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
