RE: Definition for Safety Critical Component
Dear Colleagues, One year ago I put together some information regarding this subject; (I have as well the Bibliography for it). In my opinion, all the participants at this discussion, made very useful observations. Respectfully yours, Constantin Constantin Bolintineanu P.Eng. DIGITAL SECURITY CONTROLS LTD. 3301 LANGSTAFF Road, L4K 4L2 CONCORD, ONTARIO, CANADA e-mail: bolin...@dscltd.com telephone: 905 760 3000 ext 2568 Visit our web site at www.dscgrp.com -Original Message- From: lcr...@tuvam.com [mailto:lcr...@tuvam.com] Sent: Tuesday, October 30, 2001 12:27 PM To: emc-p...@majordomo.ieee.org Subject: Definition for Safety Critical Component All, Does anyone have a concise definition of Safety Critical Component? I understand that the definition of this term is highly dependent on context, so let me frame it a bit I am interested in the components that may be in "high-tech" industrial equipment such as those used in the semiconductor manufacturing industry. And as for "regulatory space" I am considering the typical application of electrical design standards such as EN 60204, NFPA 79, ULK 508, EN 61010 as well as similar standards that may address the design of pneumatic, mechanical and process chemical delivery systems. I am also considering three potential populations. Operators - who interact with the tool only to get it to perform its intended function (this group can also include 'passers by' Maintenance personnel - who work with the tool to perform prescribed, well document procedures intended to keep the tool in good working order. Service personnel - who do anything necessary to get a broken tool back into operating condition. Thanks for any ideas. -Lauren Crane TUV America / TUV Product Service CRITICAL COMPONENTS_DEFEX.doc Description: MS-Word document
Re: Definition for Safety Critical Component
From: Douglas Beckwith@MITEL on 10/31/2001 12:00 PM I agree with everthing that has been said so far. The trouble comes with what the agency "deems" to be critical. My experience with approvals agencies has been that their definition of "Safety Critical" is somewhat unscientific. I have often found that they tend to arbitrarily define a component as safety critical because they don't understand the function of circuit and what the component does in the application. The application of the compnent is best understood by the designer, not the approvals agency. I have spent many hours arguing with a well known Canadian safety agency on this question. I spent a number of years in the defence industry doing fault tree analysis and failure modes, effects and criticality analysis of components and circuits, and this to me seems like a more scientific way to approach the definition of what components ae safety critical. I tend to follow this process in definining the critical components, by looking at their failure modes and contribution to the overall flammability of the circuit, and I do not allow the safety approval agency to define them, primarily for the reason above. In fairness to the agencies, most of the time I come up with the same list as they come up with, but at least I have a technical reason behind the decision. I also only specify the critical parameters in the safety report, e.g. rating only, not manufacturer where it is not critical. Doug Beckwith geor...@lexmark.com on 10/31/2001 08:40:17 AM Please respond to geor...@lexmark.com To: emc-p...@ieee.org cc:(bcc: Douglas Beckwith/Kan/Mitel) Subject: Re: Definition for Safety Critical Component There are at least two possible definitions of this term. Under the 60950 standards, these would be the components listed by an approving agency deemed to be "safety critical". The other is any part, listed or not, that contributes to the overall safety of the device. For example, a metal housing will not show up on a critical parts list, but can have sharp edges. As pointed out earlier, even a caution label could be considered such a part. Based on the single fault theory on which the standards are based, the failure of a single "safety critical component" should NOT introduce a hazard. For example, if the insulation between primary and exposed metal parts fails in a Class I design, the fault current will go to ground via the earthing path, and blow the fuse. At no time should the exposed metal carry hazardous voltages. The failure of two safety critical components can result in a hazard. If in the example given the ground path does not exist (a second fault), the "bare" metal may bear hazardous voltages. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Definition for Safety Critical Component
George & friends As I actually said in one of my earlier messages, the metal enclosure/housing CAN be a "safety critical part" AND can also be a "compliance critical part", so I think it SHOULD show up on the "critical parts list". John Allen -Original Message- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: 31 October 2001 13:40 To: emc-p...@ieee.org Subject: Re: Definition for Safety Critical Component There are at least two possible definitions of this term. Under the 60950 standards, these would be the components listed by an approving agency deemed to be "safety critical". The other is any part, listed or not, that contributes to the overall safety of the device. For example, a metal housing will not show up on a critical parts list, but can have sharp edges. As pointed out earlier, even a caution label could be considered such a part. Based on the single fault theory on which the standards are based, the failure of a single "safety critical component" should NOT introduce a hazard. For example, if the insulation between primary and exposed metal parts fails in a Class I design, the fault current will go to ground via the earthing path, and blow the fuse. At no time should the exposed metal carry hazardous voltages. The failure of two safety critical components can result in a hazard. If in the example given the ground path does not exist (a second fault), the "bare" metal may bear hazardous voltages. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Definition for Safety Critical Component
Hi Folks
I agree strongly with Oscar's comments and previous approach - "Compliance
critical" is a far better term. It also means that you can have "EN60950
compliance critical", " EMC compliance critical" etc, as you like without
confusion.
However the widespread existing use of "safety critical component" among the
test and certification authorities, will still result in confusion for a
long time - maybe we need an education programme for everybody?
How about it: UL/VDE/BSI/etc., etc?
Regards
John Allen
Thales Defence Communications Division
Bracknell, UK
-Original Message-
From: oover...@lexmark.com [mailto:oover...@lexmark.com]
Sent: 31 October 2001 12:43
To: emc-p...@majordomo.ieee.org
Subject: RE: Definition for Safety Critical Component
Gregg brings up a good point.
I haven't followed all of this thread and I hope I'm not repeating someone
else;
but, just in case:
Some of the things necessary to comply with the standards have less to do
with
safety than they do with compliance to the standard.
Or in some cases the safety implications are less obvious.
At a previous place of employment, in these cases we called them Compliance
Critical Components. Unfortunately this was often easier to get through the
management gauntlet that a Safety Critical Component. If management could
not
see the safety implications (or didn't buy into the rationale) they would
not
buy into the term "Safety Critical". When we told them that third party
approval would not be obtained unless this requirement was met, they
basically
had to acquiesce and accept it. It was from this understanding that we
coined
the term "Compliance Critical Component"
It was a cop-out but it got the job done. You just have to be careful and
not
overuse the term.
Oscar
Please note that this case in not representative of my current
employer/management.
These opinions are mine and are in no way to be construed to represent those
of
my employer.
"Gregg Kervill" on 10/30/2001
11:25:48 PM
Please respond to "Gregg Kervill"
To: "'Doug McKean'" ,
emc-pstc%majordomo.ieee....@interlock.lexmark.com
cc:(bcc: Oscar Overton/Lex/Lexmark)
Subject: RE: Definition for Safety Critical Component
Sorry the change to HTML was necessary to format the table.
Critical Components will including Paint (colour of the product), Labels and
Instructions. There can be no definitive answer - hazards are in the eye of
the beholder.
The following is a good starting point - use the similarity rule to identify
pneumatic and other products that store or control energy - electrical
connectors - securing clips for hoses
REMEMBER that safety devices that OPEN pneumatic pressure can create worse
hazards that they prevent.
G
IEC
or European Component Standard
UL94 Flammability Standard
Component
Possible Operator-Service warning
94-V2
Air Filter
Y
Mains Capacitors
Stored Charge
Y
CRT's
Stored Charge
Y
Circuit Breakers
Y
Conductive Coatings
Y
Connectors
Y
Transformers and PSU
Y
UL Recognised
Fans above 30 V
UL Recognised
low power fans
94 VW1
Fibre optic cable
Eye Damage
Y
Fuses and Fuse holders
Replacement
Y
Safety Switches
Y
Line filters
Lithium Batteries
Replacement - disposal instructions
Y
Mains connectors
UL94-various
ALL Plastic Parts
Y
Power cords and Mains Cables
Y
Mains voltage motors
UL94-V1
Printed Circuit boards
Y
Relays in safety applications or switching hazardous voltages
Y
Products using primary power
Y
Switches in safety applications or switching hazardous voltages
Isolate before removing cover
Y
Transient voltage surge suppressers
Y
Thermal controls
Min - Maximum
Y
External cables
UL94-VW1
Internal equipment wiring
Eurolink Ltd. -One Link-199 Countries
P.O. Box 310
Reedville, Virginia 22539
Phone: (804) 453-3141
Fax: (804) 453-9039
Web:www.eu-link.com
-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Doug McKean
Sent: Tuesday, October 30, 2001 6:43 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: Definition for Safety Critical Component
Definition for Safety Critical ComponentI'll add to Richard's
definition by saying a "Safety Critical Component"
is a component necessary for the safety approval of the product.
It's a component that prevents a person (end user or service person)
from being exposed to a hazardous condition either during
normal operation or from a
RE: Definition for Safety Critical Component
It is a major misconception that SAFETY CRITICAL ITEMS (SCI) must be big or even tangible - as John so rightly points out ANYTHING that affects safety is a SCI and must be controlled. Hence Colour - Language and Size of FONT. G Eurolink Ltd. -One Link-199 Countries P.O. Box 310 Reedville, Virginia 22539 Phone: (804) 453-3141 Fax: (804) 453-9039 Web:www.eu-link.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Allen, John Sent: Wednesday, October 31, 2001 3:30 AM To: 'lcr...@tuvam.com'; emc-p...@majordomo.ieee.org Subject: RE: Definition for Safety Critical Component Hi Folks A few words of warning on the context of the above Most of the definitions or descriptions for "safety critical component" given so far are reasonably accurate and straightforward in the context of strict compliance with IEC/EN/UL EQUIPMENT safety standards such as 60335, 60950 61010 etc. HOWEVER, the term takes on an entirely different meaning in the context of RISK ASSESSMENT standards such are IEC 61508 and DEF Stan 00-56. Under these standards, a "safety critical component" may be a small component in an equipment which may affect the overall safety of the system, in which that equipment is incorporated - nevertheless the failure of that component may not result in a fire/shock/mechanical hazard in the the context of 60950! In other words, the equipment might fail "safe" but the system could fail to an overall dangerous condition. This won't affect most of you but you should be aware that you might meet the term in this context - and that may become common as more large projects are subject to formal risk assessments to 61508, DEF 00-56 or MIL STD 882. Regards John Allen Thales Defence Communications Division Bracknell UK -Original Message- From: lcr...@tuvam.com [mailto:lcr...@tuvam.com] Sent: 30 October 2001 17:27 To: emc-p...@majordomo.ieee.org Subject: Definition for Safety Critical Component All, Does anyone have a concise definition of Safety Critical Component? I understand that the definition of this term is highly dependent on context, so let me frame it a bit I am interested in the components that may be in "high-tech" industrial equipment such as those used in the semiconductor manufacturing industry. And as for "regulatory space" I am considering the typical application of electrical design standards such as EN 60204, NFPA 79, ULK 508, EN 61010 as well as similar standards that may address the design of pneumatic, mechanical and process chemical delivery systems. I am also considering three potential populations. Operators - who interact with the tool only to get it to perform its intended function (this group can also include 'passers by' Maintenance personnel - who work with the tool to perform prescribed, well document procedures intended to keep the tool in good working order. Service personnel - who do anything necessary to get a broken tool back into operating condition. Thanks for any ideas. -Lauren Crane TUV America / TUV Product Service --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Definition for Safety Critical Component
There are at least two possible definitions of this term. Under the 60950 standards, these would be the components listed by an approving agency deemed to be "safety critical". The other is any part, listed or not, that contributes to the overall safety of the device. For example, a metal housing will not show up on a critical parts list, but can have sharp edges. As pointed out earlier, even a caution label could be considered such a part. Based on the single fault theory on which the standards are based, the failure of a single "safety critical component" should NOT introduce a hazard. For example, if the insulation between primary and exposed metal parts fails in a Class I design, the fault current will go to ground via the earthing path, and blow the fuse. At no time should the exposed metal carry hazardous voltages. The failure of two safety critical components can result in a hazard. If in the example given the ground path does not exist (a second fault), the "bare" metal may bear hazardous voltages. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Definition for Safety Critical Component
Gregg brings up a good point. I haven't followed all of this thread and I hope I'm not repeating someone else; but, just in case: Some of the things necessary to comply with the standards have less to do with safety than they do with compliance to the standard. Or in some cases the safety implications are less obvious. At a previous place of employment, in these cases we called them Compliance Critical Components. Unfortunately this was often easier to get through the management gauntlet that a Safety Critical Component. If management could not see the safety implications (or didn't buy into the rationale) they would not buy into the term "Safety Critical". When we told them that third party approval would not be obtained unless this requirement was met, they basically had to acquiesce and accept it. It was from this understanding that we coined the term "Compliance Critical Component" It was a cop-out but it got the job done. You just have to be careful and not overuse the term. Oscar Please note that this case in not representative of my current employer/management. These opinions are mine and are in no way to be construed to represent those of my employer. "Gregg Kervill" on 10/30/2001 11:25:48 PM Please respond to "Gregg Kervill" To: "'Doug McKean'" , emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: Oscar Overton/Lex/Lexmark) Subject: RE: Definition for Safety Critical Component Sorry the change to HTML was necessary to format the table. Critical Components will including Paint (colour of the product), Labels and Instructions. There can be no definitive answer - hazards are in the eye of the beholder. The following is a good starting point - use the similarity rule to identify pneumatic and other products that store or control energy - electrical connectors - securing clips for hoses REMEMBER that safety devices that OPEN pneumatic pressure can create worse hazards that they prevent. G IEC or European Component Standard UL94 Flammability Standard Component Possible Operator-Service warning 94-V2 Air Filter Y Mains Capacitors Stored Charge Y CRT's Stored Charge Y Circuit Breakers Y Conductive Coatings Y Connectors Y Transformers and PSU Y UL Recognised Fans above 30 V UL Recognised low power fans 94 VW1 Fibre optic cable Eye Damage Y Fuses and Fuse holders Replacement Y Safety Switches Y Line filters Lithium Batteries Replacement - disposal instructions Y Mains connectors UL94-various ALL Plastic Parts Y Power cords and Mains Cables Y Mains voltage motors UL94-V1 Printed Circuit boards Y Relays in safety applications or switching hazardous voltages Y Products using primary power Y Switches in safety applications or switching hazardous voltages Isolate before removing cover Y Transient voltage surge suppressers Y Thermal controls Min - Maximum Y External cables UL94-VW1 Internal equipment wiring Eurolink Ltd. -One Link-199 Countries P.O. Box 310 Reedville, Virginia 22539 Phone: (804) 453-3141 Fax: (804) 453-9039 Web:www.eu-link.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Doug McKean Sent: Tuesday, October 30, 2001 6:43 PM To: emc-p...@majordomo.ieee.org Subject: Re: Definition for Safety Critical Component Definition for Safety Critical ComponentI'll add to Richard's definition by saying a "Safety Critical Component" is a component necessary for the safety approval of the product. It's a component that prevents a person (end user or service person) from being exposed to a hazardous condition either during normal operation or from a fault. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new se
RE: Definition for Safety Critical Component - Safety Critical Fe atures
Hi Folks
This is sent separately to my reply regarding IEC 61508 etc., as it
addresses an entirely different issue.
The decision as to what should be classified as a safety critical component
("SCC") in the context of 60950 (etc.) should take into account the overall
construction and use of the equipment, and so we always devise another list
- that of the "safety critical features" ("SCF").
The attached file gives examples of the features I would consider "critical"
for a large cabinet (for example). This cabinet has to comply with EN60950,
and also with the requirements of its specific intended application (which
means that it has to be transported from time to time). However, for your
own equipments and applications you might to delete some features and add
other.
Then, AFTER you have defined the SCF list, you can begin to list out the
list of "safety critical components" - which are the components which are
critical to ensuring compliance with the SCF list.
When you look at the latter you may have a few surprises - for example, how
many people realise the components forming the equipment enclosure are
"safety critical components"? They most definitely are, and not just for
flammability etc. - the enclosure openings and fixings can also be
"critical".
The combination of the SCF and SCC lists then provides a valuable
aid-memoire to the equipment designer at the time of product certification
and then - later - when SOMEONE ELSE is detailed to review, modify or update
that equipment, to avoid the latter operations taking the equipment out of
compliance with the appropriate safety standard(s) and related requirements
Regards
John Allen
Thales Defence Communications Division.
-Original Message-
From: lcr...@tuvam.com [mailto:lcr...@tuvam.com]
Sent: 30 October 2001 17:27
To: emc-p...@majordomo.ieee.org
Subject: Definition for Safety Critical Component
All,
Does anyone have a concise definition of Safety Critical Component?
I understand that the definition of this term is highly dependent on
context, so let me frame it a bit
I am interested in the components that may be in "high-tech" industrial
equipment such as those used in the semiconductor manufacturing industry.
And as for "regulatory space" I am considering the typical application of
electrical design standards such as EN 60204, NFPA 79, ULK 508, EN 61010 as
well as similar standards that may address the design of pneumatic,
mechanical and process chemical delivery systems.
I am also considering three potential populations.
Operators - who interact with the tool only to get it to perform its
intended function (this group can also include 'passers by'
Maintenance personnel - who work with the tool to perform prescribed, well
document procedures intended to keep the tool in good working order.
Service personnel - who do anything necessary to get a broken tool back into
operating condition.
Thanks for any ideas.
-Lauren Crane
TUV America / TUV Product Service
SAFETY FEATURES LIST.doc
Description: MS-Word document
RE: Definition for Safety Critical Component
Hi Folks A few words of warning on the context of the above Most of the definitions or descriptions for "safety critical component" given so far are reasonably accurate and straightforward in the context of strict compliance with IEC/EN/UL EQUIPMENT safety standards such as 60335, 60950 61010 etc. HOWEVER, the term takes on an entirely different meaning in the context of RISK ASSESSMENT standards such are IEC 61508 and DEF Stan 00-56. Under these standards, a "safety critical component" may be a small component in an equipment which may affect the overall safety of the system, in which that equipment is incorporated - nevertheless the failure of that component may not result in a fire/shock/mechanical hazard in the the context of 60950! In other words, the equipment might fail "safe" but the system could fail to an overall dangerous condition. This won't affect most of you but you should be aware that you might meet the term in this context - and that may become common as more large projects are subject to formal risk assessments to 61508, DEF 00-56 or MIL STD 882. Regards John Allen Thales Defence Communications Division Bracknell UK -Original Message- From: lcr...@tuvam.com [mailto:lcr...@tuvam.com] Sent: 30 October 2001 17:27 To: emc-p...@majordomo.ieee.org Subject: Definition for Safety Critical Component All, Does anyone have a concise definition of Safety Critical Component? I understand that the definition of this term is highly dependent on context, so let me frame it a bit I am interested in the components that may be in "high-tech" industrial equipment such as those used in the semiconductor manufacturing industry. And as for "regulatory space" I am considering the typical application of electrical design standards such as EN 60204, NFPA 79, ULK 508, EN 61010 as well as similar standards that may address the design of pneumatic, mechanical and process chemical delivery systems. I am also considering three potential populations. Operators - who interact with the tool only to get it to perform its intended function (this group can also include 'passers by' Maintenance personnel - who work with the tool to perform prescribed, well document procedures intended to keep the tool in good working order. Service personnel - who do anything necessary to get a broken tool back into operating condition. Thanks for any ideas. -Lauren Crane TUV America / TUV Product Service --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Definition for Safety Critical Component
Sorry the change to HTML was necessary to format the table. Critical Components will including Paint (colour of the product), Labels and Instructions. There can be no definitive answer - hazards are in the eye of the beholder. The following is a good starting point - use the similarity rule to identify pneumatic and other products that store or control energy - electrical connectors - securing clips for hoses REMEMBER that safety devices that OPEN pneumatic pressure can create worse hazards that they prevent. G IEC or European Component Standard UL94 Flammability Standard Component Possible Operator-Service warning 94-V2 Air Filter Y Mains Capacitors Stored Charge Y CRT's Stored Charge Y Circuit Breakers Y Conductive Coatings Y Connectors Y Transformers and PSU Y UL Recognised Fans above 30 V UL Recognised low power fans 94 VW1 Fibre optic cable Eye Damage Y Fuses and Fuse holders Replacement Y Safety Switches Y Line filters Lithium Batteries Replacement - disposal instructions Y Mains connectors UL94-various ALL Plastic Parts Y Power cords and Mains Cables Y Mains voltage motors UL94-V1 Printed Circuit boards Y Relays in safety applications or switching hazardous voltages Y Products using primary power Y Switches in safety applications or switching hazardous voltages Isolate before removing cover Y Transient voltage surge suppressers Y Thermal controls Min - Maximum Y External cables UL94-VW1 Internal equipment wiring Eurolink Ltd. -One Link-199 Countries P.O. Box 310 Reedville, Virginia 22539 Phone: (804) 453-3141 Fax: (804) 453-9039 Web:www.eu-link.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Doug McKean Sent: Tuesday, October 30, 2001 6:43 PM To: emc-p...@majordomo.ieee.org Subject: Re: Definition for Safety Critical Component Definition for Safety Critical ComponentI'll add to Richard's definition by saying a "Safety Critical Component" is a component necessary for the safety approval of the product. It's a component that prevents a person (end user or service person) from being exposed to a hazardous condition either during normal operation or from a fault. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Definition for Safety Critical Component
Definition for Safety Critical ComponentI'll add to Richard's definition by saying a "Safety Critical Component" is a component necessary for the safety approval of the product. It's a component that prevents a person (end user or service person) from being exposed to a hazardous condition either during normal operation or from a fault. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Definition for Safety Critical Component
A safety critical component is a component were the failure during normal use, forseeable misuse and fault conditions is likely to result in a hazardous condition for the operator and/or service person (includes maintenance). Richard Woods Sensormatic Electronics -Original Message- From: lcr...@tuvam.com [mailto:lcr...@tuvam.com] Sent: Tuesday, October 30, 2001 12:27 PM To: emc-p...@majordomo.ieee.org Subject: Definition for Safety Critical Component All, Does anyone have a concise definition of Safety Critical Component? I understand that the definition of this term is highly dependent on context, so let me frame it a bit I am interested in the components that may be in "high-tech" industrial equipment such as those used in the semiconductor manufacturing industry. And as for "regulatory space" I am considering the typical application of electrical design standards such as EN 60204, NFPA 79, ULK 508, EN 61010 as well as similar standards that may address the design of pneumatic, mechanical and process chemical delivery systems. I am also considering three potential populations. Operators - who interact with the tool only to get it to perform its intended function (this group can also include 'passers by' Maintenance personnel - who work with the tool to perform prescribed, well document procedures intended to keep the tool in good working order. Service personnel - who do anything necessary to get a broken tool back into operating condition. Thanks for any ideas. -Lauren Crane TUV America / TUV Product Service
Definition for Safety Critical Component
All, Does anyone have a concise definition of Safety Critical Component? I understand that the definition of this term is highly dependent on context, so let me frame it a bit I am interested in the components that may be in "high-tech" industrial equipment such as those used in the semiconductor manufacturing industry. And as for "regulatory space" I am considering the typical application of electrical design standards such as EN 60204, NFPA 79, ULK 508, EN 61010 as well as similar standards that may address the design of pneumatic, mechanical and process chemical delivery systems. I am also considering three potential populations. Operators - who interact with the tool only to get it to perform its intended function (this group can also include 'passers by' Maintenance personnel - who work with the tool to perform prescribed, well document procedures intended to keep the tool in good working order. Service personnel - who do anything necessary to get a broken tool back into operating condition. Thanks for any ideas. -Lauren Crane TUV America / TUV Product Service
