing it in the conditions of use.  I have seen
this scenario before in solar systems located in very cold climates.  In
that case it was fortunate that the daytime temperatures warmed things up
when the sunlight was available.

All the best,

-Doug


Douglas E Powell
Laporte, Colorado USA
doug...@gmail.com
http://www.linkedin.com/in/dougp01



On Tue, Apr 17, 2018 at 11:12 AM, Nyffenegger, Dave <
dave.nyffeneg...@bhemail.com> wrote:

> If power is available to charge the battery then the product could also
> employ a battery strip heater thermostatically controlled to bring the temp
> up to minimum.
>
> I have a low voltage low power strip heater on the battery in my listed
> outdoor gate opener controller.  It happens to be a sealed lead acid
> battery but something similar should work for Li.  The heater sits flush on
> the entire side of the battery, a few mm thick.
>
> -Dave
>
> -Original Message-
> From: Brian O'Connell [mailto:oconne...@tamuracorp.com]
> Sent: Tuesday, April 17, 2018 12:54 PM
> To: EMC-PSTC@LISTSERV.IEEE.ORG
> Subject: Re: [PSES] EN50131-1 Battery spec vs. Environmental class
>
> Depends on Security Grade requirements and where the battery is stored.
>
> Li batteries can be used in discharge mode to -20C.  Have only done one
> project for this, where the battery temperature was monitored by the
> charger, and shut down charge current when outside rated temperature range,
> but allowed discharge to -20C.
>
> Brian
>
>
> From: Amund Westin [mailto:am...@westin-emission.no]
> Sent: Monday, April 16, 2018 11:42 PM
> To: EMC-PSTC@LISTSERV.IEEE.ORG
> Subject: [PSES] EN50131-1 Battery spec vs. Environmental class
>
> EN50131-1: Alarm systems - Intrusion and hold-up systems -- Part 1: System
> requirements
>
> From the standard:
> Environmental Class II: Indoor General (-10º to +40º)
>
>
> Li-Ion batteries may have this spec:
> Charging: 0º C to 45º C
> Discharge/standby: -20ºC to +50º C:
>
> As I understand the Li-Ion tech, the batteries should not be charged when
> temperature is below 0º C and that means it's not possible to qualify for
> Environmental Class II (-10º to +40º) Indoor General.
> Unless you monitor the temperature and prevents charging when temperature
> is under 0º C, but that may lead you into other trouble if temperature
> remains low over a long period.
> Any others who has considered the same case and agree?
>
> Best regards
> Amund
>
> -
> 
> 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 <
> emc-p...@ieee.org>
>
> 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 <
> emc-p...@ieee.org>
>
> 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: 
>



-- 

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:

Re: [PSES] EN50131-1 Battery spec vs. Environmental class

[Nyffenegger, Dave]

If power is available to charge the battery then the product could also employ 
a battery strip heater thermostatically controlled to bring the temp up to 
minimum. 

I have a low voltage low power strip heater on the battery in my listed outdoor 
gate opener controller.  It happens to be a sealed lead acid battery but 
something similar should work for Li.  The heater sits flush on the entire side 
of the battery, a few mm thick.

-Dave

-Original Message-
From: Brian O'Connell [mailto:oconne...@tamuracorp.com] 
Sent: Tuesday, April 17, 2018 12:54 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] EN50131-1 Battery spec vs. Environmental class

Depends on Security Grade requirements and where the battery is stored.

Li batteries can be used in discharge mode to -20C.  Have only done one project 
for this, where the battery temperature was monitored by the charger, and shut 
down charge current when outside rated temperature range, but allowed discharge 
to -20C.

Brian


From: Amund Westin [mailto:am...@westin-emission.no]
Sent: Monday, April 16, 2018 11:42 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] EN50131-1 Battery spec vs. Environmental class

EN50131-1: Alarm systems - Intrusion and hold-up systems -- Part 1: System 
requirements

>From the standard:
Environmental Class II: Indoor General (-10º to +40º)


Li-Ion batteries may have this spec:
Charging: 0º C to 45º C
Discharge/standby: -20ºC to +50º C:

As I understand the Li-Ion tech, the batteries should not be charged when 
temperature is below 0º C and that means it's not possible to qualify for 
Environmental Class II (-10º to +40º) Indoor General.
Unless you monitor the temperature and prevents charging when temperature is 
under 0º C, but that may lead you into other trouble if temperature remains low 
over a long period.
Any others who has considered the same case and agree?

Best regards
Amund 

-

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] EN50131-1 Battery spec vs. Environmental class

[Brian O'Connell]

Depends on Security Grade requirements and where the battery is stored.

Li batteries can be used in discharge mode to -20C.  Have only done one project 
for this, where the battery temperature was monitored by the charger, and shut 
down charge current when outside rated temperature range, but allowed discharge 
to -20C.

Brian


From: Amund Westin [mailto:am...@westin-emission.no] 
Sent: Monday, April 16, 2018 11:42 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] EN50131-1 Battery spec vs. Environmental class

EN50131-1: Alarm systems - Intrusion and hold-up systems -- Part 1: System 
requirements

>From the standard:
Environmental Class II: Indoor General (-10º to +40º)


Li-Ion batteries may have this spec:
Charging: 0º C to 45º C
Discharge/standby: -20ºC to +50º C:

As I understand the Li-Ion tech, the batteries should not be charged when 
temperature is below 0º C and that means it's not possible to qualify for 
Environmental Class II (-10º to +40º) Indoor General.
Unless you monitor the temperature and prevents charging when temperature is 
under 0º C, but that may lead you into other trouble if temperature remains low 
over a long period.
Any others who has considered the same case and agree?

Best regards
Amund 

-

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] UL's Direct Support Requirements symbol on PCB

[Brian O'Connell]

1. See UL796, 9.1 for support of current-carrying components at specified 
voltage levels.
2. See UL796, clause 9. Some test methods for DSR rating are in the UL746 
series.
3. Yes for PLC, which can 'infer' CTI.

Brian



From: Vincent Lee [mailto:08e6c8d35910-dmarc-requ...@ieee.org] 
Sent: Monday, April 16, 2018 8:47 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] UL's Direct Support Requirements symbol on PCB

Hi all,

Good evening

1) May I know what does the UL's Direct Support Requirements (DSR) triangle 
symbol printed on PCB really mean ?

2) What are the requirements to be met before this symbol can be printed on PCB 
?

3) Does Direct Support Requirements have any relationship with other key 
parameters, e.g. Comparative Tracking Index?

Hope to hear from you soon. Thank a lot.

Vincent


Regards, Vincent

-

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] distribution xfmrs

[Lauren Crane]

Brian, 

I have reviewed the federal regs for distribution transformers including the 
2016 final rule which I expect to provide detailed commentary on what is in and 
out of scope, and why, and I find only one occurrence of 'door', and it is not 
an exclusion/exemption. Hopefully your customer can back up their swearing with 
a chapter and verse reference, or accept your position.  


Regards, 
Lauren Crane
Tokyo Electron

-Original Message-
From: Brian O'Connell [mailto:oconne...@tamuracorp.com] 
Sent: Monday, April 16, 2018 3:22 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] distribution xfmrs

Good People,

Have a customer that swears up and down that low-voltage 3-phase distribution 
transformers that are intended for indoor use are not subject to Canada and 
U.S. efficiency regulation. Can find no such scope/exemption statement in NRCan 
stuff, and certainly not in 10CFR429 and 431. And the particular models in 
question do not have a tap range > 20%.

Perhaps this might not be in admin law but is found somewhere in the federal 
register?

Brian

-

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] Medical device risk assessment - faulty chargers

[John Woodgate]

Thanks for the explanations. However, I still think that at some point 
risk assessment is inevitable.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-04-17 00:22, Richard Nute wrote:


… how do you test *objectively* the adequacy of a symbol like the ! in 
a triangle…


The ! is not a safeguard.  Ultimately, the safeguard is some 
prescribed behavior on the part of a person.  The manufacturer of 
equipment can only describe the desired behavior.   The behavior can 
be tested to determine its effectiveness at safeguarding a body.  
However, the manufacturer cannot enforce a behavior.  Hence, a 
behavior safeguard is not necessarily an effective safeguard as is a 
physical safeguard.


… requirement for two layers of plastic film or insulation, in case 
one layer had a pinhole…


The pinhole was a hypothesis.  We totally ignored the fact that the 
insulation system is comprised of solid-air-solid (a thin layer of air 
separated the two layers).  The voltage divides inversely according to 
the capacitance.  Most of the voltage appears across the thin layer of 
air, not the two solid insulations.  So, we built in a failure 
mechanism to thwart a hypothesis.  Fortunately, the system has 
sufficent electric strength and the transient voltages at the electric 
strength voltage are years apart and of short duration that breakdown 
during equipment lifetime is not likely.


Product safety is rife with “conventional wisdom.”

Rich




-

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: